Emer Tucay Quezon's personal collection : Scipedia

Modeling Public Transport Users’ Trip Production in Hawassa City, Ethiopia
G. Gebre, E. Quezon

Emer Tucay Quezon's personal collection (2021). 57

Abstract
Today, overcrowded public transport demand, resulting in huge costs in an urban area. Similarly, there are a lot of people who use public transport in Hawassa city. This study aimed to develop public transport users' trip production models at the household level. Some socio-economic characteristics and trip detail of the public transport users were collected randomly from the different households through a questionnaire survey. The data gathered was fed into IBM SPSS package version 20 to develop linear regression models. The developed models are associated with trips for purpose and time intervals of trips made. The developed linear regression models, general trips, work trips, educational trips, and trips made before 8:00 AM and after 4:00 PM had good explanatory power. The value of explanatory power comprised of 0.656, 0.722, 0.549, 0.610 and 0.510. These values indicated the explanation power of the socio-economic characteristics on the trips made. It means the daily trips production was significantly affected by the number of working individuals, the different age brackets, cars and motorcycles, and the monthly income per household. The most frequent public transport users’ trips production regarding the trip purpose and time are work trips and occurred after 4:00 PM. This scenario represented a good model developed in this study. Hence, it is suggested that Hawassa city’s traffic management office use the developed models to predict the future trips demand to provide a proper scheme to avoid congestion during the peak hour of the day.
Abstract
Today, overcrowded public transport demand, resulting in huge costs in an urban area. Similarly, there are a lot of people who use public transport in Hawassa city. This study [...]
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Factors Affecting Supervision Practice of Public Building Construction Projects in Dire Dawa Administration
A. Getu, E. Quezon, T. Genie

Emer Tucay Quezon's personal collection (2021). 56

Abstract
Proper completion of a public building construction project is dependent on the effectiveness of the construction supervision. However, it has become increasingly difficult to finish construction projects within the specified time, budget, and quality standards due to poor supervision practices. Approaches such as quantitative and qualitative research and descriptive research types were used in this study. Questionnaires survey were issued to 104 respondents, with 11 representing clients, 22 representing consultants, and 71 representing contractors. There were 33 factors identified, which were then divided into seven groups for further analysis. It was discovered that the top-ranked factors that influence construction supervision practice are: supervisors' lack of skills and experience, incompleteness and consistency in the design, lack of appropriate decision making, location of the project, material and equipment costs, a lack of construction materials supply, and effect of weather conditions. The Relative Importance Index was calculated to determine whether or not the parties agreed on the factors and ranked them according to their importance. Most respondents suggested that supervisors should receive proper training, and comprehensive and detailed drawings should be provided on time. In addition, it was discovered that the top three essential group elements affecting supervision practice of the public building project are supervisory, design, and management-related aspects.
Abstract
Proper completion of a public building construction project is dependent on the effectiveness of the construction supervision. However, it has become increasingly difficult [...]
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Material Cost Optimization and Quality Control Improvement of Building Construction
S. Tesema, W. Ararsa, J. Chimdi, E. Quezon

Xi'an Dianzi Keji Daxue Xuebao/Journal of Xidian University (2021). Sori Tesema, Woyesa Ararsa, Jifara Chimdi and Emer T. Quezon. Material Cost Optimization and Quality Control Improvement of Building Construction. Xi'an Dianzi Keji Daxue Xuebao/Journal of Xidian University. VOLUME 15, ISSUE 8, 2021, 520- 541

Abstract
A building construction project cannot be completed successfully by only planning and scheduling. Project controlling that consists of project monitoring and updating, is the other critical stage. Construction materials cost and quality are becoming a severe problem in Ethiopia, especially in Ambo Town, where little consideration is given. The study tried to evaluate different factors affecting the materials cost and quality on building construction site, rank significant factors that are prevalently affecting the cost and quality of materials used for building projects from the point of view of the respondents, and established a model to optimize materials cost and materials quality using multilinear regression method to come up with the model best fit. Purposive sampling was used, and 180 questionnaires were administered to building construction firms to analyze Material cost Optimization and quality control ImprovementCase Study of Ambo Town. To achieve this, a questionnaire survey containing factors affecting Building construction material cost and quality, which were identified by literature and Interview, was analyzed by using the Relative Importance Index, Pearson's correlation, and Multilinear regression model. Variables are statistically significant at 95% confidence level is assessed that all of the independent variables are positively related to Building Construction material cost and quality. The RII results showed that Material Wastage minimization (RII = 0.908), Proper workmanship (RII= 0.859), Sufficient Training of workers/staff (RII = 0.876), Proper forecasting of materials price in the market (RII = 0.850), Using suitable, safe and secure storage (RII = 0.886), Quality checking for each delivery of the aggregates to the site (RII = 0.889), Cutting of materials ( glass, tiles, plywood) (RII = 0.870) and Design changes (RII = 0.770) were ranked as the most significant among factors affecting building construction materials. Also, two Multiple linear regression models were established for both dependent variables (material cost and material quality). The analysis results showed all independent variables were significant and had a strong positive relationship with dependent variables. The values of R2 for the developed equations indicated 0.771 for material cost and 0.777 for material quality. Hence, the basic recommendations such as planning and monitoring construction activities and inspection and verification of materials were anticipated to be exercised by key role players of the construction industry.
Abstract
A building construction project cannot be completed successfully by only planning and scheduling. Project controlling that consists of project monitoring and updating, is [...]
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Assessment on Materials Quality Control Implementation of Building Construction Projects and Workmanship: A Case Study of Ambo University
E. Quezon

Xi'an Dianzi Keji Daxue Xuebao/Journal of Xidian University (2021).

Abstract
Quality of material issues have been a significant source of concern since the dawn of recorded history. Building materials are essential and should be performed according to standard specifications because they cover around 60% of the project cost. Prior to project construction, specific codes, standards, and specifications should be available. Using all required materials does not guarantee a sound building appearance or function. Even with suitable materials, workmanship, and supervision, unexpected output can affect a building. Quality workmanship is a comprehensive approach to bolstering building durability, serviceability, and safety. The study evaluated Ambo University's building construction materials and quality. Convenience and quota sampling techniques were collected from all contractors and consultants involved in building construction via questionnaires and interviews. A comprehensive literature review identified 15 major factors affecting building construction materials quality and workmanship, and respondents ranked them in the order of importance. Defects in existing buildings and ongoing projects had observed due to non-compliance with construction materials and workmanship based on specifications and standards. The results indicated that Ambo University building has no defect-free structure, including the degree and type of defects vary. A 94% of the studied buildings had moisture leakage, plastering defects, paint peeling, and cracks. Hence, the consultants and Ambo University project representatives should adhere with the standard specifications, and must exercise their profession according to the ethical code of conduct. All of these, it will play a vital role in the success of construction projects.
Abstract
Quality of material issues have been a significant source of concern since the dawn of recorded history. Building materials are essential and should be performed according [...]
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Effect of Covid-19 Pandemic in Construction Labor Productivity: A Quantitative and Qualitative Data Analysis
E. Quezon, A. Ibanez

American Journal of Civil Engineering and Architecture (2021). vol. 9, no. 1 (2021): 23-33. doi: 10.12691/ajcea-9-1-4.

Abstract
This research aims to identify and analyze the various factors affecting construction labor productivity covering the period from December 9, 2020, to January 31, 2021, a year after it was declared Covid-19 a pandemic. Due to the pandemic effect, the local government units in four selected study areas imposed intermittent Enhance Community Quarantine on all places to control the Coronavirus spread in compliance with the health department protocol. Fifty-five questionnaires returned out of 63 distributed are tabulated according to each group-related factor. The correlation analysis resulted in the highest coefficient value of 0.89 between the CTDEO and contractor groups. Meaning, most respondents have the same perception of the factors affecting construction's low labor productivity. Besides, results depicted that the absence of health workers on the construction site ranked 1st in the health & safety provision factor group with an RII of 0.97, followed by no safety engineers on the construction project sites with an RII of 0.93. From all the seven groups of factors, the health and safety group-related factors ranked 1st with an RII of 0.81, next, the schedule compression group with an RII of 0.78. Hypothesis testing asserted that working six days per week was one of the significant factors affecting labor productivity on the contractor's side, suggested by more than 50% of the respondents. The workforce group-related factors with an RII of 0.77 demonstrated a slight difference with the schedule compression group-related factors. Thus, the Covid-19 pandemic has a significant effect on the essential factors affecting construction's low labor productivity.
Abstract
This research aims to identify and analyze the various factors affecting construction labor productivity covering the period from December 9, 2020, to January 31, 2021, [...]
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Evaluation of the HMA performance using combined effects of marble waste dust filler and superpave aggregate gradation
A. Mulatu, E. Quezon, O. Gudina

Australian Journal of Civil Engineering (Select a year). Adamu Mulatu , Emer Tucay Quezon & Oluma Gudina (2020): Evaluation of the HMA performance using combined effects of marble waste dust filler and superpave aggregate gradation, Australian Journal of Civil Engineering. 12(1); 1-11, Doi: 10.1080/14488353.2020.1854942

Abstract
During the fabrication of new products, a variety of wastes discharged and stored by causing harsh environmental problems. The marble processing plant is amongst the industrial sector that produces huge waste. Thus, the main purpose of this study is to evaluate the combined effects of marble waste dust filler and Superpave aggregate gradation on the performance of HMA. Based on the Marshall Mix design, seventy-two (72) specimens were produced from three below-restricted zones (BRZ) of Superpave gradation (BRZ4, BRZ5, & BRZ6) by using the 0.45 power chart. The design gradation obtained to be BRZ5 with 4.96% OBC with corresponding values 9.13 KN of stability, 2.96 mm of flow, 73.51% of VFA, 15.73% of VMA, 2.308 gm/cm3, of bulk density, and 4% of air void. The crushed stone dust filler was partially replaced by Marble Waste Dust filler (under No. 200 sieve) at a replacement rate of (1%, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, and 5%) by keeping design gradation and OBC constant. The test showed satisfactory results. The Marshall mix design parameters of all mixtures are within the specification limit under international and local specifications. Marble waste dust filler when blended with a BRZ of Superpave gradation indicated a substantial effect on Marshall stability with 10.18 KN value at 3% MWD filler content.
Abstract
During the fabrication of new products, a variety of wastes discharged and stored by causing harsh environmental problems. The marble processing plant is amongst the industrial [...]
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Evaluation of waste engine oil rejuvenation for highly short term aged asphalt binder
B. Tadele, E. Quezon

Australian Journal of Civil Engineering (2021). Biruk Tadele & Emer Tucay Quezon (2021): Evaluation of waste engine oil rejuvenation for highly short term aged asphalt binder, Australian Journal of Civil Engineering, DOI: 10.1080/14488353.2021.1896124

Abstract
The aging property of the asphalt binder is time-dependent. A time-dependent short-term aging property of 80/100 penetration grade bitumen and the possibility of waste engine oil rejuvenation for the highly aged asphalt binder performance were investigated. Four specimens of equal weight from the penetration grade-80/100 bitumen are collected. The first specimen was checked for quality requirements. The other three specimens were aged using a rolling thin film oven for 85, 115, and 145 minutes to simulate the delay during hot mix asphalt production, hauling, and compaction. The highly aged bitumen was rejuvenated with 2%, 5%, and 10% Waste Engine Oil by weight. Results indicated that as the aging time increased, penetration and ductility decreased, softening point, flash point, fire point, and mass loss increased. A conventional test showed that highly aged bitumen from the trial period was 145 minutes and 10% waste engine oil obtained the optimum dosage. Further, multiple stress creeps recovery analyses indicated the rejuvenated binder is prone to pavement rutting above 70°C, and rejuvenation is effective for pavement temperature below 70°C. Hence, exposing the asphalt binder for temperature for a more extended period affects pavement performance.
Abstract
The aging property of the asphalt binder is time-dependent. A time-dependent short-term aging property of 80/100 penetration grade bitumen and the possibility of waste engine [...]
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Statistical Analysis on Shear Strength Parameter from Index Properties of Fine-grained Soils
T. Bakala, E. Quezon, M. Yasin, S. contributions

Journal of Engineering Research and Reports (2021). Tariku Tafari Bakala, Emer Tucay Quezon and Mohammed Yasin. Statistical Analysis on Shear Strength Parameter from Index Properties of Fine-grained Soils. Journal of Engineering Research and Reports. 2021; 20(4): 15-28. DOI: 10.9734/JERR/2021/v20i417291

Abstract
Shear strength is the essential engineering property of soil required to analyze and design foundations, retaining walls, bridges, embankment, and related infrastructure. The laboratory equipment and field instruments are not sufficient in developing countries to obtain soil engineering properties, especially strength properties. Thus, Geotechnical engineers usually endeavor to develop statistical models that best fit a particular area and soil type, especially for analysis and design purposes. In this research, a Statistical Analysis on the Shear Strength parameter from the Index Properties of Fine-Grained Soils was studied. For predicting the undrained shear strength parameter, single linear regression (SLR) and multiple linear regressions (MLR) analyses were developed. To develop the intended statistical models for a study, SAS JMP Pro 13, SPSS v22, and Microsoft Excel-2013 software were introduced. The results of a study indicated that undrained shear strength(Cu) was significantly correlated with liquid limit(LL), plastic limit(PL), bulk density (ρbulk), dry density(ρdry), natural moisture content(NMC), and plasticity index(PI). While it was not significantly correlated with a specific gravity (Gs) and liquidity index (LI) of study area soil. Finally, a strong Model of Cu with a coefficient of determination (R2 = 0.806), good significance level, and less Std. error was obtained from multiple linear regression (MLR) analysis. The developed model can figure undrained shear strength parameter and wide application in the construction industry to minimize the cost, effort, and time for laboratory tests of shear strength parameter of a study area.
Abstract
Shear strength is the essential engineering property of soil required to analyze and design foundations, retaining walls, bridges, embankment, and related infrastructure. [...]
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Model-Based Urban Road Network Performance Measurement Using Travel Time Reliability: A Case Study of Addis Ababa City, Ethiopia
S. Assen, E. Quezon

American Journal of Civil Engineering and Architecture (2019). Seada Mohammed Assen, and Emer Tucay Quezon, “Model-Based Urban Road Network Performance Measurement Using Travel Time Reliability: A Case Study of Addis Ababa City, Ethiopia.” American Journal of Civil Engineering and Architecture, vol. 7, no. 5 (2019): 202-207. doi: 10.12691/ajcea-7-5-2.

Abstract
In heterogeneous traffic conditions, the performance of the road network is described by vehicles and driver characteristics. Nowadays, traffic congestion, delay, and unreliability are terms that are most associated with present-day travel, in which transport users spend their precious time on long traffic queues. Due to this, late arrival at the workplace and appointment for social or business activities have become a perennial problem in the study area. In addition, during traffic queues, vehicle fuel emission increases in congested traffic segments affecting the environment, particularly the issue of global warming. This research study evaluated the performance of the road network in terms of travel time reliability in order to determine the main factors affecting travel time reliability. Ten road segments were selected to analyze the performance level and efficiency of the road network, considering the travel time probability distribution, and reliability of road segments in Addis Ababa City. From these road segments, nine were selected to formulate the model, and one road segment considered for validation of the result. The reliability of the road segments was analyzed using travel time reliability measures such as buffer time, buffer time index, planning time index, and the travel time index. It was used a multiple linear regression model to predict the travel time reliability of the road segments with R2
Abstract
In heterogeneous traffic conditions, the performance of the road network is described by vehicles and driver characteristics. Nowadays, traffic congestion, delay, and unreliability [...]
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Performance Evaluation of Grade Separation Within the Selected Major Intersection in Addis Ababa City
S. Leleisa, E. Quezon, T. Wedajo

American Journal of Traffic and Transportation Engineering (2018). Sentayehu Leleisa, Emer Tucay Quezon, Teyba Wedajo. Performance Evaluation of Grade Separation Within the Selected Major Intersection in Addis Ababa City. American Journal of Traffic and Transportation Engineering. Vol. 3, No. 3, 2018, pp. 41-49. doi: 10.11648/j.ajtte.20180303.11

Abstract
Urban City Traffic Management introduced various remedies to decongest traffic and to reduce the severity of accidents, such as providing traffic signal controls at the intersecting roads at different levels, or grade separating the traffic movement towards different directions. One type of grade separation is Road Underpass or Flyover. The construction of Road Underpass or Flyover poses some doubts whether it is effective or ineffective from the point of view of the travelers or motorists. It is for this reason that this research sought to evaluate the performance and effectiveness of the Road Underpass structure on traffic flow at the major intersection, specifically the Wellosefer intersection in Addis Ababa City. The primary data used the existing traffic volume recorded between 7:00 AM – 6:00 PM from Monday to Friday. While the secondary data obtained from the Consulting Office 'before' the improvement of Wellosefer intersection, including the previous study, which served as the control analysis for the research. From these data, the analyses provided results on vehicle travel time and delay for a case 'before' and 'after' improvement of the intersection. SIDRA Software was used to analyze the traffic conditions of the intersection. Based on the findings of the study, a case 'before' Improvement of Wellosefer Unsignalized T-Intersection indicated an average delay of vehicles of about 535.7 seconds and a travel time of vehicles of about 574.7 seconds. On the other hand, in a case 'after' Improvement of Wellosefer intersection, three alternatives considered; such as 1) Signalized T-Intersection, 2) Roundabout and 3) Road Underpass with Roundabout at the upper level. The results of the first alternative showed the Signalized T-intersection indicated an average delay and travel time of 344.3 seconds and 365.0 seconds, respectively. It means, there could be a reduction of 15.4% in average delay if signalized intersection implemented. The second alternative, a case of Roundabout using the same traffic data at current condition, the results indicated the motorists and commuters would be experiencing an average delay of about 355.8 seconds and average travel time of 390.0 seconds. The third alternative considering Road Underpass with Roundabout at the upper level, the results revealed that there was a significant reduction in an average delay of vehicles of about 42% from the Unsignalized T-Intersection. Comparing this result with the Signalized intersection using the same traffic data, showed that there was a significant decrease in average delay. Therefore, the findings of the study, a combination of Road Underpass and Roundabout at the upper level as in the case of Wellosefer intersection performed well than the other traffic control design alternatives.
Abstract
Urban City Traffic Management introduced various remedies to decongest traffic and to reduce the severity of accidents, such as providing traffic signal controls at the intersecting [...]
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Traffic Safety Evaluation at Unsignalized road Intersection using Proactive Approach
. Abstract, E. Quezon

Proceedings of the 2nd Annual Ethiopian Road Safety (RSC2018) (2018). Seifeddin Haji, Prof. Emer T. Quezon, Murad Mohammed, Biruk Yigezu. Traffic Safety Evaluation on Urban Road Un-signalized Intersection using Proactive Approach: A Case Study in Adama City. Proceedings of the 2nd Annual Ethiopian Road Safety (RSC2018) Addis Ababa, Ethiopia, August 23-24, 2018

Abstract
Deaths and injuries as a result of road accidents are a recognized global problem and authorities are aware of the consequences this global phenomenon might lead to. Because of the rapid development of urbanization and motorization in developing and transitional countries, like Ethiopia, actions to improve traffic safety conditions are urgently needed. Highway intersections are among the greatest safety challenges because they are some of the most common highway features. Improving the safety level of the urban intersection is an important way to increase safety. Safety evaluations can help to develop effective safety countermeasures to lower crash rates and reduce crash severity. So how to diagnose safety problems and improve urban road intersection safety effectively becomes an important issue. Now, there have been quite a number of safety analysis methods and theories in the city intersection, but these methods and theories are formed on the basis of traffic accidents. However, the data on traffic accidents is not accurate enough, these theories are not appropriate for our country. Also, it is impractical and unethical to wait for accidents to occur before being able to draw statistically sound conclusions regarding safety improvement. Hence there is a need to develop a proactive approach, a non-accident-based approach, to evaluate urban road Unsignalized intersection safety performance. A proactive approach (indirect and non-accident based approach) was attempted to that of traditional reactive approach (direct and accident based approach) which is purely based on the existing conditions that have direct relationships or impacts to traffic safety such as the geometric, traffic control & engineering, road Surface and environment characteristics. The non-accident-based approach is based on field surveys under the conditions mentioned previously, summarizes the intersection safety diagnosis in a safety index to indicate the safety performance of the intersection. The study indicates that the proposed methodology and intersection safety diagnosis technique can be used to perform an evaluation of traffic safety and improvement at an intersection even when there are few resources available. Also, the use of intersection safety diagnosis is a more resource-efficient and ethically appealing alternative for fast, reliable, and effective safety assessment.
Abstract
Deaths and injuries as a result of road accidents are a recognized global problem and authorities are aware of the consequences this global phenomenon might lead to. Because [...]
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Investigation of Pedestrian Safety Problems and Its Countermeasures: A Case Study in Nekemte City, Ethiopia
H. Alemgena, P. Quezon, T. Kumela, E. Quezon

International Journal of Engineering and Technical Research (2018). Alemgena, H.; Quezon, ET.; Kumela, T. Investigation of Pedestrian Safety Problems and Its Countermeasures: A Case Study in Nekemte City, Ethiopia. International Journal of Engineering and Technical Research. 2018; 8(2): 58-64

Abstract
The actual growth of urban economic activities and simple movements of peoples and goods measured through its primary transport system. The requirements of the pedestrian should be considered in the design of the urban environment and transportation facilities. Since road infrastructure improvements and designed pedestrian environments are an essential part of road safety enhancements that increase walking and decrease fatalities. This study investigated the pedestrian safety problems and its countermeasures on road segments in Nekemte city. This study examined the existing issues affecting the safety of pedestrian movement, evaluates the service quality of walking facilities, and finally identified the most significant factors affecting pedestrian safety with engineering countermeasures in the city. For the data analysis, the study used both objective measurements and subjective assessments to model PLOS using Australian methods. As per field study indicates 60% of the respondents' think the sidewalk is not user-friendly. In the city, the built road infrastructure is lacking pedestrian facility management and appropriate maintenance activities. Since the walkways in Nekemte city, in general, have almost the same problems like non-continuous, crack, and non-covered utility holes which are difficult especially for pedestrians with disabilities. The current sidewalk is encroached either by vendors, utility poles, parking carts or illegal construction materials in different places, and crosswalk facilities are not visible and not enough provided at a logical distance. The Pedestrian LOS analysis indicates that poor pedestrian conditions exist and the factors that negatively affect pedestrian LOS are wide-ranging in this city road segment. It concluded that Pedestrian facilities and all the concerned factors should be provided and maintained to more efficient for both encouraging people to walk and improve pedestrian safety.
Abstract
The actual growth of urban economic activities and simple movements of peoples and goods measured through its primary transport system. The requirements of the pedestrian [...]
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Analysis of StressStrain and Deflection of Flexible Pavements Using Finite Element Method Case Study on Bako-Nekemte Road
S. Wayessa, E. Quezon, T. Kumela

Journal of Civil, Construction and Environmental Engineering (2017). Shiferaw Garoma Wayessa, Emer Tucay Quezon, Tarekegn Kumela. Analysis of Stress- Strain and Deflection of Flexible Pavements Using Finite Element Method Case Study on Bako-Nekemte Road. Journal of Civil, Construction and Environmental Engineering. Vol. 2, No. 4, 2017, pp. 100-111. doi: 10.11648/j.jccee.20170204.11

Abstract
In Ethiopia, the failure of roads is before the handover period. Most roads found in Ethiopia are flexible pavements. Nowadays, the failure of the surface of flexible pavement roads is common before the expected design period. For example, the Bako-Nekemte road/ has become a critical issue in our country. The most common parameters that cause stress, strain, and deflection of the roads are loads and pressures that come from vehicles. Moreover, the modulus of elasticity, Poisson’s ratio, and thickness of each layer need to be characterized. Further, the load magnitude, contact pressure (or load radius), and location are defined for each load (wheel) considered. The finite element method (FEM) is a numerical analysis technique to obtain the stress-strain and deflection of each pavement layer. The analytical method usually uses layers thickness, loads, elastic modulus, and Poisson’s ratio of the pavement materials as design parameters. The objective of this research was to study the sensitivity of the road parameters in analyzing the major causes of failure in asphalt pavement layers fatigue cracking and rutting deformation which came due to the critical tensile strains at the bottom of the asphalt layer and the critical compressive strains on the top of subgrade using the finite element method by relating the standard specification of ERA and laboratory test result. This thesis studied the analysis of stress-strain and deflection of flexible pavements using the Everstress finite element method. The Ever stress program will take into account any stress-dependent stiffness characteristics. This thesis dealt with ways to reduce deflections by varying the design configuration, such as increasing the HMA modulus, the base modulus, sub-base modulus, the subgrade modulus, and increasing the thickness of each layer. Based on the type of materials to use the value of elastic modulus and poison’s ratio are various in each layer, in layer 1 is varied from 1500 to 3500 MPa, in layer 2 is varied from 200 to 1000MPa, in layer 3 is varied from 100 to 250 MPa and in layer 4 is varied from 20MPa to 150MPa.
Abstract
In Ethiopia, the failure of roads is before the handover period. Most roads found in Ethiopia are flexible pavements. Nowadays, the failure of the surface of flexible pavement [...]
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Calcined Termite Hill Clay Powder: As Partial Cement Replacement in Production of C-25 Grade Concrete
G. Danbala, E. Quezon, G. Kebede

American Journal of Civil Engineering and Architecture (2019). Guyo Konso Danbala, Emer Tucay Quezon, and Getachew Kebede, “Calcined Termite Hill Clay Powder: As Partial Cement Replacement in Production of C-25 Grade Concrete.” American Journal of Civil Engineering and Architecture, vol. 7, no. 3 (2019): 128-134. doi: 10.12691/ajcea-7-3-2.

Abstract
Cement is one of the components of concrete plays a great role in the construction industry. Nevertheless, it is the most expensive and environmentally unfriendly material. Therefore, requirements for economical and more environmentally-friendly cementing materials have extended interest in other cementing materials that can be used as partial replacement of the ordinary Portland cement. This research was, conducted to examine the suitability of calcined termite hill clay powder as a cement replacing material in the production of C-25 grade concrete as a relief for this problem. The Termite Hill Clay sample was collected from Bokuluboma vicinity. The sample was calcined at the temperature of 650°C using muffle furnace, ground to the fineness of 150 µm and its chemical composition was investigated. Normal consistency and setting time of the paste having Ordinary Portland Cement and calcined termite hill clay powder from 0% to 40% replacement in 5% increment percentage investigated. The compressive strength of eight different concrete mixes with the CTHCP replacing the ordinary Portland cement prepared for 22MPa and 34MPa (i.e., for 7th and 28th days targeted compressive strength) concrete with water cement ratio of 0.5 and 360kg/m3 cement content. The properties of the mixture assessed both at the fresh and hardened state. Results revealed that calcined termite hill clay powder found pozzolanic and can partially replace cement. It has shown that up to 11.3% replacement of the ordinary Portland cement by CTHCP, the cubes achieved a target mean compressive strength of C-25 grade concrete at 28th day 34Mpa. Although, the replacement percentage greater than 11.3% of the cement of calcined termite hill clay powder in the concrete has shown a slightly lower compressive strength. Moreover, the mix indicated workable up to 25% replacement percentage and also the setting time of the paste containing calcined termite hill clay powder found faster than that of the control mix. Hence, it is concluded that CTHCP was suitable to replace cement partially with 11.3% replacement of cement by calcined termite hill clay powder as the optimal percentage of the production of C-25 grade concrete. The fresh concrete mix was workable up to 25% replacement, and the mineral admixture served as an accelerator which is suitable for cold weather concreting works.
Abstract
Cement is one of the components of concrete plays a great role in the construction industry. Nevertheless, it is the most expensive and environmentally unfriendly material. [...]
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Evaluation of the Performance of Brick Dust as a Filler Material for Hot Asphalt Mix Design A Case Study in Jimma Zone
F. Wagaw, P. Quezon, A. Geremew, E. Quezon

The International Journal of Engineering and Science (2018). Fisseha Wagaw, Prof. Emer Tucay Quezon, Anteneh Geremew. Evaluation of the Performance of Brick Dust as a Filler Material for Hot Asphalt Mix Design: A Case Study in Jimma Zone. The International Journal of Engineering and Science. 2018; 7(3): 64-72. DOI:10.9790/1813-0703026472

Abstract
A bituminous paving mixture is a mixture of coarse aggregate, fine aggregate, and bitumen mixed in suitable proportion to result in a strong and durable mix in order to withstand traffic load. In this paving mix, ordinary stone dust, and cement used as filler material. One of the main problems in the construction of a bituminous paving mixture is the insufficient amount of filler from crushing stone aggregate, and cement supply is low. A study has been carried out in this research to explore the use of Brick dust as filler material for the bituminous mixture. The objective is intended to evaluate the performance of brick dust as fillers in Hot Asphalt Mix design, according to the test procedure specified by ASTM. Several specimens of hot asphalt mixture were prepared according to ASTM D 1559 using an aggregate blend with brick filler and aggregate blend without brick filler. The aggregate blending made by using Job mix formula to obtain the percentage of mixed material. For aggregate blended without brick G-1 32%, G-2 23%, and G-3 45% for Aggregate blended with brick filler G-1 30%, G-2 18%, G-3 45% and G-4 7%; where G-1 Coarse Aggregate 3/4, G-2 Coarse Aggregate 3/8, G-3 Fine Aggregate, and G-4 brick filler. It concluded that the results of the Marshall test of mix design showed satisfactory when hot asphalt mixed with these brick fillers. The Specimens blended with brick filler lead produce asphalt mixture with higher Marshall stability, lower flow, a less void filled with asphalt. Hence, brick dust can replace stone dust and cement filler in the bituminous paving mix. It is recommended to use brick dust as filler material in a bituminous paving mix may save considerable investment; as well as a reliable performance of the in-service highway can be achieved.
Abstract
A bituminous paving mixture is a mixture of coarse aggregate, fine aggregate, and bitumen mixed in suitable proportion to result in a strong and durable mix in order to withstand [...]
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International Journal of Scientific & Engineering Research
E. Quezon

International Journal of Scientific & Engineering Research (2016). Tarekegn Kumala, Prof. Emer T. Quezon, Bogale Shiferaw. Effect of Cycle Time and Signal Phase on Average Time Delay, Congestion and Level of Service: A Case Study at Hager Astedader Signalized Intersection in Addis Ababa. International Journal of Scientific & Engineering Research. 2016; 7(10): 524-530.

Abstract
High urbanization rate and Economic development have caused many challenges to transportation systems. Among these, long time delay and high fuel consumption of vehicles at congestion places are a few to mention. Some literatures have revealed that road traffic congestions are caused by inadequate infrastructures, long signal cycle time, and poor traffic management, such as incapable roads, inefficient public transit, and high travel demand. The research study was focused on the effect of traffic congestion on average time delay at a selected signalized road intersection in Addis Ababa. The study area was the Hager Astedadrerroad traffic signal intersection. The methodology that has been employed for the study was a quantitative descriptive research design method. The data needed were; road geometry data, signal data, traffic vehicles flow data including the pedestrian data were collected on-peak hours (with 15minutes intervals) from 7:30 to 9:30 AM and from 5:30 – 7:30 PM for the four consecutive working days. Data of traffic classes were extracted manually on a separate worksheet. The volume of each vehicle category was converted to the same vehicle category using the passenger car unit (PCU) of each vehicle class. Data analysis and processing have been performed using SIDRA (Signalized and Unsignalized Intersection Design and Research Aid) intersection software in order to know the traffic flow condition at the intersection. The result of average time delay was used to know the corresponding level of service and operational performance of the intersection. The outcomes of the research work minimize average time delay by adopting different improving strategies that range from low-cost measures such as improvements to signal timing and phase numbers, to high-cost measures such as intersection reconstruction, which be applied in the study area after knowing the amount of average time delay as well as the types of the level of service within the intersection area.
Abstract
High urbanization rate and Economic development have caused many challenges to transportation systems. Among these, long time delay and high fuel consumption of vehicles at [...]
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Regression Analysis of Index Properties of Soil as Strength Determinant for California Bearing Ratio (CBR)
D. Abdella, T. Abebe, P. Quezon, E. Quezon

GSJ (2017). Dino Abdella, Tadesse Abebe, Prof. Emer Tucay Quezon. Regression Analysis of Index Properties of Soil as Strength Determinant for California Bearing Ratio (CBR). GSJ. 2017; 5(6): 1-12

Abstract
Investigation of the variation in different soil types and origins is an essential task for Geotechnical engineers. To overcome the effects of this change, the Geotechnical engineers, as well as other professionals, attempted to develop empirical equations unique to a region and soil type to use the soil for its intended purpose. However, these empirical equations are more reliable for the kind of soil where there is a strong relationship of parameters is developed. Hence, it is good practice to develop empirical equations that best fit the soil available in the location that we can access. On the flexible pavement, the subgrade is considered to be an ideal layer to resist wheel load, and its CBR value is considered as the strength measuring a parameter. Conducting a CBR test is an expensive and time-consuming procedure. Also, it is challenging to mold the sample at a desired in-situ density in the laboratory. Furthermore, if the available soil is of poor quality, suitable additives are mixed with soil, and the resulting strength of the soil is assessed by the CBR value which is cumbersome. To overcome such a problem, statistical approaches such as regression-based models are used. This can be used for quick and easily determined parameters. Relative to this, the study has been conducted to develop an equation to show the relationship between the index properties and CBR values precisely located along WelkiteArekit –Hosanna Road of about 121km stretches. It was carried out using thirty samples retrieved from this road and tested in a laboratory. The test result of the regression-based statistical analysis was used to develop the predetermined relationship. The relationship development was performed in the form of an equation of CBR as a function of grain size parameters, Atterberg’s liquid limits, and compaction parameters by considering the effect of individual soil properties as well as the effect of a combination of soil properties on the CBR value. Based on the results of the study for both linear and multiple linear regression analyses, it was revealed that there was a relatively fair relationship obtained by combining plasticity index, the percentage of fine content, and maximum dry density which are strength determinants of fine-grained soils. Also, the results showed that the coefficient of determination for multiple linear regression is R2=0. 731, while for single linear regression is R2=0. 682. Therefore, it is concluded that the index properties of soils are sufficiently accurate in determining the CBR values, of which it can be utilized for preliminary characterization.
Abstract
Investigation of the variation in different soil types and origins is an essential task for Geotechnical engineers. To overcome the effects of this change, the Geotechnical [...]
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Effects of human behaviors and geometric factors in road traffic accidents a case study along Sululta-Fiche road, Ethiopia
E. Quezon

GJS (2017). Galeta Chala, Prof. Emer Tucay Quezon, Tarekegn Kumela. Effects of human behaviors and geometric factors in road traffic accidents: a case study along Sululta-Fiche road, Ethiopia. GSJ: 2017; 5(11). 163-172

Abstract
A road traffic accident was one of the severe problems which are affecting once’s a country and leading to death, injuries and property damage resulted in economic loss. The objective of this research was to investigate the effects of Human behaviors and Geometric factors in road traffic accidents along the road of Sululta-Fiche, which is located in the Northern Shewa of the Oromia region. Both probability sampling and non-probability sampling techniques were applied. The primary data were obtained from site observation of blackspot locations. While the secondary source of data was taken from records compiled by the North Shewa traffic office and Oromia Special Zone Surrounding Finfinne traffic Office. Descriptive and analytical design methods were used in this research, while the results were displayed by graphs, tables, and pie charts. From the study, the status of road traffic accidents showed that there were dramatically increase in accidents every year within the study period. A total of 830 crashes occurred in the past three years. From this, 237 accidents happened in 2012, 279 accidents in 2013, and 314 accidents in 2015. From the traffic police report analysis, there were 41 locations in Sululta Town, and 70 locations in Sululta Wereda, where those accidents happened. Based on the results of this research using the priority value approach, there were 12 selected locations in Sululta Town and 10 chosen locations in Sululta Wereda. Therefore, it is concluded that the significant factor in traffic accidents along Sululta –Fiche road was the driver errors such as over-speeding, night driving, and driving without attention, and it was followed by the geometric factors. These road deficiencies contributory to some errors of the drivers, which were inadequate road width, insufficient sight distance, and narrow bridge at sag curves, and improper intersection design. Based on the findings of the study, some of the countermeasures recommended reducing the road traffic accidents are the provision of speed limit signs to forewarn drivers, installation of speed barkers and rumble strips, widening the lane width of pavement, maintenance of the deteriorated road, repair of the road signs and provision of adequate sight visibility for drivers.
Abstract
A road traffic accident was one of the severe problems which are affecting once’s a country and leading to death, injuries and property damage resulted in economic loss. [...]
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Effectiveness of using Geosynthetic Material for Improvement of Road Construction and Performance Case Study on Adis Ababa
M. Gurara, K. Getachew, E. Quezon, E. Quezon

International Journal of Engineering Research & Technology (2017). Mikiyas. J Gurara, Kabtamu Getachew, Emer Quezon. Effectiveness of using Geosynthetic Material for Improvement of Road Construction and Performance - Case Study on Adis Ababa. International Journal of Engineering Research & Technology. 2017; (6)2: 640-642

Abstract
The research is concerned with the Effectiveness of geosynthetic to improve the performance of the pavement. It has been done on road construction projects under Addis Ababa Road Authority. Results indicated that the performance of bottom pavements structures constructed on poor subgrades with CBR values not greater than 4% was significantly enhanced using geosynthetic material. An increase of bearing capacity for subgrade and can improve the subgrade quality without excavating and filling of select material only by using geomembrane. Geosynthetic reinforcement in pavement design and construction should be widespread. Geosynthetic reinforcements are incorporated into permanent, paved roads either as base (or subbase) reinforcement - in flexible pavements to aid in the support of vehicular loads over the life of the pavement; or as subgrade restraint for construction of flexible or rigid roadways over weak subgrade conditions to aid in support of equipment loads on the unpaved base, or subbase, course during construction. Clearly, both base reinforcement and subgrade restraint with geosynthetics are proven techniques for use in pavement design and construction effectively.
Abstract
The research is concerned with the Effectiveness of geosynthetic to improve the performance of the pavement. It has been done on road construction projects under Addis Ababa [...]
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Cost and Benefit Analysis of Rigid and Flexible Pavement: A Case Study at Chancho –Derba-Becho Road Project
E. Quezon

International Journal of Scientific & Engineering Research (2016). Yonas Ketema, Prof. Emer T. Quezon, Getachew Kebede. Cost and Benefit Analysis of Rigid and Flexible Pavement: A Case Study at Chancho –Derba-Becho Road Project. International Journal of Scientific & Engineering Research. 2016; 7(10): 181-188

Abstract
Road construction projects have been implemented all over Ethiopia as part of the national development plan. Roads are one of the country’s basic infrastructural facilities where high amounts of the budget allocated every fiscal year planning period. Since the cost comprises of a large portion of government investment, a careful evaluation of the alternatives is of utmost importance to make the right choice for a particular project. In the history of Ethiopia's road development program, almost all of the road pavements are flexible, and it demands high foreign currency for asphalt material importing from abroad. In addition, flexible pavement needs to be maintained and rehabilitated within a few years after its initial construction. In view of the emerging cement factories and the availability of cement in Ethiopia, it is practical to consider rigid pavement as one of the alternatives. Relative to this, the research project was conducted with the main objective of identifying the cost and benefit of rigid and flexible pavements at the Chancho-Derba-Becho road project, North Showa Zone in Oromia. The research work had been focused on the specific objectives to determine and compare the life cycle costs of rigid and flexible pavements and to investigate all other qualitative merits of rigid and flexible pavement. To achieve these objectives, a review of related literature, design and specifications, observations and investigations of the actual pavement construction projects, evaluation of life cycle costs, the future value of money and present worth calculation were undertaken with an analysis period of 40 years. While the data considered was gathered through investigation at the actual rigid and flexible pavement projects, an examination of specifications, drawings and pavement design, Ethiopian Road Authority manuals, rehabilitation, and maintenance strategy. In this regard, the cost parameters investigated are initial construction cost, maintenance cost, rehabilitation cost, user’s cost, and salvage value, in addition to other qualitative and quantitative data. Based on the results of the research project, it revealed that the initial cost of rigid pavement was almost twice of the flexible pavement, but in the long run, the cost of flexible pavement per kilometer was found out to have 7.9 Million ETB more than the rigid pavement because of the incurring costs of maintenance through its design life. Therefore, it is suggested that Portland Cement Concrete Pavement (PCCP) shall be used in pavement construction to cater to local material requirements.
Abstract
Road construction projects have been implemented all over Ethiopia as part of the national development plan. Roads are one of the country’s basic infrastructural facilities [...]
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Comparative Study of Labor-Based Method and Machine-Based Method at Rural Road Construction and Maintenance in Jimma Zone, Oromia Region, Ethiopia
A. Dunffa, E. Quezon, E. Agon

American Journal of Civil Engineering (2017). Anwar Kassahun Dunffa, Emer Tucay Quezon, Elmer De Castro Agon. Comparative Study of Labor-Based Method and Machine-Based Method at Rural Road Construction and Maintenance in Jimma Zone, Oromia Region, Ethiopia. American Journal of Civil Engineering. Vol. 5, No. 4, 2017, pp. 212-219. doi: 10.11648/j.ajce.20170504.13

Abstract
The construction of physical infrastructure is contributory to poverty alleviation in every country. The road is one of the major components which is very significant in Ethiopia due to the lack of highly developed infrastructure, particularly in the rural road sector. Selection of the appropriate road construction and maintenance methods such as a labor-based method or machine-based method is necessary to be financially viable. Most rural road construction projects usually suffer from the problem of selecting the appropriate technology for the proposed project and implementation of the chosen technology. In Ethiopia, Universal Rural Road Access Program (URRAP) is an employment-intensive program for employment purposes as a first step, out of poverty using labor-based road construction. However, there are problems, constraints, and challenges encountered when implementing labor-based methods leading to enforce the mobilization of machines. The aim of this research study is to carry out the comparative analysis of ongoing and finished rural road projects in Jimma Zone and to establish qualitative and quantitative merit of various technologies used in rural road construction and maintenance. Results showed from financial cost comparison, the labor-based method was 47% cheaper than a machine-based method to carry out the same tasks. On the other hand, the share of unskilled average direct labor cost comprised an astounding 65% more of the total direct cost of a labor-based method. Also, the labor-based method directly employed 300 unskilled laborers per workday for a month to complete a 1.0 km section of a rural road.
Abstract
The construction of physical infrastructure is contributory to poverty alleviation in every country. The road is one of the major components which is very significant in Ethiopia [...]
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Combined Effects of Molasses-Lime Treatment on Poor Quality Natural Gravel Materials Used for Sub-Base and Base Course Construction
Y. Mamuye, E. Quezon, A. Geremew

GSJ (Select a year). Yibas Mamuye, Emer Tucay Quezon, Anteneh Geremew. Combined Effects of Molasses-Lime Treatment on Poor Quality Natural Gravel Materials Used for Sub-Base and Base Course Construction. GSJ: V2018; 6(7): 621-633

Abstract
At the time of industrial development, the production of large amounts of wastage required proper disposal. To reduce the disposal problem, utilization of wastage in construction works is a very important aspect. The reuse of industrial waste had gained high momentum for achieving sustainable waste management locally and globally. Keeping this in mind, research carried out to assess the utilization of molasses, lime, and molasses-lime for improving natural gravel for sub-base and base course construction from the Jimma Jiren quarry site. The natural gravel from this quarry site is known to have poor quality since it did not satisfy the ERA standard specification for sub-base and base course construction. To use Jiren natural gravel as a sub-base or base course construction material, it is necessary to improve its engineering properties. The laboratory test matrix in each test plan included variations in additive type, additive content, and curing period. It was established 8% cane molasses by weight of dry soil as the maximum for effective stabilization of natural gravel for sub-base construction, but not suitable for a base course layer. Results indicated that the natural gravel specimens from the Jiren quarry site stabilized with lime provided higher CBR values than molasses used alone. On the other hand, replacing 50% of lime content with molasses indicated better results than the performance of either individual additive. Therefore, the natural gravel blended with the molasses-lime combination is much better when it used for sub-base and base course construction to treat such an inferior quality of natural aggregates.
Abstract
At the time of industrial development, the production of large amounts of wastage required proper disposal. To reduce the disposal problem, utilization of wastage in construction [...]
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Geotechnical Conditions and Stability Analysis of Landslide Prone Area A Case Study in Bonga Town, South-Western Ethiopia
E. Quezon

International Journal of Scientific & Engineering Research (2017). Damtew Tsige, Prof. Emer T. Quezon, Dr. Kifle Woldearegay. Geotechnical Conditions and Stability Analysis of Landslide Prone Area: A Case Study in Bonga Town, South-Western Ethiopia. International Journal of Scientific & Engineering Research. 2017; 8(4): 239-248

Abstract
There were several slides and associated ground subsidence which brought significant impact on the cracking of walls and floor of several private and governmental buildings in Bonga Town. The principal and secondary roads were also affected by subsidence with vertical displacement up to 1m which hampered the traffic in the town. Water pipelines along the road were disturbed by the sliding which was later repaired. Cracking of the walls and floor of more than 120 private residences and more than 10 government buildings were recorded. The main highway that connects Bonga-TepiMasha via Alamo and Gatiba has been disrupted at four locations. This resulted in hampering traffic for several days. This research aimed to evaluate the cause and failure mechanism as well as the stability condition of the landslides. The study involved the investigation of the Geotechnical parameters of soil and the terrain characteristics to be used for the stability analysis of the slope, including distribution and characteristics of soils, the groundwater table, and the depth and geometry of the failures. The Slope stability analysis is supplemented by using Geo-studio 2004 software. Soil samples were collected and were tested for grain size analysis, distribution analysis (sieve & hydrometer) plastic limit, liquid limit, plasticity index, water content, unit weight of soil, specific gravity, and shear strength parameters following the ASTM procedures. Based on the findings, the landslides were triggered by heavy rainfall. Therefore, the main factors controlling the stability of the slope are soil type and characteristics, slope angle, water (surface and groundwater), and slope steepness. The design of the retaining wall is recommended to mitigate the impact of landslides in the study area.
Abstract
There were several slides and associated ground subsidence which brought significant impact on the cracking of walls and floor of several private and governmental buildings [...]
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Investigation of the Damping Ratio and Shear Modulus of Soil along Light Rail Transit Route in Megenagna-Hayat Road
E. Quezon

International Journal of Scientific & Engineering Research (2017). Abenezer Takele, Emer T. Quezon, Tadesse Abebe. Investigation of the Damping Ratio and Shear Modulus of Soil along Light Rail Transit Route in Megenagna-Hayat Road. International Journal of Scientific & Engineering Research. 2017; 8 (1):111-122

Abstract
Soil vibration may also cause by the movement of heavy vehicles and train, which affect adjacent structures along the route. The response of soils for incoming vibration from the train is measured by the dynamic properties of soils such as shear modulus and damping ratio. These soil parameters are very significant to study the ground motion as well as the site response of soil deposits under cyclic loading and soil-structure interaction. About this, the research study has been sought to give some information about the condition, specifically the shear modulus and damping ratio of the soil along the Addis Ababa light rail transit route from Megenagna to Hayat road. Also, this study was dealt with soil distribution along the route, which was conducted to determine soil properties. The sand replacement method was also utilized to investigate the controlling factors for the dynamic soil properties. From related literature, it was known that the dynamic soil properties are influenced by soil types and location of the soil profile. Five Test pits, designated A, B, C, D & E, were considered randomly for soil sampling to determine the properties of soil. The soil samples were taken from a depth of 2.5m below the surface of the roadside. Aside from the soil laboratory testing for common tests, another test was performed using a simple cyclic shear test for the representative samples. The values of normalized shear modulus and damping ratio are compared with already known curves from literature. The research study found out that the values of normalized shear modulus G/Gmax plotted against the shear strain, showed scattered points when it was compared with the curves of Seed and Idriss. Likewise, for the wet clay from the study area, all measured points were close to the known curve of the plot. On the other hand, the values of damping ratio were also compared to curves provided by Seed and Idriss. The Soil properties from all test pits had almost closer values as seen in the plot. However, the sample collected from test Pit D has the highest value of G/Gmax only, while samples from test Pit C has high values both for Gmax and Damping ratio. Test Pit C showed values of Dry density and liquid limit higher than the other test pits. Based on the comparison of the sand; for the strain less than 1%, all measured points of G/Gmax lying close to the extended curve given by Seed and Idriss. The strain of 0.2%, measured points of G/Gmax is closed to curve plot within the boundary, and it was below the curve given by Seed and Idriss. Likewise, for saturated clay, the measured points are close to the curve of Seed and Idriss. The values of damping ratio obtained for strain less than 1% obtained within the range of either the curves given by Seed and Idriss considers sand or clay soils. For strain, less than and equal to 1% the points lie within a range of clay. Therefore, the controlling factor that affects dynamic soil properties from a comparison of shear modulus and damping ratio curves based on consolidation pressure is the confining pressure, which shows high influence on the values of shear modulus and damping ratio based on the test results of the shear strain amplitudes. Index Terms—Damping Ratio, Dynamic Properties, Index property, Normalized Shear Modulus, Sand Replacement, Shear Modulus, Shear Strain Amplitude, Simple Cyclic Shear Test.
Abstract
Soil vibration may also cause by the movement of heavy vehicles and train, which affect adjacent structures along the route. The response of soils for incoming vibration from [...]
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Causes of Delays During Construction Phase of Road Projects due to the Failures of Contractor, Consultant, and Employer in Addis Ababa City Road Authority
E. Quezon

International Journal of Scientific & Engineering Research (2017). Amare, Y.; Quezon, ET.; Busier, M. Causes of Delays During Construction Phase of Road Projects due to the Failures of Contractor, Consultant, and Employer in Addis Ababa City Road Authority. International Journal of Scientific & Engineering Research. 2017; 8(3): 15-25.

Abstract
Construction delay considered as one of the most recurring problems in the implementation of construction projects. It is widely known to have an adverse impact on project success in terms of time, quality, and cost. The effect of construction delay is not only confined to the construction industry but also its influence on the overall economy of a country like Ethiopia. This research was conducted to assess the causes of excessive delays in the completion of road projects during the construction phase due to the failures of Employer, Consultant, and Contractor in Addis Ababa City Road Authority projects. Spearman rank correlation coefficient from the Relative Importance Index (RII) analysis was used to test the agreement between different groups of respondents who participated in the questionnaire survey and to rank the three construction parties according to their responsibility area and importance as perceived by the respondents which factor causing the delay of road projects. This research identified sixty-five (65) causes of delay. There were fifty-one (51) valid questionnaires received back from Contractors, Consultants, and Employer (AACRA). Based on the results, the contractors have the highest percentage of responsibility area that causes the delay of about 40%. While the second was on the part of the Employer, which comprised 26.15%, and the consultant which placed third of 23.08%. On the other hand, there were 10.77% of the respondents attested that the Shared groups (3-parties) have the responsibility area which causes project delay during the implementation phase. About this, the research study identified and ranked the top ten factors causing delays of construction projects in Addis Ababa City Road Authority. Poor ﬁnancial control of the project ranked 1st with Relative Importance Index (RII) of 0.905. Difficulties in financing projects by contractors ranked 2nd with the Relative Importance Index (RII) of 0.854. Type of project bidding and award (lowest bidder) ranked 3rd with an RII of 0.850. Poor site management and supervision of contractors ranked 4th with an RII of 0.839. Selecting inappropriate contractors ranked 5th with an RII of 0.823. Lack of high-technology mechanical equipment ranked 6th with an RII of 0.819. Inaccurate initial project scope estimate and Ineffective project scheduling ranked 7th and 8th with an RII of 0.803. Weak control of the project progress ranked 9th with an RII of 0.788. And the Contractor’s staff is not adequately trained in professional construction management techniques ranked 10th with an RII of 0.784. Therefore, it concluded that the main party Contractor did not perform properly his duties and obligations leading to the main contributory factor causing the failure of the project.
Abstract
Construction delay considered as one of the most recurring problems in the implementation of construction projects. It is widely known to have an adverse impact on project [...]
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A Study on the Effect of Time Duration by Vibrating or Tamping Fresh Concrete on the Compressive Strength of C-25 Concrete
A. Achalu, E. Quezon, G. Macarubbo

Effect of Time Duration by Vibrating or Tamping Fresh Concrete on the Compressive Strength (Select a year). Afework Achalu, Emer Tucay Quezon, Gerry Bangayan Macarubbo. A Study on the Effect of Time Duration by Vibrating or Tamping Fresh Concrete on the Compressive Strength of C-25 Concrete. American Journal of Construction and Building Materials. Vol. 2, No. 2, 2017, pp. 40-47. doi: 10.11648/j.ajcbm.20170202.11

Abstract
Many years ago, consolidation accomplished by laborers wielding a variety of spades, tampers, and similar tools. In Ethiopia, there is no enough knowledge by the laborers, while the site engineers ignored the correct application due to some constraints. The agreement of acceptable vibration level in fresh concrete to which tamping time duration is optimum is an issue to obtain the desired specific compressive strength. This research study aims to evaluate the maximum time length and techniques used to Vibrating or Tamping fresh concrete and its effect on the compressive strength of C-25 Concrete through internal Rodding. Therefore, to study the effects of the period by vibrating or tamping, the needle-type internal vibrator was used to test new concrete cubes based on ACI309R-96. The quality of concrete is important to make physical tests on materials used before any actual experiments to perform. The fresh concrete samples tested by using internal vibration methods and techniques of compaction with different time duration of 1sec, 2sec, 3sec, 4sec, and 5sec. These tests performed by using steel rod in fresh concrete to know the Optimum time of compaction by internal vibration on the cube test of new concrete. Laboratory experiments had been conducted to check the methods and techniques applied to construction sites, as well as site observation on the effects of the vibration time of fresh concrete on the compressive strength and flexural strength of C-25 Concrete with varying vibration time duration and steel rod tamping. Based on the results of cube tests of compressive strength of Concrete Samples have been checked on the 3rd day, 7th day, and 28th day. This research study found out that the Optimum period of compaction was 3sec to produce an acceptable right quality of the concrete mix. Likewise, the flexural strength of the Concrete Sample, when it tested in the laboratory on the 7th day and 28th day, results revealed that the flexural strength improved when vibration time increased, but the amount of water has to be reduced to obtain the desired strength. Finally, Tamping is needed to place fresh concrete in the mold correctly. Furthermore, new concrete produced should match the properties and avoid improper tamping or vibration applications. This situation must not cause differences in the compressive strength of concrete.
Abstract
Many years ago, consolidation accomplished by laborers wielding a variety of spades, tampers, and similar tools. In Ethiopia, there is no enough knowledge by the laborers, [...]
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Contract claim Analysis on Building Construction Project in Addis Ababa: A case study at Yeka Sub City
E. Quezon

International Journal of Scientific & Engineering Research (2016). Zenebe, E.; Quezon, ET.; Mosisa, A. Contract claim Analysis on Building Construction Project in Addis Ababa: A case study at Yeka Sub City. International Journal of Scientific & Engineering Research. 2016; 7(7): 1154-1160

Abstract
Contract claims are an inevitable fact of life in the construction industry. Contract claims are one of the problems that construction projects may face. Claims might cause many effects such as payment delay, an extension of time, and work suspension. The main aim of this research was an analysis of contract claims on building construction projects in Addis Ababa, Yeka Sub City by investigating the causes of contract claims and determining the factors to be considered in the selection of appropriate methodology for contract claims analysis. Literature and survey-based studies were made to provide an overview of the different contribution effects of contract claim analysis on building construction projects at the selected site. Interviews were also conducted with the three parties which have direct involvement in construction activities to get concrete ideas on the subject matter. A total of 75 questionnaires was distributed to respondents in Addis Ababa, Yeka Sub City building construction projects. Out of these 12 for client representatives, 35 for contractors representatives, 20 for consultant representatives, and 8 for other companies in order to identify claim causes that occurred in the study area. The quantitative data were analyzed using Excel and SPSS version 20 software, while qualitative data were analyzed by content analysis. The main factors of contact claim cause in the study area were identified. These factors further categorized into four groups; client-related, contract document-related, contractor related and consultant-related factors. While types of delays, knowing the strength and weakness of the project (project complexity) and conditions of the contract were identified as the factor to be considered in the selection of appropriate methodology for contract claim analysis. It is recommended that the three main contracting parties (Owner, Contractor, and Consultant) have responsibility for the effective accomplishment of the project. So each party would take part in their homework on time by developing technical knowledge about the effects of Contract claims on the progressive construction projects. Index Terms— causes, claim analysis, Contract claims, construction project, and risks.
Abstract
Contract claims are an inevitable fact of life in the construction industry. Contract claims are one of the problems that construction projects may face. Claims might cause [...]
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Evaluation of Health and Safety Practice in Building Construction: A Case Study in Addis Ababa
E. Quezon

International Journal of Scientific & Engineering Research (2016). Fekele, L.; Quezon, ET.; Macarubbo, YC. Evaluation of Health and Safety Practice in Building Construction: A Case Study in Addis Ababa. International Journal of Scientific & Engineering Research. 2016; 7(10): 122-131

Abstract
The construction industry has been seen as one of the hazardous industries. This is because the industry has a poor health and safety performance record compared to other industries all over the world. Labor law in every nation provides that it is the duty of an employer to ensure that every worker employed works under satisfactory, safe and healthy conditions. The research is focused on evaluating the health and safety issues in building construction projects in Addis Ababa, Ethiopia. The roles of the Client, Consultant and Contractor in health and safety consideration during project implementation were examined. It also determined the factors affecting health and safety performance of laborers. Whether, safety is used as criteria in selecting a contractor during the prequalification phase of public bidding was also identified. Building Construction Companies were involved in the sampling. All the information that could help in attaining the study objectives were collected, reviewed and formalized from the literature review. Data were collected and evaluated and the Relative Importance Index for each factor affecting health and safety was determined. The study determined the practical situation of building construction projects in consideration of health and safety, which was evaluated as low to medium. Relative Importance (RII) index of 12 factors affecting health and safety performance of labors were calculated. The top three factors identified were: (1) Non availability of a clear company Health and safety policy (0.85); (2) Inadequate enforcement of the existing building rules and regulations (0.82); and (3) Safety awareness of the company's top management (0.80). To improve the safety and health performance of building construction projects, the following major recommendations were proposed: each building, construction projects should have their own safety and health policy; include safety as a pay item in contract document; and allocate budget and time frames for health and safety in the contract document. Index Terms— Addis Ababa, Company Policies, Hazards, Health and Safety Practices, Rules and Regulations .
Abstract
The construction industry has been seen as one of the hazardous industries. This is because the industry has a poor health and safety performance record compared to other [...]
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Assessment on the effects of weather change on road construction planning at some selected projects in Addis Ababa and Oromia
E. Quezon

International Journal of Scientific & Engineering Research (2016). Befkadu, A.; Quezon, ET.; Busier, M. Assessment on the effects of weather change on road construction planning at some selected projects in Addis Ababa and Oromia. International Journal of Scientific & Engineering Research. 2016; 7(12): 134-145.

Abstract
Road construction in Ethiopia is in high demand to meet its short and long-term goals in infrastructure development programs. The road network is constructed radiating outwards North-South and East-West direction of the Capital City. Some projects are experiencing weather malady due to changing weather conditions in project locations. The study area of this research was focused on some selected projects in Addis Ababa and Oromia. The research had been addressed the effects of changes in weather in the three project planning phases, namely conception planning, design planning, and construction planning. A quantitative research design was used in this study. A literature review was undertaken and the result of which showed that the effects of weather changes are not extensively researched in the construction industry and there are limited references on the effects of weather change within the road construction industry. Sample data were obtained from sixty-three (63) construction practitioners through questionnaires, which were mailed to prospective respondents to assess their opinions. Questions were subdivided into three relevant areas covering demographics, experience with weather change factors, and the effects of weather change on road construction project planning. The study found that the effects of weather change on road construction project planning are similar to those found in other construction industries. The effects of weather change factors on road project planning vary with planning phases. These weather change factors as well as their effects were listed and ranked based on their frequency of occurrence and mean score. An independent sample t-test was used to compare respondents’ opinions on weather change effects between the two sample groups taken in Addis Ababa and part of Oromia. A partial correlation was also employed to identify the relationship between weather change factors and their effect on road construction project planning using SPSS-20. Delay of site preparation activities as a result of weather change on road project conception planning phase has a mean score of 4.30 Addis Ababa and 4.00 in for Oromia, while the influence of weather change on the selection and specification of construction materials for road project design planning phase has the highest mean score of 4.23 for Addis Ababa and 4.03 for Oromia. The effect of weather change on road workers' physiological comfort and quality of work for the road project construction planning phase has the highest mean score of 4.80 and 4.58 in Addis Ababa and Oromia, respectively. The study concludes with recommendations for potential research and with useful information and considerations on the effects of weather change on road construction project planning for construction professionals and project managers.
Abstract
Road construction in Ethiopia is in high demand to meet its short and long-term goals in infrastructure development programs. The road network is constructed radiating outwards [...]
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Evaluation on the Performance of Lowest Responsive Bid Contract and the Quality of Materials Used on Governmental Building Projects in Jimma Town
E. Quezon

International Journal of Scientific & Engineering Research (2016). BinyamLetarge, Emer T. Quezon, Yolente C. Macarubbo. Evaluation on the Performance of Lowest Responsive Bid Contract and the Quality of Materials Used on Governmental Building Projects in Jimma Town. International Journal of Scientific & Engineering Research. 2016; 7(12): 60-73

Abstract
Construction industry participants have started recognizing that accepting the least bid price does not guarantee maximum value. Continuous problems of inferior quality of constructing facilities, high incidence of claims and litigation, frequent cost overruns, and use of poor quality of materials have become the main features of Ethiopian’s public construction work contracts. This research was undertaken to evaluate the performance of publicly owned construction projects awarded on a lowest bid awarding system, to determine the effect of advance payment on the contractor’s performance, compare lowest and average bid systems, and check the quality of local construction materials use by lowest price won contracts. A literature review was carried out to identify different practices and floated questionnaire survey and laboratory test was conducted for selected and expected materials. Two alternative bid evaluation methods were discussed and suggested the better one from a performance point of view. The questionnaire was distributed to contractors, clients, consultants, and other related professionals. Additionally, interviews were conducted with them. A total of 88 questionnaires were distributed, including laboratory test results for selected and expected materials found in Jimma town. The data were collected and 80 valid questionnaires were analyzed by using SPSS-20, Excel, and laboratory test results requirement. The study identified that the causes of the poor performance of contractors were won projects with the lowest price; therefore more of the respondents do not like the lowest bidding method. Advance payment is the main solution to support the financial problems of contractors, but instead of paying in cash, purchasing the necessary construction materials is seen as an alternative to protect contractors from using the money for other uses. Obviously known that in the current bid awarding method of Ethiopia, most of the time, in order to be the winner of the bid price should be lesser. This leads the bidder not to get adequate profit, this pushes them to use poor quality of local construction materials. Finally, this work provides valuable information to the Ethiopian government, clients, consultants and contractors, and other stakeholders who desire to improve bidding methods; usage of advance payment; ways to improve performance of contractors, and to protect the project from contractors using poor quality of construction materials.
Abstract
Construction industry participants have started recognizing that accepting the least bid price does not guarantee maximum value. Continuous problems of inferior quality of [...]
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PARAMETRIC MODELLING ON THE RELATIONSHIPS BETWEEN ATTERBERG LIMITS AND COMPACTION CHARACTERISTICS OF FINE-GRAINED SOILS
P. Quezon, E. Quezon

International Journal of Advanced Research in Engineering and Applied Sciences (2019). Worku Firomsa, Prof. Emer Tucay Quezon; (2019). “PARAMETRIC MODELLING ON THE RELATIONSHIPS BETWEEN ATTERBERG LIMITS AND COMPACTION CHARACTERISTICS OF FINE-GRAINED SOILS.” International Journal of Advanced Research in Engineering and Applied Sciences, 8(7), 1-20. https:// www.garph.co.uk

Abstract
Compaction is one of the essential engineering techniques, performed to assure the stability of soils based on specified strength. However, in most construction projects such as large-scale projects, obtaining the desired compaction characteristics, namely optimum moisture content (OMC) and maximum dry density (MDD), becomes time-consuming. In this case, predicting the compaction characteristics from the Atterberg's limits that involve a more straightforward and quicker method of testing becomes a vital task. This study focused on obtaining valid correlations between Atterberg's limit parameters and compaction characteristics of fine-grained soils. A series of laboratory tests for 50 samples conducted for the investigation. Statistical relationships of all the parameters were analyzed. The laboratory test results indicated that both OMC and MDD showed a strong correlation with LL and PL together using multiple linear regressions than with single parameters from single linear regression. Therefore, the study concluded that during the prediction of OMC and MDD from Atterberg's limits, the combined parameters of Atterberg's limits should be used rather than single parameters. It is recommended, the result of this research could be applied in different civil engineering practices, directly related to the parameters to be known.
Abstract
Compaction is one of the essential engineering techniques, performed to assure the stability of soils based on specified strength. However, in most construction projects such [...]
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A Study on the Effect of Time Duration by Vibrating or Tamping Fresh Concrete on the Compressive Strength of C-25 Concrete
A. Achalu, E. Quezon, G. Macarubbo

American Journal of Applied Scientific Research (2017). Vol. 3, No. 6: pp. 72-79. doi: 10.11648/j.ajasr.20170306.11

Abstract
Many years ago, consolidation accomplished by laborers wielding a variety of spades, tampers, and similar tools. In Ethiopia, there is no enough knowledge by the laborers, while the site engineers ignored the correct application due to some constraints. The agreement of acceptable vibration level in fresh concrete to which tamping time duration is optimum is an issue to obtain the desired specific compressive strength. This research study aims to evaluate the maximum time length and techniques used to Vibrating or Tamping fresh concrete and its effect on the compressive strength of C-25 Concrete through internal Rodding. Therefore, to study the effects of the period by vibrating or tamping, the needle-type internal vibrator was used to test new concrete cubes based on ACI309R-96. The quality of concrete is important to make physical tests on materials used before any actual experiments to perform. The fresh concrete samples tested by using internal vibration methods and techniques of compaction with different time duration of 1sec, 2sec, 3sec, 4sec, and 5sec. These tests performed by using steel rod in fresh concrete to know the Optimum time of compaction by internal vibration on the cube test of new concrete. Laboratory experiments had been conducted to check the methods and techniques applied to construction sites, as well as site observation on the effects of the vibration time of fresh concrete on the compressive strength and flexural strength of C-25 Concrete with varying vibration time duration and steel rod tamping. Based on the results of cube tests of compressive strength of Concrete Samples have been checked on the 3rd day, 7th day, and 28th day. This research study found out that the Optimum period of compaction was 3sec to produce an acceptable right quality of the concrete mix. Likewise, the flexural strength of the Concrete Sample, when it tested in the laboratory on the 7th day and 28th day, results revealed that the flexural strength improved when vibration time increased, but the amount of water has to be reduced to obtain the desired strength. Finally, Tamping is needed to place fresh concrete in the mold correctly. Furthermore, new concrete produced should match the properties and avoid improper tamping or vibration applications. This situation must not cause differences in the compressive strength of concrete.
Abstract
Many years ago, consolidation accomplished by laborers wielding a variety of spades, tampers, and similar tools. In Ethiopia, there is no enough knowledge by the laborers, [...]
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Influence of Subsurface Courses Materials On Pavement Performance: A Case Study in Yebu-Agaro Road
E. Quezon

International Journal of Scientific & Engineering Research (2016). Anteneh Geremew, Prof. Emer T. Quezon, Getachew Kebede. Influence of Subsurface Courses Materials On Pavement Performance: A Case Study in Yebu-Agaro Road. International Journal of Scientific & Engineering Research. 2016; 7(10): 1252- 1260.

Abstract
The properties of subsurface materials would vary from place to place while it is true the performance of pavement along the route also differs. The research study had been undertaken at the Yebu-Agaro road section with the main objective to determine the Influence of Subgrade Soil on pavement performance. In order to realize the desired objective, a systematic methodology was adopted which includes field investigation, field test, and laboratory tests. While the purposive sampling method was used to extract soil samples from the road section that are severely damaged showing different failure types and non-distress surfaces. Those severe types of failures observed along the road section are reflective crack, pothole, rutting, alligator crack, and block crack. From these failure types, five representative samples were extracted at different locations along the failures section and one non-distress pavement of the road section using a manual hand auger. The analyses of soil samples were carried out based on the Geotechnical properties such as wash gradation, Atterberg limit, and Modified proctor test, California Bearing Ratio (CBR) and field test, as well as Axle load analysis. It was found out that the liquid limit of subgrade soil varies from 33% -60.5% and the plasticity index from 20.3% -30.1% while there was a significant increase in moisture content at the field and observed beyond the OMC in the laboratory result due to the distress of pavement affected by water infiltration through cracks, that tend to reduce the dry density. The recorded soaked CBR values of subgrade soil materials range between 8% -13%, which was below the 15% minimum value specified by the ERA manual. However, the existing CBR values of the subgrade soils indicate a poor material used for pavement structures. According to ASSHTO, the soil is classified as A-2-6 and A-7-6 category which means the existing soils are fair to poor as a sub-grade material while USCS classification shows that the soil falls into the SC group. In addition, the failures that are frequently observed on the road surface were significantly influenced by subgrade soil. For the sub-base layer materials, it was noted to have satisfied the minimum requirements as compared with standard specification, except deficiency of its thickness. For the base course materials, inferior qualities of material were used in some sections. The overall results showed that heavy vehicles or traffic loads are one of the major causes of road failure along the study road section. Hence, the influence of other factors such as poor drainage courses, level of groundwater table, variety of geologic materials along the road route, and poor construction materials should be thoroughly addressed before the start of the rehabilitation of the road section in the future. Finally, a possible remedial measure is recommended for every observed failure or distress on the pavement condition of the study area in order to sustain the design life of the pavement.
Abstract
The properties of subsurface materials would vary from place to place while it is true the performance of pavement along the route also differs. The research study had been [...]
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Investigation of Traffic Accident Prone Areas Related to Existing Road Condition and Driver’s Behavior along Menagesha- Ambo Road Section
E. (MSc), P. (MSc), E. Quezon

World Journal of Engineering Research and Technology (2018). Eyob Mekonnen (MSc), Prof. Emer Tucay Quezon and Murad Mohammed (MSc). Investigation of Traffic Accident Prone Areas Related to Existing Road Condition and Driver’s Behavior along Menagesha- Ambo Road Section. World Journal of Engineering Research and Technology. wjert, 2018, Vol. 4, Issue 2, 64-81

Abstract
Traffic accidents worldwide are increasing due to pragmatic vehicle ownership, acquisition, which necessitates daily activities. The primary objective of this research work was to identify the most hazardous location and provide countermeasures that will minimize traffic accident at the designated sites. The scope of the study was limited to Ambo-Ginchi- Addis Ababa road, a total length of the study road section of 87kms. The traffic accident data collected from each Wededa Police station covering the period of 2012-2015. It was analyzed using a Priority value formula for EjereWereda and Holota town, and accident frequency for Ambo wereda, Dendiwereda, and Welmeraweredato rank the traffic accident areas. Based on the results of the analysis, thirteen locations of the road stretch were found to be accident-prone areas. Out of these sites, three of them are in Ambo Wereda, two in Ejerewereda, one in Welmerawereda, and seven in Holota town. The time when most of the accidents occurred from 3:00 PM-6: 00 PM. The primary causes of the accidents were overspeeding, driving without attention, and some unknown reasons. Also, it showed that the drivers’ age group who caused most of the accidents composed of 25-34 years old. Based on the findings of the study, it is concluded that there was a significant increase in the number of crashes in the afternoon. Young drivers are believed to cause more accidents than older ones due to aggressiveness. To minimize the occurrence of accidents along the study road section, it is recommended that provision of speed limit signboards and warning signs at the strategic locations where traffic accident areas are identified to forewarn the overspeeding drivers. It is also recommended that the road agency should have to undertake to widen the lane width of the road, provision of sufficient climbing lane, installation of roadside Delineator, conduct roadside improvements, and repaint faded pavement markings.
Abstract
Traffic accidents worldwide are increasing due to pragmatic vehicle ownership, acquisition, which necessitates daily activities. The primary objective of this research work [...]
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Engineering Properties of Mechanically Stabilized Subbase Material Using Natural Gravel around Jimma Quarry Sites for Unpaved Road Construction
E. Quezon

Global Scientific Journals (2017). Almaz Ejeta, Emer Tucay Quezon, Kabtamu Getachew. Engineering Properties of Mechanically Stabilized Subbase Material Using Natural Gravel around Jimma Quarry Sites for Unpaved Road Construction. Global Scientific Journals. GSJ: 2017; 5(5): 93-102

Abstract
Unpaved roads are designed with a small input and are constructed from the nearest available materials as possible. It requires routine and periodic maintenance, and its condition can be significantly affected by a period of excessive traffic volumes or inclement weather conditions. The accurate estimation of maintenance cost is difficult. Many problems occur in the economic analysis of unpaved roads in comparison with paved roads. D effects that may affect unpaved roads are dusty, potholes, stoneness, corrugations, and rutting. Hence, it needs to apply a sufficient stabilization method to strengthen and increase the durability of the unpaved road. Mechanical stabilization is an important application in engineering for different types of construction to improve the performance of road construction materials. The objective of this research was to determine the Engineering properties of natural gravel materials by mechanical stabilization method to be used in subbase material for the unpaved road. The methodology carried out in this research study includes: (a) field visual inspection and sampling of natural gravel materials from three quarry sites around the Jimma area; and (b) laboratory tests to identify the physical and mechanical properties of natural gravel. Based on the laboratory test results, natural gravel materials from the Seka quarry site has an excellent Abrasion resistance of 35.26%, Plasticity Index of 13% a little bit above the upper limit, and good gradation (coarser and less subtle or binder materials), right CBR value. While the Jiren quarry site has a little Abrasion resistance of 52.09%, medium plasticity index, poor gradation (moderate fine material), CBR value of 28.90% which was below 30% minimum requirement, but had good MDD. On the other hand, the Merewa quarry site comprised of a very poor Abrasion resistance of 78.3 4%, Plasticity Index of 2 3.90% which was beyond the upper limit plasticity index of 1 2%, and poor gradation (more fine materials), poor CBR value and poor MDD. Therefore, it is concluded that the natural gravel from the Seka quarry site is suitable for the subbase course. But since road construction around Jimma is booming, the natural gravel from this quarry site would be soon depleted. About this, mechanical stabilization is recommended by blending the natural gravel from the Seka quarry site with 54% by weight with Jiren natural gravel of 46% by weight to meet the minimum requirements for subbase materials.
Abstract
Unpaved roads are designed with a small input and are constructed from the nearest available materials as possible. It requires routine and periodic maintenance, and its condition [...]
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EFFECTS OF MECHANICALLY STABILIZED GRADED ASSORTED COARSE-GRAINED SOILS IN THE PERFORMANCE OF UNPAVED ROAD: A CASE STUDY IN GOFFA ZONE, SAWLA AREA
E. Esho, E. Quezon

International Journal of Research - Granthaalayah (2019). Edire Erko Esho, Prof. Emer Tucay Quezon, and Democracy Dilla. (2019). “Effects of Mechanically Stabilized Graded Assorted Coarse-Grained Soils in the Performance of Unpaved Road: A Case Study in Goffa Zone, Sawla Area.” International Journal of Research - Granthaalayah, 7(8), 133-156. https://doi.org/10.5281/zenodo.3380234

Abstract
Road network development in Ethiopia is booming, radiating from Addis Ababa towards NorthSouth directions, and East-West directions, due to the good economic growth of the country. However, there are challenges always facing by the pavement designers, and materials engineers for every road project, specifically the unpaved roads in Goffa Zone. It was because, most parts of the existing unpaved road sections within the study area are heavily damaged, and lack proper maintenance. The source of good quality sub-base course materials limited and becoming depleted. It is for this reason that the research study focused on the investigation of the effects of mechanically stabilized graded assorted coarse-grained soils. Disturbed and undisturbed samples from different quarry sites were considered and tested in the laboratory. Laboratory tests for each location performed, and the results served as control values of the engineering properties of natural soils. The Disturbed samples tested for Gradation, Atterberg's Liquid Limit Tests, and Compaction, while, the undisturbed sample tested for the CBR strength, using the ASTM manual. The results of the assorted materials for the sub-base course were analyzed and compared with the AASHTO and ERA Standard Specifications.
Abstract
Road network development in Ethiopia is booming, radiating from Addis Ababa towards NorthSouth directions, and East-West directions, due to the good economic growth of the [...]
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Identification of Road Traffic Accident Blackspot locations and its countermeasures in Oromia Region, East Wollega Zone
E. Quezon

International Journal of Scientific & Engineering Research (2016). Gashaw Fekadu, Prof. Emer T. Quezon. Identification of Road Traffic Accident Blackspot locations and its countermeasures in Oromia Region, East Wollega Zone. International Journal of Scientific & Engineering Research. 2016; 7(10): 1372-1379

Abstract
One of the inputs for the economic development of a country is the expansion of the road network, which is important for the transportation of people and freights from place to place. With this expansion, the occurrences of a road traffic accident is increasing in all parts of the world from time to time, killing the lives of many peoples and damage to properties. This problem is growing with the highest rate in sub-Saharan African countries like Ethiopia. The general objective of this study is to identify the hazardous locations of road traffic accidents and suggest countermeasures to mitigate the occurrence of road accidents. The study area was conducted in the East Wollega Zone of the Southwestern part of Ethiopia in the Oromia Region. Districts exposed to high traffic volume are sampled using the purposive sampling method. Those sampled districts include Digga, Sibbu Sire, Nekemte town, Wayyu Tuka, Guto Gidda, Gobbu Sayyo, Leka Dullacha, and Jimma Arjo. Road accident data are collected from all administrative districts from September 2012 to June 2015 (2005 -2007 E.C), and it was used for the analysis. In addition, a field survey was made to observe the existing geometry, an environment of the roadside, traffic flow regulators, and markings of the road sections. To rank each of the sample districts, evaluation of Priority value had been used consisting of a number of deaths, minor and major injuries that occurred for three years. Based on these parameters, each of the districts was listed from highest to lowest (i.e. Digga, Nekemte town, Sibbu Sire, Wayyu Tuka, Guto Gidda, and Gobbu Sayyo) out of the whole sample districts. This research study had found out that there was a significant increase in terms of the number of deaths occurring due to road traffic accidents as a result of the increase in the coverage of road crashes and their consequences. The major causes of road accidents include over-speeding, ignoring warning posts, road geometry, deterioration of pavement, and roadside environment. In order to minimize the frequency of road traffic accidents at the identified hazardous road locations, countermeasures are recommended, addressing to the concerned agency which includes speed breakers, installation of guardrails at curvatures, installation of hazard light to minimize night-time road accidents, removing roadside obstructions, repair, and maintenance of pavement defects to restore to as-is good condition and building additional facilities for pedestrians in an urban area.
Abstract
One of the inputs for the economic development of a country is the expansion of the road network, which is important for the transportation of people and freights from place [...]
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Investigation on the Suitability of Waste Plastic Bottle as Partial Replacement of Sand in a Cement Tile Production
E. Haile, E. Quezon, G. Kebede

American Journal of Civil Engineering and Architecture (2019). Elshaday Haile, Emer Tucay Quezon, and Getachew Kebede, “Investigation on the Suitability of Waste Plastic Bottle as Partial Replacement of Sand in a Cement Tile Production.” American Journal of Civil Engineering and Architecture. 2019; 7(3): 121-127. Doi: 10.12691/ajcea-7-3-1.

Abstract
The rapid growth of the world's construction industry is profoundly affecting the cost of construction materials, as well as the natural resources required to produce the materials and environment. Besides, waste plastic bottles are also becoming another challenge in our surroundings due to their presence in large amounts and their nonbiodegradability property. Even if various methods were attempted to manage this waste, applying it as the partial replacement for different construction materials seems feasible concerning solving the above-stated problems. The objective of this research was to investigate the competency of waste plastic bottles as partial replacement of sand in a cement tile production through conducting workability, dry density, water absorption, and compressive strength test on it at the particular 7th and 21st days of curing. Experimental laboratory method used in this research design for testing some physical and mechanical properties of cement tiles. Other than this comparative method was also applied to compare different properties of controlled cement tile with cement tile made with just 3%-33% ground waste plastic bottle as sand at 3% incremental ratio and also cement tile produced by sodium hypochlorite treated plastic sand. The result showed an increment in the workability of the fresh concrete of the cement tile, decrement in compressive strength, reduction in dry density, and declined water absorption result. Finally, the study concluded the possibility of partial plastic replacement of sand in a cement tile production up to 32.11% replacement ratio for 21st day curing ages and even if the replacement above 32.11% had an adverse effect on the compressive strength and workability of cement tile, it also got an advantage with respect to dry density and water absorption. Also, the study revealed the power of sodium hypochlorite solution in improving the high physical and mechanical properties of cement tile. It recommended for the responsible parties to apply this technology in the real production process of cement tile.
Abstract
The rapid growth of the world's construction industry is profoundly affecting the cost of construction materials, as well as the natural resources required to produce [...]
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Assessment of Factors Affecting Labor Productivity on Road Construction Projects in Oromia Region, Bale Zone
E. Quezon

International Journal of Scientific & Engineering Research (2016). Melese Mengistu, Prof. Emer T. Quezon, Getachew Kebede. Assessment of Factors Affecting Labor Productivity on Road Construction Projects in Oromia Region, Bale Zone. International Journal of Scientific & Engineering Research. 2016; 7(11): 899- 910.

Abstract
Road construction in Ethiopia is booming and radiating from Addis Ababa towards North-East and East-West directions to fulfill its long-term development program. Transportation is a prime mover to all sectors in the country to uplift the economic activities of the populace in the locality. In most countries, experience and related literature have revealed that road construction labor costs accounted for 30-60% of the total cost of a project, depending on the terrain and source of materials, labor, and equipment to be utilized. Therefore, construction labor productivity plays a vital role in the performance and profitability of road construction projects. Road sector construction projects in Ethiopia are means through which development strategies are achieved. This research study gives insight on the assessment of the factors affecting labor productivity in road construction projects through a structured questionnaire survey of 83 respondents working on construction road projects in Oromia Region, Bale Zone. Respondents were required to rate how the 61 factors affecting labor productivity with respect to the importance and frequency of occurrence. Understanding these factors is helpful for the construction professionals who work on the initial phase of construction planning in order to efficiently deliver the project plan and to solve poor labor productivity. The results of this survey were then analyzed using the Relative Importance Index (RII) and ranked. The reliability of these 61 factors for assessing the effect on labor productivity was tested by Chronbach’s alpha measurement, and the results indicated that the 30 factors tested are reliable (α= 0.973), and checked by SPSS. The result of this analysis showed that there are 11 groups that have significant impacts on the labor productivity ranked as Material and Equipment Factor with RII=0.819, Manpower and WorkForce Factor with RII=0.764, Management Factor with RII=0.737, Quality Factors with RII=0.720, Supervision Factor with RII=0.699, Safety Factor with RII=0.691, Motivation Factor with RII=0.682, Schedule Factor with RII=0.647, Political Factor with RII=0.620, Natural and environmental Factor with RII=0.566 and Cultural and Religious Factor with RII=0.541. Based on the results of this research study, the top factors that affect labor productivity includes Lack of experience of labor, Material construction shortage, Lack of labor skills, Accident, Tools and Equipment shortage, Labor’s bad habit, Poor site management, Lack of Labor surveillance, Payment delay and Ignore safety precautions. Therefore, this research study suggests that the contractors should assign project managers and construction supervisors with sufficient managerial skills in road construction projects so that when there are any problems which may arise, it would be acted and solved immediately at the project site. On the other hand, the role of the Ethiopian government in project implementation is very significant, which requires proper attention to the productivity issue to enforce hard and fast laws and regulation which help to obtain productive workforce in the road construction industry.
Abstract
Road construction in Ethiopia is booming and radiating from Addis Ababa towards North-East and East-West directions to fulfill its long-term development program. Transportation [...]
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Analysis of Road Traffic Accident Related of Geometric Design Parameters in Alamata-Mehoni- Hewane Section
E. Quezon

International Journal of Scientific & Engineering Research. (2017). Teyba Wedajo, Emer T. Quezon, Murad Mohammed. Analysis of Road Traffic Accident Related of Geometric Design Parameters in Alamata-Mehoni- Hewane Section. International Journal of Scientific & Engineering Research. 2010; 8(1): 874- 881.

Abstract
Geometric design deficiencies on existing roads would lead to a potential accident, such as an accident that happens at the sharp curves, layered pavement conditions, and slippery pavement surface. A road traffic accident has been increasing in the Southern Region of Tigray, of which this area was shown to have alarming rates. According to the Southern Tigray Regional Police, a high figure of road traffic accidents was recorded in Alamata, Mehoni, and Hewane districts. This research study focused on the analysis of traffic accidents related to geometric design parameters of the existing asphalt road. While the data for the analysis covered route data, traffic accident reports from the police station containing some injuries, crashes, and damage to properties, as well as interviews and questionnaire surveys to people who are directly involved in road travels, are considered. The primary data have mainly covered the geometry of the road which was measured during the site survey, road safety audit using the checklist, interview, and questionnaire survey. On the other hand, the secondary data collected from the traffic management office in the district offices. On this, the results presented in the form of line graphs, pie charts, figures for road traffic accidents, and sketches for the suggested improvement in the road design problem. Based on the results of the study in the year 2010 to the year 2015, it found out that there were 866 Road Traffic Accidents have been occurring in the vicinity of the survey road sections. From this figure, the road traffic accident and damage to properties expressed as an equivalent amount of about 33,565,122.00 Birr. It revealed that the primary cause of road traffic accidents in the study area emanated from the road design elements due to some geometric deficiencies in the traffic accident-prone areas. Therefore, this study concluded that the frequency of occurrence of road traffic accidents and the figure of casualties is significantly increasing. This road accident would persist if the concerned agencies do not adequately address the malady.
Abstract
Geometric design deficiencies on existing roads would lead to a potential accident, such as an accident that happens at the sharp curves, layered pavement conditions, and [...]
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Comparative Study on Compressive Strength of Locally Produced Fired Clay Bricks and Stabilized Clay Bricks with Cement and Lime
M. Hiwot, P. Quezon, G. Kebede, E. Quezon

Global Scientific Journals (2017). Miskir Gebre Hiwot, Prof. Emer Tucay Quezon, Getachew Kebede. Comparative Study on Compressive Strength of Locally Produced Fired Clay Bricks and Stabilized Clay Bricks with Cement and Lime. Global Scientific Journals. GSJ: 2017; 5(12): 147- 157.

Abstract
The local fired brick production technique is the known method of brick making, especially in Jimma Town. Firing of bricks in local brick production method is conducted by burning of much amount of woods. But this method of firing bricks by burning of woods will affect the environment. The locale firing technique is difficult to control the firing temperature, which will result in non-uniform burnt bricks. The major objective of this experimental study was to compare the compressive strengths of locally fired clay bricks and the local unfired cement and lime stabilized clay bricks. Specifically, the index properties of soil used for brick production, the compressive strength of locally fired clay bricks, and stabilized clay bricks had been determined and compare with the standard specifications. This study, it was used contents of the stabilizer for cement and lime of 10%, 12%, and 14%, respectively. The mix ratio applied 1:9, 1:7, and 1:6 by volume of clay with stabilizer 10%, 12%, and 14%. Based on the result on the 28th day, the mean compressive strength test, the 10%, 12%, and 14% cement Stabilized clay bricks have compressive strengths of 2.91Mpa, 3.28Mpa, and 3.79Mpa respectively, which are better than the mean compressive strength of the locally fired clay bricks which is 2.73Mpa. On the other hand, the 28th day means compressive strengths of the lime stabilized clay bricks were 2.19Mpa, 2.51Mpa, and 2.69Mpa, respectively. Therefore, these results showed that the Fired Clay Brick fails the minimum mean compressive strength requirement based on the ES, ASTM, and IS standards. But the Stabilized Clay Bricks fulfill the minimum compressive strength requirements of IS standard for stabilized bricks. Among these three methods, the cement stabilized clay bricks indicated better quality than both locally fired and lime stabilized bricks.
Abstract
The local fired brick production technique is the known method of brick making, especially in Jimma Town. Firing of bricks in local brick production method is conducted by [...]
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Evaluation on the Operational Characteristics of Gerji-Imperial Roundabout: A Case Study in Addis Ababa
E. Quezon

International Journal of Scientific & Engineering Research (2017). Bewket Aynetaw, Prof. Emer Tucay Quezon, Tarekegn Kumela. Evaluation on the Operational Characteristics of Gerji-Imperial Roundabout: A Case Study in Addis Ababa. International Journal of Scientific & Engineering Research. 2017; 8(12): 1002-1009.

Abstract
Highly congested roundabouts are usually considered as the critical points within the urban road network and the evaluation of their performance provides valuable understanding and useful indication about the performance of the city road network system. Roundabouts should be designed to operate at no more than 85 percent of their estimated capacity. Beyond this threshold, delay and queues vary significantly from their mean values. The roundabout approach is dependent on the conflicting circulating flow and the roundabout’s geometric elements. In Addis Ababa, most of the intersections are congested and operate in poor LOS. During peak hours, it is common to see congestion, long queues, and delay at junctions. Accordingly, the objective of the study was to evaluate the operational characteristics of the selected roundabout in Addis Ababa. This research focused on the capacity and evaluation of the level of service at Gerji Imperial Roundabout and addressed the most important element of operational characteristics. The methodology employed for this study was the quantitative descriptive research design method. The necessary geometric data for the analysis (average entry width, circulatory road width, number of entry and circulatory lanes, and island diameter), traffic movement data with vehicle characteristics, and pedestrian volume were collected from the study area. The capacity analysis was done based on the gap – acceptance method that is adopted by the SIDRA Software program. Based on the results, the degree of congestion of the roundabout found out to have 1.749 which is far beyond the recommended values for a satisfactory level of service. Therefore, this indicates that the Gerji-Imperial roundabout is serving in a poor level of service. It is recommended to construct a road overpass or underpass at the most problematic approach to improve the operational capacity of the intersection.
Abstract
Highly congested roundabouts are usually considered as the critical points within the urban road network and the evaluation of their performance provides valuable understanding [...]
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EXPERIMENTAL STUDY OF STABILIZED EXPANSIVE SOIL USING PUMICE MIXED WITH LIME FOR SUBGRADE ROAD CONSTRUCTION
R. Mesfun, P. Quezon, A. Geremew, E. Quezon

International Journal of Research - Granthaalayah (2019). Robel Tewelde Mesfun, Prof. Emer Tucay Quezon, and Anteneh Geremew. (2019). “EXPERIMENTAL STUDY OF STABILIZED EXPANSIVE SOIL USING PUMICE MIXED WITH LIME FOR SUBGRADE ROAD CONSTRUCTION.” International Journal of Research - Granthaalayah, 7(7), 118-124. https://doi.org/10.5281/zenodo.3355594

Abstract
Unsuitable soil materials along the alignment of road projects have a significant influence on planning, design, construction, and maintenance. Expansive soils are susceptible to considerable volume changes due to seasonal variations and moisture content. Most soils found in Jimma and Ambo Zones composed of plastic clay soil, causing severe damage at the intermittent of pavement sections. This research study conducted laboratory investigation considering combinations of materials blended to stabilize the expansive soil for subgrade construction. An experimental type of study performed started by collecting specimens. Two clayey soil specimens considered to test the free swell index obtained from a depth of 1.5m to remove the organic impurities. Results indicated the chemical analysis of pumice contained 82.68%, while its physical properties of the test of fineness specific surface and residue on 45 microns showed 3770 cm2/gm and 30%, respectively. As the lime content increased, the CBR strength also increased. But, if the percent content of lime decreased with an increasing pumice content, the CBR value did not show any significant increase. Both the chemical and physical properties satisfied the requirements according to ASTM C-618. Hence, this experiment obtained 7% lime + 3% pumice as an optimum mix ratio to stabilize expansive soils.
Abstract
Unsuitable soil materials along the alignment of road projects have a significant influence on planning, design, construction, and maintenance. Expansive soils are susceptible [...]
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Traffic Safety Evaluation on Urban Road Un-signalized Intersection using Proactive Approach: A Case Study in Adama City
E. Quezon

Seifeddin Haji, MSc; Prof. Emer T. Quezon, P.Eng; Murad Mohammed, MSc; Biruk Yigezu, MSc. Traffic Safety Evaluation on Urban Road Un-Signalized Intersection using Proactive Approach: A Case Study in Adama City. Proceedings of the 2nd Annual Ethiopian Road Safety (RSC2018). Addis Ababa, Ethiopia, August 23-24, 2018

Abstract
Deaths and injuries as a result of road accidents are a recognized global problem and authorities are aware of the consequences this global phenomenon might lead to. Because of the rapid development of urbanization and motorization in developing and transitional countries, like Ethiopia, actions to improve traffic safety conditions are urgently needed. Highway intersections are among the greatest safety challenges because they are some of the most common highway features. Improving the safety level of the urban intersection is an important way to increase safety. Safety evaluations can help to develop effective safety countermeasures to lower crash rates and reduce crash severity. So how to diagnose safety problems and improve urban road intersection safety effectively becomes an important issue. Now, there have been quite a number of safety analysis methods and theories in the city intersection, but these methods and theories are formed on the basis of traffic accidents. However, the data on traffic accidents is not accurate enough, these theories are not appropriate for our country. Also, it is impractical and unethical to wait for accidents to occur before being able to draw statistically sound conclusions regarding safety improvement. Hence there is a need to develop a proactive approach, a non-accident-based approach, to evaluate urban road Unsignalized intersection safety performance. A proactive approach (indirect and non-accident based approach) was attempted to that of traditional reactive approach (direct and accident based approach) which is purely based on the existing conditions that have direct relationships or impacts to traffic safety such as the geometric, traffic control & engineering, road Surface and environment characteristics. The non-accident-based approach is based on field surveys under the conditions mentioned previously, summarizes the intersection safety diagnosis in a safety index to indicate the safety performance of the intersection. The study indicates that the proposed methodology and intersection safety diagnosis technique can be used to perform an evaluation of traffic safety and improvement at an intersection even when there are few resources available. Also, the use of intersection safety diagnosis is a more resource-efficient and ethically appealing alternative for fast, reliable, and effective safety assessment.
Abstract
Deaths and injuries as a result of road accidents are a recognized global problem and authorities are aware of the consequences this global phenomenon might lead to. Because [...]
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Effects of Varying Dosage Replacement of Cement Content by Animal Bone Powder in Normal Concrete Mix Production
A. W/amanuel, E. Quezon, M. Busier

American Journal of Civil Engineering and Architecture (2018). Abrham Hawaz W/amanuel, Emer Tucay Quezon, and Mamuye Busier, “Effects of Varying Dosage Replacement of Cement Content by Animal Bone Powder in Normal Concrete Mix Production.” American Journal of Civil Engineering and Architecture, vol. 6, no. 4 (2018): 133-139. doi: 10.12691/ajcea-6-4-1.

Abstract
Cement being the main constituent of concrete plays a vital role in concrete production. In Ethiopia, cement consumption has grown well with a growth rate of about 16.1% per year. Hence, an alternative material to partially replace cement was initiated to reflect the needs of the local community in the study area. The waste quantity of animal bones has impacted the environment which is unusual to see in other Non-African countries. The primary aim of the research is to investigate the effects of varying dosage replacement of cement by animal bone powder (ABP) in normal concrete production. The bone samples collected from the Seka Waste Disposal Site of Jimma town, approximately 10km from the bus station where a quantity of waste animal bones can be found. After cleaning and drying, the bone samples burned in the Furnace. The average required energy to burn the animal bone obtained at a temperature of 340°C. The burnt bone was allowed to cool before grinding in a hammer mill and sieving. There were six proportions prepared to start from 0% (as control specimen), 5%, 10%, 15%, 20%, and 25% dosage increment by weight of bone powder, and evaluated the normal concrete strengths of C-25 grade concrete. The laboratory test results indicated the chemical analyses of a bone powder composed of similar compounds of oxide in cement but slightly lesser in content based on ASTM C-150. Likewise, the effects of replacing animal bone on the properties of cement such as consistency and setting time remained within the acceptable limits of the Standard Specifications. On the other hand, the results of compressive, flexural tensile, and split tensile strengths significantly declined from the control specimen during the dosage increment of the replacement made. Therefore, the optimum dosage of the bone powder indicated 10% by weight to replace cement content in normal concrete mix production.
Abstract
Cement being the main constituent of concrete plays a vital role in concrete production. In Ethiopia, cement consumption has grown well with a growth rate of about 16.1% per [...]
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Suitability of Ambo Sandstone Fine Aggregate as an Alternative River Sand Replacement in Normal Concrete Production
W. Ararsa, E. Quezon, A. Aboneh

American Journal of Civil Engineering and Architecture (2018). Woyesa Ararsa, Emer Tucay Quezon, and Abraham Aboneh, “Suitability of Ambo Sandstone Fine Aggregate as an Alternative River Sand Replacement in Normal Concrete Production.” American Journal of Civil Engineering and Architecture, vol. 6, no. 4 (2018): 140-146. doi: 10.12691/ajcea-6-4-2.

Abstract
Technical experts in construction industries are trying to improve the quality, ease of using materials in different forms, and increasing structure performance. However, in the changing cost of each item, quality of works could be sacrificed. In Ethiopia, the practice of using alternative ingredients to produce materials was observed weak in some scenarios. It was because ignoring the right procedures to perform the required material requirements for construction materials. It is known that Ambo area has a scarcity of natural sand or rivers sand which can be extracted from the river bed. Notably, if available, the quality is not good due to the presence of silt and clay. Once it used, it adversely affects the structural integrity of concrete structures. The primary objective of the research is to evaluate the suitability of Ambo Sandstone Fine Aggregate (ASFA) as an alternative replacement of river sand in normal concrete production. Samples extracted from Senkele and Aleltu quarry sites of Ambo Area. Results showed that fine aggregates from Senkele quarry site indicated 14.28% silt content, while from the Aleltu quarry site indicated 12.28% silt content, all of which exceeded 6% based on Ethiopian Standard Specification. It means the samples must be rejected or appropriately washed before use as a part of a concrete mix. After performing the procedure to remove silt content, it found out that the silt content reduced to 5.3%, less than the allowable maximum of 6%. Hence, Ambo Sandstone Fine Aggregates (ASFA) are suitable for concrete mix production and strength determination. There were nine samples of concrete cubes prepared and tested at 7th, 14th, and 28th days for concrete compressive strength with a mix ratio of 1:2:3 and water to cement ratio of 0.50. Based on the laboratory test results with full replacement of river sand by Ambo Sandstone Fine Aggregate (ASFA), the mean compressive strengths at 7th day was 16.61 MPa, while at the 14th day was 19.62MPa, and at 28th day was 25.59 MPa. It means at 28th day; it satisfied the minimum requirement for C-25 grade concrete. Likewise, the cost of production of the fine aggregate of the Ambo Sandstone quarry site is 140 ETB per cubic meter, while the price of river sand from Legeher Market is 300 ETB-400 ETB per cubic meter. Therefore, Ambo Sandstone Fine Aggregate (ASFA) is cheaper than the river sand. However, it must be given emphasis that the Ambo Sandstone Fine Aggregates must wash thoroughly before use in construction projects.
Abstract
Technical experts in construction industries are trying to improve the quality, ease of using materials in different forms, and increasing structure performance. However, [...]
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Factors Affecting the Performance in the Implementation of Government Building Construction Projects: A Case Study in Bole SubCity of Addis Ababa
S. Molla, E. Quezon, E. Mekonnen, W. Ararsa

Xi'an Dianzi Keji Daxue Xuebao/Journal of Xidian University (2020). Serkalem Molla, Emer T. Quezon, Eyob Mekonnen, Woyesa Ararsa, Dumesa Gudissa and Anteneh Tibebu. Factors Affecting the Performance in the Implementation of Government Building Construction Projects: A Case Study in Bole Sub- City of Addis Ababa. Xi'an Dianzi Keji Daxue Xuebao/Journal of Xidian University. 2020; 14(11): 247- 256. https://doi.org/10.37896/jxu14.11/020

Abstract
Building project implementation has so many issues and complex performance, such as time, cost, quality, and safety. This study identified and assessed the essential factors influencing the implementation of public building projects, particularly in the Bole Sub-city of Addis Ababa. There were 46 factors identified, validated, and divided into 9 categories. Questionnaires are distributed to 120 respondents, of which 8 for owners, 25 for consultants, 86 for contractors, and one head of the office. The key factors decided upon were: liquidity of the organization, improved availability of commodity prices for people with high experience and expertise, and the quality of equipment and raw materials in the project. The agreement between the parties on the ranking of factors was calculated based on their Relative Importance Index. Besides, the value of the Cronbach’s Alpha for variables calculated above 0.7, which means the data and scale are reliable and accepted for further analysis to correlate the different groups of factors. Results showed that cost, time, quality, productivity, and customer satisfaction are the top five essential factors affecting the performance of the government public building in the study area.
Abstract
Building project implementation has so many issues and complex performance, such as time, cost, quality, and safety. This study identified and assessed the essential factors [...]
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Experimental Study on the Use of Reclaimed Asphalt Pavement as Base Course Materials through Blending with Crushed Stone Aggregates
E. Quezon

World Journal of Engineering Research and Technology (2018). Yomiyu Reta, Prof. Emer Tucay Quezon and Tarekegn Kumela. Experimental Study on the Use of Reclaimed Asphalt Pavement as Base Course Materials through Blending with Crushed Stone Aggregates. World Journal of Engineering Research and Technology. 2018; 4(2): 126-167

Abstract
Overlay and maintenance resolve medium distress, but reconstruction may feasible and economical while Asphalt pavement are badly deteriorated with time and traffic. This requires the removal of existing pavement surfaces. Recycling such construction waste has benefited from economic to sustainability point of view and reduce the exploitation of natural resources. The shortage of virgin aggregate supplies along with the increase in processing and hauling cost have encouraged the use of reclaimed material from the old structure as base course construction materials, and involved in regular practice in various countries around the world. Unfortunately, using Reclaimed asphalt pavement (RAP) is to take off in Ethiopia despite the current ambitions of road building program ongoing. However, RAP material may be not conventional road making materials and need for improvement. This study was aimed to investigation the Engineering properties effect of using RAPs and CSA in their natural state by conducting common laboratory tests in first phase, and Second phase of the study was intended to analysis the strength and interpret the optimum allowable percentage as partial replacement of CSA blended with 10/90, 20/80, 30/70, 40/60, 50/50 proportions by total weights from the two quarries site in Jimma town for RAP as compared results with specification for highly trafficked road (GB1) materials. According to the AASHTO soil classification system the natural and blends of RAP-CSA were classified under A-1-a. The mechanical and physical properties test results for neat natural blended Jimma-Sokoru with Jimma-Agaro roads RAP aggregate gives ACV, AIV, LAA, SG, CBR and Water absorption of 7.9%, 9.5%, 7.8%, 2.31, 42.1% and 0.98% respectively. Also the mechanical blending of 30% RAP aggregate and 70% CSA test results were 15.7%, 12.8%, 16.5%, 107.63%, 2.67 and 1.24% for ACV, AIV, LAA, CBR, SG, Water absorption values respectively with 143KN and 114KN when soaked and unsoaked in water for TFV results. The results obtained from Gradation, Atterberg’s limits, SG and water absorption ACV, AIV, LAA, Compaction and CBR results indicate that Mixes containing 30% RAP contents were successful replaced CSA in highly trafficked unbound road base course layer of Asphalt concretes.
Abstract
Overlay and maintenance resolve medium distress, but reconstruction may feasible and economical while Asphalt pavement are badly deteriorated with time and traffic. This requires [...]
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Evaluation on the Potential Use of Pulverized Natural Subbase Dust as Alternative Filler Material for Hot Mix Asphalt Design, Jimma Town
B. Yohannes, E. Quezon, M. Tsegaye

American Journal of Civil Engineering and Architecture (2020). Bereket Yohannes, Emer T. Quezon, and Markos Tsegaye, “Evaluation on the Potential Use of Pulverized Natural Subbase Dust as Alternative Filler Material for Hot Mix Asphalt Design, Jimma Town.” American Journal of Civil Engineering and Architecture, vol. 8, no. 2 (2020): 62-77. doi: 10.12691/ajcea-8-2-6.

Abstract
A well-designed asphalt mixture is expected to serve effectively for many years under a variety of loading and environmental conditions. Bituminous concrete is one of the highest and costliest types of flexible pavement. One of the main problems in the construction of asphalt paving mixture is obtaining a sufficient amount of filler material and the high cost of the use of ordinary Portland cement, hydrated lime, or marble dust as filler material. Asphalt Institution restricted the use of a maximum limit of 2% proportion to improve the aggregates adhesion properties only, which is not sufficient quantity to achieve the grading requirements. To alleviate this problem, it is important to come across alternative filler material that can be used in more quantity. The study has investigated the potential use of natural subbase dust (MSD)as alternative filler material, and their characteristic on the effect of hot asphalt mixture was identified. This research was conducted by using Experimental Research Design. In total, 48 samples were prepared according to ASTM D1559, of which 15 of them used to calculate the OBC and the rest to find out the effects of adding different percentages of NSD to the asphalt mixture. For this purpose, five different bitumen contents were used (4%−6% with 0.5% increments). Aggregate mixtures blended without filler and with NSD filler were investigated to evaluate their Marshall properties on HMA mixtures. Four varying percentages of NSD ranging from (2% - 8% at 2% increments) were used for Marshall experiments. And for the control mix, 2% hydrated lime (HL) and 2% ordinary Portland cement used in the mixture besides, 4% Marble Dust was used as a reference. The aggregates were blended by using the Job mix formula to obtain the percentage of material proportion. As a result for aggregates blended without filler G-1 (26%), G-2 (23%), and G-3 (51%) proportion were used whereas for aggregates blended with NSD filler, G-1 (26%), G-2 (22%), G-3 (46%) and G-4 (6%) was utilized. Where G-1 is Coarse Aggregate 3/4, G-2 is Intermediate Aggregate 3/8, G-3 is Fine Aggregate, and G-4 is NSD filler. Based on Marshall's test results, the OBC was found 5.1% by the total asphalt mix. Furthermore, examining Marshall mixes containing different percentages of filler showed the optimum percentage of NSD was 6%. The Marshall properties of the experiments at 6% NDS filler resulted in high stability, low flow, lower VFB, low VMA & lower air voids that are consistent with the standard specifications. The investigation of NSD filler has resulted in good effects on the Marshall properties of the asphalt mixture. Furthermore, the outcome of Marshall parameters like stability, air voids, and bulk density values was consistent with the standard specifications. Therefore, NSD filler can potentially be used as an alternative filler material in HMA with optimum filler content of 6%. Besides, it is recommended to exercise the use of NSD as filler material in HMA projects in order to ensure the quality of works, save transportation costs and save time spend importing other filler materials from far away. It is also recommended combining NSD filler with other materials may produce a better outcome on the effects on the asphalt mix properties.
Abstract
A well-designed asphalt mixture is expected to serve effectively for many years under a variety of loading and environmental conditions. Bituminous concrete is one of the [...]
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EFFECTS ON MODIFIED PROPERTIES OF EXPANSIVE CLAY SOIL USING WASTE HOLLOW CONCRETE BLOCK (HCB) AND CEMENT PLASTER WASTE MATERIALS FOR SUBGRADE CONSTRUCTION
G. Chala, P. Quezon, E. Mekonnen, W. Ararsa, E. Quezon

International Journal of Research - Granthaalayah (2020). Galeta Chala, Professor Emer Tucay Quezon, Eyob Mekonnen, and Woyesa Ararsa. (2020). “EFFECTS ON MODIFIED PROPERTIES OF EXPANSIVE CLAY SOIL USING WASTE HOLLOW CONCRETE BLOCK (HCB) AND CEMENT PLASTER WASTE MATERIALS FOR SUBGRADE CONSTRUCTION.” International Journal of Research - Granthaalayah, 8(3), 342-347. https://doi.org/10.5281/zenodo.3742944.

Abstract
Expansive soils characterized by changing its volume and strength due to seasonal variations. Due to this volume changes, expansive clay soil caused many problems in road construction and is relatively common in Ethiopia. As a result, such types of soil are not adequately for road construction, which requires proper attention. The focus of this study was to improve the engineering properties of the expansive clay soil with the addition of waste materials to use as a subgrade construction material. Soil samples were taken from three locations within the study area and performed laboratory tests for the moisture content, specific gravity, free swelling, Atterberg limit, and compaction test on its natural state. The expansiveness of the soil from the three locations were determined. The highest value of expansiveness from these samples considered for the experiment by the addition of waste materials concentration with 5%, 10% 20%, and 30% by weight. Test results indicated that the moisture content, free swelling, specific gravity Atterberg limit decreased, while the maximum dry density increased as the concentration of waste material increase. Hence, the minimum amount of waste materials comprised of 10% that will improve the strength of expansive clay soil for use in road subgrade construction.
Abstract
Expansive soils characterized by changing its volume and strength due to seasonal variations. Due to this volume changes, expansive clay soil caused many problems in road [...]
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. Effects of Poor Workmanship on Building Construction and Its Implication to Project Management Practice: A Case Study in Addis Ababa City
E. Quezon

Xi'an Dianzi Keji Daxue Xuebao/Journal of Xidian University (2020). Alsen Fromsa, Woyesa Ararsa, Emer T. Quezon. Effects of Poor Workmanship on Building Construction and Its Implication to Project Management Practice: A Case Study in Addis Ababa City. Xi'an Dianzi Keji Daxue Xuebao/Journal of Xidian University. 2020; 14(9): 1174-1188. Doi: 10.37896/jxu14.9/128

Abstract
sup>— The construction of building structure involves very complicated undertakings. It requires a trained workforce at the design stage, approval process, supervision, and construction stages. Inferior quality of workmanship is one of the significant issues facing the workforce to perceive and apply the proper construction methods and techniques following the quality control assurance for building projects. This study considered some of the construction stakeholders participated in the implementation of projects in Addis Ababa City. It focused on assessing and investigating poor workmanship on the quality of projects that included concreting works to accessible ongoing construction sites across the study area. It involved determining the cause of low-level workmanship and identifying factors that would significantly minimize the problems and increase client satisfaction. The study comprised of 20 construction sites, of which 55 questionnaires were collected. The data collected are related to the challenges facing the construction industry and concrete quality as well. The causes and strategies applied to improve construction quality were analyzed using the study's variable. Results indicated that inadequate construction management represented a low level of workmanship and a lack of training rated first with RII of 0.9556. At the same time, the Workers' motivation was placed second with RII 0.775. Hence, it recommends close observation of construction management factors like supervision, training, motivation, and good communication on-site to minimize the cost and effects associated with poor workmanship when implementing building projects.
Abstract
sup>— The construction of building structure involves very complicated undertakings. It requires a trained workforce at the design stage, approval process, supervision, [...]
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Effect of Partial Replacement of Crushed Stone Dust Filler with Waste Glass Powder in Hot Mix Asphalt Concrete Production
D. Kifile, E. Quezon, A. Tesfaye

Xi'an Dianzi Keji Daxue Xuebao/Journal of Xidian University (2020). Destaw Kifile, Emer Tucay Quezon, Abel Tesfaye. Effect of Partial Replacement of Crushed Stone Dust Filler with Waste Glass Powder in Hot Mix Asphalt Concrete Production. Xi'an Dianzi Keji Daxue Xuebao/Journal of Xidian University. 2020; 14(9): 578- 587. Doi: 10.37896/jxu14.9/060

Abstract
The use of waste recycled materials in road construction nowadays is considered a positive means of providing improved pavement performance. This research focused on evaluating the effect of waste glass powder as a partial replacement of crushed stone dust filler in hot mix asphalt. Three hot mix asphalt samples were produced using crushed stone dust of 5%, 6.5%, and 8% as mineral filler with five different bitumen content of 4%, 4.5%, 5%, 5.5%, and 6%, respectively. From the preliminary series tests of asphalt contents, a 6.5% crushed stone dust filler selected, providing the highest waste glass powder stability. The content of crushed stone dust filler was replaced with a rate of 0%, 25%, 50%, 75%, and 100% to test Marshal stability to obtain the Optimum bitumen content and Optimum filler content. Results indicated at 75% replacement of crushed stone dust with waste glass powder at 5.10% bitumen content, 12.0kN Marshall stability value, 2.84mm Flow value, 4.0% Air voids, 72.3% VFB, and 2.360g/cm3 Bulk density. Hence, the mixture of 75% waste glass powder by weight of crushed stone dust filler meets the minimum requirements of the Ethiopian Road Authority and Asphalt Institute Specifications.
Abstract
The use of waste recycled materials in road construction nowadays is considered a positive means of providing improved pavement performance. This research focused on evaluating [...]
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Correlation Analysis of Factors Affecting Shoring Construction Techniques in Central Business District of Addis Ababa, Ethiopia
H. Kassu, E. Mekonnen, D. Gudissa, E. Quezon

Xi'an Dianzi Keji Daxue Xuebao/Journal of Xidian University (2020). Hailemariam Kassu, Eyob Mekonnen, Dumesa Gudissa and Emer T. Quezon. Correlation Analysis of Factors Affecting Shoring Construction Techniques in Central Business District of Addis Ababa, Ethiopia. Xi'an Dianzi Keji Daxue Xuebao/Journal of Xidian University. 2020; 14(10): 692-706. https://doi.org/10.37896/jxu14.10/074

Abstract
Recent urbanization of central parts of Addis Ababa has necessitated the use of deep excavations for the foundation of highrise buildings and related infrastructure projects. The conditions of the subsoil, the safety of neighboring structures, groundwater conditions, experience by contractors, working space, the effect of vibration, and noise must be considered for the choice of deep excavation support system. Besides, economic factors, local availability of equipment, and technical staff are also governing factors for choosing an appropriate shoring technique. The study focused on the major construction methods and techniques of shoring works in Addis Ababa, Ethiopia. Only four projects utilized shoring construction techniques from the total number of high-rise buildings available in the City. The target population included a minimum of twenty respondents from the four construction sites constructed around Beherawi, Lideta sub-city in Addis Ababa. Two of the projects were supervised by Specialists from Varnero Foundation and Meseret Foundation PLC. Primary and secondary data are gathered to support the objective of the study. All the frequency distribution, Reliability, and Pearson correlation were analyzed using SPSS. All groups of factors that affect shoring construction were ranked using the Relative Importance Index (RII). Results indicated that geotechnical investigation, building type, and excavation depth were the major factors with an RII value of 0.89 and 0.86, respectively. Besides, the analyses showed that were strong correlations between the different factors within each group of factors in undertaking the shoring construction. Hence, it is suggested to take a deep and detailed sub-soil investigation to determine the suitability of shoring materials, appropriate construction methods, and techniques.
Abstract
Recent urbanization of central parts of Addis Ababa has necessitated the use of deep excavations for the foundation of highrise buildings and related infrastructure projects. [...]
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Expert Choice-Based Approach on Analytical Hierarchy Process for Pavement Maintenance Priority Rating Using Super Decision Software in Addis Ababa City, Ethiopia
E. Quezon

American Journal of Civil Engineering and Architecture (2020). Hanna Mengistu; Emer Tucay Quezon; Markos Tsegaye and Tegegn Markos. Expert Choice-Based Approach on Analytical Hierarchy Process for Pavement Maintenance Priority Rating Using Super Decision Software in Addis Ababa City, Ethiopia. American Journal of Civil Engineering and Architecture. 2020; 8(3): 105-118. Doi:10.12691/ajcea-8-3-4

Abstract
Untimely maintenance activities resulting from budget fluctuations and improper prioritization can lead to further pavement deterioration. Selecting the most cost-effective maintenance activities to control and minimize road users' risk under current budget constraints is necessary. The study tried to fill the gap that decision-makers in Addis Ababa City Road Authority often performed pavement repair and maintenance without considering a systematic procedure. Ten road sections selected that are planned for pavement maintenance in the study area. The most dominant distresses ranked in Decision Analysis Module in Excel, including road class, weights for each criterion, and sub-criteria obtained using the Analytical Hierarchy Process approach and calculated in Super Decision Software for maintenance prioritization. Results indicated that the developed analytical hierarchy process model works sufficiently and yields adequate output for providing accurate decisions. Hence, considering the multi-criteria to prioritize the pavement sections for maintenance, this model can give affirmative action for the decision-maker.
Abstract
Untimely maintenance activities resulting from budget fluctuations and improper prioritization can lead to further pavement deterioration. Selecting the most cost-effective [...]
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Effect of Selected Conventional and Non-conventional Mineral Fillers with ‘Enset’ Fibers on Compaction Characteristics of Stone Mastic Asphalt Pavement (SMAP)
S. Belay, E. Quezon, A. Geremew

Jordan Journal of Civil Engineering (2021). Sinishat Belay, Emer Tucay Quezon and Anteneh Geremew. Effect of Selected Conventional and Non-Conventional Mineral Fillers with Enset Fibers on Compaction Characteristics of Stone Mastic Asphalt Pavement (SMAP). Jordan Journal of Civil Engineering. 2021; 15(1): 30-40

Abstract
The content and type of ingredient materials are used to prepare the asphalt mix to affect the pavement surface's quality. This study aimed to investigate the compaction characteristics of Stone Mastic Asphalt Pavement (SMAP) mix using two different types of mineral fillers; namely, crushed stone and Ambo sandstone dust with local material enset fiber. Results indicated that the filler type and the content with or without fiber have a great effect on compaction characteristics of Stone Mastic Asphalt Pavement. The test results also showed that the addition of enset fiber in asphalt mix increases density, compaction energy, and strength of asphalt mix and reduces Marshall flow of the mixes. Besides, crushed stone dust and Ambo sandstone dust with enset fiber affect the Marshall property and compaction characteristics of the stone mastic asphalt mix differentially. The Ambo sandstone dust filler has a low density and has high binder absorption capacity compared with crushed stone dust filler in SMA mixes. In this study, the optimum binder content for the mixture by using Ambo sandstone dust (8%, 6.41%), (8.5%, 6.48%) & (10%, 6.43%) as well as the mixture using crushed stone dust filler at (8%, 5.84%), (8.5%,6.32%) & (10%,5.96%) was determined. The optimum fiber content obtained at 0.3% suggests that using enset fiber in stone mastic asphalt mixture improves the strength of asphalt pavements to resist external loads. The enset fiber at 0.3% better modifies stone mastic asphalt pavement properties. Finally, it is postulated that the performance of pavement is affected by filler type and content. Simultaneously, the Marshall property has a linear relationship with compaction characteristics. It showed the possibility of constructing stone mastic asphalt pavement in Ethiopia by using locally available materials.
Abstract
The content and type of ingredient materials are used to prepare the asphalt mix to affect the pavement surface's quality. This study aimed to investigate the compaction [...]
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Experimental Study on Application of Marble Waste as Conventional Aggregate for Base Course Materials
L. Gonfa, E. Geremew, E. Quezon

Journal of Civil Engineering, Science and Technology (2020). Lami Gonfa, Emer Tucay Quezon and Anteneh Geremew. Experimental Study on Application of Marble Waste as Conventional Aggregate for Base Course Materials. Journal of Civil Engineering, Science and Technology. 2020; 11(2): 144- 163. Doi: 10.33736/jcest.2337.2020

Abstract
Recently, highway and construction industries utilize a substantial quantity of conventional aggregates. The increasing demands for conventional aggregate cause an increase in the cost of construction, reduction of natural resources, and continuing deterioration of the earth's surface. On the other hand, the waste generated from the marble industries during the process of cutting and polishing was increasing day by day all over the world. In Ethiopia, the use of Marble Waste Aggregate materials in road construction as a base course material was not well-known, and it was simply wasted at every place where the marble production was continuing. Therefore, this paper focused on evaluating the possibility of using marble waste aggregate as conventional aggregate in the base course layer of flexible pavements by experimental method. To achieve the objectives of the research, mechanical stabilization and laboratory tests have been carried out at different percentage replacement of Conventional Aggregate by (0%, 20%, 40%, 50%, 60%, 80%, and 100%) of Marble Waste Aggregate weights. Marble wastes materials are collected from Burayyu city, Alisha marble processing industry. The laboratory test results for MWA indicated SG, ACV, AIV, LAA, Flakiness Index , Elongation Index, Plastic Index, Water Absorption, and CBR of 2.74%, 23.63%, 26.21%, 27.03%, 26.48%, 13.29%, Non Plastic, 0.50% and 73.3%, respectively. These test results fulfilled the ERA standard specification for some tests, and they showed marginal quality values to the standard specification for GB2 and GB3 base course materials. CBR and gradation test results shown failure to meet the standard specification. Thus, mechanical stabilization was done to improve the mechanical and physical properties of the Marble Waste Aggregate. Blending of 80%MWA with 20% CA results in SG, ACV, AIV, LAA, Flakiness Index, Elongation Index, Plastic Index, Water Absorption, and CBR of 2.83%, 18.2%, 21.52%, 22.58%, 23.79%, 16.29%, Non Plastic, 0.80%,and 82.5% respectively. At this proportion, the gradation also observed to fit with the required ERA standard specification of GB2 and GB3 materials. Therefore, the use of marble waste aggregate up to 80% by weight is recommended for the road base course layer, when it is found near to the construction site and in places where the materials are abundantly available.
Abstract
Recently, highway and construction industries utilize a substantial quantity of conventional aggregates. The increasing demands for conventional aggregate cause an increase [...]
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Analysis of influential factors affecting workers’ productivity on highway construction projects during Covid-19 pandemic in Cagayan Valley Region, Philippines
E. Quezon

Analysis of influential factors affecting workers’ productivity on highway construction projects during Covid-19 pandemic in Cagayan Valley Region, Philippines (2021). [1] Koźlak A. Role of the Transport System in Stimulating the Economic and Social Development. Transport Economics and Logistics. 2017; 72: 19-33; Doi:10.5604/01.3001.0010.6873. [2] McTague B, Jergeas G. Productivity Improvements on Alberta Major Construction Projects, Construction Productivity Improvement Report/Project Evaluation Tool. Alberta Economic Development, Alberta, Canada. 2002. [3] Alaghbari W, Al-Sakkaf AA, Sultan B. Factors Affecting Construction Labor Productivity in Yemen, Intl. Journal of Construction Management. 2017; 1-13 Doi.10.1080/15623599.2017.1382091 [4] Natawidjana R, Nurasiyah R. Study of labor cost escalation in delay projects; presented at the Intl. Conference on Innovation in Research. 2020. Doi:10.1088/1742-6596/1469/1/012034. [5] Naoum SG. Factors influencing labor productivity on construction sites: A state-of-the-art literature review and a survey. International Journal of Productivity and Performance Management. 2016; 65(3):401-421. DOI: 10.1108/IJPPM-03-2015-0045. [6] Nyando CK, Strasheim JA. Assessing Labor-based Construction Works Management Processes. Proceedings of the Institution of Civil Engineers - Management, Procurement and Law. 2012; 164(4): 239-251. [7] Hicksona BG, Ellis A. Factors affecting Construction Labor Productivity in Trinidad and Tobago. The Journal of the Association of Professional Engineers of Trinidad and Tobago. 2014; 42: 4-11. [8] Irfan M, Zahoor H, Abbas M, Ali Y. Determinants of Labor Productivity for Building Projects in Pakistan. Journal of Construction Engineering, Management & Innovation. 2020; 3(2): 85-100. Doi: 10.31462/jcemi.2020.02085100. [9] Low SP, Chan YM. Managing Productivity in Construction. JIT Operations and Measurements, Brookfield (VT). 1997. [10] Thomas HR, Daily J. Crew Performance Measurement via Activity Sampling. Journal of Construction Engineering and Management. 1983; 109(3): 309-320. [11] Banik GC. Construction productivity improvement. In Proceedings of the 35th ASC Annual Conference, San Luis Obispo, CA. 1999: 165-178. [12] Dabirian S, Khanzadi M, Taheriattar R. Qualitative Modeling of Sustainability Performance in Construction Projects Considering Productivity Approach. International Journal of Civil Engineering. 2017; 15(8): 1143-1158. [13] Al-Shahri M, Assaf S, Atiyah S, AbdulAziz A. The management of construction company overhead costs.” International Journal of Project Management. 2001; 19: 295-303. [14] Cronbach, L. Coefficient alpha and the internal structure of test. Psychometrica. 1951; 16: 297-334. [15] Mekdim M. A Study on Construction Equipment Planning and Management Problems in Road Construction Project. A Case Study: The Addis Ababa City Roads Authority. 2017. [Unpublished]. [16] George D. SPSS for Windows Step by Step: A simple guide and reference. 11.0 update (4th ed.). Allyn & Bacon. 2003. [17] Gliem JA. Calculating, Interpreting, and Reporting Cronbach's Alpha Reliability Coefficient for Likert-type Scales. 2003. [18] Hedaoo H. Delay Analysis by Using Relative Importance Index Method in Infrastructure Projects. Int. J. Civil Engg. Conc.Structs. 2016. [19] Dong Z. The Relationship Between Information Technology and Construction Productivity. University of Kentucky Doctoral Dissertations. 2010; 44. Http://Uknowledge.Uky.Edu/Gradschool_Diss/44 [20] Hafez SM, Aziz RF, Morgan ES, Abdullah MM, Ahmed EK. Critical Factors Affecting Construction Labor Productivity in Egypt. American Journal of Civil Engineering. 2014; 2(2): 35-40. Doi: 10.11648/j.ajce.20140202.14. [21] Olomolaiye P, Kaming P, Holt G, Harris F. Factors influencing craftsmen's productivity in Indonesia. International Journal of Project Management. 1996: 21–30.

Abstract
In highway construction projects, labor-oriented work is an integral part of the management process, requiring analysis of factors affecting labor productivity during the Covid-19 pandemic. This research identified 53 influential factors affecting construction labor productivity at selected cities and towns in Cagayan Valley Region, Philippines. Due to the pandemic, the construction industries incurred substantial profit losses. More so, the construction workers are too much affected because of the Enhance Community Quarantine (ECQ) imposed by the local government. Results indicated there was laxity on the Covid-19 protocols. No health worker in the project site ranked the highest in the health & safety factor group with an RII of 0.97 and ranked 1st among 53 factors on the different groups. Besides, no safety engineer was assigned to the projects and ranked 2nd with an RII of 0.93. Among the 7 groups of factors, the health and safety group ranked 1st with 0.81, followed by the schedule compression group with an RII of 0.78. Hence, these two groups of factors have a strong relationship, as evidenced by the number of workers reduced. It was learned that the contractors’ strategy was to increase the number of working days to cope with their schedules. Hypothesis testing supported that there are various significant factors influencing labor productivity loss during the Covid-19 pandemic, as suggested by more than 50% of the respondents.
Abstract
In highway construction projects, labor-oriented work is an integral part of the management process, requiring analysis of factors affecting labor productivity during the [...]
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Effect and Suitability of Calcined Montmorillonite Clay Powder and Waste Khat Husk Ash in the Strength and Durability of C-25 Concrete and its Benefits Cost Analysis
G. Wakoya, E. Quezon, W. Ararsa, J. Chimdi, D. LEMU

JSC Matls. Proj. Mangt. (2021). 1

Abstract
{| style="width: 100%;" |- | style="vertical-align: top;"|''Some environmental issues are industrial wastes and cement productions, which cause high gas emissions. Cement is vital in the global construction industry. The research goal was to find a cheaper material locally. Using OPC, calcined Montmorillonite clay powder (CMMT) and waste Khat Husk Ash (KHA) were tested as a partial replacement. Water entering the interlayer molecular spaces and adsorption, a material in expansive soil, causes Montmorillonite clay to expand more than other clays. Most of Ambo's land is expansive soil, from which samples were taken to determine Montmorillonite clay content. The average temperature required to calcine MMT clay was performed at 8000C using a muffle furnace, ground to the fineness of 150μm, and its chemical composition was investigated. Similarly, the waste KH was heated at a temperature of 6000C. The proportions by weight are applied for the OPC, Calcined MMT clay powder and Waste Khat Hush Ash as follows: Proportion-A (100%: 0%: 0%); P-B (85%:10%:5%); P-C (75%:20%:5%); P-D (65%:30%:5%); P-E (55%:40%:5%) and P-F (45%:50%:5%). The production of concrete for the C-25 Grade mix design was performed based on the ASTM manual, ERA manual, and the ACI code to evaluate the strengths and durability of concrete. These materials were calcined and then tested for strength and durability using ASTM C 618-5 to determine the chemical compounds at various temperatures. The experiments used aggregates up to 25mm in size. The results showed that when OPC was partially replaced with Calcined MMT clay powder and KHA, the consistency and setting time remained within the ASTM C-191 Standard Specifications. Moreover, the compressive, flexural, and split tensile strengths gradually decreased from the control specimen as the replacement was increased. The optimal amount of calcined MMT clay powder and Waste KHA indicated up to 15% by weight to replace OPC content in normal concrete mix production. The benefit cost analysis revealed that using OPC with calcined MMT clay powder and KHA is more cost-effective than using OPC alone.'' | style="vertical-align: top;"|'''ARTICLE HISTORY''' Received: xxxxx 2021 Accepted: xxxx 2021
Abstract
{| style="width: 100%;" |- | style="vertical-align: top;"|''Some environmental issues are industrial wastes and cement productions, which cause [...]
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Quezon, Emer T. 12372

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