COLLECTIONS

JOURNALS

Documents published in 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 [...]

  • 13
  •  read

• 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 [...]

  • 14
  •  read

• 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 [...]

  • 8
  •  read

• 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 [...]

  • 173
  • 1/5
  •  read

• 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 [...]

  • 3
  •  read

• 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, [...]

  • 37
  •  read

• 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 [...]

  • 0
  •  read

• 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 [...]

  • 13
  •  read

• 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. [...]

  • 2
  •  read

• 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 [...]

  • 10
  •  read