Scipedia: Documents published in 2020

How to Determine when a New Building Product is Suitable - Certifications and Experience

Scipedia content — Mon, 21 Sep 2020 13:15:35 +0200

Previously, only solutions with long-term experience were used in the building sector and it was sufficient to describe, e.g. in the building regulations, how they should be constructed. However, the innovation rate has gradually increased, encouraged by industrialization and by building regulations becoming more functional based. As a result, the required performance is often described for the whole building or for a building component, but not at product level. Furthermore, CE marking makes it possible to market and sell a product in any country within the European Union if only one or a few properties are declared, and these may even not be the most relevant ones for a specific application in a technical solution. A CE mark is therefore neither a quality mark nor an approval of the product for a specific application, although clients and consultants often believe this is the case. It is therefore a major challenge for the building sector to determine if a new building product is suitable in a specific technical solution (wall, roof, etc.). The paper identifies a gap between performance-based requirements for a technical solution and specific requirements to properties of building products. Two cases (flat roofs with no slope, MgO-containing boards used as wind barriers) show the possible economic consequences of not closing this gap; the technical solution failed, as one of the products was not suitable for Danish weather conditions. The first case initiated the formation of the Danish Building Defects Fund in 1986, the second one from 2015 shows that the gap still exits, 30 years later. The cases show how difficult it can be even for professionals to understand different certifications, especially when a product seems to be well suited for a specific use. Based on the cases, the paper presents a systematic approach that guides users through important issues relating to requirements for a moisture-safe building envelope.

Detection Sensitivity of Iron-Foil Corrosion Sensor in Simulated Concrete Solution

Scipedia content — Mon, 21 Sep 2020 13:15:28 +0200

This examined the performance of the iron-foil sensor in concrete and its relationship with the amount of chloride in the solution simulating concrete. The corrosion sensor reacted at a chloride ion concentration of 500 ppm. From the results, it was inferred that the sensor has a high sensitivity. Furthermore, to evaluate the performance of the sensor, it was built a wireless system using radiofrequency identification (RFID), embed it into an actual concrete structure, and subsequently initiate observation.

Quality Evaluation of Granulated Blast Furnace Slag Sand Via Acid Immersion and Freeze-Thaw Tests

Scipedia content — Mon, 21 Sep 2020 13:15:21 +0200

In recent years, the use of granulated blast furnace slag (GBFS) sand as fine aggregate in concrete has been increasingly discussed from the viewpoint of environmental impact reduction and effective utilization of by-products in Japan. The various physical properties of concrete with GBFS sand, such as the compressive strength, drying shrinkage, and carbonation, were evaluated. Especially, it was demonstrated that GBFS sand can modify the hardened cement paste around it owing to the reaction of amorphous phase in the sand. Moreover, its resistance to sulfuric acid is considered to be as excellent as that of BFS powder. Therefore, in this study, we attempted to evaluate the performance of GBFS sand using a freeze-thaw (F-T) and acid immersion tests. Consequently, it was found that GBFS sand mortar had a significantly higher resistance to F-T and sulfuric acid than crushed sand mortar. In addition, it improved the resistance to freezing and thawing by prolonged curing. In our experiments, the resistance of GBFS sand mortar to sulfuric acid was measured to be approximately four times higher than that of crushed sand mortar. In contrast, in the case of nitric acid, the ratio was measured to be only two times higher. From the above results, it was concluded that the performance of GBFS sand can be easily judged by F-T and sulfuric acid immersion tests.

Observations of Moisture Damages in Historic and Modern Wooden Constructions

Scipedia content — Mon, 21 Sep 2020 13:15:05 +0200

With the introduction of new building products made of planar glued board lamellas, the CLT, the restriction of load-bearing structures to linear and thus additively used load-bearing members was abolished. As a result, new, technically determined boundary conditions for moisture management in the interior of buildings have arisen. Due to the emergence of massive, planar wall and floor components as in concrete construction, the integration of building services technology in timber construction must now take place differently than was traditionally the case. In addition, it can be observed that the damage to building components is increasing, the detection of moisture damage is becoming more difficult and, ultimately, the consequences and risks are not yet foreseeable. The study focuses on the cause-effect relationship of increased water input and uses selected examples to reveal the problem of moisture exposure in the interior of buildings with planar load-bearing structures, the damage mechanisms and direct consequences set in motion. This paper shows the necessity for moisture protection measures in modern timber structures in comparison to traditional ways to construct with timber. It shows where moisture intake with modern structures must be considered and avoided from the engineering perspective in order to minimize the risk of moisture damage.

Long-term Performance of Repairs to Reinforced Concrete Exposed to Coastal Conditions

Scipedia content — Mon, 21 Sep 2020 13:01:01 +0200

Reinforced concrete (RC) specimens were treated using different combinations of surface coating and/or patch repair methods and materials, left in a coastal region with frost damage risk, and their properties characterized after 25 years of exposure. Specimens were prepared by chipping away concrete from one section of concrete block with embedded reinforcement bars to expose the bars, followed by patch repair and then surface coating. Four types of material were used for patch repair: cement mortar, styrene-butadiene rubber (SBR) polymer cement mortar, rust-resistant SBR polymer cement mortar, and lightweight epoxy mortar. Two types of material were used for surface coating: multi-layer textured and thin textured coating. Following exposure, cracks were visible only on the surfaces of untreated specimens, apparently due to rebar corrosion; they were absent from all specimens that had undergone surface coating and/or patch repair. In addition, the corrosion resistance of these methods and materials was investigated by measuring and comparing the surface areas of corroded rebar between three segments: the repaired part, the unrepaired part, and the boundary between them. Concrete carbonation and rebar corrosion were greatly dependent on surface coating material, with the multilayer-textured coating especially effective at blocking chloride penetration. In addition, rebar corrosion was more effectively prevented by patch repair with the SBR polymer cement mortar than with the lightweight epoxy mortar.

Development of a Service Life Database of Building Elements Based on an International Data Collection

Scipedia content — Mon, 21 Sep 2020 13:00:54 +0200

This paper presents a new service life database (DUREE database) for building elements, based on international service life data. The database includes 7‘000 service life data, for more than 2‘000 building elements. In addition, the fitting of the data to a lognormal distribution is presented. The study contributes to the increasing demand of probabilistic building LCA and LCC and provides the possibility to define statistical distributions, with a systematic way, for a large number of building elements and different levels of details (LOD), appropriate for BIM-based assessments.

The Impact of Climate Change on Material Degradation: Finding a Feasible Approach for Climate Model Evaluation

Scipedia content — Mon, 21 Sep 2020 13:00:47 +0200

Understanding how climate change accelerates or slows down the process of material deterioration is the first step towards assessing adaptive approaches for the preservation of historical heritage. Analysis of the climate change effects on the degradation risk assessment parameters like freeze-thaw cycles and salt crystallization is also a key parameter when considering mitigating actions. Due to the vulnerability of cultural heritage in Iran to climate change, the impact of this phenomenon on basic parameters like temperature was analyzed. Choosing an appropriate regional climate model is the first and most crucial step in the analysis of climate change effects on heritage. The outputs of two different regional climate models: the ALARO-0-SURFEX model (Ghent University, Belgium) and the REMO model (HZG-GERICS, Germany) were analyzed to find out which model is more adapted to the region. So the focus of this research is mainly on the evaluation process to find a feasible approach for validation study to determine the reliability of each model. For model validation, a comparison between model data and observations was performed for 30 years from 1980-2017. Besides, some climatic parameters which are likely critical for heritage like freeze-thaw cycles were studied to find out how reliable these models are in the field of building pathology.

Durability Assessment of Gypsum Boards with Glass Mat Reinforcement Used in Light Facade Systems

Scipedia content — Mon, 21 Sep 2020 13:00:41 +0200

Gypsum boards with glass mat reinforcement are used in light weight facade systems. These boards were recently brought to the Brazilian market. Therefore, there are few studies and little practical knowledge of their performance over time, mainly concerning to durability. The gypsum boards manufacturers set that these boards always need to be coated, however they can be exposed to natural conditions during the construction site period. A study is necessary to evaluate the feasibility of using these boards in Brazil, since the exposure conditions relating to humidity, temperature and solar radiation are different from Europe and North America. The aim of this paper is to show the approach used to evaluate the durability of the gypsum board with glass mat reinforcement, and also show the test results. In order to establish the durability approach, standards were adopted, as well as the functional performance concept. In addition, the tests considered that such boards would be used on the facade and should behave similarly to other boards used in facades in Brazil, such as fiber cement boards. Thus, mechanical tests were done in steady state, saturated and after aging in cycles of immersion, drying and heating. Other evaluations were made on gypsum boards applied on exposed walls. The results showed that even the board strength decreases after the accelerated aging cycles, the final value remains in an acceptable level. In addition, boards applied on exposed walls for 12 months have been presenting a good performance; meaning no cracks neither detachments, even though the follow-up still needs to be maintained longer.

A Spatially Continuous Driving Rain Map of India at 0.5°×0.5° Gridded Scale

Scipedia content — Mon, 21 Sep 2020 13:00:34 +0200

Driving rain is one of the most critical sources of moisture affecting the hygrothermal and durability performance of building envelopes. The estimation of severity in terms of annual driving rain indices using annual and monthly weather data (aaDRI and maDRI respectively) aids towards contemplating potential moisture loads, and hence in the efficient design of buildings in the geographical area of interest. In this study, monthly and annual gridded datasets of wind and rainfall, pertaining to the thirty-year period of 1988-2017 have been used to design a spatially continuous driving rain map for India at 0.5°×0.5°(lat./long.) resolution. The observations reveal that the use of annually averaged data leads to underestimation of the driving rain severity thereby highlighting the inefficiency of a coarser temporal scale. A linear relationship has subsequently been developed to enable refinement of aaDRI into maDRI. The analysis of the monthly driving rain map reveals that the entire western coastal belt and a few regions in the north-eastern part of the country observe high to severe exposure conditions. Furthermore, a trend analysis of the yearly driving rain index values reveals statistically significant decreasing trends over the northern and eastern regions of the country, whereas increasing trends in the shielded regions surrounding central India is observed.

Experimental Study on Carbonation Resistance and Water Absorbing Property of Concrete Crack with repair

Scipedia content — Mon, 21 Sep 2020 13:00:27 +0200

Existing RC Buildings have some cracks and the repairing service might last the buildings for long life. The durability of the RC component is evaluated by several ways as like as carbonation resistance test, permeability test, water penetration test, and so on. Therefore, it need to be measured how much advantage the concrete crack with repair have for the durability. The aim of this paper is to study on advantage of repairing a crack of concrete to the carbonation resistance and the waterabsorbing property by the experimental way. The specimens were prepared in the following point. The finishing (direct finishing and mortal tile finishing), crack width (0, 0.05, 0.5, and 2mm), and choice repairing or not. All concrete specimens were formed 10 x 10 x 20cm and those W/C were 0.55. Then, the specimens were tested by the accelerated carbonation. After 4, 8 and 26weeks accelerated carbonation, the carbonation depth and the carbonation shape of the concretes were measured by 1% phenolphthalein reaction. Also, the amount of absorbed water from the bottom were measured at 1, 3, 6, 24, 48, 72 and 168h. From the results, the carbonation went rapidly located in 2cm around the crack in the case of the no-repair specimens, regardless of any finishing. But in the case of the specimens repaired, it went evenly from the exposure side. And water absorbing test results show a trend that water amount of the concrete with a crack more increase than one of the no-crack concrete.

Statistical Analysis of Sulfate Attack Resistance of Reactive Powder Concrete

Scipedia content — Mon, 21 Sep 2020 13:00:19 +0200

This paper is the study of sulfate attack resistance of reactive powder concrete (RPC). RPC that is also known as ultra-high performance concrete is a special type of concrete material obtained when fine powders like silica fume (SF) are added into the concrete mortar along with very low waterto-binder ratio (w/b). SF is a pozzolanic material obtained as a by-product of silicon metal or ferrosilicon alloys production. In this study, total 6 different RPC mixtures with various w/b (0.18, 0.22 and 0.26) and various SF content were studied. SF was added into the concrete mixtures in the amount of 15%, 20% and 25% of cement by weight. The other testing parameter includes 3 different concentrations of sodium sulfate (Na2SO4) solutions (0.35 M, 0.7 M and 1.4 M concentrations). Broad laboratory investigations of behavior of the RPC mixtures were conducted in terms of compressive strength and mass gain of cubes (50×50×50 mm3) and expansion and mass change as in accordance with ASTM C1012. Test results had been analyzed and assessed by Taguchi method. The significance level of experimental parameters was determined by using Analysis of variance (ANOVA) method. According to statistical and analytical results it was observed that RPC has high sulfate attack resistance. Moreover, addition of optimal amount of SF into the RPC mixtures as well as decreasing w/b can significantly improve Na2SO4 resistance of RPC.

Intrinsic Differences on the Photodegradation Mechanisms between Pigmented and Non-Pigmented Coatings Determined by Multi-Scale Analysis

Scipedia content — Mon, 21 Sep 2020 13:00:12 +0200

Multi-scale analysis of photodegradation are conducted for pigmented coating containing acrylic urethane + TiO2 pigment and for non-pigmented coating containing only acrylic urethane. We discuss the intrinsic differences in the photodegradation mechanism between the pigmented and nonpigmented coatings and the effect of the interface between the pigment and the binder. Photo-aging tests are conducted using artificial ultraviolet (UV) irradiation under conditions of 60 °C and dry atmosphere. The results of Fourier transform infrared spectroscopy (FTIR), solvent swelling experiments, ultrasonic measurements of elastic moduli, and colourimetry used for material characterisation before and after photo-aging. Although the behaviour of E and the carbonyl index (CI) show common trends for both samples, the overall trends of yellowness index (YI) and swelling degree (Q) differ significantly between the pigmented and non-pigmented samples. The results reveal that changes in macroscopic properties may not necessarily correspond with the CI behaviour and that characteristic interfacial effects exist between the pigment and the binder. The onsets of coating erosion and chalking are observed in the pigmented coating as surface topological changes. The different behaviour of YI and Q between the sample types can be attributed to the interfacial effect at pigment/binder interface based on the photocatalytic effect from TiO2 pigment

Ionic Diffusivity and Pore Structure of Hardened Cement Paste Exposed to High Temperature Environment for Long Period

Scipedia content — Mon, 21 Sep 2020 13:00:03 +0200

Ion diffusion through cement-based barrier is key to safe radionuclide transfer in intermediate radioactive waste disposal facilities. The purpose of this research is to elicit the behavior of ionic diffusivity and pore structure of hardened cement paste specimens for the barrier system when exposed to high temperatures (up to 80°C) for long periods (up to one year). The cement paste is made of an ordinary Portland cement base- and a low-heat Portland cement / fly ash / limestone filler (LF)system. The results of the adsorption isotherms of N2 and water vapor of the specimens exposed to limesaturated water of different temperatures, 20, 40, 50, 60, and 80°C, are presented, and their pore size distributions are analyzed by the Barrett-Joyner-Halenda method. The change of specific surface areas is measured and the influence of high temperature on the pore structure is discussed. Additionally, results of chloride ionic diffusivity test for the specimens after the high-temperature exposure are contrasted with the tendency of pore structure change. It is found that the LF system has much higher resistance to high-temperature exposure than ordinary Portland cement; however, temperatures greater than or equal to 60°C deteriorate the ionic diffusivity. These experimental results may indicate the ionic diffusivity of hardened cement paste can be influenced by the spatial electrical charge in micropores depending on the electrical charge of pore wall and the ion composition of pore solution.

Use of Steel Fiber Reinforced Concrete for the Protection of Buildings Against High Dynamic Actions

Scipedia content — Mon, 21 Sep 2020 12:59:57 +0200

Nowadays ensuring the safety of people and the protection of infrastructure is a socially relevant topic, which requires a thorough investigation. The Institute of concrete construction at the University of the German Armed Forces in Munich is investigating the possibilities of using steel fiber concrete for the protection of military facilities and state-owned special buildings in Germany. In this research project steel fiber reinforced concrete is investigated under high dynamic loads specifically under contact detonation loading. Plates with varying reinforcement systems, different thicknesses, different fiber geometries, fiber contents and fiber types were produced.The following concrete compressive strengths C20/25, C40/50, C80/95 were used in this research project.The plates were loaded with 500 g, 750 g, 1000 g, 1500 g and 2000 g PETN explosive at the test facility of the German Armed Forces Technical centre for Protective and Special Technologies. An important property of construction material during ballistic threats and contact detonation is the concrete tensile strength. Through the addition of fibers, the post cracking behavior and the ductility of concrete components can be improved. All fiber-reinforced specimens showed less damage than the non-fiber reinforced elements. The aim of the study is to optimize the concrete mixture for the fiber concrete protection components considering the following factors: concrete quality, fiber content, fiber geometry, as well as aggregate size of the concrete. Another aim is to record and evaluate the damage parameters of the steel fiber reinforced concrete slabs after the highly dynamic load, and to investigate to offer suggestion for retrofitting. In this article, the test results of different steel framed concretes under highly dynamic conditions are presented.

Environmental Deterioration Factors in Metal Claddings and GFRC Panels Implemented on Facades: An Assessment through Two Cases in Istanbul

Scipedia content — Mon, 21 Sep 2020 12:59:50 +0200

Decrease in performance of building facades, components, and materials before their service life is an unexpected situation. Therefore, detecting the probable causes of these anomalies plays a crucial role in maintenance planning. This study aims to determine the environmental deterioration factors which affect the performance of buildings, especially building façades, through two case buildings situated in the same university campus in Istanbul. The methodological framework of the study is based on visual observations and literature review. Through observations on a different period of time, anomalies have been detected and photographed. In the first case, it has been focused on metal claddings on building façade. In the second case, it has been focused on GFRC panels which have the majority of the North façade. Within the help of literature and observations, two cases have been compared to each other in terms of their deterioration factors and interpreted through graphs. In the first case, occurred deteriorations have been detected such as uniform dirt, corrosion, joint degradation, mechanical impacts, and delamination. in the second case, deteriorations have been observed such as biological staining, uniform dirt, moisture rising, and design failures

Analysis of the Variation of Thermal Conductivity of Rigid Polyisocyanurate Foam (PIR) in The Context of Aging

Scipedia content — Mon, 21 Sep 2020 12:59:44 +0200

For most building insulation materials, dependency of the thermal conductivity on temperature is close to linear, and it increases with rising materials temperature, but the thermal conductivity of the polyisocyanurate foam (PIR) increases in the lower temperature range, so the heat transfer through the partition insulated with this material is increased in the cold season. The thermal conductivity of PIR also increases during the aging process, especially during the later operating period, which is not covered by the standard aging procedure used to determine the declared thermal conductivity value. Also, there is a lack of information how PIR reacts to the certain temperatures and other climate conditions, and how fast it loses its thermal properties. The aim of this experimental research was to analyse the change of the thermal conductivity depending on aging temperature. 30, 50mm thick PIR samples were prepared for the test, and the thermal conductivity of all specimens was measured at the standard conditions prior to the start of the test using the heat flow meter FOX 314, and again after each stage of aging, when the samples were kept at the certain temperature for 21 days. The results showed that the thermal conductivity of PIR increases more (up to 10 %) when kept at higher temperatures (+50 °C, and +70 °C), and after specimens undergo negative temperatures (-18 °C) it has a minor influence to the change of thermal conductivity of PIR.

Study on the Practical Use of Urea to Reduce Drying Shrinkage of Concrete by Spraying Urea Solution under Cold Environment

Scipedia content — Mon, 21 Sep 2020 12:59:37 +0200

Concrete cracking caused by drying shrinkage adversely affects the durability of a structure. The results of past research has shown that drying shrinkage can be reduced by adding urea as an admixture to the concrete. However, mixing various admixtures at the factory increases the costs for equipment and labor. To reduce drying shrinkage more easily and inexpensively, the urea solution can be applied to the concrete surface by soaking or brushing. However, urea solutions are not suitable for use in cold weather because urea in solution crystallizes at low temperatures. This study attempted to solve this problem by mixing antifreeze, which resists freezing, with a urea solution. It was found that the crystallization temperature of urea can be lowered by mixing the urea solution the antifreeze. Furthermore, it was confirmed that the antifreeze/urea solution reduced drying shrinkage for both mortar and concrete.

Monitoring Durability of Limestone Cement Paste Stored at Conditions Promoting Thaumasite Formation

Scipedia content — Mon, 21 Sep 2020 12:59:30 +0200

The durability of Portland-limestone cement with high limestone content was monitored at conditions promoting thaumasite formation. Pore structure and deterioration characteristics were assessed with X-ray micro-computed tomography and correlated with material‘s strength. Changes in crystalline and amorphous phases of the cement paste were investigated with X-ray powder diffraction and solid state nuclear magnetic resonance spectroscopy. Rapid deterioration was observed, evolving as a front causing concentric crack patterns followed by detachment of the part of specimen in contact with the corrosive solution. This ultimately led to loss of structural integrity after 4 months of exposure. During sulfate attack, thaumasite, ettringite and gypsum formed at the expense of portlandite, calcite and monocarboaluminate hydrate. Furthermore, polymerization of silicate chains in C-S-H and deterioration of C-S-H also occurred

Higher Incidence Pathologies in Installations of Solar Energy, Gas, Cooling, Heating and Ventilation

Scipedia content — Mon, 21 Sep 2020 12:59:24 +0200

This paper focuses on the study and quantifications of pathologies in solar energy, gas, cooling, heating and ventilation installations, based on complaints filed in the courts by the owners of a large number of houses in which errors appeared in those installations. The relevant complaints filed across all of Spain were studied, in what is an important contribution to forensic engineering, given that access to the outcome of civil court cases is seldom obtained. The representativeness of the data is not partial but total, since the entirety of cases existing in the period under study was part of the sample, enabling us to consider this to be a general exposition on the epidemiology of construction pathologies in installations in houses in Spain. It should be noted that the Spanish construction sector is one of the most problematic ones, due to the dissatisfaction generated in homeowners, and as it is one of the ones leading to the highest number of complaints filed with consumer protection bureaus and in the courts. In the investigation, results have been obtained for each of the installations (183 cases in total), according to the type of anomaly (the most important are dysfunctions, leaks and humidity), the pathological origin (poorly arranged encounters, omissions of elements, among others) and the type of construction where it is produced (especially in block dwellings).

Degradation of Concrete Structures from the Climate Change Perspective

Scipedia content — Mon, 21 Sep 2020 12:59:17 +0200

The negative effects of climate change are underway despite the global efforts to mitigate them and the future scenario are unsettling. Climate change poses critical challenges to urban environments and highlights the need for research its impacts on the built environment. One of the most significant effects of climate change on reinforced concrete structures is associated with the carbonation of these structures. The increase of parameters such as temperature and carbon dioxide jeopardise the degradation of such structures by carbonation-induced corrosion. This paper presents the results of the monitoring and analysis of a set of buildings that determine carbonation as the main degradation mechanism of structures in Paraguay. Through the application of a previously developed carbonation model, the worsening of the carbonation-induced degradation has been determined after considering the climate change effects in the coming 50 years. The outcomes of the study determined that the poor quality of the structures in Paraguay cause premature degradation in them. Furthermore, considering climate change effects, it has been determined that this phenomenon could accelerate corrosion failure times in reinforced concrete structures.

Platform Development for Drone Utilization in the Architectural Field

Scipedia content — Mon, 21 Sep 2020 12:59:11 +0200

The utilization of drones is expected to streamline the process of building inspection in Japan; however, no known drone utilization platform exists in the region‘s architectural sector. Therefore, in this study we pioneered the development of a drone platform based on an industry- government-academia collaboration within Japan‘s architectural field. We first investigated drone related trends, such as a utilization roadmap, flight rules, the drone market, new technologies and issues relating to the architecture field. Subsequently, we worked on solutions for drone utilization in the building sector, including methods for building inspection, determination of drone-flight risk factors relative to building inspection and the creation of a drone safety operation manual. Through field tests, we validated the effectiveness of the drone platform in building inspection, i.e., the determination of a cost-time relation during inspection, the merits of applying a high-resolution camera for inspection, the possibility of utilizing an infrared camera for exfoliation detection in exterior wall tiles and the development and efficiency of a built-in automatic inspection system. Furthermore, trial tests were conducted for the application of a drone-inspection system in disaster areas and a micro-drone in small building spaces. The findings of this study confirmed that the new drone platform achieved inspection- and disaster-related objectives within the architectural sector.

Effect of Crack Repair by Bio-Based Materials Using Alginate and Bacillus Subtilis under Wet and Dry Environment Part-I

Scipedia content — Mon, 21 Sep 2020 12:59:05 +0200

This study examined crack repair methods using alginate gel films (1.5 wt.%) mixed with healing agents under wet and dry actions. The healing agents consist of Bacillus subtilis (natto) as an aerobic microorganism and glucose as an organic carbon source, thereby producing insoluble calcium carbonate in the gel films in the presence of calcium ions. In this study, repaired surface in cracked mortar specimens (50×100mm) was observed by microscope. In addition, water absorption test was carried out in assessing the effectiveness of crack repair for the cases of alginate gel films with or without calcium carbonate precipitation induced by the microbial activities. Based on the observations made by microscope, precipitates in white color were clearly observed after 8 weeks on the cracked surface of specimens especially under wet conditions. In the case of the specimens with higher sealing rate of crack repair, the alginate gel films were remained intact under dry and wet actions, which is advantageous to keep moisture by swelling. Water absorption test was carried out using repaired mortar specimens with average crack size of 0.5 mm. Based on the results obtained, water absorption rate is substantially decreased in the specimens with increasing sealing rate of crack repair. The results suggest that higher crack sealing rate associated with calcium carbonate precipitation leads to higher resistance against water absorption tested in accordance with ASTM C 1585.

Effect of Crack Repair by Bio-Based Materials Using Alginate and Bacillus Subtilis under Wet and Dry Environment Part-II

Scipedia content — Mon, 21 Sep 2020 12:57:54 +0200

This study examined durability of mortar after repairing crack using alginate gel films (1.5wt.%) mixed with healing agents under seawater splayed condition. The healing agents consist of Bacillus subtilis (natto) as an aerobic microorganism and glucose as an organic carbon source, thereby producing insoluble calcium carbonate in the gel films in the presence of calcium ions. In this study, repaired mortar was dried under room condition for half year and exposed at seawater splayed condition for another half year. After that, surface condition, elastic wave velocity was measured. In addition, the inside situation in the crack was observed by X ray computed tomography. Based on the results of elastic wave velocity, the property of repair material in mortar was improved under the seawater splayed condition. Additionally the substance in crack derived from healing agents was remained even after seawater splayed exposure.

An Experimental Evaluation of the Thermal Performance of Felt Type Vegetated Facade System

Scipedia content — Mon, 21 Sep 2020 12:25:24 +0200

Vegetated facade systems (VFS) have been used as green building envelope systems in recent years. Using VFS for ecological strategies and evaluating thermal performance of these sytems are not a new concept. However, there is not any experimental study in literature which evaluates thermal performance of felt type VFS applied on an insulated existing building wall which is located in Csa climate during cooling and heating periods. Hence, an experimental study was conducted to measure thermal performance of felt type (type which used felt material as growing media) VFS in Kocaeli (under Csa climate). Test results indicate that in day time with high amount of solar radiation, felt type VFS decreased exterior surface temperatures of an insulated existing wall by maximum of 30°C. Also, interior surface temperatures of vegetated facade were lower than interior surface temperatures of reference facade with the maxiumum difference of 1.8°C. Although high differences between exterior surface temperatures of vegetated and reference walls were observed, there was no significant difference between interior surface temperatures of vegetated and reference walls. This is due to the fact that existing building exterior wall assembly includes 5 cm thickness expanded thermal insulation material which enchance thermal performance of brick wall. In addition, indoor air temperatures behind both facades were close to each other, and were not suitable according to ISO 7730 and ASHRAE 55 Standards comfort range for representative summer days with high ambient air temperatures. Nevertheless, indoor air temperatures behind vegetated facade were in the comfort range in the fall representative day which required cooling, while indoor air temperatures behind reference facade were not in the comfort range in summer representative day.

Spatial variability of soil infiltration in the improvement and utilization area of aeolian sandy land in northwest Liaoning

Yaxi Li — Sat, 19 Sep 2020 15:36:04 +0200

In order to study the characteristics of spatial variability of soil infiltration in the aeolian sandy land improvement and utilization area, this paper conducted a study on the six different land use types in the aeolian sandy land in northwest Liaoning by means of average and random distribution. With bare land as the control group, the physical parameters of the soil in the test area were analyzed and processed through traditional statistical analysis and geostatistical analysis, and the spatial distribution of various physical parameters was studied using ordinary Kriging interpolation. The results show that the bulk density of different land use types in the aeolian sandy land improvement and utilization area in northwestern Liaoning has been reduced, and the total porosity, capillary porosity, water content and the ratio of clay particles have increased to varying degrees. Soil infiltration has a negative correlation with moisture content and clay particles, and a positive correlation with the ratio of total porosity. In addition, among all types of improved utilization, other forest land has the largest infiltration and the research land has the smallest one.

Analysis of the Degradation Condition of Elementary Schools

Scipedia content — Thu, 17 Sep 2020 16:30:35 +0200

Currently, there is still no information regarding the performance of public buildings after their construction and the relationship with the needs for carrying out maintenance activities. This paper presents some of the main anomalies detected in six schools, built between 1997 and 2003 in Lisbon. The analysis of the degradation condition of these schools was based on data obtained through detailed visual inspections, carried out in three distinct periods of their operation phase, 2007, 2013 and 2018. The highest level of severity mainly concerns defects on buildings structure and buildings envelope and results from bad decisions made during design and/or construction. Therefore, there are serious problems related to the premature deterioration of these educational buildings, requiring expensive, complex and unplanned major repairs to achieve their specified design service life. This work highlights the need for greater involvement of school building management entities, in the early stages of the building process, including design, tendering, construction and handover.

Influence of Lightweight Concrete Block Support on Physical and Mechanical Characteristics of Applied Mortars

Scipedia content — Thu, 17 Sep 2020 16:30:28 +0200

The objective of the present work is to analyze the influence of the lightweight concrete block support on the physical and mechanical characteristics of the applied mortar. This work aims to understand how the physical and mechanical properties of the mortar are modified by the support. The methodology used consisted of conducting laboratory experimental tests to compare the behavior of mortar molded in standard moulds with the behavior of mortar applied to lightweight concrete block supports. Open porosity, bulk density, capillary water absorption, water vapor permeability and compressive strength were studied. These results have shown how the support influences the characteristics of the mortar, improving the understanding of the performance of the applied mortar. This study provides a global approach to the assessment of mortar characteristics, considering the analysis and comparison of mortar applied to the support and molded in the laboratory, according to current standards. Such understanding may contribute to the reassessment of the way mortars are produced, seeking to optimize their characteristics and compatibility with the support.

Strategies to Support Facility Management Resourcing Building Information Modelling

Scipedia content — Thu, 17 Sep 2020 16:30:21 +0200

The significant growth of the building stock in the 20th century allied to the low rate of building retrofitting over the last years results in the current low conservation level of the Portuguese building stock. The building natural aging, associated with the lack of planned maintenance actions and the climate changes consequences contributed to accelerating the degradation of building materials in the existing buildings, leading to a poor conservation of Portuguese public building stock. So, to extend the service life of the materials, the application of appropriate maintenance actions is imperative. This work aims to assess the building performance and to prioritize the maintenance actions employing Key Performance Indicators using Building Information Modelling (BIM) as a supporting tool for building condition assessment and maintenance management. To achieve these goals the following methodology was applied to a case study: 1)Building Information Collection; 2) Building Life Cycle Cost Estimation, and 3) Automated calculation of Building Performance Indicator supported by BIM, using Revit software and Dynamo programming. The application of this maintenance management automated strategy shows the importance of BIM in Facility Management; permits the model‘s permanent update of information decreasing the probability of information loss and the consequent investment in data collection, and has high potential to prioritise the building maintenance actions, extending the materials service life and building durability.

A Risk-Based Approach for Quantifying Durability and Life-Expectancy of the Wall-Foundation Construction Detail in Timber Buildings

Scipedia content — Thu, 17 Sep 2020 16:30:14 +0200

Understanding and predicting the durability of timber structural components of buildings can lead to a more reliable and efficient use of this material in constructions. The work described herein presents a methodology to assess the life-expectancy of wall-foundation details in timber buildings based on the estimation of the durability of the timber structural element. Risk classes were defined starting from the inputs from the most relevant standards addressing the durability of timber available in Europe. The attribution of a risk class to the wall-foundation detail requires decision trees that consider the key aspects that affect the durability of this construction detail in the case of fungal attack. The methodology was then applied to three case studies and the results were compared to the observations from onsite inspections carried out on the decayed structural timber elements. The present work represents the first step towards the development of a tool capable of predicting the durability of timber components within the building structure. The work reported herein was carried out within the framework of the TSafe project.

Transport of Moisture and Chlorides into Sprayed Concrete

Scipedia content — Thu, 17 Sep 2020 16:30:07 +0200

This contribution is a study of the durability and transport properties of sprayed concrete used in an actual construction site. It considers whether concrete spraying can generate different porosities as the thickness of the sprayed layer increases. The work consisted of a study of the properties of the interior and exterior concrete layers with a particular focus on chloride penetration. A few of the methodologies and techniques used are compressive strength at 28 days, depth of penetration of water under pressure UNE EN 12390-8, boiled absorption and volume of permeable voids ASTM C642, and accelerate chloride penetration NT BUILD 443. Calculated transport property values included absorption (A) and volume of permeable voids (VPV), porosity interconnection, and chloride diffusion coefficient (De). The conclusion obtained is that there are no significant differences between the physical microstructural properties of the interior and exterior sprayed concrete layers, they present a similar porosity, and behave in the same way under a chloride attack when test tubes are completely saturated.

The Efficiency of Fly Ash Concrete in the Context of the Combined Action between Chlorides and Carbonation

Scipedia content — Thu, 17 Sep 2020 16:29:59 +0200

The fly ash concrete (FAC) has often been used in chloride contaminate environments. The aluminates present in fly ash (FA) react with free chlorides binding them and reducing the amount of chlorides able to penetrate into concrete. However, Ca(OH)2 present in FAC is easily consumed by pozzolanic reactions, making easier the advance of carbonation. In this context, it is important to know the FAC behaviour in environments subjected simultaneously to chlorides and carbonation. Chloride diffusion coefficient (D) increases in environments containing chlorides and CO2 when compared to one containing only chlorides. This increase is related to the effects of carbonation on concrete. Therefore, this paper investigates the efficiency of FAC in context of the combined action of chlorides and carbonation. Two different concretes were cast, a FAC (40% FA) and a reference concrete (RC), that is a concrete with similar properties to FAC but without FA. After 90 days humid curing, half of specimens were subjected to accelerated carbonation (20ºC, 55% RH and 4% CO2) during 1, 2 and 7 months. The other half was protected and remained in laboratory during the same period. Afterwards, non-steady-state migration tests were performed. The results show that, under the studied conditions, the efficiency of the FAC against chloride penetration is not affected when compared to the results obtained for RC. The carbonation depth in FAC is higher than in RC, but the D in FAC remain lower than in RC. This behaviour can be attributed to the higher capacity of FAC binding chlorides.

Towards the Determination of Chloride Profiles by means of Resistivity Measurements in Reinforced Concrete

Scipedia content — Thu, 17 Sep 2020 16:29:52 +0200

Reinforced concrete (RC) structures, such wharfs or floating structures, are submitted to chloride ingress which can lead to rebar corrosion. Before the corrosion initiation, in a preventive point of view, engineers can be interested in non-destructive evaluation and inspection methods. In that way, electrical resistivity tomography is a promising tool to access to resistivity profiles then to chloride profiles in real RC structures in the future. We would like to present herein the advances in the necessary research developments to reach this goal, i.e. the resistivity profiles obtained in reinforced concrete slabs submitted to chloride ingress. The 4 slab dimensions are 90x70x13 cm. The specimens are cured, dried during 9 months then submitted to salted water imbibition during 4 months. Electrical resistivity tomography measurements are performed at short terms during 1 week of imbibition. The monitoring show that several phenomena influence the resistivity profiles such as the penetration of water and chloride ions. Meanwhile, steel rebar effect can be considered thus eliminated from electrical resistivity profiles following the method developed by (Alhajj et al. 2019).

Implementation of an Embedded Sensor Based on Electrical Resistivity to Monitor Drying in Thick Concrete Structures

Scipedia content — Thu, 17 Sep 2020 16:29:44 +0200

Electrical resistivity is a parameter sensitive to several properties of concrete, including water content, which is one of the key parameters governing concrete long-term durability. In this paper, the monitoring of the concrete water content profile throughout its entire thickness is discussed using an electrical approach as a measurement method. This is very relevant to applications requiring a centimeter resolution over a large thickness. The aim of this paper is to implement a multi-electrode embedded sensor in a concrete slab to determine the resistivity profile over concrete depth in order to monitor its drying. The sensor, designed as a printed circuit board (PCB), is integrated in two 30 cm thick concrete slabs. Different measurement configurations are presented. Following qualification in laboratory and controlled conditions, the study focuses on characterizing the sensor‘s response during the drying of the slabs. The results demonstrate the capability of the sensor to monitor concrete drying by measuring the resistivity profiles with a spatial centimetric resolution.

Identification of the Influence of Concrete Cover Thickness and ∅/ρ Parameter on Crack Spacing.

Scipedia content — Thu, 17 Sep 2020 16:29:37 +0200

Cracks due to the service load in the reinforced concrete structures are controlled at the design stage, by limiting the calculated crack width. Widely used crack width calculation models (Eurocode 2 and Model code 2010), estimates the crack width by multiplying the crack spacing with the mean strain difference of concrete and reinforcement. Concrete cover thickness and the ratio of diameter to reinforcement area to effective tensile area of concrete (∅/ρp,ef) are the two main crack spacing governing parameters in the aforementioned models. The existing models are mostly applicable when concrete cover thickness is within the specified limit. For example, Model Code 2010 model limits the concrete cover thickness to 75 mm. In order to identify the influence of aforementioned two governing parameters on crack spacing, the results of recent experiments have been considered. According to some recent studies, it is found that the concrete cover thickness has a significant influence and the ∅/ρp,ef parameter has a negligible effect on crack spacing. To investigate the reasons why the ∅/ρp,ef parameter has a negligible effect on crack spacing, the involvement of bond properties is needed to study. Some authors have specified that the large diameter bars consist of higher bond force per unit surface area than the small diameter bars, due to the high rib area. Due to this reason, the similar bond behavior could be identified, from low number of large bar diameters and high number of small diameter bars. A literature review has been carried out to study the bond behavior on specimens subjected to pure tension. With the facts and available data, it is further verified that the ∅/ρp,ef parameter has a negligible influence and concrete cover thickness has a significant effect on crack spacing.

Statistical Analysis on Belgian Building Defects

Scipedia content — Thu, 17 Sep 2020 16:29:30 +0200

The lack of systematization in the collection of building defects leads to a wide range of data that is not used to its full potential. Unfortunately, this opportunity is missed since lessons could be drawn from analyzing this data by systematically mapping and investigating building defects. This paper presents the results of a statistical analysis on 27074 cases of building defects provided by a Belgian insurance company, ranging from 1991 up to 2019. This analysis focuses on the types of damage, the occurrence in relation to the construction time and the typology of the claims. Spearman correlation tests, X² tests, and Kruskal-Wallis tests are performed to assess the significance of correlations. Moisture problems constitute 49% of all technical defects, followed by structural issues (19%), and cracking (17%). Within the category of moisture problems, the roof is the dominant location for problems to occur, followed by basements, façades, windows, and rising damp. 50% of the judicial cases were closed after 3 years, whereas cases without lawsuit are typically settled after 1-2 years.

Performance of Fibre-Reinforced Slag-Based Alkali Activated Mortar in Acidic Environment

Scipedia content — Thu, 17 Sep 2020 16:29:22 +0200

The main aim of the work is to study the effect of different fibres (steel, glass and basalt) on resistance of blast furnace slag-based alkali-activated mortar in acidic environment. The alkaliactivated slag mortars were exposed to 5% sulfuric and acetic acid solutions for 30 days. Mass change, compressive strength and microstructural changes were evaluated. In plain mortar, it was observed that 70% of the strength was retained in acetic acid environment whereas only 20% of residual strength remains in sulphuric acid environment. FTIR spectroscopy shows the degradation of the matrix, which implies the alkali-activated mortar was more vulnerable in sulphuric acid environment due to its aggressive nature compared to acetic acid. Decalcification and formation of calcium acetate also hinders the further progress of damage in acetic acid attack. Fibres helped in improving the performance of the mortar by holding the matrix together when the degradation occurred in acidic environment. Compared to plain mortar, incorporation of steel fibres exhibited a maximum strength retention of 19% in acetic acid and 7% in sulphuric acid, followed by glass and basalt fibres. SEM images clearly show the debonding of fibres and disintegration of matrix in acidic environment, which resulted in strength loss.

Study on Technical Standards of Reinforced Concrete Structures with Long Service Life when Using Blended Cement and Finishing Materials

Scipedia content — Thu, 17 Sep 2020 16:29:15 +0200

It is very important to improve and secure durability of reinforced concrete (RC) building and housing, in order to extend the service life of it. In this study, these were studied experimentally that the contribution ratio of blended cement to the carbonation resistance of concrete when a part of OPC replaced to FA or BFS much more were used for concrete, and the effect of carbonation suppression required for an effective finishing materials when these were applied for concrete surface. As a result, we were able to obtain the knowledge that the contribution ratio to the carbonation resistance of concrete using blended cement with different mixture replacement ratio, and the effect of carbonation suppression required for 4 types of finishing materials and its specifications, from the viewpoint of securing durability and extending the service life of RC structures. Therefore, these were considered to be able to sufficiently contribute to the review of the evaluation method or technical standards concerning about the durability of RC structures prescribed in "Housing Quality Assurance Act" in Japan.

Influence of Different Types of Metakaolin on Compressive Strength and Chloride Migration of Concrete

Scipedia content — Thu, 17 Sep 2020 16:29:08 +0200

The use of mineral admixtures in concrete has grown in recent years, specially the highperformance ones, such as silica fume, nanosilica and metakaolin. Metakaolin has been extensively studied due to its high reactiveness. Thus, an experimental program was conducted to evaluate the behavior of compressive strength and non-steady state chloride migration due to differences of metakaolin characteristics. Three different metakaolins were characterized, then used in a 10% replacement ratio (of mass of cement), among two water/binder ratios (0.40 and 0.60) in concrete mixes. The results show that metakaolin increased compressive strength in every age tested. Moreover, durability properties were significantly enhanced due to the addition of metakaolin. Nonsteady state chloride migration coefficient of metakaolin concretes were noticeably lower than plain concrete. In general, the addition of metakaolin in concrete caused pore refinement and reduction in total porosity, which lead to enhancements of mechanical e durability properties of concrete.

Field Study on Hydrophobised Internally Insulated Masonry Walls

Scipedia content — Thu, 17 Sep 2020 16:29:00 +0200

This paper presents a field study on the hygrothermal performance of hydrophobised masonry walls, provided with vapour tight or capillary active interior insulation. As a reference, also nonhydrophobised and non-insulated walls are analysed. To study the hygric performance, apart from traditional relative humidity sensors, in-house made moisture pins are embedded in the walls and are shown to yield valuable information in the high moisture range. Attention is given to the hygric performance of the wooden beam heads, the impact of wind-driven rain on the moisture conditions in the masonry wall, as well as to the impregnation depth of the water repellent agent. For the latter, the field study is supplemented with X-ray and liquid droplet measurements on a small semi-duplicate test wall. During the hydrophobisation process, an increased moisture level was induced. A drying period was needed to again reduce this level. After this period, a hydrophobic treatment showed a positive impact on the wall‘s hygric performance. The non-hydrophobised wall with a vapour tight interior insulation system showed the highest moisture level, especially deeper in the wall and thus where the wooden beam ends are located.

Stability Assessment of Historic Plaster Ceilings on Wood Lath

Scipedia content — Thu, 17 Sep 2020 16:28:53 +0200

Plaster (often lime plaster, reinforced with animal hair) installed on wood lath secured to wood framing was a common ceiling system for hundreds of years in the Americas, and for thousands of years in Europe. Despite having a relatively good record of stability, some ceilings of this type have collapsed. Given their overhead position, often above large groups of people, when cracks or localized areas of displacement or damage occur in these ceilings, the question often arises as to whether the ceiling is stable and safe. Because procedures for stability assessment of historic plaster ceilings on wood lath are not well quantified in building codes or technical literature, this article proposes key considerations and best practices for assessing these ceilings.

Effect of Supplementary Cementitious Material and Fine Recycled Aggregates on Shrinkage Properties of Self-Compacting Microconcrete

Scipedia content — Thu, 17 Sep 2020 16:28:46 +0200

An increase in the population has led to the progressive construction of infrastructures and buildings. This causes severe environmental problems, firstly high emissions of CO2 are caused in cement production; secondly, a high volume of construction and demolition waste is landfilled and thirdly, it is necessary to look for new, no natural resources for the production of construction materials. The objective of this work is to analyse the influence of fine recycled aggregates and high volumes of fly ash in the properties of high-performance self-compacting (SC) microconcrete. The experimental work presented in this paper was carried out in two phases. In phase 1, SC- microconcrete were produced with 100% of Portland cement, and natural sand was replaced by both mixed and ceramics recycled aggregates in 30% and 50%. In phase 2, SC- microconcretes were produced with the replacement of 50% of Portland cement by fly ash, and natural sand was replaced by both mixed and ceramics recycled aggregates in 30% and 50%. In each phase, the drying and autogenous shrinkage of all mortars was measured via their storage in a climate chamber after 24 hours of casting and the determining of properties during 90 days. In order to assess the influence of the shrinkage effect on the mechanical properties, the prismatic samples were also stored in a climatic chamber, and the compressive strength at several ages was determined in all of the SC mixtures. The results showed that the microconcretes produced employing mixed and ceramic fine aggregates achieved higher compressive strength and lower autogenous shrinkage. Although the C-N achieved the lowest drying shrinkage, the mixtures with 30% of CRA and MRA were found to have similar values. The employment of the CRA aggregates improved the drying shrinkage and compressive strength of the C-FA-N mixture.

Properties of Czech WW2 Concrete Fortifications after 80 Years

Scipedia content — Thu, 17 Sep 2020 16:28:39 +0200

This paper deals with the investigation of properties of Czech fortification concrete bunkers built before Second World War (WWII). The Czech defense system consisted mainly of light bunkers type No. 37. The vast numbers of these bunkers have been preserved in various conditions to nowadays. The light bunkers type No. 37 were designed to last limited lifetime of decades. According to the preserved test protocols, strength of used concrete varied from 40 to 50 MPa, measured on cube specimens with dimensions 200×200×200 mm. There is an information, in general public, about high quality and strength of used concrete. The non-destructive analysis of compressive strength, determined by Schmidt hammer was performed. This method was used to maintain a historical value of the structures. Three were analyzed different bunkers type No. 37 located in Western Bohemia - Pilsner region. Tested bunkers are preserved in various conditions with various quality of concrete. The measurements by Schmidt hammer took place in several locations especially in the interior part. The exterior was also investigated but only in the locations of surface which were not covered with camouflage plaster. Non-destructive testing had shown high quality of concrete older than 80 years old concrete, with compressive strength between 50 to 60 MPa. On the other hand, based on the visual assessment, the concrete showed very different characteristics, especially in compactness and the quality of surface layer. We can find places with insufficiently compacted concrete with exposed steel reinforcement.

Restoration of Historic Windows: Methodology and Case Studies

Scipedia content — Thu, 17 Sep 2020 16:28:32 +0200

All too often, the original windows are unnecessarily removed and replaced from historic buildings. In some instances, replacement is justified due to the extent of deterioration resulting from years of deferred or inappropriate maintenance. However, often historic windows are unnecessarily replaced as a result of incorrect assumptions or misinterpretation of their condition. Alternatively, a designer may believe that a new window will perform better, require less maintenance, increase energy efficiency, or just last longer than the existing original windows. This may not be the case. This paper will address issues related to the evaluation and restoration of historic wood and metal windows. An overview of the methodology used by the authors to evaluate the condition of windows and determine repairs that are necessary to maintain structural integrity, repairs that are necessary to address air and water infiltration, and repairs relative to aesthetics and function, will be presented.

Do We Need Hygrothermal Simulations to Evaluate the Design for Durability?

Scipedia content — Thu, 17 Sep 2020 16:28:24 +0200

The Danish Building regulations are function based and describe in broad terms which requirements must be fulfilled. The main message is that buildings and their structures must be built in such a way that they have a satisfactory functionality and durability i.e. that materials and constructions used can resist the stresses they are exposed to under use. However, there are no Danish guidelines on how to document fulfillment of the requirements. Durability largely depends on moisture related problems, and many failure modes/mechanisms are linked to moisture conditions. It is a prerequisite that the hygrothermal performance of a building component is satisfactory if a long service life shall be obtained. The paper will demonstrate how the risk of moisture problems is assessed in Denmark by using a stud wall as an example. However, simulations can be used for documenting the expected performance of wall assemblies, under in use conditions, however is not a conditional necessity. Even though an evaluation or simulation of moisture conditions show satisfactory results problems can occur e.g. if unsuited materials are used or if materials or building elements are used in another way than foreseen. A few examples are shown how simulations could and could not be used to determine whether a structure would have a long service life or not. Finally, a comparison of simulations, calculations and measurements are performed to illustrate the difference in results from moisture assessment that can be achieved based on assessment methodology.

Effect of Cement Type and Micro-cracks on Chloride Penetration in Concrete

Scipedia content — Thu, 17 Sep 2020 16:28:15 +0200

Chloride-induced corrosion of reinforcing steel rebar is one of the major durability issues affecting reinforced concrete structures (RC). Various models have been developed to assess the durability design with regard to corrosion prevention in chloride-bearing environments, which refer mainly to uncracked concrete. Cracks, however, are frequently present in real RC structures and accelerate corrosion initiation of steel reinforcement, resulting in a shortened service life. This paper presents preliminary results concerning chloride-penetration resistance of different types of uncracked and cracked concrete, made with Ordinary Portland (OPC), Portland-Limestone (PLC) and Pozzolanic cement (PC) and a water/cement ratio of 0.45. Load-induced micro-cracks were obtained with a specifically developed technique. Cracked and uncracked concrete specimens were immersed in a sodium chloride solution for 32 and 90 days. The chloride penetration front was detected on split surfaces, perpendicular to the exposed surface, with a colorimetric technique to evaluate the combined effect of cracks and cement type on the chloride-penetration resistance of different concretes. Results showed that in uncracked conditions cement type strongly affected chloride penetration depth in concrete. A mathematical model was applied to evaluate chloride diffusion coefficient (D) from chloride penetration depth measurements and exposure time. The lowest value of D was found for PC concrete, that can be attributed to a higher pore refinement in the cement paste, five times higher for OPC and nine times higher for PLC. In cracked conditions, an additional penetration of chlorides occurred in correspondence of crack, even for micro-cracks 10-50 μm wide and 8-30 mm deep, leading to a decrease in chloride penetration resistance. The model however did not provide for an estimation of D in correspondence of the crack.

Possible Applications of Neural Networks in Managing Urban Road Networks

Scipedia content — Thu, 17 Sep 2020 16:28:06 +0200

Life-cycle management of urban road networks as a part of an urban system is a very complex process from the management standpoint of social, technical and economic aspects. The complexity and multidisciplinarity of such a problem suggest the need for using soft computing tools as well as multicriteria analysis and group decision-making. Recently, there is a significant increase in using various soft computing tools, especially neural networks, for different prediction purposes in the field of road construction planning and management. Along with known advantages of such a prediction method, yet some applications showed the shortcomings. In that sense, the focus of this research is on possible applications of neural networks related to the life-cycle phases during the management of urban road projects. This is done in both horizontal (projects‘ life-cycle phases) and vertical (hierarchical decisionmaking levels) approach. The final aim of the research is to compare and highlight the possible applications of neural networks as a prediction tool and support for decision-making in urban road management.

Carbonation Behavior of Powdered Cement-Based Materials Under Different Relative Humidities and CO2 Concentrations

Scipedia content — Thu, 17 Sep 2020 16:27:56 +0200

The aim of the current study is to investigate the carbonation behavior of cement hydrates at different environments. Hardened cement pastes are prepared using OPC and BFS and crushed into ~90μm powder. The powder samples are carbonated at 5/20% CO2 and at 60/85%RH. TGA, XRD and phenolphthalein tests are conducted before and after carbonation. The results show that CH remain uncarbonated even after CO2 uptake apparently ended and that the amount of the residual CH affects the results of phenolphthalein test. External humidity strongly affects the carbonation behavior of both CH and other hydrates. The degree of CH carbonation is greater at higher humidity, while the degree of other hydrates carbonation is greater at lower humidity. This conflicting effect can occur at surface of bulk concretes and changes in its properties (coarsening of pore structure and cracking) can be caused without apparent carbonation detected by phenol phthalein test. The effect of relative humidity on CSH carbonation should be taken into consideration when estimating long-term performance of carbonated concretes.

Behavior of Mortars with Different Porosities in Front of Attack of Aggressive Agents

Scipedia content — Thu, 17 Sep 2020 16:27:48 +0200

Chemical reactions that lead to decreased durability in concrete structures may result from chemical interactions between aggressive agents present in the external environment and cement paste compounds or may result from internal reactions. The chemical reactions are manifested by the physical properties of the concrete, such as porosity and permeability and the decrease of resistance and cracking. Among the several aggressive agents that attack the reinforced concrete structures it can be highlighted chloride ions, sulphate ions and carbon dioxide. In this context, the study presents the analysis of different traces of mortar executed with cement type CPII-F-32 (OPC Cement, in Brazil one of the most used cements) with w/c ratios of 0.4 and 0.7, when subjected to the attack of sulphates, chlorides and carbonation. The analyzes quantitatively evaluated the amount of ions present after exposure to the agents and demonstrate the importance of evaluating the dosage of water in the mortars to minimize future problems with durability.

Development of an Integrated Durability Assessment Methodology of Thermal Mortars Applied in Multi-layer Systems

Scipedia content — Thu, 17 Sep 2020 16:27:40 +0200

A gap in the durability assessment of thermal mortars applied in multi-layer systems was observed. The existing standardisation for the durability assessment of hardened mortars does not include a consistent evaluation of thermal coatings applied in multilayer systems, which motivated the development of a new durability assessment methodology. The determination of the physical, hygrothermal and mechanical properties allowed deepening the knowledge of thermal mortars, contributing to develop more reliable simulations. The existing durability methodologies applicable to one-coat mortars and those applicable to thermal multilayer systems (such as ETICS - External Thermal Insulation Composite Systems) are suitable to be adapted to thermal rendering and plastering systems since they present some similar characteristics. The methodology takes into account the material characteristics and specific requirements, such as the application and climatic conditions. The knowledge of these parameters allows the definition of representative accelerated ageing cycles of the relevant degradation mechanisms. The combination of existing procedures with hygrothermal simulation allowed the development of accelerated ageing cycles, taking into account the European climatic context. The existing procedures allowed analysing several degradation mechanisms, but the fixed parameters are not transversal to different climates. The developed methodology allows a realistic durability evaluation since the ageing cycles are adapted to thermal mortars and real climate conditions, contrary to the existing standardised procedures.

Evaluation of ETICS Characteristics that Affect Surface Mould Development

Scipedia content — Thu, 17 Sep 2020 16:27:27 +0200

External Thermal Insulation Composite Systems (ETICS) are nowadays often used in new constructions but are also one of the most frequently used thermal retrofitting solutions for buildings.These systems have several advantages such as low installation cost, ease of application and increased thermal efficiency. Nevertheless, a number of questions have been raised on their long-time durability particularly related to biodeterioration. Biological growth is strongly influenced by several parameters, such as water content, temperature, pH but also by the type and hygroscopic properties of the building materials. It is therefore essential to understand and correlate those properties with biological growth. This paper aims at evaluating some ETICS characteristics that might influence surface mould development which is recognized as one of the major groups of deteriorating organisms. The susceptibility of the surface finishing layer and thermal insulation to biological growth was assessed through natural inocula and selected fungi and, whenever possible, correlated with water absorption and drying capacity. This study is part of a wider research project: WGB_Shield (Shielding building‘ facades on cities revitalization. Triple-resistance for water, graffiti and biocolonization of external thermal insulation systems) that aims at the development of ETICS with improved durability in the urban environment. Further development on this issue are ongoing.

Freeze-Thaw Risk in Solid Masonry: Are ‘Hygrothermal Response Based‘ Analyses Mandatory when Studying the Sensitivity of Building Envelopes to Climate Change?

Scipedia content — Thu, 17 Sep 2020 16:27:03 +0200

The 5th Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) reports important evolutions in the climate system. These changes are likely to affect the durability of the built environment. Although many contemporary studies investigate the future energy efficiency of buildings, research on the impact of climate change on the hygrothermal behaviour and degradation of building envelopes is rather scarce. Using climate projections, we studied the advantage of ‘hygrothermal response based‘ analyses over ‘climate based‘ analyses when assessing the impact climate change on façades. This paper presents a sensitivity study on solid masonry wall assemblies, before and after internal retrofitting, using three RCP (Representative Concentration Pathways) projections of the ALARO-0 Regional Climate Model at the grid point of Brussels (BE). The findings suggest the necessity of a ‘hygrothermal response based‘ analysis to study the sensitivity of the building envelope to climate change. Moreover, the largest sensitivity is observed for RCP 8.5, the scenario having the highest projected greenhouse gas concentrations by the end of the century.

Vinyl and Linoleum Floorings in Health Infrastructures: Maintenance Recommendations Based on Fieldwork Data

Scipedia content — Thu, 17 Sep 2020 16:07:27 +0200

Resilient flooring is a popular choice in healthcare facilities, given its durability, comfort, low maintenance and cost. However, anomalies that occur in vinyl and linoleum floorings (VLF) often do not fulfil the expectations of a flooring with good performance and durability. In fact, studies show that pathological phenomena in VLF occur more often in the first years in service, indicating a probable connection with the design and execution stages. These stages are crucial to the quality of VLF, since, if not given adequate attention, pathological symptoms are likely to increase, hence decreasing service life.The authors developed an inspection, diagnosis and rehabilitation system for VLF in healthcare facilities, including: the classification of anomalies, their probable causes, in situ diagnosis methods and repair techniques; anomalies - causes, inter-anomalies, anomalies - diagnosis methods, and anomalies - repair techniques correlation matrices. The same system was validated through the visual inspection of 101 compartments in six health infrastructures in Lisbon, Portugal, and the respective descriptive statistics analysis of the collected data. That analysis showed, for instance, that the summed contribution of "design errors" and "execution errors" to "faulty welding joints" was 59%. Making an effort to change the situation diagnosed in the mentioned inspection sample, some design and application stages‘ recommendations are highlighted, according to the main sensitive issues of the flooring system during its service life. The sensitiveness of VLF highlights the importance of a suitable maintenance plan to minimise susceptibility to various degradation mechanisms.

Testing Joints of Air and Vapour Barriers, Do We Use Relevant Testing Methods?

Scipedia content — Thu, 17 Sep 2020 16:02:49 +0200

This article describes testing of peel and shear resistance and airtightness of joints of air and vapour barrier systems before and after artificial aging. The testing of peel and shear resistance was based on standardised methods while the test of airtightness was a method invented for this project. The results show that while peel and shear strength increased with aging, the airtightness was significantly reduced. As these two results seem to contradict each other, the methods are discussed, especially whether the standardised tests are too far from the conditions on site or joints should be tested on other materials as well. Furthermore, weaknesses in the airtightness method is also pointed out.

Influence of Fly Ash on Strength Development of Concrete and its Temperature Dependence

Scipedia content — Thu, 17 Sep 2020 16:01:31 +0200

Experiments on the development of compressive strength and static and dynamic Young’s moduli were performed by the following mix proportions of concrete: the first uses different types of Portland cement without fly ash (FA) with a water-cement ratio of 45%, keeping at different curing temperatures; the second partially use FA in place of the cement, with the other conditions same as above; the third uses only blast furnace cement B instead of Portland cement. With these specimens, we comparatively examined in terms of temperature adjusted concrete age, how the mechanical properties change with the use of cement only, FA replacement for cement and with variation in curing temperatures. As a result, it was confirmed that the replacement of cement by fly ash enhanced the long-term mechanical properties of concrete regardless of the curing temperature applied in this experiment.

Assessing the Condition of Reinforced Concrete Bridge Using Visual Inspection Ratings

Scipedia content — Thu, 17 Sep 2020 14:41:21 +0200

The evolution of the state of a structure is characterized by deterioration. This is mainly due to corrosion of the steel reinforcement and damage from mechanical solicitations. The maintenance of existing infrastructures involves a good grasp of their condition and a high level of expertise on the part of the project managers. An accurate assessment of the bridge state condition is required to plan maintenance and repair activities for better durability, and to maintain the level of service of the road network. In this paper, an effective management framework for bridge is proposed using field observations from visual inspections. Each element of the bridge was evaluated separately by a visual inspection from which were derived ratings to quantify the structural performance and the material condition. The element ratings were also combined to obtain an overall rating for the bridge considering its defects and impact on the behavior of the complete structure. The modelling approach proposed in this work can better represent the deterioration of concrete-built bridges when the defect is visible. A representative structure in Quebec was studied to illustrate how to apply the methodology for the assessment of a real structure condition at specific times.

Comparative Life-Cycle Analysis of Two Repair Measures for Chloride Contaminated Concrete Structures

Scipedia content — Thu, 17 Sep 2020 11:58:50 +0200

Often the mere mention of the word “Sustainability” leads to the reflection of the effect of our actions on environment and future generations. Especially the application of reinforced concrete as the most used construction material has a huge impact on a society being sustainable. Thus, the construction industry focuses on the design of environmentally- and resource-friendly buildings. However, due to our aging infrastructure and expected high demand of maintenance and repair in future, a further look on the sustainability of different repair measures for reinforced concrete structures has been neglected in the past. This paper presents a comparative case study of the life-cycle analysis of two different repair measures for reinforced concrete affected by chloride-induced corrosion. The selected repair measures – removal of the chloride-contaminated concrete and cathodic protection – are the most common repair measures in Germany. In future way concrete repair measure could be selected not only by the costs but as well by their environmental impact. This paper provides first information to achieve this target.

Comparative Study on (Non-)Destructive Techniques for On-Site Strength and Durability Assessment of Limestone Based Concrete Slabs

Scipedia content — Thu, 17 Sep 2020 11:45:46 +0200

For rehabilitation of existing concrete structures, strength and durability related properties of the reinforced element are of high importance. Assessment of these properties of existing structures can be performed by (i) destructive testing of drilled cores and testing the extracted samples in lab environment and (ii) indirect methods by using non- or semi-destructive techniques on site. The use of core-drilling is a time-consuming and labour-intensive method that weakens the existing concrete structure, leaving a lasting impression on it. As an alternative, many different non and semi-destructive techniques are available for the in-situ determination of compressive strength and durability related properties. An experimental program is conducted on concrete slabs of different strength classes intended for various exposure classes (according to EN206), based on a limestone aggregate matrix, which is typically used for Belgian applications. The plates have an age of approximately 5 years, which were also characterized at younger stage (in 2014). Besides destructive core drilling and testing (compressive strength tests, chloride migration testing, and determination of carbonation rate), several non-destructive techniques were selected for this study: the rebound hammer, the ultrasonic pulse velocity tester, the Wenner probe for concrete resistivity and the air permeability tester. Best fit correlations between the output of these different techniques were established. The effect of age (e.g. carbonation) on the established predictive models is being evaluated.

Durability Studies of Polyurethane-Based Structural Adhesives Used in Engineered Wood Products in New Zealand

Scipedia content — Mon, 14 Sep 2020 13:24:06 +0200

The New Zealand Building Code is unique in the world in requiring evidence of a minimum durability of 50 years for all structural building elements. This prescriptive durability requirement equally applies to the adhesives used in structural applications such as engineered wood products (EWPs), including glulam, CLT and LVL. Conventional resorcinol-based structural adhesives have a long history of use in New Zealand, providing evidence of their ability to meet stringent durability requirements. Structural adhesives based on polyurethanes (PURs) are used extensively in other parts of the world and are rapidly gaining increasing interest in New Zealand due to their perceived environmental and production advantages. However, without a sufficiently long history of use, and a lack of data around their performance in the preservative treated pine EWPs typically manufactured in New Zealand, it is difficult to provide evidence of long-term durability for PURs in our domestic building industry. In this work, attenuated total reflectance Fourier transform infrared (ATR FTIR) spectroscopy in conjunction with multi-component analysis (chemometrics) was used to understand the changes that accelerated ageing cause in the chemistry of five PUR-based adhesives. The effect of hygrothermal stress was investigated through exposure of samples to accelerated ageing cycles of varying temperatures and humidities for up to 3 years’ duration. Different samples were affected to different extents by each cycle. Spectroscopic data were also used to build predictive models which have the potential to be used in long-term durability assessment. Spectroscopic investigation in conjunction with mechanical testing offers the opportunity to provide a robust, fit-for-purpose test methodology for assessing the long-term durability of PUR-based structural adhesives.

Salt and Ice Crystallization Resistance of Lime Mortars with Natural Lightweight Aggregate

Scipedia content — Mon, 14 Sep 2020 13:24:02 +0200

In this study, the comparison of lava sand, pumice, and natural zeolite as lightweight aggregate in air lime mortars, natural hydraulic lime mortars, and cement-lime mortars has been investigated with emphasis on the resistance of salt and ice crystallization. The lava sand and pumice improved frost resistance of the mortars while natural zeolite mortars remained without this effect due to their high water absorption. Salt crystallization resistance of the mortars was improved by using lava sand and natural pumice, while the mortars with natural zeolite were not resistant to crystallization of sodium chloride. The mortars have relatively little resistance to the reacting of Na2SO4, where gypsum and calcium sulfoaluminates were formed breaking the structure of the mortars. The best results were obtained using natural pumice.

Use of Machine Learning in the Function of Sustainability of Wastewater Treatment Plants

Scipedia content — Mon, 14 Sep 2020 13:23:58 +0200

Wastewater treatment plants (WWTP) are complex and dynamic systems whose management and sustainability can be improved by using different modelling and prediction approaches of their work. A machine learning tool for development of model trees was used in this paper in order to develop a model for chemical oxygen demand (COD) in the wastewater effluent from the WWTP with activated sludge to increase its sustainability and helps in its management purposes.Measured data, both in influent and effluent of the WWTP were used for modelling. For the COD model, machine learning tool Weka and algorithm for development of model trees M5P were used.Obtained model has a high descriptive power and correlation coefficient and thus can be used for prediction and modelling purposes, which can help in management and sustainability of the WWTP.Also, the purpose of this paper is to show the benefits of using machine learning tools for developing WWTP models.

Early Stage Construction Cost Prediction in Function of Project Sustainability

Scipedia content — Mon, 14 Sep 2020 13:23:54 +0200

Construction project costs often reach values higher than planned. Accuracy in project cost estimation is one of the most important criteria for project success, even for its sustainability.The main idea of this research is to examine the relationship between realized cost and contracted cost values for residential buildings. The aim of the research is to determine the mathematical relationship between realized and planned costs in the project implementation phase by using a few mathematical methods and some machine learning methods in comparison to linear regression. This would enable validation of methods themselves by comparing and evaluating the obtained relevant parameters.Comparison would be performed on two levels, based on its general characteristics, as well as on the results of their application on the basis of 24 building reconstructions and new buildings by comparing the mean absolute percentage error (MAPE) and the determination coefficient (R2) using Predictive Modelling Software DTREG (pronounced D-T-Reg). The relationship of realized and planned costs will be determined for the building as a whole and for certain types of construction works. That relationship would enable more realistic budget planning of similar future projects. Cost overrun factors will be analysed for particular types of construction works, as well as the probability of their occurrence, and what measures should be undertaken to prevent or reduce them in similar future projects. The phenomenon known in project planning as "optimism bias" will be analysed in the context of research focus of exceeding the construction cost.

Field Survey of Hygrothermal Behaviour within Wall Assembly Derived from Rain Penetration and Ventilation Performance of Exterior System

Scipedia content — Mon, 14 Sep 2020 13:23:50 +0200

Rainwater and moisture control are key factors for maintaining the durability of wooden houses. Wall assemblies with sidings are installed on vented cavities to build durable wooden houses.Moisture condensation does not occur generally behind a vapor retarder in walls assembled with a vented cavity; however, it is reported that the condensation mechanism which occurs in the wall assembly due to the high humidity of the vented cavity by rain penetration in Japan, there are only a few studies that investigate hygrothermal behaviour considering effects such as rain penetration in the exterior system. To unravel the mechanism of internal condensation derived from rain penetration, labexperiments and field measurements were conducted. In the lab experiments, rain penetration from siding joints were quantitated using a water spray test. In the field measurements, for the exterior finishes of the experimental house, the sidings were installed on three types of vented cavities. To verify hygrothermal behavior within the wall assembly, intermittent long-term rain penetration into the vented cavity was reproduced for the experimental house. The measurements confirmed that internal condensation occurs with low ventilation performance, when moisture retained in the vented cavity is released into the wall assembly. This phenomenon is caused when the surface temperature on the sidings is increased because of solar radiation after rain. In conclusion, rain penetration through exterior finishes has a significant effect on the moisture behavior of wall assemblies. The obtained results verify that moisture condensation at the vapor retarder was caused by several factors including rain penetration, insufficient ventilation, and solar radiation. To maintain durability, it is important to ensure a ventilation performance and not retain moisture.

Seismic Performance of the Reinforced Concrete Girders Obtained from Existing Building Constructed in 1961

Scipedia content — Mon, 14 Sep 2020 13:23:44 +0200

This study examines, through experiments, two reinforced concrete girders obtained from a residential building constructed in 1961. The average concrete strength obtained from the material tests was approximately consistent with the specified strength. Honeycombs were observed in girders; hence, one of the girders was repaired using an epoxy resin injection to investigate the effect of retrofitting.The original and retrofitted girders were subjected to reverse loadings with displacement control and had a sectional area of 250 mm × 800 mm, according to the structural draft. Both girders were designed to exhibit a common shear span length of 1,200 mm to evaluate the validity of the current equations for shear capacity in seismic evaluation, as recommended in the criteria for seismic assessment in Japan. Using these equations, the ratio of the shear strength to flexural strength of the test girders was found to be 1.67. No significant difference was observed in the crack patterns of both girders. Their maximum strength reached the calculated flexural strengths; however, the shear cracks apparently progressed with the increase in drift angle. The hysteresis loops were slip-type because of the bond slippage of the main bars. The final failure mechanism was shear failure mode. The equation for flexural strength predicted the observed value of the original girder; the maximum strength of the retrofitted girder was approximately 1.1 times that of the original. Consequently, the epoxy resin injection recovered the seismic performance of the girders in this building.

Reliability Assessment of Pressurized Pipes with Inclined Defect

Scipedia content — Mon, 14 Sep 2020 13:23:39 +0200

Inclined defects in pipelines can lead to failures in the form of mixed mode fracture. A review of the literature suggests that few studies have been carried out on reliability assessment of pipelines considering mixed mode fracture. This paper intends to present a reliability-based method for assessing fracture failures of pressurized pipes with inclined defects. Richard’s criterion is employed in the development of the limit state function for reliability assessment. A Stochastic model of load effects is developed, and first passage method with a developed analytical solution is used to predict the pipe failures. A worked example is provided to illustrate the application of the proposed method. The method presented in this paper can help pipe engineers and asset managers to develop a reliability-based maintenance strategy for better management of pipelines.

Self-Compacting Concrete with Recycled Concrete Aggregate: Resistance against Aggressive External Agents

Scipedia content — Mon, 14 Sep 2020 13:23:34 +0200

The use of waste in civil-engineering products, such as concrete and asphalt mixes, is a very effective strategy for reducing high consumption levels of Natural Aggregates (NA) in the construction sector. In this research, rejected precast concrete elements of high compressive strength are studied,following their crushing for use as a high quality Recycled Concrete Aggregate (RCA) in the manufacture of Self-Compacting Concrete (SCC). High volumes of this waste stream are employed in the mixture, completely replacing the coarse fraction of the natural aggregate (100% replacement rate)and half of the fine fraction (50% replacement rate). Once hardened, samples of the recycled SCC are exposed to several aggressive external agents, in order to evaluate their performance and durability in aggressive environments. Behavioral tests on the concrete in the presence of the most frequent aggressive agents in the surrounding environment demonstrated that the SCC containing RCA was resistant to freeze/thaw and moist/dry cycles, and sulphate attack, according to the results obtained in 4, 3 and 2 samples respectively, and of sufficient durability for use in structural concrete components.

Global Inspection, Diagnosis and Repair System for Buildings: Homogenising the Classification of Repair Techniques

Scipedia content — Mon, 14 Sep 2020 13:23:30 +0200

Building inspection systems are a useful tool for surveyors, standardising the collection of information. Thisresearch is framed within the development of a global inspection system based on twelve expert inspection systems for twelve types of building elements used in the envelope of current buildings. Homogenised classification lists replace the use of several records and unify designations used in fieldwork. A homogenised global classification list of repair techniques comprises, in a single component, all the techniques used to repair defects and eliminate their causes for different types of building elements. It includes curative and preventive repairs, as well as planned maintenance works. Well-defined criteria guided the harmonisation process of a large set of repair techniquesin a user-friendly list. For instance, the association of different operations in a single repair technique took into account: similarities between procedures, applicability to one type of building element, solving identical defects and the use of similar repair materials. Considering data from the validation samples of the expert inspection systems, it is observed that techniques "R-A1 Cleaning" in painted façades and "R-A12 Application of a new (adequate) cladding/finishing coat over the existent/replacement" in wall renders are the most commonly prescribed. The provision of a homogenised classification list of repair techniques is expected to improve the quality of information collected on-site and give a comprehensive view of the most relevant repair techniques used in the envelope of current buildings.

Condition-Based Maintenance Models for Stone Claddings

Scipedia content — Mon, 14 Sep 2020 13:23:24 +0200

Most of the maintenance actions in the construction sector are still reactive and sporadic, based on subjective criteria. Usually, maintenance actions are performed when the building already presents unacceptable degradation levels, and the reactive maintenance actions carried out only correct the anomalies observed, not dealing with the causes, thus leading to additional costs and risks for owners. This study establishes a condition-based maintenance model applied to natural stone claddings. This model has a stochastic nature, in order to deal with the complexity of the degradation phenomena. For that purpose, Petri nets are used, providing an efficient tool to model the deterioration process and the maintenance decisions considered for stone claddings. The maintenance model is a full life-cycle model that encompasses: (i) the stochastic assessment of the degradation condition of the stone claddings, and their expected service life; (ii) and the inspections, maintenance and renewal processes. In this study, three maintenance strategies are considered: (i) major intervention only; (ii) combination of minor and major interventions; and (iii) combination of cleaning operations, minor and major interventions. The impact of the different maintenance strategies in the future performance and remaining service life of stone claddings is analysed, also evaluating the economic impact of each maintenance plan.

Effect of limit equilibrium zone energy on the volume of coal and gas outburst

Jinzhang Jia — Tue, 08 Sep 2020 09:19:01 +0200

In order to study the effect of the limit equilibrium zone energy in front of the heading face on the volume of coal and gas outburst, the concept of coal-gas mixed matrix was put forward, then the width of the limit equilibrium zone was calculated, and thus the energy transformation mathematical model of the limit equilibrium zone was established through theoretical analysis and mathematical derivation. In addition, the energy density calculation formula of the limit equilibrium zone was derived and then the intensity prediction formula of coal and gas outburst was derived combining elastic energy of coal body, expansion energy of gas, crushing work and throwing work of coal body. The results showed that the energy in the limit equilibrium zone has a certain effect on the volume of coal and gas outburst and the intensity prediction formula has high accuracy in Yangou Coal Mine. These conclusions have certain guiding significance for energy calculation and intensity prediction of coal and gas outburst.

List of Equations in https://doi.org/10.23967/j.rimni.2020.09.001

Dejan Brkić — Sat, 05 Sep 2020 14:50:02 +0200

Is the utilization of methane gas, the sollution of air pollution in difuse sectors?. The case of port of Castellón

Jesús Sánchez Pinedo — Fri, 04 Sep 2020 13:39:30 +0200

Within an scenario of highly sensitivity on environmental questions, followed by an international regulation body, that is restricting the emission levels from ships in ports with the future possibilit y of more stringent local regulations; the challenge for the world’s fleet are not only technical but economic and logistical. From one side, there are different technical alternatives affording to accomplish the nowadays international regulations. Even avoiding on board modifications, the owner can decide to use low sulphur content fuels, together with slight changes in engines to reduce the levels of nitrogen oxides. But the question posed in this paper is how to support the decision to use high quality oil derivatives, because environment questions, but with a favorable economic balance. That superior cost will be translated in a higher transport chain cost. Additionally regarding coastal navigation, it is possible in the future that some new regulations could penalize elevated rates of CO2 emissions, not yet considered by MARPOL convention. This paper will analyze the availability of the use of methane as ideal fuel to get compliment of the nowa days and even future, local and international regulations of CO2 and NOX, regarding the fuel derivatives and no emissions of sulphur oxides and ashes.

Selection of short sea shipping transport chains in western europe based on external factors

Jesús Sánchez Pinedo — Fri, 04 Sep 2020 13:27:35 +0200

According to the mid term review of the EU White Paper on Transport, Short Sea Shipping is expected to grow at a rate of 59% in metric tonnes, from 2000 to 2020. If we consider that the overall expected growth in freight exchanges is of 50% (also in volume), sea transport is one of the most feasible way to reduce traf-fic congestion on European roads. Marine transport is a possible way to compete with road transport in certain traffics, mainly when assuming external costs. This paper is going to analyse five multimodal routes, considering three different lev-els of powered ships, which one is going to be the most efficient in terms of exter-nal costs.

The Pyrenées bottleneck. A chance for short sea shipping?

Jesús Sánchez Pinedo — Fri, 04 Sep 2020 13:20:42 +0200

On the one hand, around 45% of European Union foreign trade is still carried by road and is consequently conditioned by traffic congestion or high fuel consumption, implying disadvantages related to pollution and safety, while on the other hand, 40% is carried by short sea shipping. Short Sea Shipping in European waters has been considered by national and European governments as one of the most feasible ways to alleviate the congestion that gets worse every day on the roads and highways across Europe. This paper poses criteria providing recommendations for the best alternative means of transport for carrying cargo across the Pyrenees.

Studies of suitability on short sea shipping routes in SW Europe

Jesús Sánchez Pinedo — Fri, 04 Sep 2020 12:55:40 +0200

Around 45% of European Union (EU) foreign trade is carried by road, which is conditioned by traffic congestion and high fuel consumption, and lead to implying the pollution and safety problem. Short Sea Shipping forms another 40% of the EU foreign trade. National and European governments have considered the Short Sea Shipping in European waters as one of the most feasible ways to alleviate the congestion which is getting worse each day on roads and highways in Europe. The main aim of this paper is to both study and identify the feasible routes in SW Europe which appear to be a viable solution for avoid road transport problems.

Stern twin-propeller effects on harbor infrastructures. Experimental analysis.

Jesús Sánchez Pinedo — Tue, 01 Sep 2020 16:24:00 +0200

The growth of marine traffic in harbors, and the subsequent increase in vessel and propulsion system sizes, produces three linked problems at the harbor basin area: higher erosion rates damaging docking structures, sedimentation areas reducing the total depth; resuspension of contaminated materials deposited at the seabed. The published literature demonstrates that there are no formulations for twin stern propellers to compute the maximum scouring depth. Another important limitation is the fact that the formulations proposed only use one type of maneuvering during the experimental campaign, assuming that vessels are constantly being undocked. Trying to reproduce the real arrival and departure maneuvers, 24 different tests were conducted at an experimental laboratory in a medium-scale water tank using a twin propeller model to estimate the consequences and the maximum scouring depth produced by stern propellers during the backward/docking and forward/undocking scenarios. Results confirm that the combination of backward and forward scenario differs substantially from the experiments performed so far in the literature using only an accumulative forward scenario, yielding deeper scouring holes at the harbor basin area. The results presented in this paper can be used as guidelines to estimate the effects of regular vessels at their docking location.

A ship routing system applied at short sea distances

Jesús Sánchez Pinedo — Tue, 01 Sep 2020 14:06:31 +0200

New generation of high-resolution meteo-oceanographic predictions provides useful tools for routing of ships in short maritime distances. In this work, the optimal ship routing analysis is investigated in maritime routes in the Western Mediterranean Sea for relative short sea distances. A* algorithm is implemented in order to obtain the optimal path under an energetic wave events. The methodological aspects are presented including the grid description and weather prediction systems. The optimized cost function is the travel time and it is obtained considering the added resistance due to waves. A practical example considers the maritime route between Barcelona and Algiers. The results show the influence of this factor in the optimum path recovered by the algorithm. The relevance of the relative direction between wave and ship route is proven comparing the ship routing results.

A proposal to modernize and harmonize maritime curricula in Montenegro and Albania

Jesús Sánchez Pinedo — Tue, 01 Sep 2020 14:01:47 +0200

The Black Sea region, a large horizon ready to open, ready to explore, ready to show her energy, her power and opportunities. But how we are preparing for this? It is a high competition between all the “actors” implicated in this field. The industry was informed to this potential resources by a major study undertaken by Purvin and Gertz in 2011, which predicted the development of a Romanian offshore industry and now exist many recently studies that confirmed the “black resources” of the Black Sea. We all know about the emergence of shale gas in Europe, in the last years, because is increasing evidence of a more united approach on energy, so the exploration and development of gas reserves in the Black Sea is an optimal alternative to supply gas from the Caspian to south-eastern Europe. But this good alternative implicates problems generated by costs, transportation and security of the very long pipelines that will pass through several countries till reaching their final destination. I try in this paper to pay attention on the main objective in the Black Sea Region, in this offshore field, that required the cooperation and sustainability from part of European Union and all its members’ state and countries situated in the Black Sea, Mediterranean Sea or Caspian Sea.

The exploration, development and perspective of oil and gas in the Black Sea region

Jesús Sánchez Pinedo — Tue, 01 Sep 2020 13:56:49 +0200

Analysis of viability to promote a hub Ro/Ro terminal in Palma de Mallorca (Spain) Port

Jesús Sánchez Pinedo — Tue, 01 Sep 2020 13:36:04 +0200

The presented paper is going to analyze the opportunity to develop a Ro/Ro hub in the Port of Palma de Mallorca. In order to get introduced in the study, the state of art related to geographical, economic tra c and human; conditions, will be reviewed; together with an in deep analysis of the port future capacities and main shipping lines crossing the western Mediterranean. At a ﬁrst glance is it easy to understand that the competition with other container hub ports in Mediterranean does not a ord Palma de Mallorca to be positioned in this market. But the chance to become a hub in rolled tra c will be studied. The ﬁnal results of this paper are going to identify the main particulars to be enforced to attract the main shipping companies that are providing transport services between the North and South coasts of the Mediterranean and the tra c between Italy and Spain.

SHIPPOL, Towards an automatic green house effect gases tracing and accounting system in harbor areas by using AIS

Jesús Sánchez Pinedo — Tue, 01 Sep 2020 13:31:29 +0200

Identification, tracing and monitoring of ships have been widely exploited by means of the Automatic Identification System (AIS). Considerable improvements in safety, collision avoidance and vessel traffic services operations (VTS) have been reached since the system was mandatory in 2002 and applied to ships built on or after 1 July 2002 and to ships engaged on international voyages constructed before 1 July 2002. Nevertheless, the possibility to storage, exchange and exploit dynamic and static information, for other reasons different to those mentioned above, can result in complementary associated phenomena analysis in shipping industry. Because of the possibility to observe and identify a vessel data services in a specific place and time, dynamic parameters like speed and position can be linked to the identification vessel data services in order to compute real time fuel consumption and therefore, the volume of pollutant gases emissions, providing more precise air pollutants emissions accounting different than the fuel consumption declarations. With this assumption, we have proposed a model which applies identification and speed information from AIS, and in consequence, the type of engines operating during the voyage, extracting data from public EQUA-SIS databases. With the help of Geographic Information Systems (GIS), real time and dynamic air pollution data can be computed and mapped in congested waters. Critical infrastructures like ports and its surroundings need other kind of data treatment because of the maneuvering operations during berthing or piloting, most of the them under different consumption conditions in the main engines. The present paper shows our first steps in analyzing a suitable mathematical model which fits the three components (earth observation, communications and navigation satellite, airborne and land data acquisition) in air pollution from shipping dynamic mapping. This is our first step to approach to an Automatic Green House Effect Gases Tracing and Accounting System.

Manoeuvring and hotelling external costs: enough for alternative energy sources?

Jesús Sánchez Pinedo — Tue, 01 Sep 2020 12:42:36 +0200

Local air pollution is the most relevant externality of maritime transport and its effects are more acute in urban areas as a result of manoeuvring, hoteling, and load/unload activities at ports. This paper is intended to assess ships' local air pollution impact in generally densely populated harbor areas, in order to decide whether or not alternative power supply measures are feasible. First, an optimized infrastructure investment model is developed to ease implementation and maximize the efficiency of alternative power supply projects. Once target harbors and traffic (ship types) within a national port network have been chosen, a vessel traffic analysis (ship type, tonnage, manoeuvring and hoteling times) is carried out to quantify and evaluate annual polluting emissions (PM2,5, SO2, NOx and VOC-s) and their externalities. Finally, the assessment model is applied and results of the Spanish port network case study are discussed. The results obtained are significant and bring the possibility of further controlling the ship's environmental performance at berth.

Cost assessment simulator for transport between mediterranean spanish ports and the Black Sea

Jesús Sánchez Pinedo — Tue, 01 Sep 2020 12:01:46 +0200

There is a strong imbalance in EU transport mode shares. In addition, issues like road traffic, noise, accident rates, and especially polluting emissions result not only in external costs to society, but also in high logistical costs to transport service customers. The present paper proposes an assessment model to evaluate final internal and external costs of transport chains served by trucks and short sea shipping (SSS). An efficient and fast tool is presented to help customers decide on the most convenient mode of transportation for a specific trade link. The trade links in this paper connect 19 Spanish provinces to the main ports in the Black Sea region (Bulgaria, Georgia, Romania, Russia, Turkey, and Ukraine) through the ports of Barcelona and Valencia.

Road and maritime transport enviornmental performance : short sea shipping vs road transport

Jesús Sánchez Pinedo — Tue, 01 Sep 2020 11:48:48 +0200

Motorways of the Sea (MoS) are part of the European transport strategy towards an efficient, safe and environmentally friendly transport system. This paper develops a model for short sea shipping (SSS) and road transport environmental performance comparison, estimating direct emissions and quantifying their impacts due to air pollutant and greenhouse (GHG) gas emissions. Ultimately a case study is presented to analyse and valuate each transport alternative to design an action plan determining intervening actions favouring the rebalance of the current transport system.

Implementación CGPS y altimetría en los Puertos de Ibiza, l’Estartit y Barcelona para monitorización del nivel del mar

Jesús Sánchez Pinedo — Tue, 01 Sep 2020 10:54:33 +0200

Dos campañas aéreas con el LIDAR Optech ALTM-3025 del ICC (Instituto Cartogáfico de Cataluña) fueron realizadas el 16 de Junio de 2007 de día con un Partenavia P-68 y el 12 de Octubre de 2007 de noche con un Cessna Caravan 208B. La validación posible de esta nueva tecnología LIDAR puede ser útil para suministrar medidas en áreas costeras, de unos 15 a 20 km desde la línea de costa, donde la altimetría radar por satélite da problemas severos debido al amplio haz («footprint») que abarca zona de tierra. La segunda campaña aerotransportada se realizó coincidiendo con el paso del satélite ICESat provisto de un láser altímetro. Se describe la situación actual de las infraestructuras CGPS en Ibiza, l’Estartit y Barcelona así como sus aplicaciones a la monitorización del nivel del mar y calibración altimétrica. El objetivo principal es la integración de datos geodésicos espaciales, aerotransportados e in-situ para establecer áreas de calibración altimétrica en el Mediterráneo Occidental en el marco del estudio del Cambio Global. Two airborne calibration campaigns carrying an Optech Lidar ALTM-3025 (ICC) were made on June 16, 2007 with a Partenavia P-68 and October 12, 2007, with a Cessna Caravan 208B flying along two ICESat target tracks including crossover near l’Estartit. The validation of this new technology LIDAR may be useful to fill coastal areas where satellite radar altimeters are not measuring due to the large footprint and the resulting gaps of about 15-30 km within the coastline. The second airborne campaign was made at night at the same time of the ICESat overflying. A description of the actual geodetic CGPS (Continuos GPS) infrastructures at Ibiza, l’Estartit and Barcelona is presented as their applications to sea level monitoring and altimeter calibration. The main objective is the integration of spaceborne, airborne and in-situ data for the establishment of altimeter calibration areas in the western Mediterranean in the framework of Global Change.

Is the utilization of methane gas the solution to air pollution in diffuse sectors? The case of port of castellon

Jesús Sánchez Pinedo — Tue, 01 Sep 2020 10:46:40 +0200

Considering environmental regulations, imposed by an international regulation body restricting the emission levels from ships in ports, with even more stringent local regulations envisaged, the challenges for the world’s fleet are not only technical but economic and logistical. On the one hand, there are different technical alternatives enabling the current international regulations to be met. Even avoiding on board modifications, the owner can decide to use low sulphur content fuels, together with slight changes in engines to reduce the levels of nitrogen oxides. But the question posed in this paper is how to support the decision to use high quality oil derivatives, bearing in mind environmental considerations, but with a favourable economic balance. That enormous cost will be translated into a higher transport chain cost. Additionally, regarding coastal navigation, it might become possible for some new regulations to penalize elevated rates of CO2 emissions, not yet considered by the MARPOL convention. This paper analyzes the availability of the use of methane as an ideal fuel which meets the nowadays and even future, local and international regulations on CO2 and NOx , regarding the fuel derivatives and no emissions of sulphur oxides and ashes.

Development of a costs simulator to assess new maritime trade routes

Jesús Sánchez Pinedo — Tue, 01 Sep 2020 10:40:03 +0200

This paper is going to describe the design process of a simulator that assesses the costs of different means of transport. The evaluation not only will be done regarding the internal costs but also the external costs that will be translated to environmental costs, based on existing databases. The paper shows the development carried out to create this simulator and analyse all components of the logistical chain, i.e. port operation costs, road haulage costs and maritime leg costs. The simulation results have been validated with real data of actual maritime routes to check its reliability. As a conclusion, the costs simulator permits assess costs of new maritime trade routes comparing them with road transport.

Port-city closeness and turnaround time critical for short sea shipping sustainable performance. A case study: Spain.

Jesús Sánchez Pinedo — Tue, 01 Sep 2020 10:30:27 +0200

Air pollution is the most relevant externality of maritime transport and its effects are more acute in urban areas. As Short Sea Shipping (SSS) services call ports frequently and expend significant time in port, both the overall turnaround time and the port city closeness, become critical in its sustainable performance. This paper analyses the impact of maritime transport at Spanish SSS ports and identifies the ideal ones, reflecting the differences in their sustainable performance and finally identifying the characteristics that a harbour needs to gather in order to minimize air pollution impact in the maritime transport sector.

¿Riesgo de mareas negras procedentes del mar abierto?

Jesús Sánchez Pinedo — Tue, 01 Sep 2020 10:25:02 +0200

El Objetivo fundamental de este artículo es el de analizar, identificar y posteriormente cuantificar, las áreas de la costa Española Mediterránea, con mayor riesgo de sufrir un derrame de hidrocarburos procedente del tráfico marítimo de hidrocarburos. En el estudio que fundamenta este artículo, se han tomado en consideración una serie de variables, de entre las que destacamos, las peculiaridades geográficas, climáticas o la densidad de tráfico, que alimenten una función aleatoria. Esta función objetiva ponderará los diferentes puntos de la costa e identificará los que tengan una mayor probabilidad de riesgo. En la investigación aquí presentada, se pretende evidenciar dónde pueden ubicarse las áreas del Mediterráneo Occidental español con mayor riesgo potencial de marea negra procedente de derrames de hidrocarburos.

Improvement of the Energy Efficiency of Vessels as a Measure for the Reduction of Greenhouse Gases Emission from Sea Shipping

Jesús Sánchez Pinedo — Tue, 01 Sep 2020 10:18:31 +0200

This paper describes how pollution is a serious problem that currently affects many areas of society. Maritime transport is responsible for part of that pollution and measures need to be taken in the logistics of the maritime transport field to reduce ship emissions. Air pollution is not the only problem, greenhouse gas emissions are also a major factor. This paper attempts to do a quick view of the last measures taken by the International Maritime Organization (IMO) in order to reduce greenhouse gas emissions of shipping. An energy efficiency index for ships was created by the Marine Environment Protection Committee (MEPC) to improve the energy efficiency and fuel consumption for ships. This index was developed in voluntary interim guidelines established in the last session of the MEPC during 2009 and 2010, and can be applied to both new designs and ships in operation. For now it is just a voluntary measure that whatever ship-owner could take and verify, but until its approval comes there are no sanctions.

A study of the riskiest points in front of an oil slick due to an accident in the spanish mediterranean coast

Jesús Sánchez Pinedo — Tue, 01 Sep 2020 10:10:48 +0200

Pollution from shipping traffic poses a real risk to the Spanish coast. Memories of the Fedra bulk disaster in the Strait of Gibraltar, the Prestige sinking in Finisterre or the Castor near accident off Almeria coast are still fresh. The main objective of this paper is to analyse, identify and quantify the Spanish Mediterranean coastal areas where spills from tankers are most likely to occur. The article is based on a study which uses a set of variables such as geographical peculiarities, climate, ship age and traffic density to feed and algorithm. This objective function weighs these parameters all along the coast and identifies the Spanish coastal areas having the highest risk of spills.

An analysis of pollution risk on the Spanish Mediterranean coast

Jesús Sánchez Pinedo — Tue, 01 Sep 2020 09:56:47 +0200

Pollution from shipping traffic poses a real risk to the Spanish coast. Memories of the Fedra bulk carrier disaster in the Strait of Gibraltar, the Prestige sinking in Finisterre or the Castor near accident off Almeria coast are still fresh. The main objective of this paper is to analyse, identify and quantify the Spanish Mediterranean coastal areas where spills from tankers are most likely to occur. The article is based on a study which uses a set of variables such as geographical peculiarities, climate, ship age and traffic density to feed an algorithm. This objective function weighs these parameters all along the coast and identifies the Spanish coastal areas having the highest risk of spills

The ecobono: a proposal based on external costs savings

Jesús Sánchez Pinedo — Tue, 01 Sep 2020 09:31:20 +0200

According to the mid-term review of the EU White Paper on Transport, Short Sea Shipping is expected to grow at a rate of 59% (metric tonnes) between 2000 and 2020. If we consider that the overall expected increase in both freight exchanges and volume is 50%, sea transport appears as one of the most feasible options to reduce traffic congestion on European roads. However, this alternative has not been definitely adopted because of technical, administrative and legal reasons. Moreover, society still regards maritime transport as a slow, inefficient mode since shippers do not yet offer the best value for money. Infrastructures need to be balanced by using tariff principles which reflect the exact external costs incurred by these infrastructures. Along this line of action, in 1998 the European Union published the White Paper on Fair Payment for Infrastructure Use: A Phased Approach to a Common Transport Infrastructure Charging Framework in the EU COM (1998) 466. This paper will conclude proposing an environmental bonus based on external cost savings associated with the use of the short sea alternative instead of road-only transport

The external costs of speed at sea: An analysis based on selected short sea shipping routes

Jesús Sánchez Pinedo — Tue, 01 Sep 2020 09:05:26 +0200

According to the mid-term review of the EUWhite Paper on Transport, Short Sea Shipping (SSS) is expected to grow at a rate of 59%(metric tonnes) between 2000 and 2020. If we consider that the overall expected increase in both freight exchanges and volume is 50%, sea transport is one of themost feasible alternatives to reduce traffic congestion on European roads. Maritime transportation may compete with road transport as far as certain traffics are concerned, but only when assuming external costs. This paper analyzes several intermodal transport chains involving a sea leg by comparing the effect of pollutant emissions from different ship types and road transport in terms of potential external cost savings.The translation of these emissions into environmental costs shows, for certain conditions, savings in the case of sea transport that would justify the use of an environmental bonus to promote the sea option.

The external costs of short sea shipping. analysis with selected ships

Jesús Sánchez Pinedo — Mon, 31 Aug 2020 16:22:48 +0200

La profesión del marino, ha sido un arcano nutrido de un altísimo nivel de conocimiento práctico derivado de la propia experiencia, que se ha traducido en doctrina científica en los últimos siglos. De entre la amplia panoplia de conocimientos que recibe el alumno o cadete de náutica, destaca la meteorología náutica y en concreto, conceptos relacionados con la formación y efectos del oleaje y de su generador, el viento. Ambos fenómenos están descritos científicamente en la dinámica de fluidos, pero desde el punto de vista del navegante, se analizan desde una perspectiva muy pragmática. En cualquier caso y en atención al interés que suscita al marino, iniciaremos este artículo con una somera descripción de los efectos del viento, de las variables que definen el oleaje y de cómo se relacionan entre sí, hablaremos de situaciones extremas y terminaremos con unas breves conclusiones.

Análisis medioambiental de una línea entre España y los puertos de Patras y Estambul.

Jesús Sánchez Pinedo — Mon, 31 Aug 2020 15:57:36 +0200

En el artículo se evaluan los costes internos y externos (medioambientales) entre los modos de transporte de carretera y el marítimo. Para ello se utiliza la base datos del observatorio de costes del transporte por cerretera del Ministerio de Fomento y la base de datos REALISE, que establece una tarificación de loas externalidades generadas por cada medio de transporte. La línea analizaba parte de España con destino a Patrás en Grecia e Izmir en Turquía.

Una nueva generación de ayudas a la navegación y de publicaciones náuticas

Jesús Sánchez Pinedo — Mon, 31 Aug 2020 15:16:39 +0200

Bajo el concepto de un sistema de información y ayuda a la navegación costera, el presente artículo muestra el desarrollo de una aplicación informática que hace posible visualizar datos hidrográficos, meteorológicos y de publicaciones náuticas que tradicionalmente se publican en papel como los "derroteros". Esta herramienta combina además la visión 3D de la costa y la posibilidad de consultar la información textual, correspondiente a los puntos conspicuos que se pueden observar desde la embarcación, conforme se aproxima a las líneas de costa o a los puertos. El desarrollo consta de una base de datos que actualiza la información a petición del usuario, ya sea vía Internet si se dispone del alcance de conexión necesario, o mediante la señal de posición que recibe el GPS, la cual proporciona las coordenadas al sistema, si éste está instalado a bordo como una base de datos independiente vinculada al sistema de visualización tridimensional

Selection of short sea shipping transport chains in western Europe based on external factors

Jesús Sánchez Pinedo — Mon, 31 Aug 2020 14:55:05 +0200

Wave height incidence on Mediterranean Short Sea Shipping routes

Jesús Sánchez Pinedo — Mon, 31 Aug 2020 14:47:57 +0200

According to the recent mid term review of the EU white paper on transport, Short Sea Shipping in EU waters is expected to grow from 2000 to 2020 at a rate of 59% in volume (metric tonnes). If we consider that the overall expected growth in freight exchanges is of 50% (also in volume), sea transport is one of the most feasible ways to reduce traffic congestion on European roads. High speed vessels are a possible way to compete with road transport in certain traffics; however these ships are highly affected by heavy weather. This paper is going to analyse the weather influence on several short sea shipping Mediterranean routes to be served by fast ships.

Las autopistas del Mar: solución al tráfico transpirenáico

Jesús Sánchez Pinedo — Mon, 31 Aug 2020 13:35:49 +0200

En este trabajo se plantea la importancia del Transporte Marítimo de Corta Distancia y las Autopistas del Mar como uno de los pilares fundamentales de la implementación de la Política Europea de Transportes, cuyas líneas generales han sido propuestas en el Libro Blanco de Transporte (2001) y complementadas, en lo que a la Política Marítima se refiere, en el Libro Verde (2006). Se revisan las acepciones de ambos conceptos, tanto en el ámbito académico como institucional, así como se subraya la relevancia del transporte marítimo en los intercambios comerciales europeos y su incidencia en el desarrollo portuario

El navegante y las olas

Jesús Sánchez Pinedo — Mon, 31 Aug 2020 13:28:45 +0200

Intermodalidad entre España y Europa, la cuenca Mediterránea y Atlántica, una alternativa clara al transporte terrestre

Jesús Sánchez Pinedo — Mon, 31 Aug 2020 13:10:26 +0200

El presente capítulo es un resumen de los estudios realizados dentro del proyecto INECEU1 (Intermodalidad entre España y Europa), llevado a cabo por cuatro integrantes del Grupo de Investigación TRANSMAR, del Departamento de Ciencia e Ingeniería Náuticas de la Universidad Politécnica de Catalunya. El Ministerio de Fomento fue la parte financiadora e interesada en los resultados de este proyecto, dada la importancia de la fluidez del transporte para la economía española en el contexto europeo, y asimismo debido también a la sensibilidad y voluntad política de promocionar el Transporte Marítimo de Corta Distancia y cabotaje en Europa. El objetivo principal de este proyecto, que partió del análisis de la situación actual en el ámbito del transporte, y en concreto de la exportación e importación de cargas unitizadas desde España, era la justificación del trasvase de mercancías de los pasos Pirenaicos a la mar, consiguiendo un desplazamiento más rápido y eficiente de las mercancías, analizando las potencialidades del transporte marítimo. Este capítulo es un resumen del proyecto INECEU; si el lector está interesado en conocer con más profundidad la metodología y el proceso de cálculo del proyecto existen dos publicaciones donde se detalla su totalidad (ver pie de página). A primera vista algunos de los datos parecerán desfasados ya que la fecha de realización del proyecto INECEU fue de diciembre del 2003 hasta abril 2005, siendo los valores y las estadísticas utilizados de periodos anteriores. Las conclusiones obtenidas en el proyecto INECEU han servido como punto de partida para la realización de los siguientes capítulos.