46 publications from this institution
An experimental study was conducted to predict the flexural strength of corroded full-scale reinforced concrete (RC) beams. Two different concrete strength levels at two different steel ratios were tested for different corrosion levels ranging from 0 to 17%. An accelerated corrosion aging method was applied to corrode the reinforcing bars embedded in concrete. The actual corrosion levels were obtained by breaking the concrete and extracting the reinforcing bars. A practical model was developed for the prediction of the flexural strength of corroded RC beams. The developed model predicted the experimentally obtained flexural strength of corroded beams found in the literature well. The results revealed that the structural behavior of corroded RC beams requires consideration of the corrosion levels at both the tensile bars and the stirrups (which are more exposed to corrosion because of their use as outer reinforcing bars) and have significant effects on the flexural strength of corroded RC beams.
Marginal value of a building is the subjective part of the value of the constructed facility and depends on how the decisions made by the contributing parties at different stages of the implementation of the project of a building. To increase the marginal value of a building, decisions made during the stages of a project need to be in close agreement with the value criteria of the decisions. Traditionally, during the implementation of a building project designers and clients make decisions with a little knowledge of the effects contributed by the decisions on the value the constructed facility. Knowledge of decisions to be made during the stages of a building project, value criteria of the decisions and their effects on the value of the constructed facility are important for successful project implementation. Therefore, determination of marginal value of a construction project lends itself to a knowledge-based application. This paper presents a knowledge-based system called COMVOB for the determination of the marginal value of a building project. To the user COMVOB presents criteria of decisions together with their importance weights at stages of a building project and with the input and confirmation of the details of the decisions it reports anticipated positive and negative marginal values.
Con el fin de confirmar la utilización de una fibra de acero para reforzar un hormigón, se puso en práctica un método consistente en un test de resistencia al impacto, sencillo, práctico y económico. Los resultados obtenidos indicaron que existe una relación logarítmica entre la tenacidad a flexión (E^..^.) y la energía (Ej) de impacto para estos hormigones. En la realización de este estudio se tuvieron en cuenta tres factores diferentes en lo concerniente a las fibras, con extremo en forma de gancho, con relación longitud/diámetro (mm/mm): 30/0,50:60/0,80y 50/0,60. Las fibras se añadieron al cemento en cuatro porcentajes en volumen diferentes: 0,5, 1,0, 1,5 y 2,0 %. A la vista de los resultados obtenidos, puede decirse que las fibras mejoran, tanto la resistencia al impacto, como la flexión en el hormigón, habiéndose establecido, asimismo, una buena correlación entre la energía de resistencia a flexión y la energía de impacto.
Upon the completion of national road projects, their cost and time deviations are often reported. These deviations from the projected values are a result of complications in the time and cost management of such projects. Controlling the cost and time overrun of projects is important for successful implementation and efficient project management. However, few studies have attempted to measure the project cost and time management efficiency in civil engineering. Thus, this issue requires further investigation. In this study, large road projects that had poor cost and time management were selected. The chosen projects were configured as Decision Making Units (DMUs) in a Data Envelopment Analysis (DEA). DEA is a non-parametric modern mathematical tool for measuring relative managerial performance and determining efficient DMUs. A list containing the causes of cost and time deviations and the percentage deviation for each DMU was prepared. The cost and time management efficiency of the DMUs was calculated using DEA, and the resulting values were ordered according to importance. It is believed that this process will contribute to better cost and time management.
The main disadvantage of high-strength concrete is its highly brittle behavior and this can beovercome by adding fibers to the concrete. This would also improve some other mechanical properties of high-strength concrete such as tensile strength and compressive strength. These properties are not very well established for high-strength steel-fiber reinforced concrete (HSFRC) yet. In this study the influence of silica fume on the properties of HSFRC were investigated by using silica fume of two different percentages and three different hooked-end fibers namely, 30/0.50, 60/0.80 and 50/0.60 length/diameter (mm/mm). Fibers were added to concrete in three different volume percentages of 0.5, 1.0 and 2.0 by volume of concrete. The results indicated that there is a linear function between splitting tensile strength (F splt) and volume percentage of fibers (V f) [i.e. F plt = A(V f) + B, where A and B are correlation coefficients] as well as between splitting tensile strength (F splt) and compressive strength (F c) of plain series A concrete [i.e. F splt = C (√F c) + D, where C and D are correlation coefficients]. These relations can describe the development of splitting tensile strength of HSFRC containing no silica fume, 5% silica fume and 10% silica fume by weight of cement. On the other hand, although silica fume has an effect on compressive strength, volume percentage and aspect ratio of steel fibers has little effect.
This article utilizes gene expression programming (GEP) technique to develop a prediction model in order to automate estimating the construction cost of water and sewer replacement/rehabilitation projects. A database gathered for developing the model was established on the basis of data related to 210 actual water and sewer projects obtained from the City of San Diego, California, USA. To verify the predictability of the GEP model, it was examined to estimate the cost of the projects that were not included in the modelling process. Sensitivity analysis technique and professional experiences were employed to determine the contributions of the qualitative factors and quantifiable parameters affecting the cost estimate. The proposed model with correlation coefficient of 0.8467 is adequately capable of estimating the cost of water and sewer replacement/rehabilitation projects. The GEP-based design equation can easily be used for predesign purposes to help allocate budgets and available limited resources effectively.
Prevention through Design (PtD) and Design for Safety (DfS) are now being considered in relation to occupational health and safety and building design. A recent collection of studies suggests that certain decisions made by designers during the design process are at the root of many risks. A study was undertaken to relate falls from height to the conventional design process for reinforced concrete buildings. This was achieved by dividing the building design process into stages. During the design phase, input was gathered from architects and engineers working in the sector. Accident types were identified based on studies of occupational accident investigation reports from the Ministry of Labor. Of the 15 types of fall from height accidents studied, 12 were attributed to design decisions. Of these, 6 different accident types were associated with 5 or more design decisions, while 2 of these were associated with 3 or 4 design decisions. The remaining 4 types were linked to only 1 design decision.
This study, carried out in the northern part of Cyprus, encompasses accidents that happened in the country between the years 1994-2014 and were recorded, based on the archives of the Ministry of Labor and Social Security. Findings obtained as a result of this research, will be presented in an order and will provide a powerful source for the industrial, and even institutional Occupational Health and Safety policies in developing countries Speciall in Turkey and T.R.NC. Within the scope of the study, victims were initially classified according to their industry of work. As a result of this classification, it was established that 793 victims (26.4%) worked in the Construction industry. Further classifications was made, focusing on the Construction industry, establishing date and hour of the accident, type of accident, result of accident, loss of workday, type and place of injury, age, profession, experience, etc. These classifications showed that falls type of accidents were the most frequent (37.7%) and causing the highest number of deaths. It also became clear that unskilled workers encountered accidents most (34.4%). Looking at the frequency of accidents through the year, spring and summer appeared to be the periods in which accidents, and deaths resulting from accidents, were the most frequent.
No abstract is provided for this article.
Total Quality Management (TQM) is based on the conceptions of managing and enhancing the success of construction projects. When applied, TQM improves execution of time management of project, satisfies clients’ needs, minimizes the expenses and increases the profit of contractor, and fulfils safety regulations on the construction site. This research is aimed at evaluating the impacts of employing the concepts of TQM to the construction projects in Saudi Arabia. The results of the study were obtained through utilization of a descriptive analytical approach, where 300 questionnaires were distributed to engineering firms and companies with a response rate of 200 questionnaires, hence achieving the study sample for this research. The data gathered was analyzed by applying the Statistical Package for Social Science (SPSS) program and calculating the relative importance index (RII) and the mean values. From the research conducted, the outcomes showed that the management’s ability to commit using TQM while applying BIM obtained a relative importance of (0.717), while the relative importance for the management’s ability to commit using TQM without the application of BIM is (0.552). The results showed that construction projects in Saudi Arabia still sustain setbacks from applying TQM concepts and suffer from the lack of administrative, scientific, and technical applications.
The effects of aggregate type and size are important parameters in the formation of interfacial transition zone (ITZ) structure and subsequently in the failure process of concrete. The influence of surface, rigidity and size of aggregates and water/cement (w/c) ratio of the matrix on bond strength at the ITZ and the interrelationship between the bond and the matrix in the failure process of concrete under uniaxial compression were studied. For this purpose a series of experiments were designed and carried out on mortars (with two different w/c ratios) containing single spherical steel aggregates. The ITZ properties and the failure process of concrete were investigated by means of tensile and compressive strength, and stress–volumetric strain measurements. It was observed that the effect of aggregate properties (high modulus of elasticity, smooth surface texture and size) on the weakness of ITZ and the failure process of concrete are of paramount importance for low w/c ratio composites. The effect of reduced bond properties was reflected in lowered critical stress levels for the low w/c ratio composites with larger aggregates.
The construction industry has continuously changed its work processes, methods, techniques and associated hazards. In addition, the way in which work is carried out on construction sites varies from project to project. As a result, it is difficult to prevent workplace accidents. What is worrying is that the majority of hazardous situations that arise as a result of decisions made during the design phase are not identified until construction begins. According to studies carried out around the world, some of the hazardous situations in construction are due to decisions made during the design process. The aim of this study was to minimise the hazards that arise from design decisions and cause occupational accidents. To this end, a system has been developed that operates in a BIM environment used by designers during the design phase. Thus, if a designer makes a decision that could cause a hazard, he/she would be warned by the BIM software. Therefore, in terms of occupational health and safety, safer buildings should be designed. This study uses multi-storey building projects and a system that detects and alerts on design decisions that cause fall accidents. The study concluded that most of the hazards that cause falls can be identified at the design stage. Consequently, the majority of these hazards can be eliminated through alternative design recommendations.
Purpose The purpose of this paper is to investigate the practice of stakeholder engagement as a social network dynamics for stakeholder satisfaction and project success in the lifecycle of mega transport infrastructure projects (MTIPs). Design/methodology/approach Hypotheses indicating the positive relationships between stakeholders’ effective attributes, stakeholder engagement as social network dynamics and project success through stakeholders’ satisfaction have been developed. Based on a questionnaire survey and semi-structured interviews, responses have been gathered from the representative groups and organizations on their social network dynamics for their satisfaction and project success. A hypothesized structural equation model has been tested using AMOS statistical software package. Findings The analysis highlighted the engagement of the stakeholders within the strategic intents of the project with the public needs and expectations. The model depicts the processes of building social network models based on the capturing of the project’s data in relation to the stakeholders’ communication and satisfaction across the key issues for success in the lifecycle of MTIP. Practical implications The model is applicable on most MTIP with a diverse stakeholder base and the underlying complexity associated with the community participation and consultation processes. The model will also support wider stakeholder engagement in the planning of MTIP with optimal operationalization and service delivery from a community perspective. Originality/value The research involves an approach for rationalizing the stakeholder engagement policies of the MTIPs by providing an empirically grounded model simultaneously linking various aspects of stakeholder effective attributes, stakeholder engagement and their relationships to stakeholder satisfaction and project success in MTIPs.
The construction industry in developing countries faces persistent challenges, including limited funding, poor infrastructure, insufficient use of technology, and weak quality management practices. These issues reduce productivity, compromise safety, and lower efficiency, often resulting in project delays, cost overruns, and substandard structures. This study introduces a safety and quality management framework that uses affordable camera technology and a structured web-based platform to address these challenges. The proposed system is designed to identify, document, and resolve potential issues systematically, fostering safer and more efficient construction environments. This research addresses the gap between the potential of technological advancements and their limited adoption in resource-constrained settings. Financial barriers often limit the availability of expertise on-site and restrict access to sophisticated tools, while inadequate quality control exacerbates risks, wastes resources, and undermines project outcomes. By introducing an affordable, easy-to-deploy solution, this study aims to bridge that gap and improve industry practices. Initial case studies have demonstrated promising results, including achieving acceptable quality and safety levels through the help of expertise from abroad. This paper details the design, implementation, and scalability of the proposed system while highlighting its adaptability to diverse construction contexts in developing nations. Additionally, it emphasizes the broader benefits of integrating technology into the construction industry, such as promoting economic growth and supporting sustainable development. Adopting this high-impact, cost-effective solution has the potential to significantly enhance technical capabilities, improve efficiency, and elevate social conditions through safer and more sustainable construction practices. This framework represents a transformative opportunity for the construction industry in developing countries, contributing to long-term progress and prosperity.
Effects of coarse aggregate size and water/cement (w/c) ratio of the matrix on the formation of interfacial transition zone (ITZ) and subsequently on the failure process of concrete under uniaxial compression were studied. For this purpose, a series of experiments were designed and carried out on mortars with two different w/c ratios containing single spherical steel aggregates of different sizes. The ITZ properties and the failure process of concrete were investigated through tensile strength tests both before and after compressive preloading, stress–axial strain, stress–volumetric strain and stress–lateral strain measurements. It was observed that ITZ becomes critical for larger aggregates and lower w/c ratio mortar matrices. The negative effect of smooth surface texture of the aggregate and the large difference between aggregate and matrix moduli of elasticity on the properties of ITZ is of paramount importance for low w/c ratio composites. The effect of reduced bond properties of ITZ relative to its matrix was reflected in the lower critical stress levels for the low w/c ratio composites with larger aggregates.
No abstract is provided for this article.
For the Jordanian government, meeting the growing demand for goods and services on its own is very difficult, leading to the increased dependence on other sectors of society. This research is aimed at understanding the critical success factors of local public-private partnership projects, identifying the most vital risk factors affecting projects, and establishing a quantitative model for risk assessment. The model can assist public-private partnership contributors by transforming the basic risk assessment principles into a more facilitated and systematic arithmetical based approach. The results showed that the risk factors with the highest ranks (respectively) are transfer phase, organizational risks, financing phase, project management risks, and feasibility study phase. The research is ultimately aimed at developing a framework for the risk evaluation of public-private partnerships within the construction industry in Jordan.
Value of a product, such as a component of a building, reflects on owner's desire to retain and obtain the product, and this introduces subjective aspects to the value. The value of a constructed facility depends on how much the design details of its components agree with the value system of the client. Traditionally, selection of design details is performed by the designers with little consultation with the client. A successful selection of components of construction needs a knowledge of design alternatives, components' criteria and utilities and agreement with the value system of the client. Therefore, determination of value of a constructed facility lends itself to a knowledge based application. This paper presents a knowledge based system called VOBE for the determination of the value of the envelope of a residential building based on the client's value system. To the user VOBE presents design alternative details for each component of the envelope and with the input/confirmation of his/her value system it reports the costs and values of the components of the building envelope.
This research is aimed at evaluating two different scenarios, firstly, appraising the impacts of employing the concepts of Total Quality Management (TQM) to the construction projects in Saudi Arabia. The results of the study were obtained through utilization of a descriptive analytical approach, where 300 questionnaires were distributed to engineering firms and companies with a response rate of 200 questionnaires, hence achieving the study sample for this research. The data gathered was analyzed by applying the Statistical Package for Social Science (SPSS) program and calculating the Relative importance index (RII) and the mean values. From the research conducted, the outcomes showed that the management’s ability to commit using TQM while applying BIM obtained a relative importance of (0.717), while the relative importance for the management’s ability to commit using TQM without the application of BIM is (0.552). The results showed that construction projects in Saudi Arabia still sustain setbacks from applying TQM concepts and suffer from the lack of administrative, scientific and technical applications. In a second scenario, a hybridized support vector regression (SVR) Harris-hawks optimization (HHO) (i.e., SVR-HHO) were used to predict the TQM. The performance accuracy of the models was checked through three different evaluation metrics namely; mean square error (MSE), correlation co-efficient (CC) and Nash-Sutcliffe efficiency (NSE). the hybridized emerging SVR-HHO outperformed the other two data driven approaches in both the training and testing stages based on the employed evaluation metrics. Overall, the obtained results showed that both the machine learning and metaheuristic approaches were capable of predicting TQM.
