Journal of Construction Engineering The latest articles from Hindawi © 2017 , Hindawi Limited . All rights reserved. Construction Practices Contributing to Rising Damp in Kumasi Metropolitan and Ejisu Municipal Assemblies in Ghana Thu, 24 Aug 2017 00:00:00 +0000 Buildings represent significant investment of developers and, as such, it is important to ensure value for the capital injected into the construction of buildings. Unfortunately, due to neglect of proper construction practices, buildings are facing defects, and one of such defects is rising damp. This study sought to identify some of the construction practices contributing to rising damp in buildings and their effects and suggest some remedial measures for controlling and treatment of rising damps. Snowball sampling and purposive sampling techniques were used to gather data from a cross section of 78 building environment professionals in Kumasi and Ejisu who have experienced the effects of moisture rise. Relative Importance Index was used to rank the significance of the causes. The study revealed that failure to use damp-proof membrane or course, presence of groundwater, porosity of masonry, and concrete element sand flooding were the main causes of rising damp. Undersetting and saw slotting, making good plumbing leakages, using approved waterproof chemical injection, and application of admixtures were the main measures recommended to avert rising damp. Richard Oduro Asamoah, John Solomon Ankrah, Philip Bannor, and Kofi Ofei-Nyako Copyright © 2017 Richard Oduro Asamoah et al. All rights reserved. Multilevel Safety Intervention Implementation Strategies for Nigeria Construction Industry Mon, 10 Apr 2017 06:26:11 +0000 This study was aimed at examining the relationships between the effectiveness of safety intervention programmes and implementation strategies in the Nigeria construction industry. Structured questionnaires were distributed to construction stakeholders across some selected states in Nigeria and the data generated were analysed using Pearson’s product moment correlation. The study found that the effectiveness of safety intervention programmes for construction site accidents prevention is significantly related to the communication implementation strategies. Based on the principles of social ecological theory and UNICEF’s communication for development strategies, this study developed a multilevel safety intervention implementation strategy for construction industries in Nigeria. Four communication strategies, namely, advocacy, social mobilisation, social change communication, and behaviour change communication, which are central to the effectiveness of safety intervention implementation programmes for construction site accidents prevention, were identified. It further revealed that these communication strategies could be individually and collectively applied at different intervention levels but that the greatest effect would be felt when all strategies are systematically combined with more efficient use of resources. The study recommended systematic actions by policy makers, construction organisations, and various community groups towards construction safety interventions, since maximum effect could only be felt when safety interventions are implemented across all levels. Peter Uchenna Okoye, Kevin Chuks Okolie, and Chukwuemeka Ngwu Copyright © 2017 Peter Uchenna Okoye et al. All rights reserved. A Study on the Dynamic Interaction between Three-Axle Vehicle and Continuous Girder Bridge with Consideration of Braking Effects Wed, 15 Mar 2017 09:25:10 +0000 Continuous girder bridges become increasingly popular because of the rapid development of highway throughout the world. Most of previous researches on vibration analysis of a multispan continuous bridge subject to complex traffic loading and vehicle dynamic interaction focus on the girder displacement not considering braking effects. In current literature, few studies have discussed the effects of braking on continuous girder bridges. In this study, we employ the finite element method (FEM) to investigate the dynamic response of continuous girder bridge due to three-axle vehicle. Vertical reaction forces of axles that change with time make bending vibration of girder increase significantly. The braking in the first span is able to create response in other spans. In addition, the dynamic impact factors are investigated by both FEM and experiments on a real bridge structure. The results of this study extend the current understanding of the bridge dynamic behaviors and can be used as additional references for bridge codes by practicing engineers. Xuan-Toan Nguyen, Van-Duc Tran, and Nhat-Duc Hoang Copyright © 2017 Xuan-Toan Nguyen et al. All rights reserved. Estimating Concrete Workability Based on Slump Test with Least Squares Support Vector Regression Tue, 06 Dec 2016 09:48:58 +0000 Concrete workability, quantified by concrete slump, is an important property of a concrete mixture. Concrete slump is generally known to affect the consistency, flowability, pumpability, compactibility, and harshness of a concrete mix. Hence, an accurate prediction of this property is a practical need of construction engineers. This research proposes a machine learning model for predicting concrete slump based on the Least Squares Support Vector Regression (LS-SVR). LS-SVR is employed to model the nonlinear mapping between the mix components and slump values. Since the learning process of the LS-SVR necessitates two hyperparameters, the regularization and the kernel parameters, the grid search method is employed search for the most desirable set of hyperparameters. Furthermore, to construct the hybrid model, this research collected a dataset including actual concrete slump tests from a hydroelectric dam construction project in Vietnam. Experimental results show that the proposed model is capable of predicting concrete slump accurately. Nhat-Duc Hoang and Anh-Duc Pham Copyright © 2016 Nhat-Duc Hoang and Anh-Duc Pham. All rights reserved. Risk Level Assessment in Construction Projects Using the Schedule Performance Index Mon, 14 Nov 2016 14:22:20 +0000 Construction projects are risky in both physical implementation and management. The characteristics of the risk reinforce the necessity of efficient management to increase the chances of success without commitment to its goals. This study explores the correlation of delay and the schedule performance index (SPI) to evaluate the risk of a construction project completed with time overruns. The hypothesis that the SPI of projects with a delay is distinct from those projects without a delay is assumed. A database with 19 elements was used to test this hypothesis and to calculate limit values to the SPI. Therefore, the risk of delay will be small when the observed SPI is greater than the superior limit and large when the SPI is below the inferior limit. The simplicity involved in the calculation of these values showed an advantage in comparison with other methods of risk evaluation. Another strong point observed is that any company can determine the value of risk by considering its own history and support decisions like doing corrective actions. Roberto Barbosa dos Santos and Antônio Edésio Jungles Copyright © 2016 Roberto Barbosa dos Santos and Antônio Edésio Jungles. All rights reserved. Cost Analysis of Precast and Cast-in-Place Concrete Construction for Selected Public Buildings in Ghana Wed, 26 Oct 2016 09:18:58 +0000 The construction industry in Ghana is becoming efficient in the area of cost and achieving advance technologies. The effective management of cost enables clients, developers, and facilitators to achieve value for money. Concrete is a major component in every construction project. The use of precast concrete technology has been embraced by the construction industry in Ghana. This study seeks to analyze cost estimating of the structural frame (column and slab) by considering cast-in-place and precast concrete slabs and columns, respectively. Relative importance and Kendall’s concordance agreement were used to determine the rankings and agreement of advantages of using precast concrete. The study established that precast concrete slabs were on average 23.22% cheaper than the cast-in-place concrete elements and precast columns were averagely 21.4% less than cast-in-place concrete columns. The study established that professionals prefer the use of precast concrete products because of the life cycle cost. Richard Oduro Asamoah, John Solomon Ankrah, Kofi Offei-Nyako, and Ernest Osei Tutu Copyright © 2016 Richard Oduro Asamoah et al. All rights reserved. A Review on Mechanical and Hydraulic System Modeling of Excavator Manipulator System Sun, 16 Oct 2016 07:56:53 +0000 A recent trend in the development of off-highway construction equipment, such as excavators, is to use a system model for model-based system design in a virtual environment. Also, control system design for advanced excavation systems, such as automatic excavators and hybrid excavators, requires system models in order to design and simulate the control systems. Therefore, modeling of an excavator is an important first step toward the development of advanced excavators. This paper reviews results of recent studies on the modeling of mechanical and hydraulic subsystems for the simulation, design, and control development of excavator systems. Kinematic and dynamic modeling efforts are reviewed first. Then, various approaches in the hydraulic system modeling are presented. Jiaqi Xu and Hwan-Sik Yoon Copyright © 2016 Jiaqi Xu and Hwan-Sik Yoon. All rights reserved. Maximizing Sustainability of Concrete through the Control of Moisture Rise and Drying Shrinkage Using Calcined Clay Pozzolan Tue, 11 Oct 2016 13:11:36 +0000 The Ghanaian concrete industry is really a booming industry due to many infrastructural developments and the surge in residential development. However, many developmental projects that utilize concrete do suffer from the negative impact of moisture rise including paint peeling-off, bacterial and fungi growth, and microcracks as well as unpleasant looks on buildings. Such negative outlook resulting from the effects of moisture rise affects the longevity of concrete and hence makes concrete less sustainable. This study seeks to develop materials that could minimize the rise of moisture or ions through concrete medium. The experimental works performed in this study included pozzolanic strength activity index, water sorptivity, and shrinkage test. Calcined clay produced from clay was used as pozzolan to replace Portland cement at 20%. The strength activity test showed that the cement containing the calcined material attained higher strength activity indices than the control. The thermal gravimetric analysis showed that the pozzolan behaved partly as a filler material and partly as a pozzolanic material. The sorptivity results also showed that the blended mix resulted in lower sorptivity values than the control mortar. The study recommends that calcined clay and Portland cement mixtures could be used to produce durable concrete to maximize sustainability. John Solomon Ankrah, Mark Bediako, Kwadwo Twumasi-Ampofo, Kofi Offei-Nyako, Charles Dela Adobor, and Eric Opoku Amankwah Copyright © 2016 John Solomon Ankrah et al. All rights reserved. Corrigendum to “Current State of Off-Site Manufacturing in Australian and Chinese Residential Construction” Wed, 17 Aug 2016 12:44:55 +0000 Malik M. A. Khalfan and Tayyab Maqsood Copyright © 2016 Malik M. A. Khalfan and Tayyab Maqsood. All rights reserved. Management of Highway Projects in Egypt through Identifying Factors Influencing Quality Performance Tue, 09 Aug 2016 07:35:11 +0000 While project management success focuses upon the processes and the successful accomplishments of cost and time objectives, product success deals with the quality of the final product. Recently, quality of the constructed highway has been considered highly important reason for the pavement response and its design life. The main objective of this paper is to improve the management of highway projects in Egypt by determining the most important factors influencing the quality performance of this industry. In total, 39 factors that may influence the quality of highway projects have been defined through a detailed literature review. The factors are tabulated in a questionnaire form, which is sent out to 13 owners of divided highways, 27 owners of regional roads, and 15 consultants. The analysis of the respondents’ perspectives using fuzzy triangle approach shows that the most important factors affecting the quality are availability of experienced staff in the owner’s and contractor’s teams during the project execution; efficiency of the owner’s inspection team; clarity of responsibilities and roles for each owner, consultant, and contractor; pavement which is not designed according to the regional conditions (e.g., soil type, temperature, and traffic volume); and asphalt quality and type used in the construction process. Ahmed Ebrahim Abu El-Maaty, Ahmed Yousry Akal, and Saad El-Hamrawy Copyright © 2016 Ahmed Ebrahim Abu El-Maaty et al. All rights reserved. An Integrated Expert System for Linear Scheduling Heavy Earthmoving Operations Wed, 27 Jul 2016 11:10:58 +0000 Heavy earthmoving operations are repetitive in nature and vulnerable to time-related restraints and uncertainties. Therefore, at the conceptual stage, scheduling these operations can take a linear form, known as linear schedule or line of balance (LOB). In such type of work, generating a preliminary line of balance for variable sequencing of activities is crucial. In this paper, an integrated expert system for determining preliminary linear schedules for heavy earthmoving operations at the conceptual stage is presented. The proposed system incorporates numerous factors that influence the analysis of earthmoving operations, which include geological and topographical parameters used to determine productivity rates at the conceptual stage. Also, the proposed system is capable of automatically generating a line of balance based on a stochastic scheduling technique via the metaheuristic simulated annealing intelligent approach to incorporate randomness and uncertainties in performing the associated activities. A parametric analysis is conducted in order to quantify the system’s degree of accuracy. An actual case project is then utilized to illustrate its numerical capabilities. Generating accurate linear schedules for heavy earthmoving operations at the conceptual design stage is anticipated to be of major significance to infrastructure project stakeholders, engineers, and construction managers by detecting schedule’s conflicts early in order to enhance overall operational logistics. Nizar Markiz and Ahmad Jrade Copyright © 2016 Nizar Markiz and Ahmad Jrade. All rights reserved. Renovation versus New Construction and Building Decision Tool for Educational Facilities Tue, 28 Jun 2016 12:19:11 +0000 Renovation of an existing building is an accomplished stem of the construction industry because it supplies financial diversification for construction stakeholders. Although several construction planning tools and stakeholder alignment exercises have been developed, no tool exists to assist project owners to decide between renovating an existing building and new construction with a comprehensive decision criteria. The objective of this research is to create and test a renovation versus new building support decision tool for construction project stakeholders. The renovation versus new building support decision tool was created based on an extensive review of existing support tools and construction industry needs. The created tool was implemented to evaluate decisions of educational facilities by university officials experienced in project management. Results show the tool was effective in identifying relevant topics for discussion and guiding a group of stakeholders through an exercise in decision-making. Specifically, the tool was implemented by construction management personnel for university facilities currently under construction to evaluate the decision to renovate an existing building or new construction. The main contribution of this research is a framework and support decision tool readily implementable for construction project stakeholders desiring to determine if renovation or new construction is the optimal path for their specific objectives. Carrie Pope, Eric Marks, Edward Back, Tim Leopard, and Thomas Love Copyright © 2016 Carrie Pope et al. All rights reserved. Deviations between Contract Sums and Final Accounts: The Case of Capital Projects in Ghana Tue, 07 Jun 2016 12:45:46 +0000 Cost estimation is particularly difficult, often leading to considerable deviations. For capital projects, especially transport infrastructure projects, deviations hover around an average of 28% of the estimated cost. There are several factors that cause these deviations between the final accounts and the contract sum. How these factors combine to cause deviations between the contract sum and the final account in recent times has been of great concern to construction managers and researchers alike. This study sought to identify the significant factors that result in deviations between contract sums and the final accounts of capital projects. Using a sample size of 45, comprising contractors, consultants, and clients, the factors identified using Relative Important Indices were “price fluctuations,” “late material delivery,” “changes in the scope of work,” “fluctuations in the market demand,” and “changes in design.” Using Kendall’s coefficient of concordance, a coefficient value of 0.068 was obtained. As such, the null hypothesis was rejected as there was a level of agreement among the respondents. Again, based on a significance test run, 26 out of the 40 identified factors used for the analysis were seen to be significant in influencing the deviations between contract sums and final accounts figures. Kofi Offei-Nyako, Leslie Cyprian Ohene Tham, Mark Bediako, Charles Dela Adobor, and Richard Oduro Asamoah Copyright © 2016 Kofi Offei-Nyako et al. All rights reserved. People Centered Innovation: Enabling Lean Integrated Project Delivery and Disrupting the Construction Industry for a More Sustainable Future Wed, 11 May 2016 13:25:44 +0000 People-centered innovation is a paradigm shift in the construction industry. It is derived from the supposition that people not methods, schedules, or budgets deliver projects. Our data suggest that a multilevel, multidisciplinary project team through shared vision, values, and a common vernacular defines, designs, and delivers more successful projects than traditional methods. These projects meet the needs of shareholders, the community, stakeholders, and the planet. We employ the concepts of emotional intelligence and agency theory to explain an integrated project delivery (IPD) construction project using lean tactics that not only delivered, but also exceeded expectations resulting in a six-month schedule acceleration and $60M savings over the original estimated cost of the project calculated assuming traditional project delivery methods. The safety rating for this project was 50% better than the national average and the expected improvement in operating margin for the new building is 33% greater. This paper introduces the notion of people-centered innovation to an industry that has struggled to adapt and show positive results over recent decades. Our case study describes the significance of people-centered innovation in construction project delivery. We discuss the implications for the construction industry going forward. William Paolillo, Branka V. Olson, and Edward Straub Copyright © 2016 William Paolillo et al. All rights reserved. Communities’ Satisfaction towards Housing Rehabilitation and Reconstruction Program after September 30, 2009, Earthquake in West Sumatra Wed, 13 Apr 2016 14:02:55 +0000 The government of Indonesia had provided the Rehabilitation and Reconstruction (RR) assistance to 194,636 houses for communities after September 30, 2009, earthquake in West Sumatra. The community-based development model was adopted in this housing program aid. This study aims to explore people’s satisfaction towards the RR program and to identify the difference of satisfaction level between urban area and rural area. The research was carried out by conducting a questionnaire survey to 200 communities. The beneficiaries were invited to determine their satisfaction level based on 5 Likert scale from 1 as “not satisfied at all” to 5 as “absolutely satisfied.” The satisfaction level was assessed by two factors, process of reconstruction and result of reconstruction. It was found that the level of communities’ satisfaction is at average level. The satisfaction level of urban communities is 2.75, while the satisfaction level of rural communities is slightly higher at 2.88. The satisfaction levels of urban and rural communities with the reconstruction process are at 2.63 and 2.75, respectively, while the satisfaction level with the results of the program is at 2.84 and at 2.95, respectively. Communities’ satisfaction with the result of reconstruction is higher than that with the process of reconstruction. Bambang Istijono, Taufika Ophiyandri, Diah Chairisna, and Ade Tadzkia Copyright © 2016 Bambang Istijono et al. All rights reserved. Using the Network Metaphor to Design, Deliver, and Maintain a Construction Management Curriculum Thu, 03 Dec 2015 11:55:44 +0000 Construction management programs accredited by the American Council for Construction Education (ACCE) are responding to new standards for accreditation, as the accreditation process itself is being changed to primarily focus on learning outcomes. These changes offer an opportunity and a challenge for existing programs to readjust and restructure to meet the increasingly changing expectations within the construction market. Using a network metaphor, with a critical path consisting of critical activities, activity codes, and constraints, can be a successful methodology to develop/align a construction management curriculum. As with any network, this approach can be used as both planning and control tool, being revisited regularly for further fine-tuning responding to the feedback resulting from assessment efforts to “close the loop.” The resulting network can be presented in both tabular and/or graphical format highlighting the critical path and particular critical activities (learning concepts) within that path. Different resources can be applied to the schedule reflecting their commitment and availability limits (space, labs, computers, etc.). Ihab M. H. Saad Copyright © 2015 Ihab M. H. Saad. All rights reserved. Nature of Communication Ineffectiveness Inherent in the Procurement Systems on Mass Housing Projects Mon, 23 Nov 2015 14:04:27 +0000 Mass housing projects (MHPs) are deemed to exhibit unique procurement systems which consequently induce communication ineffectiveness that continues to dominate the challenges among mass housing project teams. However, this acknowledged communication ineffectiveness inherent in the unique procurement system features of mass housing project among the project team remains to be empirically examined. This study seeks to investigate the influence of procurement system (PS) features of MHPs to communication ineffectiveness among the mass housing project team. By adopting a quantitative method design, a structured questionnaire survey on project team leaders managing MHPs in Ghana was used in collecting empirical data. Structural equation modeling (SEM) was used to explore the communication problems inherent in the PS features of mass housing projects. The results revealed moderate to high effects of communication ineffectiveness in information flow and information composition inherent in the unique PS features of MHPs. The results further revealed misunderstanding, inaccuracies, barriers, and information dissemination challenges as the major communication ineffectiveness induced by the PS features of MHPs. By gaining knowledge and understanding into the communication ineffectiveness associated with these features of MHPs, practitioners are well positioned to plan communication and management strategies to engender success in mass housing delivery. Titus Ebenezer Kwofie, Emmanuel Adinyira, and Frank Fugar Copyright © 2015 Titus Ebenezer Kwofie et al. All rights reserved. An Integrated BIM System to Track the Time and Cost of Construction Projects: A Case Study Mon, 16 Nov 2015 14:09:39 +0000 Many construction projects suffer from poor design and from inconsistent time and cost management. This situation has led to rethinking of the industry’s performance and how it could be improved. Technology is breaking through design and management practices. Earned value management (EVM) enables better management of time and cost constraints. Building Information Modeling (BIM) is recognized to improve the planning and realization of a construction project. The present paper proposes an integrated time and cost management system (ITCMS), where an EVM platform is used in a virtual environment during the planning and construction phases of a project. The ITCMS enables early involvement and project integration plus thorough time and cost management. The system consists of four modules and 13 different processes. The ITCMS is beneficial at the design stage; construction professionals are able to synchronize the building model with time and cost parameters as well as optimize it through a clash detection process that results in budget and schedule compressions early on. The ITCMS is a useful tool for construction and engineering managers that strive to increase projects’ performance. The authors demonstrate in this paper the validity of using the ITCMS through an actual project. Ahmad Jrade and Julien Lessard Copyright © 2015 Ahmad Jrade and Julien Lessard. All rights reserved. Identification of Risks Pertaining to Abandoned Housing Projects in Malaysia Tue, 10 Nov 2015 14:23:22 +0000 Housing industry is one of the most dynamic, risky, and challenging industries. In Malaysia, this industry has a poor reputation for managing risks, with many major projects failing to be completed within the allotted time. Due to the inherent risks involved in construction projects, it is essential to recognize the risks that cause problems associated with abandoned housing projects. Therefore, this study aims to identify the risks that contribute to issues of abandoned housing projects and to propose mitigation strategies. The methodologies used in this study are combination of qualitative and quantitative methods of literature review, questionnaire survey, and interview. The results show that many risks are involved in housing project, including risks related to environmental impacts, construction, politics, law, management, finance, materials, and economy, of which the probability of risks from unexpected ground condition, project delays, bureaucracy, contractual disputes between developer and landlord, weakness in management by inexperience developer, and financial crisis is very high. It was also found that all relevant parties involved in housing industry are required to have extensive cooperation in advance and should perform systematic risk management strategies in order to mitigate the risks leading to problems associated with abandoned housing projects. Hamzah Abdul-Rahman, Chen Wang, and Nur Hamizah Ariffin Copyright © 2015 Hamzah Abdul-Rahman et al. All rights reserved. The Use of Project Time Management Processes and the Schedule Performance of Construction Projects in Mexico Thu, 15 Oct 2015 11:26:32 +0000 Delays have been frequently reported as the cause of several conflicts that affect the different parties involved in construction projects. Project Time Management (PTM) includes a number of planning and controlling processes that are recommended for complying with requirements related to project time. The study reported in this paper aimed at assessing the use of PTM processes and its relation with project schedule performance (i.e., timely completion). Seven PTM processes and seventy-seven tasks associated with them were identified from the literature that is globally relevant to project management. The study included the assessment of fourteen school construction projects executed by a public agency in the Yucatan Peninsula, Mexico. These projects were monitored during the construction phase in order to measure two different variables: the use of processes related to PTM (i.e., schedule planning and controlling processes) and the project schedule performance. For each of these projects a Use Index was obtained for assessing the first variable, while the Schedule Performance Index and the Schedule Variance were computed to assess the second one. The results demonstrated there is statistical dependence between these two variables. Most of the projects that attained timely completion also made a greater use of the PTM processes. Rómel G. Solís-Carcaño, Gilberto A. Corona-Suárez, and Aldo J. García-Ibarra Copyright © 2015 Rómel G. Solís-Carcaño et al. All rights reserved. Risk Determination, Prioritization, and Classifying in Construction Project Case Study: Gharb Tehran Commercial-Administrative Complex Tue, 13 Oct 2015 07:26:40 +0000 Construction projects play an important role in infrastructure projects in developing countries. According to type, size, and complexity of the project, the number and importance of each risk could be different and many projects cannot reach the project goals due to exposure to multiple risks. Many papers have been published on the subject of risk management in construction projects; unfortunately most of them have not been implemented in practical conditions. The aim of this study is to identify and prioritize risks in construction projects. The classical approach used probability and impact for risk assessment, but these criteria do not sufficiently address all aspects of projects risks and there might be a relationship between different criteria. This study proposes the hierarchical dependencies between criteria. A case study of construction project is presented to illustrate performance and usage of the proposed model. Utilizing library studies and interview with experts, managers, and specialists, decision criteria were identified through brain storming. Risks were categorized by the experts into eleven risks. Important risks were evaluated based on the fuzzy ANP, fuzzy DEMATEL, and fuzzy TOPSIS methods. The proposed model is more suitable than the traditional decision-making methods in prioritizing risk concerning cost, time, and quality. Azadeh Sohrabinejad and Mehdi Rahimi Copyright © 2015 Azadeh Sohrabinejad and Mehdi Rahimi. All rights reserved. Development of the Asphalt Multi-Integrated Roller Field and Experimental Studies Thu, 17 Sep 2015 16:02:42 +0000 Asphalt pavements have been compacted using steel drum rollers for a century. However, the problems that are observed today on these pavements are universal with no solution in sight. Intensive research work has been invested to identify the mechanisms that cause these problems. A recent development was the introduction of SuperPave mix design, GP asphalt cements, and the use of reinforcing elements ranging from polymer to steel bars. Yet it seems that none of these solutions have succeeded in eliminating any of the old problems. The pavements suffer from serious distresses regardless of the geographic location of the pavements and its design, materials, traffic loads, and climate condition. This paper presents a new approach to deal with the problems facing the asphalt pavements. While the research efforts to date concentrated on materials-related solutions, this paper identifies conventional compaction equipment as the cause of many problems observed on the pavements. The paper provides the development of the new Asphalt Multi-Integrated Roller, AMIR, and discusses new developments leading to a number of commercial field trials on several Ontario highways. The paper concludes that current compactors must be replaced with soft flat plates in order to achieve the required specifications for long term performance. Abd El Halim Omar Abd El Halim, Amir Omar Abd El Halim, Moustafa Awadalla, and Mohamed Adel Hassanin Copyright © 2015 Abd El Halim Omar Abd El Halim et al. All rights reserved. A Reliable Visual Inspection Method for Vulnerability Assessment of Hyperstatic Structures Using Fuzzy Logic Analysis Tue, 04 Aug 2015 12:55:39 +0000 Fuzzy logic applied to the visual inspection of existing buildings has been proposed in relation to simple structures. Isostatic structures are characterized by a unique and known collapse mechanism, which does not vary with geometry or load change. In this paper we apply fuzzy logic to visual inspection for complex structures such as hyperstatic ones in which the collapse mechanism depends not only on the geometry but also on the size and disposition of loads. The goal of this paper is to give relevant weight, in the fuzzy analysis, not only to the single expression of degradation, due to its localization within the element, but also to the structural element itself by assigning a different resistance to the various elements. The underlying aim of the proposed method is to manage, evaluate, and process all the information coming from visual inspections in order to realize a management information system for the evaluation of the safety level of even complex structures. Maria Valeria Piras, Fausto Mistretta, Maria Luisa Fadda, and Luisa Deias Copyright © 2015 Maria Valeria Piras et al. All rights reserved. Implementation of Risk Management in Malaysian Construction Industry: Case Studies Tue, 28 Jul 2015 08:52:29 +0000 Construction industries are exposed to wide array of risks, such as financial, design, and contractual ones, which might have a direct impact on their performance toward achieving the desired objectives. Risk Management is a proactive decision-making process used to minimize and manage the risks in the most efficient and appropriate manner. However, most construction firms in Malaysia do not apply formal risk management in their projects. Thus, this study aims to identify the actual process of risk management that is being applied in the construction projects and to determine the effects of risk management implementation on the performance of the construction projects in terms of time and cost. The data were obtained from four case studies in Kuala Lumpur, Malaysia, through semistructured interviews. It was found that the implementation of risk management process in Malaysian construction industry is still at a low level, mainly due to the fact that most of the construction employees involved in risk management are not fully aware of the available risk management techniques that can be applied in construction projects. Hamzah Abdul-Rahman, Chen Wang, and Farhanim Sheik Mohamad Copyright © 2015 Hamzah Abdul-Rahman et al. All rights reserved. Critical Factors Inhibiting Performance of Small- and Medium-Scale Contractors in Sub-Saharan Region: A Case for Malawi Wed, 01 Jul 2015 09:56:59 +0000 The construction industry is dominated by small- and medium-scale contractors (SMCs) who face an emerging trend of unique challenges in the implementation of projects. The study was aimed at examining inhibiting factors that influence performance of SMCs in terms of “quality of work,” “tender estimation,” “tender preparation,” and “timely completion of construction projects” in Malawi. A survey questionnaire was administered to 370 players in the construction industry which included public sector clients, contractors, consultants, and construction resource trainers in order to elicit data from 118 variables that were identified through a careful literature review. The inhibiting factors were generally dominated by economic issues, which was an emerging trend to what has been previously reported in the sub-Saharan region. The first highest ranked inhibiting factors were high lending interest regimes offered by financial institutions; stringent conditions to access capital; fluctuation of currency; stringent requirements for obtaining bonds; and high taxes. The research lays the foundation for further understanding of inhibitors on performance of SMCs in an evolving world which is being impacted by global factors and punctuated by sudden changes. Paul John Kulemeka, Grant Kululanga, and Danny Morton Copyright © 2015 Paul John Kulemeka et al. All rights reserved. Structural Properties of Concrete Materials Containing RoadCem Tue, 16 Jun 2015 12:16:45 +0000 This paper presents findings from a preliminary study to assess the structural and material properties of a nonstandard, concrete type mix containing RoadCem, a traditional soil stabilising additive. Two different mixes determined the effect of adding RoadCem in terms of compressive and flexural strengths, breaking strain, thermal expansion and contraction behaviour, permeability using a falling head, and Young’s modulus. RoadCem is a fine powder containing alkali metals and synthetic zeolites which are complemented with a complex activator. RoadCem modifies the dynamics and chemistry of cement hydration by enhancing the crystallisation process and forming longer needle crystalline structures. It reduces the heat of hydration with an early strength development. Varying the volume in the mix varies the viscosity and alters curing times while maintaining the water cement ratio. The results from this study have shown a modest increase in compressive strength and Young’s modulus with improvements in thermal performance, particularly at low temperatures. The flexural strength of the two mixes was similar with a much reduced permeability in the RoadCem mix. The results demonstrate the improved performance of concrete incorporating RoadCem but further improvements are possible by using a better graded aggregate and controlling the maximum dry density and moisture contents. Niall Holmes Copyright © 2015 Niall Holmes. All rights reserved. Hard-Hat Detection for Construction Safety Visualization Sun, 01 Feb 2015 08:43:43 +0000 In 2012, 775 fatalities were recorded, and many more were injured at construction sites in the United States. Of these, 415 fatalities (54%) were due to fall, slips, and trips as well as being struck by falling objects. In order to decrease fatalities at construction sites to these types of events, the Occupational Safety and Health Administration (OSHA) provides Fall Prevention and OSHA-10 trainings to construction workers. Moreover, safety personnel monitor whether the workers use personal protective equipment (PPE) properly. Data shows that construction fatalities have decreased by 2% annually since 1994; however, the owners still are not satisfied with this result. Various studies have shown that fall is the biggest contributor for construction fatalities. One study showed that half of the fall fatalities were because the workers either had not used PPEs or had not used them properly. In addition, studies showed that, with proper use of hard hats, the fatalities due to fall, slips, trips, and being struck by falling objects could be reduced. This study developed and tested a hard-hat detection tool that uses image-processing techniques to identify whether workers are wearing hard hats. The tool dispatches warning messages if the workers do not use hard hats. Kishor Shrestha, Pramen P. Shrestha, Dinesh Bajracharya, and Evangelos A. Yfantis Copyright © 2015 Kishor Shrestha et al. All rights reserved. Optimizing Traffic Operation in Designing Specific Upgrades Sun, 18 Jan 2015 14:14:15 +0000 Transport forms one of the primary needs in all categories of the population in modern society; it is of paramount concern for traffic engineers, transport planners, and policy makers to understand and evaluate the quality of service being provided by the transport facilities designed by them. This paper presents an investigation in profile geometric design and traffic flow operation on two-lane two-way highways and provides analyses that will help in a better understanding of traffic operation on these facilities to select the optimum profile configuration. The effects of influencing parameters consisting of grade, length of grade, traffic composition, and traffic volume are evaluated and finally a systematic procedure to evaluate flow rate under the base condition is presented. Finally, based on these achievements an algorithm is introduced to select optimum Finished Ground of profile view. Results show that the percentage of heavy vehicles has a contributing effect on traffic operation so that the optimum profile configuration is incredibly affected by this factor. Source data have been obtained from Highway Capacity Manual (HCM) as a pioneer document in respect of quantifying the concept of capacity for a transport facility. Ebrahim Sangsefidi, Mohammadjafar Rashidbenam, Shahab Kabiri, Hossein Amid, and Maryam Sangsefidi Copyright © 2015 Ebrahim Sangsefidi et al. All rights reserved. Experimental Heat Transfer Study on Green Roofs in a Semiarid Climate during Summer Sun, 18 Jan 2015 09:38:32 +0000 An experimental study was conducted on green roofs under the semiarid summer climatic conditions of West Texas to investigate the effect of soil type, moisture content, and the presence of a top soil grass layer on the conductive heat transfer through the roof. Two soil types were investigated: uniform sand and local silt clay. Tests were also conducted on a control roof. A dual-needle heat-pulse sensor was used to conduct thermal property tests on the soils. The tests reveal that unlike sand, the thermal conductivity of silt clay did not increase continuously with soil moisture. Better heat transfer conditions were achieved when the sand and silt clay roofs were watered to a water depth of 10 mm per day rather than double the amount of 20 mm per day. The roof with silt clay soil had the lowest fluctuation in inner temperature between daytime and nighttime. Green roofs with silt clay soil required more than twice the amount of soil moisture than green roofs with sand to achieve similar roof heat transfer rates. The best net heat flux gains for vegetated green roofs were 4.7 W/m2 for the sand roof and 7.8 W/m2 for the silt clay roof. Roy J. Issa, Kenneth Leitch, and Byungik Chang Copyright © 2015 Roy J. Issa et al. All rights reserved. An Automated BIM Model to Conceptually Design, Analyze, Simulate, and Assess Sustainable Building Projects Thu, 06 Nov 2014 12:41:56 +0000 Quantifying the environmental impacts and simulating the energy consumption of building’s components at the conceptual design stage are very helpful for designers needing to make decisions related to the selection of the best design alternative that would lead to a more energy efficient building. Building Information Modeling (BIM) offers designers the ability to assess different design alternatives at the conceptual stage of the project so that energy and life cycle assessment (LCA) strategies and systems are attained. This paper proposes an automated model that links BIM, LCA, energy analysis, and lighting simulation tools with green building certification systems. The implementation is within developing plug-ins on BIM tool capable of measuring the environmental impacts (EI) and embodied energy of building components. Using this method, designers will be provided with a new way to visualize and to identify the potential gain or loss of energy for the building as a whole and for each of its associated components. Furthermore, designers will be able to detect and evaluate the sustainability of the proposed buildings based on Leadership in Energy and Environmental Design (LEED) rating system. An actual building project will be used to illustrate the workability of the proposed methodology. Farzad Jalaei and Ahmad Jrade Copyright © 2014 Farzad Jalaei and Ahmad Jrade. All rights reserved.