Journal of Construction Engineering http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2016 , Hindawi Publishing Corporation . 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 http://www.hindawi.com/journals/jcen/2016/6574989/ 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 http://www.hindawi.com/journals/jcen/2016/4823630/ 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 http://www.hindawi.com/journals/jcen/2016/2312057/ 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 http://www.hindawi.com/journals/jcen/2016/5737160/ 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 http://www.hindawi.com/journals/jcen/2016/2814126/ 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 http://www.hindawi.com/journals/jcen/2016/3704289/ 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 http://www.hindawi.com/journals/jcen/2016/2148408/ 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 http://www.hindawi.com/journals/jcen/2015/465493/ 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 http://www.hindawi.com/journals/jcen/2015/914520/ 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 http://www.hindawi.com/journals/jcen/2015/579486/ 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 http://www.hindawi.com/journals/jcen/2015/524717/ 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 http://www.hindawi.com/journals/jcen/2015/868479/ 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 http://www.hindawi.com/journals/jcen/2015/203468/ 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 http://www.hindawi.com/journals/jcen/2015/752674/ 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 http://www.hindawi.com/journals/jcen/2015/171989/ 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 http://www.hindawi.com/journals/jcen/2015/192742/ 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 http://www.hindawi.com/journals/jcen/2015/927614/ 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 http://www.hindawi.com/journals/jcen/2015/795080/ 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 http://www.hindawi.com/journals/jcen/2015/721380/ 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 http://www.hindawi.com/journals/jcen/2015/254548/ 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 http://www.hindawi.com/journals/jcen/2015/960538/ 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 http://www.hindawi.com/journals/jcen/2014/672896/ 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. Study of the Causes and Magnitude of Wastage of Materials on Construction Sites in Jordan Wed, 29 Oct 2014 08:25:39 +0000 http://www.hindawi.com/journals/jcen/2014/283298/ The research aims to study the causes and magnitude of wastage of construction materials on construction projects sites in Jordan. To achieve the research aim, the researcher had prepared a questionnaire form included questions about the causes of wastage and the estimated percentages of wastage of ten most popular kinds of materials used on construction sites in Jordan. Prior to the final formulation of the questionnaire form, a pilot survey was conducted. The form was revised in accordance with the feedback received. The number of causes adopted was 60 distributed on the six major categories. The form was distributed to 240 participants (clients, contractors, and consultants). The study revealed that the most important causes of wastage of materials on construction sites in Jordan are frequent design and client’s changes; rework due to workers mistakes; poor contract documents; wrong and lack of storage of materials; poor strategy for waste minimization; shortage and lack of experience of skilled workers; poor site conditions; damage during transportation; theft and vandalism; and mistakes in quantity surveying and over allowance. In addition the study concluded that the percentage of wastage materials is accounted for by values between 15% and 21% on Jordanian construction sites. Ghanim A. Bekr Copyright © 2014 Ghanim A. Bekr. All rights reserved. Identification and Classification of the Unique Features of Mass Housing Projects Thu, 23 Oct 2014 09:12:18 +0000 http://www.hindawi.com/journals/jcen/2014/927652/ Mass housing projects (MHPs) are said to differ significantly from the “one-off” traditional building projects often encountered in the construction industry and thus require unique management skills and approach in MHPs delivery. This unique nature of MHPs contributes to managerial inefficiencies that result in delivery failures when management approaches are not adapted to the project characteristics. However, understanding and knowledge of the unique attributes of MHPs are critical towards improving the organisation, planning, managerial effectiveness, and delivery success of mass housing projects. To date, extensive studies establishing the unique features of mass housing projects are lacking. This study is set out to identify what constitutes the unique features of mass housing projects by comparing mass housing projects to traditional “one-off” building projects. A questionnaire survey was used to establish mass housing practitioners’ perception of the unique characteristics of MHPs. Data analysis involving mean scores and ANOVA revealed 10 unique features of MHP. A clear and systematic understanding of these unique features of MHPs is crucial for evolving effective project management practices and critical competencies towards successful delivery of current and future MHPs. Titus Ebenezer Kwofie, Frank Fugar, Emmanuel Adinyira, and Divine Kwaku Ahadzie Copyright © 2014 Titus Ebenezer Kwofie et al. All rights reserved. Quantitative Analysis of the Sources of Construction Waste Mon, 20 Oct 2014 09:20:45 +0000 http://www.hindawi.com/journals/jcen/2014/651060/ The construction industry is traditionally environmentally unfriendly. The environmental impacts of construction waste include soil contamination, water contamination, and deterioration of landscape. Also, construction waste has a negative economic impact by contributing additional cost to construction due to the need to replace wasted materials. However, in order to mitigate waste, construction managers have to explore management options, which include reduction, recycling, and disposal of wastes. Reduction has the highest priority among the waste management options but efficient reduction cannot be achieved without adequate identification of the sources of waste. Therefore, the purpose of this paper is to present a study that was carried out on the contribution rates of nine identified sources of construction waste. Establishing the contribution rates of different waste sources will enhance knowledge-based decision-making in developing appropriate strategy for mitigating construction waste. Quantitative research method, using survey questionnaire, was adopted in this study to assess the frequency and severity of contribution of the sources of waste. As one of the findings of the study, residual waste such as material off-cuts was identified as the highest contributor to construction waste. This study consequently demonstrated that waste has a significant contribution to the cost of construction. Olusanjo O. Fadiya, Panos Georgakis, and Ezekiel Chinyio Copyright © 2014 Olusanjo O. Fadiya et al. All rights reserved. NIDE: A Novel Improved Differential Evolution for Construction Project Crashing Optimization Sun, 19 Oct 2014 09:16:40 +0000 http://www.hindawi.com/journals/jcen/2014/136397/ In the field of construction management, project crashing is an approach to shortening the project duration by reducing the duration of several critical project activities to less than their normal activity duration. The goal of crashing is to shorten the project duration while minimizing the crashing cost. In this research, a novel method for construction project crashing is proposed. The method is named as novel improved differential evolution (NIDE). The proposed NIDE is developed by an integration of the differential evolution (DE) and a new probabilistic similarity-based selection operator (PSSO) that aims at improving the DE’s selection process. The PSSO has the role as a scheme for preserving the population diversity and fending off the premature convergence. The experimental result has demonstrated that the newly established NIDE can successfully escape from local optima and achieve a significantly better optimization performance. Nhat-Duc Hoang Copyright © 2014 Nhat-Duc Hoang. All rights reserved. Current State of Off-Site Manufacturing in Australian and Chinese Residential Construction Thu, 25 Sep 2014 09:26:50 +0000 http://www.hindawi.com/journals/jcen/2014/164863/ Many techniques have been implemented to make construction industry more productive. The key focus is on reduction of total duration, reduction in construction cost, improvements in the quality, achieving more sustainable development, and safer construction sites. One of the techniques, which is emerging in the last two decades, is the use of off-site manufacturing (OSM) within the construction industry. Several research projects and industry initiatives have reported the benefits and challenges of implementation of OSM. The focus of this paper is Australian and Chinese residential construction industry and the uptake of the OSM concepts. The paper presents a brief review of the current state of OSM in the last five to seven years with the context of the above-mentioned two countries. The paper concludes that the construction industry, both in Australia and China, needs to start walking the talk with regard to OSM adoption. The paper also highlights some of the research gaps in the OSM area, especially within the housing and residential sector. Malik M. A. Khalfan and Tayyab Maqsood Copyright © 2014 Malik M. A. Khalfan and Tayyab Maqsood. All rights reserved. Do Building Information Modelling Applications Benefit Design Teams in Achieving BREEAM Accreditation? Mon, 22 Sep 2014 05:25:35 +0000 http://www.hindawi.com/journals/jcen/2014/390158/ Using building information modelling (BIM) within a design team allows for integration of sustainability analysis such as daylighting analysis, water harvesting, and thermal assessment whilst capturing the data which can be used for BREEAM assessment. Therefore, the availability of data compared to traditional methods can be used to design teams, stakeholders, and environmental assessment bodies’ advantage. Since BIM boasts extensive building performance analysis capabilities, design teams should be provided with standard methodologies and guidance into successfully achieving certain BREEAM criteria. This paper highlights gaps in the existing theory to develop a solid understanding for further research in order to achieve BIM integrated BREEAM design team protocol. Further to this and running parallel to the protocol and guidance, an internal conceptual framework existing within BIM software could be instigated from future research. This will require detailed and innovative solutions to link the credits with the software both from an IT and from a software coding perspective; also, there is great merit into analysing design teams’ cultural and behavioural factors towards sustainable design through the BIM model. Josh Harding, Subashini Suresh, Suresh Renukappa, and Sabah Mushatat Copyright © 2014 Josh Harding et al. All rights reserved. Holistic Diagnosis of Rising Damp and Salt Attack in Two Residential Buildings in Kumasi, Ghana Thu, 24 Jul 2014 08:38:53 +0000 http://www.hindawi.com/journals/jcen/2014/398627/ Rising damp is one of the most severe phenomena that leads to decay and deterioration of both old and modern types of buildings. This study employed a holistic approach to dampness investigation and sought to examine the problem of rising damp in the walls of two residential apartments in Kumasi, Ghana. The study sought to determine the types of soluble salts and their concentrations in the soils and accumulated percentages in the walls over time and whether there exists any linkage between the salts in the walls and those in the ground. Results from the geotechnical survey of the building sites found that the soils on site 1 consisted of silty sandy gravel with some clay particles and those on site 2 consisted of silty sandy soil with some clay and traces of gravel. The study identified several groups of salts in the walls of the buildings, with the most damaging and dangerous being magnesium sulphate, magnesium chloride, and sodium sulphate salts. Similar salts were identified in the soil samples from the trial pits. The results therefore indicate a linkage between the salts found in the ground and those found in the walls and therefore confirm the presence of rising dampness. Kofi Agyekum, Joshua Ayarkwa, and Christian Koranteng Copyright © 2014 Kofi Agyekum et al. All rights reserved. Investigation of Contemporary Performance Measurement Systems for Production Management of Renovation Projects Mon, 21 Jul 2014 12:10:42 +0000 http://www.hindawi.com/journals/jcen/2014/417853/ Renovation projects exhibit complex characteristics due to the presence of constraints that lead to cost and schedule overruns. Numerous researchers have concluded that the performance of renovation projects is typically lower than that of new construction projects. This paper discusses the initial phases of a research conducted at Michigan State University, which focused on developing a framework for production management of renovation projects. The emphasis of this paper is on the findings from literature review and interviews, pertinent to performance measurement in renovation projects that led to the framework development. However, the framework development and the framework itself have not been discussed. This paper primarily addresses two questions: (1) what are the complexities of renovation projects that lead to underperformance in cost, time, and quality? and (2) what are the limitations of state-of-the-art construction performance measurement systems for managing production in renovation projects? Interviews of 10 construction companies were conducted to identify current practices of production management in renovation projects. This research observed a lack of a formal production management process in renovation projects, with a limited use of performance measurement systems. The research identified essential attributes for avoiding schedule and cost overruns on renovation projects. Yash Singh, Tariq Abdelhamid, Tim Mrozowski, and Mohamed A. El-Gafy Copyright © 2014 Yash Singh et al. All rights reserved.