Showing papers in "Buildings in 2019"
TL;DR: In this paper, the authors provide an overview of available literature on structural performance, benefits, constraints and challenges of prefabricated building systems, including full-scale tests, numerical modelling, hybrid simulations, case studies and social and economic assessments.
Abstract: Volumetric prefabricated building construction is growing in most developed countries; for example, in Sweden the market share of prefabricated building systems in the housing industry was more than 80%. However, in Australia only approximately 3–4% of new building constructions are prefabricated buildings in a year. A major hindrance to the growth of prefab construction in Australia is that systems are developed under commercial and confidential conditions. There are limited publicly-available research and case studies for certifiers, regulators, engineers and academia to provide independent information on the performance, advantages and disadvantages of prefabricated building systems. Independent designers and structural engineers are relying on the strength of the structural and non-structural element, as well as the connections of the prefabricated building systems. This strength is estimated from the “commercial-in-confidence” test of individual components by manufactures, and it might result in undesired outcomes in design. This paper provides an overview of available literature on structural performance, benefits, constraints and challenges of prefabricated building systems. This paper also highlights the research needed on the prefabricated building systems such as full-scale tests, numerical modelling, hybrid simulations, case studies and social and economic assessments. Being supported by sound academic research will increase the market demand for prefabricated building systems in Australia as well as in other countries.
142 citations
TL;DR: A survey of BCT and its applications in the Architecture, Engineering, and Construction (AEC) industries is depicted and the potential incorporation within the BIM process to address post-disaster rebuilding problems is examined.
Abstract: Blockchain Technology (BCT) is a growing digital technology that in recent years has gained widespread traction in various industries in the public and private sectors. BCT is a decentralized ledger that records every transaction made in the network, known as a ‘block’, the body of which is comprised of encrypted data of the entire transaction history. BCT was introduced as the working mechanism that forms the operational basis of Bitcoin, the first digital cryptocurrency to gain mainstream appeal. The introduction of decentralized data exchange technology in any industry would require strengthened security, enforce accountability, and could potentially accelerate a shift in workflow dynamics from current centralized architectures to a decentralized, cooperative chain of command and affect a cultural and societal change by encouraging trust and transparency. BCT aims at creating a system that would offer a robust self-regulating, self-monitoring, and cyber-resilient data transaction operation, assuring the facilitation and protection of a truly efficient data exchange system. In the state of Florida, climate change and unpredicted weather disasters have put pressure on state and local decision-makers to adapt quick and efficient post-disaster recovery systems. Part of the recovery efforts is the reconstruction of buildings and infrastructure. The introduction of new technologies in the Architecture, Engineering, and Construction (AEC) industry can contribute to addressing recovery and rebuilding after the event of a natural disaster. With parallel technological advancement in geospatial data and Geographic Information System (GIS), as well as worsening climatic conditions, concerns can be suitably addressed by employing an integrated system of both Building Information Modeling (BIM) and BCT. While several potential applications of BIM must provide solutions to disaster-related issues, few have seen practical applications in recent years that indicate the potential benefits of such implementations. The feasibility of BIM-based applications still rests on the reliability of connectivity and cyber-security, indicating a strong use case for using BCT in conjunction with BIM for post-disaster recovery. This research depicts a survey of BCT and its applications in the Architecture, Engineering, and Construction (AEC) industries and examines the potential incorporation within the BIM process to address post-disaster rebuilding problems. Moreover, the study investigates the potential application of BCT in improving the framework for automating the building permitting process using Smart Contract (SC) technologies and Hyperledger Fabric (HLF), as well as discussing future research areas. The study proposes a new conceptualized framework resulting from the integration of BCT and BIM processes to improve the efficiency of building permit processes in post-disaster events.
90 citations
TL;DR: In this article, the authors present a scientometric review and metasynthesis of BIM development in the African AEC industry to explore the intellectual evolution of the BIM, the status quo of the emerging BIM across the regions, and any potential barriers hindering BIM proliferation.
Abstract: Building Information Modelling (BIM) has been gaining widespread adoption in the Architecture, Engineering, and Construction (AEC) industry across the globe. Consequently, several research studies have attempted to construct a holistic review of the increasing BIM publications to identify the development trend using manual review, scientometric review, bibliometric review, or latent semantic review. These extant studies have often adopted a global view of the development despite the adoption of BIM varying across firms, countries, and continents. This approach is often regarded as not representative of the BIM development in countries and continents at the infancy stage. As BIM is still at the germinating stage of development in Africa and previous reviews are unrepresentative of BIM development in the AEC industry of Africa. This paper aims to present a scientometric review and metasynthesis of BIM development in the African AEC industry to explore the intellectual evolution of BIM, the status quo of BIM across the regions, and any potential barriers hindering BIM proliferation. The review findings revealed a varying level of BIM growth, with North Africa, West Africa, and Southern Africa leading the research development, whilst East Africa and Central Africa are slightly lagging behind. Additionally, the major challenges facing BIM adoption was found as people/process-related barriers. This study has provided valuable insights into BIM development and application in the growing African AEC industry.
78 citations
TL;DR: Estimates for the embodied environmental impacts of residential construction from the two most widely used life cycle assessment (LCA) database-software combinations, ecoinvent with SimaPro software and GaBi, are compared to recognize the uniformities and inconsistencies.
Abstract: Traditionally, the emissions embodied in construction materials have not been considered important; however, they are becoming crucial due to the short time-frame in which the emissions should be reduced. Moreover, evaluating the environmental burden of construction materials has proven problematic and the reliability of the reported impact estimates is questionable. More reliable information from the construction sector is thus urgently needed to back and guide decision-making. Currently, the building sector environmental impact assessments predominantly employ commercial software with environmental impact databases and report results without knowledge about the impact of the software/database choice on the results. In this study, estimates for the embodied environmental impacts of residential construction from the two most widely used life cycle assessment (LCA) database-software combinations, ecoinvent with SimaPro software and GaBi, are compared to recognize the uniformities and inconsistencies. The impacts caused by two residential buildings of different types, a concrete-element multi-story residential building and a detached wooden house, both located in Finland, were assessed, including all building systems with a high level of detail. Based on the ReCiPe Midpoint method, fifteen impact categories were estimated and compared. The results confirm that the tool choice significantly affects the outcome. For the whole building, the difference is significant, around 15%, even in the most widely assessed category of Climate Change, and yields results that lean in different directions for the two cases. In the others, the estimates are entirely different, 40% or more in the majority of the categories and up to several thousand percentages of difference. The main conclusion is that extensive work is still urgently needed to improve the reliability of LCA tools in the building sector in order to provide reliable and trustworthy information for policy-making.
70 citations
TL;DR: The most important methods and technologies, which are needed to develop the AR4C application are described, which provides context-specific information on construction projects and tasks, as well as key performance indicators on the progress and performance of construction tasks.
Abstract: The information and communication technologies (ICTs) utilization ratio in the construction industry is relatively low. This industry is characterized by low productivity, time and cost overruns in projectsdue to inefficient management processes, poor communication and low process automation. To improve construction performance, a BIM-based (BIM - (Building Information Modelling) and augmented reality (AR) application (referred to as the AR4C: Augmented Reality for Construction) is proposed, which integrates a location-based management system (LBMS). The application provides context-specific information on construction projects and tasks, as well as key performance indicators on the progress and performance of construction tasks. The construction projects are superimposed onto the real world, while a site manager is walking through the construction site. This paper describes the most important methods and technologies, which are needed to develop the AR4C application. In particular, the data exchange between BIM software and the Unity environment is discussed, as well as the integration of LBMS into BIM software and the AR4C application. Finally, the implemented and planned functionalities are argued. The AR4C application prototype was tested in a laboratory environment and produced positive feedback. Since the application addresses construction sites, a validation in semi-real scenarios with end users is recommended.
67 citations
TL;DR: In this paper, the authors explore the implications, risks and applications of blockchain technology for improving flow in the end-to-end design and construction process and identify opportunities for future research on blockchain applications in construction.
Abstract: Construction customers want more complex facilities delivered faster and at a lower cost. Transaction costs account for a significant proportion of each new or refurbished facility (a 2017 report from the Infrastructure Client Group in the UK suggests as high as 50%), yet they contribute no value to the customer. Blockchain is being suggested as a way to reduce transaction costs by eliminating the need for intermediaries to build trust as a prerequisite for successfully executed agreements. This study first describes the thinking that underpins blockchain technology, outlining how it works, and the potential limitations of the technology. Second, using a case study, reviews the potential cost savings from the use of blockchain for a real estate company. The results reveal a potential cost savings from blockchain deployment at 8.3% of the total cost of residential construction, with a standard deviation of 1.26%. Third, we explore the implications, risks and applications of blockchain technology for improving flow in the end-to-end design and construction process and we identify opportunities for future research on blockchain applications in construction.
67 citations
TL;DR: In this article, discrete element models are used for the analysis of masonry, given their ability to represent the discontinuous nature of these structures, and to simulate the most common deformation and failure modes.
Abstract: Discrete element models are a powerful tool for the analysis of masonry, given their ability to represent the discontinuous nature of these structures, and to simulate the most common deformation and failure modes. In particular, discrete elements allow the assessment of the seismic behavior of masonry construction, using either pushover analysis or time domain dynamic analysis. The fundamental concepts of discrete elements are concisely presented, stressing the issues related to masonry modeling. Methods for generation of block models are discussed, with some examples for the case of irregular stone masonry walls. A discrete element analysis of a shaking table test performed on a traditional stone masonry house is discussed, as a demonstration of the capabilities of these models. Practical application issues are examined, namely the computational requirements for dynamic analysis.
53 citations
TL;DR: In this article, a holistic review and conceptual framework of the drivers of offsite construction is established, drawing on a multistage methodological framework of a systematic literature review, plenary discussions, and the total interpretive structural modeling (TISM) approach to build a holistic conceptual framework for the drivers.
Abstract: The significant ill-performances, challenges, and increasing competition within the construction sector are generating tremendous changes. One such revolution is the transition towards offsite construction (OSC). Although a plethora of studies has expounded the virtues and benefits of the approach, a holistic review and conceptual framework of the drivers of OSC is not well-established. This research draws on a multistage methodological framework of a systematic literature review, plenary discussions, and the total interpretive structural modelling (TISM) approach to build a holistic conceptual framework for the drivers of OSC. A review of 32 empirical studies distributed across four continents resulted in the extraction of 86 drivers. The 86 drivers were grouped into time, cost, quality, productivity, innovative competitiveness, market, sustainability, and policy clusters of drivers drawing on previous classifications in empirical studies. The TISM modeling revealed three hierarchical levels of the drivers, comprising dependent, linkage, and independent drivers. Based on an MICMAC analysis, “innovative competitiveness” and “sustainability” have the highest driving powers and lowest dependences, suggesting their prime significance in the adoption of OSC. Thus, this research provides a broader perspective of the drivers and may help OSC practitioners and policymakers to gain a better understanding of the ecosystem of the drivers.
53 citations
TL;DR: A systematic critical review including a bibliography analysis on delay literature in construction is conducted, including what has been learnt from a decade investigating delay causes and effects in the construction literature and what factors have been missed in the literature.
Abstract: Delay is one of the main challenges of construction projects, and there is still much to overcome in order to reach near zero delay in all construction projects. This project aims to conduct a systematic critical review including a bibliography analysis on delay literature in construction. The main questions consider what has been learnt from a decade investigating delay causes and effects in the construction literature and what factors have been missed in the literature. This paper also presents a new and challenging question regarding how digital tools and associated technologies may prevent any delay in construction projects, which can change the research direction from delay investigations to identifying prevention factors. The paper identifies the delay dataset, including 493 papers investigating delay in construction, and establishes a specific dataset of papers focusing on delay effects and causes (DEC), including 94 selected papers covering different factors examined in over 29 countries such as Iran, India, Turkey, Bangladesh, Saudi Arabia, the United Arab Emirates (UAE), Cambodia, Oman, Malaysia, Taiwan, China, Vietnam, the US, the UK, and Egypt. In addition, the paper identifies 30 critical factors with the frequency of occurrences over three times in the DEC dataset and computes their medians of ranking. This paper also discusses digital tools and methods that can be used for delay analysis and preventions, including MS Project, Oracle Primavera P6, and Open Plan by Deltek. The paper discusses the project schedule delay analysis from project management methodology perspectives. It also discusses the current method’s limitations and future directions, which are based on the identification of the deficiency areas. In total, four overlooked factors are identified and suggested, including faulty data analysis, unmatched structure of the research questionnaires with new knowledge and standards [e.g., Project Management Body of Knowledge (PMBOK)], overlooked effects of digital technologies [e.g., Digital twin, Navisworks, Building Information Model (BIM), Geographic Information System (GIS), and Integrated Project Delivery (IPD)], and ignored job-site technologies. In addition, the paper presents the DEC model for future studies, including four main key factors. These factors are resources (e.g., project budgets, labour, material, equipment, and digital tool), project context, stakeholders performance (e.g., owner/client, consultant/designer, contractor, vendor/supplier), and external factors (e.g., ground condition, site location, regulation, natural disaster), which may significantly affect delay prevention and should be concurrently considered in the future delay investigations, since they may be required for designing an effective mitigation strategy when these proof points are identified. This would significantly help to utilise digital systems to prevent time overruns in different construction contexts.
52 citations
TL;DR: In this article, the TOPSIS method was used to analyze and rank EPC critical activities across large-scale residential construction projects in Iran, by using the multi-attribute group decision-making technique.
Abstract: The Construction Industry is a complex and fragmented industry worldwide with regards to its supply chain, products, and processes, and is faced with a similar dilemma as faced by manufacturers during its time in past decades. Scope, time, and cost are the triple constraints of project management and leading factors in defining the project performance. Productivity and efficiency of each construction project is measured through its triple constraints, therefore the factors that affect project success are significantly important. Despite the importance of understanding project performance indicators, few empirical studies have been conducted over the last decade in terms of analyzing the factors that determine the performance of high-rise buildings in Engineering, Procurement, and Construction (EPC) projects. Hence, the aim of this paper is to analyze and rank EPC critical activities across large-scale residential construction projects in Iran, by using the TOPSIS method as a multi-attribute group decision-making technique. Results indicate that engineering design, project planning and controls are significant factors contributing to the project performance. In addition, engineering has a pivotal role in project performance and this significance is followed by the construction phase. On the contrary, all believe procurement is more important than Construction phase.
50 citations
TL;DR: This study has identified the top productive and influential researchers, research institutes, regions/countries, subject categories and journals in the BIM field and distinguished 11 clusters of global BIM research into 3 stages, namely formulating stage, accelerating stage and transforming stage.
Abstract: In the recent decade, Building Information Modeling (BIM) has widely been adopted in the Architectural, Engineering and Construction (AEC) industry and completely upended the way we build While BIM continues gain momentum in the industry, it has also attracted increasing attention from researchers However, most of the current study focuses on reviewing BIM for management, BIM for green building, BIM for infrastructure and BIM for Facilities Management (FM) There are few studies about Global BIM review and to discuss their complex inter-connections In this study, we adopted a scientometric analysis method to review global BIM research during 2004–2019 In total, 1455 scholarly bibliographic records obtained from Web of Science Core Collection database were established for the analysis This study has identified the top productive and influential researchers, research institutes, regions/countries, subject categories and journals in the BIM field In addition, 11 clusters of global BIM research were also identified including construction project, green BIM, construction safety planning, automated IFC-based workflow and so on The authors distinguished 11 clusters of global BIM research into three stages, namely formulating stage, accelerating stage and transforming stage Furthermore, the authors reviewed the BIM policy of Singapore and observed there is a co-production relationship between evolution of BIM policy and global BIM research These findings provide valuable information for researchers, practitioners and policymakers by visualizing the current progress in the research field of BIM and highlighting future research needs
TL;DR: How the actual restraint condition can affect the vibration parameters of a given glass member turns out in possible variations of its overall structural performance, including stress-strain-related effects, hence suggesting the need for even further dedicated studies and methods for the reliable analysis and design of structural glass assemblies and complex systems under dynamic loads.
Abstract: Given a series of intrinsic features of structural glass systems (i.e., material properties, type of restraints, operational conditions, etc.), special care should be spent at the design stage, to ensure appropriate fail-safe requirements, but also in the service life of these innovative building components and assemblies. In this paper, the dynamic characterization of simple monolithic glass elements is presented, based on non-destructive laboratory experiments and Operational Modal Analysis (OMA) techniques, including Finite Element (FE) numerical simulations, classical analytical models, and video-tracking approaches. It is shown, in particular, how the actual restraint condition (i.e., flexibility of supports, with respect to ideal boundaries) can affect the vibration parameters of a given glass member (frequency and damping capacity). This turns out in possible variations of its overall structural performance, including stress-strain-related effects, hence suggesting the need for even further dedicated studies and methods for the reliable analysis and design of structural glass assemblies and complex systems under dynamic loads.
TL;DR: In this paper, the authors present a comprehensive review of the most relevant vulnerability assessment methods applicable at different scales, as well as the most significant traditional and innovative seismic retrofitting solutions for existing masonry buildings.
Abstract: The growing concern about the protection of built heritage and the sustainability of urban areas has driven the reoccupation of existing masonry buildings, which, in the great majority of the cases, were not designed or constructed to withstand significant seismic forces. This fact, associated with territorial occupation often concentrated in areas with high seismic hazard, makes it essential to look at these buildings from the point of view of the assessment of their seismic vulnerability and retrofitting needs. However, to be effective and efficient, such an assessment must be founded on a solid knowledge of the existing methods and tools, as well as on the criteria that should underlie the selection of the most appropriate to use in each context and situation. Aimed at contributing to systematise that knowledge, this paper presents a comprehensive review of the most relevant vulnerability assessment methods applicable at different scales, as well as the most significant traditional and innovative seismic retrofitting solutions for existing masonry buildings.
TL;DR: In this paper, the authors evaluated the critical success factors (CSFs) for e-Procurement adoption in the Nigerian construction industry, and classified them into management support for physical infrastructure, and human factors and characteristics of the technology.
Abstract: Previous research works on the integration of e-Procurement technologies in the construction process in Nigeria showed that it has been slow and low. However, there are few empirical studies on the duration for which it has permeated the construction industry, the actual proponents and the metrics that can engender successful integration of e-Procurement technologies, applications, and tools in the construction procurement process, especially in a developing country like Nigeria. The study was aimed at evaluating the critical success factors (CSFs) for e-Procurement adoption in the Nigerian construction industry. The study was carried out in the six geo-political zones in Nigeria using a survey research design. Construction stakeholders were selected using purposive and random sampling techniques. A total of 1092 questionnaires were retrieved in this study, but the data of 759 actual users of e-Procurement systems were analyzed in this study using descriptive statistics and principal component analysis (PCA). An assessment of the duration users have been participating in the e-Procurement environment revealed that most Quantity Surveyors have been exposed to the use of e-Procurement technologies for over 10 years. A large proportion of the construction stakeholders picked up the use of the technology within the last 5 years. Further analysis showed that contracting firms have the largest participation in the use of e-Procurement systems. The study also revealed that construction stakeholders perceived the availability of reliable, affordable, and fast Internet services as the most critical success factor for the adoption of e-Procurement technologies. The critical success factors (CSFs) were further classified into management support for physical infrastructure, and human factors and characteristics of the technology. The study showed that these critical success factors (CSFs) are crucial for the adoption of e-Procurement systems in the Nigerian construction industry. The study recommended that there is still a need for increased awareness of the e-Procurement tools and technologies and the benefits that are accrued from their use among public sector construction participants. This will in turn influence the provision of the required information and communication technology (ICT) physical infrastructure and formulation of appropriate policies and standards for successful e-Procurement integration in the Nigerian construction industry.
TL;DR: The purpose of this paper is to compare and review the recent tools able to assess the hospital built environment and test how they measure health, sustainability, or both through Post Occupancy Evaluation (POE).
Abstract: Hospitals are complex, high-performance systems that demand continuous quality improvement. Several instruments evaluate the organizational or clinical qualities but very few focus on the built environment. The purpose of this paper is to compare and review the recent tools able to assess the hospital built environment and test how they measure health, sustainability, or both through Post Occupancy Evaluation (POE). A literature review has been conducted in the field of hospital quality assessment and 13 POE instruments have been included and analyzed through Ulrich’s Evidence-Based Design (EBD) framework. The percentage and the content of health or sustainability-related criteria have been compared and further discussed. Health related criteria the most recent tools are used three times more than in the tools developed in the nineties. The most used EBD criteria are safety enhancement (n = 131; 14%) and visual environment (n = 119; 13%). Although sustainability remains a relevant issue, today, growing attention is dedicated to the impact of built environment on occupant’s health. Further investigation is needed to understand the effectiveness of those instruments in practice.
TL;DR: The study aims at integrating BIM based approaches in a PSS context for the improvement of the management of maintenance operations of building equipment, and highlighted the benefits that can be achieved, especially in terms of reduced periods of equipment unavailability, reduced costs and augmented customer satisfaction.
Abstract: The service-centered economy has grown considerably in the last few years, shifting from product-based solutions towards service centered offerings, i.e., Product-Service System (PSS) solutions. Such an approach is also emerging in the context of building equipment, where maintenance activities play a fundamental role in facility management. In this field, Building Information Modeling (BIM) based tools are diffusely used to improve the performances of facility management. However, few studies have addressed the above issues while considering a shift from product-based approaches in favor of more advanced servitization models. The study aims at integrating BIM based approaches in a PSS context for the improvement of the management of maintenance operations of building equipment. A general framework for maintenance management has been developed, merging the implementation of the PSS components in a BIM model for the definition of maintenance management. A first application of this methodology to a real case study concerning the elevators of an existing building has shown the efficacy of the proposed approach. The study highlighted the benefits that can be achieved, especially in terms of reduced periods of equipment unavailability, reduced costs and augmented customer satisfaction, while enhancing the information exchange between the PSS actors. Hence, although further research is still needed for its validation, the proposed approach can offer practical insights for the development of promising BIM-based PSS solutions for facility management in the construction industry.
TL;DR: In this article, the authors used a survey to explore current user behaviour in residential buildings' energy performance in the city of Jeddah, KSA, and found that several factors impact the energy performance of residential buildings.
Abstract: In the Kingdom of Saudi Arabia (KSA), residential buildings' energy consumption accounts for almost 50% of the building stock electricity consumption. The KSA's economy relies heavily on fossil fuel sources, namely oil reservoirs, whose depletion will negatively affect the future development of the country. The total electricity consumption is growing by approximately 5-8% annually, which would lead to oil production and oil consumption being equal in 2035. Therefore, residential buildings need further assessment as regards their current energy consumption. This research used a survey to explore current user behaviour in residential buildings' energy performance in the city of Jeddah, KSA. The findings of the survey show that several factors impact the energy performance in residential buildings. First, the buildings' thermal properties were found to be poorly designed. Second, the cultural aspects (family member role and generous hospitality), and the majority of users within the buildings preferring a room temperature of below 24 • C, requires a massive amount of cooling due to the climate conditions. Third, an increase in user awareness has helped to slightly improve residential buildings' energy efficiency. Knowing the current high-energy-consumption sources and causes, being able to define opportunities for thermal properties' enhancement, and increasing user awareness of how to achieve self-sustaining buildings are essential.
TL;DR: In this paper, the authors identified the top five most used construction materials (cement, sand, coarse aggregates, hollow concrete blocks, and reinforcement bars), which are also prime sources of waste generation during construction in the Ethiopian building construction sector.
Abstract: Buildings use a wide range of construction materials, and the manufacturing of each material consumes energy and emits CO2. Several studies have already been conducted to evaluate the embodied energy and the related CO2 emissions of building materials, which are mainly based on case studies from developed countries. There is a considerable gap in cases of developing countries regarding assessment of embodied energy and CO2 emissions of these building materials. This study identified the top five most used construction materials (cement, sand, coarse aggregates, hollow concrete blocks, and reinforcement bars), which are also prime sources of waste generation during construction in the Ethiopian building construction sector. Then, what followed was the evaluation of the embodied energies and CO2 emissions of these materials by examining five commercial and public buildings within the cradle-to-site lifecycle boundary. The evaluation results demonstrated that cement, hollow concrete blocks (HCB), and reinforcement bars (rebars) are the major consumers of energy and major CO2 emitters. Cumulatively, they were responsible for 94% of the embodied energy and 98% of the CO2 emissions. The waste part of the construction materials has inflated the embodied energy and the subsequent CO2 emissions considerably. The study also recommended several strategies for the reduction of embodied energy and the related CO2 emissions. The research delivers critical insights into embodied energy and CO2 emissions of the five most used building materials in the Ethiopian construction industry, as there are no prior studies on this theme. This might be a cause to arouse awareness and interest among the policy makers and the wider public to clearly understand the importance of research on this crucial issue to develop national energy and CO2 descriptors for construction materials, in order to take care of our naturally endowed, but yet fragile, human habitat.
TL;DR: In this article, the effectiveness of slightly reinforced thin U-shaped cementitious mortar jacketing for the repair of damaged shear-critical reinforced concrete beams is experimentally investigated, and it is deduced that the shear strength and deformation capability of the jacketed beams were substantially increased compared to the corresponding capacities of the initial beams.
Abstract: The effectiveness of slightly reinforced thin U-shaped cementitious mortar jacketing for the repair of damaged shear-critical reinforced concrete beams is experimentally investigated. The test project includes two parts. In the first one, five concrete beams over-reinforced against flexure and under-reinforced against shear with different ratio of closed stirrups were initially subjected to monotonic loading until failure. The initially tested beams have been designed to fail in shear after wide diagonal cracking and to exhibit various strength and deformation capacities along with different levels of damages. In the second experimental part, the heavily damaged beams were jacketed with mild steel small diameter U-shaped transverse stirrups and longitudinal reinforcing bars. The retrofitted specimens using the proposed jacketing technique were tested again following the same four-point-bending load scheme. Based on the overall performance of the beams, it is deduced that the shear strength and deformation capability of the jacketed beams were substantially increased compared to the corresponding capacities of the initial beams. Further, although all beams failed in a shear abrupt manner, the retrofitted ones exhibited reduced brittleness and higher deflections at failure up to six times with respect to the initially tested specimens. The level of the initial damage influences the efficiency of the jacketing. Additional test data derived from relative shear-damaged beam specimens and retrofitted with similar thin jackets is also presented herein in order to establish the effectiveness of this repair system and to clarify the parameters affecting its structural reliability. Comparisons indicated that jacketed beams can alter the failure mode from brittle shear to ductile flexural under certain circumstances.
TL;DR: In this article, the authors investigated and proposed a practical solution for the utilisation of the world's excess biosolids in fired-clay bricks, and found that using only 15% of the leftover left overs in brick production would reduce the carbon footprint of brick manufacturing whilst satisfying all the environmental and engineering requirements for bricks.
Abstract: Millions of tonnes of leftover biosolids are increasingly stockpiled every year around the globe. Biosolids are a product of the wastewater sludge treatment process. Stockpiles necessitate the use of large areas of increasingly valuable land. Biosolids have many beneficial uses and are currently utilised in agricultural and land rehabilitation applications. However, it is estimated that 30% of biosolids are unused and stockpiled. A second and seemingly unrelated environmental issue is the massive excavation of virgin soil for brick production. The annual production of 1500 billion bricks globally requires over 3.13 billion cubic metres of clay soil—equivalent to over 1000 soccer fields dug 440 m deep or to a depth greater than three times the height of the Sydney Harbour Bridge. This paper investigates and proposes a practical solution for the utilisation of the world’s excess biosolids in fired–clay bricks. The physical, chemical and mechanical properties of fired–clay bricks incorporating 25%, 20%, 15% and 10% biosolids have been tested. Bricks were produced from three different biosolids samples collected at Melbourne’s Eastern Treatment Plant (ETP 22) and the Western Treatment Plant (WTP 10 & WTP 17–29). Compressive strength testing indicated results ranging between 35.5 MPa and 12.04 MPa for the biosolids-amended bricks. Leachate analysis was conducted on the bricks before and after firing, and the results demonstrate that between 43 and 99% of the heavy metals tested were immobilised inside the fired bricks compared to the heavy metals tested in the raw mixture. All leachate concentrations were found to be insignificant for the biosolids-incorporated bricks tested in this study. Biosolids can have significantly different chemical characteristics depending on the origin of the wastewater and the treatment procedure. Suitable leachate analysis should be undertaken on biosolids and test bricks before large-scale production is approved. Scanning Electron Microscopy (SEM) images illustrate that biosolids-amended bricks have a higher porosity than the control bricks, which corresponds to the lower thermal conductivity values recorded for biosolids-amended bricks. In addition, brick firing energy demands are estimated to decrease by up to 48.6% for bricks incorporating 25% WTP 17–29 biosolids due to the higher organic content of the mixture containing biosolids. The emissions study and comparative Life Cycle Assessment results show that the incorporation of biosolids into bricks is a positive and sustainable alternative approach with respect to all environmental impacts arising from the stockpiling of biosolids and brick manufacturing. Based on the results found in this comprehensive study, this paper proposes the inclusion of a minimum of 15% biosolids content into 15% of brick production in order to completely recycle all the approximately 5 million tonnes of annual leftover biosolids production in Australia, New Zealand, the EU, the USA and Canada. This is a practical and sustainable proposal for recycling all the leftover biosolids worldwide. Utilisation of only 15% of biosolids in brick production would reduce the carbon footprint of brick manufacturing whilst satisfying all the environmental and engineering requirements for bricks.
TL;DR: In this paper, the authors investigated the main causes of time and cost overrun in Saudi Arabian oil and gas construction projects and found that five major causes were found to be changing of design and scope by client during construction, poor planning and scheduling of project, design errors, inadequate comprehension of scope of work at the bidding stage, and underestimating of cost and schedules/overestimating of benefits.
Abstract: Many construction projects exceed time and budget. The Saudi Arabian construction projects are not an exception to this phenomenon. However, the causes of time and cost overrun of Saudi Arabian oil and gas construction projects have never been studied. Thus, this paper endeavors to investigate the main causes of time and cost overrun in Saudi Arabian oil and gas construction projects. Thirty-eight causes of time and cost overrun were identified through the literature and an interview. Responses from 48 professionals based in the Eastern Province of Saudi Arabia were obtained. The respondents were solicited to evaluate the significance of the causes, which were then ranked and a test of agreement was conducted. All survey participants agreed that the five major causes of time and cost overrun, combined, were found to be “changing of design and scope by client during construction”, “poor planning and scheduling of project”, “design errors”, “Inadequate comprehension of scope of work at the bidding stage”, and “underestimating of cost and schedules/overestimating of benefits”. On the other hand, the major cause of time overrun was found to be “changing of design and scope by client during construction”. Finally, the major cause of cost overrun was found to be “underestimating of cost and schedules/overestimating of benefits”, respectively. The findings of this study will be beneficial to project stakeholders who must operate in an industry that is highly sensitive. The findings will also facilitate organizations planning to conduct construction projects in the Saudi Arabian oil and gas industry.
TL;DR: In this article, a hygrothermal monitoring study was devised to track moisture performance of U.S. made cross laminated timber (CLT) and glulam at a three-story mass timber building.
Abstract: There are currently no standards regulating water management for mass timber elements during construction, little knowledge of impacts of moisture exposure (wetting and drying performance, dimensional stability, checking), and few precedents serving as guidelines for monitoring moisture response of mass timber. To address these gaps, a hygrothermal monitoring study was devised to track moisture performance of U.S. made cross laminated timber (CLT) and glulam at a three-story mass timber building. This paper discusses moisture measurements that were collected during the first six months of construction at a CLT rocking shear wall and a timber floor connection. Despite the limited number of structural systems monitored during construction, the distribution and number of sensors in these elements allow to draw some important conclusions. The data confirmed that moisture distribution and wetting/drying rates varied based on local conditions and details (aspect, coatings, connections, etc.), with measurements at an uncoated, north-facing area showing the highest moisture levels (reaching fiber saturation at multiple ply depths and locations). Most locations rarely exceeded 16% moisture content for more than a few months. Certain moisture-trapping details consistently showed higher moisture levels (i.e., above 16%) and poorer drying. Some interior plies continued to show slow increases in MC even after months of drying conditions. These observations suggest preventative approaches implementable in the design (e.g., avoiding moisture trapping details), during fabrication (e.g., localized coating), and construction (e.g., sequencing installation to minimize exposure and allow drying).
TL;DR: In this article, the authors investigated the factors influencing designers in the choice of a building roof system, comparing a traditional solution and a greening system, and identified their priority, and through a sustainability-based multicriteria analysis, the role played by each one in the decision process.
Abstract: A wide diffusion of green envelopes in cities can be an opportunity to improve urban environment conditions and reduce negative effects of climate change. The green roof system is a widespread solution adopted all over the world due to the relative simplicity of installation and the large private and social benefits provided. Despite this, some factors hinder the diffusion of the green roof system, not only economic factors (due to the higher installation costs compare to a traditional roof solution), but also technical factors connected to lack of knowledge. The present paper investigates the factors influencing designers in the choice of a building roof systems, comparing a traditional solution and a greening system. The involvement of architects, engineers, and researchers allows the selection of the most important factors. Results of the study identifies their priority, and through a sustainability-based multicriteria analysis, the role played by each one in the decision process. This approach provides interesting hints to identify effective strategies to support a wider diffusion of greening systems for urban resilience.
TL;DR: In this article, the authors investigated the relationship between human factors and safety management issues following a bottom-up approach and developed an easy-to-use procedure that can be used to better address workers' safety needs augmenting the company's safety climate and supporting safety management issue.
Abstract: Occupational safety in the construction industry still represents a relevant problem at a global level. In fact, the complexity of working activities in this sector requires a comprehensive approach that goes beyond normative compliance to guarantee safer working conditions. In particular, empirical research on the factors influencing the unsafe behavior of workers needs to be augmented. Thus, the relationship between human factors and safety management issues following a bottom-up approach was investigated. In particular, an easy-to-use procedure that can be used to better address workers’ safety needs augmenting the company’s safety climate and supporting safety management issues was developed. Such an approach, based on the assessment of human reliability factors, was verified in a real case study concerning the users of concrete mixer trucks. The results showed that the majority of human failures were action and retrieval errors, underlining the importance of theoretical and practical training programs as a means to improve safety behavior. In such a context, information and communication activities also resulted beneficially to augment the company’s safety climate. The proposed approach, despite its qualitative nature, allows a clearer understanding of workers’ perceptions of hazards and their risk-taking behavior, providing practical cues to monitor and improve the behavioral aspects of safety climate. Hence, these first results can contribute to augmenting safety knowledge in the construction industry, providing a basis for further investigations on the causalities related to human performances, which are considered a key element in the prevention of accidents.
TL;DR: The proposed photogrammetric Multi-View Stereo method has extensively improved the accuracy of generated points cloud compared to the SFM/CMVS/PMVS algorithm and may present a novel and robust tool for automated progress monitoring in construction projects.
Abstract: This research presents a novel method for automated construction progress monitoring. Using the proposed method, an accurate and complete 3D point cloud is generated for automatic outdoor and indoor progress monitoring throughout the project duration. In this method, Structured-from-Motion (SFM) and Multi-View-Stereo (MVS) algorithms coupled with photogrammetric principles for the coded targets’ detection are exploited to generate as-built 3D point clouds. The coded targets are utilized to automatically resolve the scale and increase the accuracy of the point cloud generated using SFM and MVS methods. Having generated the point cloud, the CAD model is generated from the as-built point cloud and compared with the as-planned model. Finally, the quantity of the performed work is determined in two real case study projects. The proposed method is compared to the Structured-from-Motion (SFM)/Clustering Multi-Views Stereo (CMVS)/Patch-based Multi-View Stereo (PMVS) algorithm, as a common method for generating 3D point cloud models. The proposed photogrammetric Multi-View Stereo method reveals an accuracy of around 99 percent and the generated noises are less compared to the SFM/CMVS/PMVS algorithm. It is observed that the proposed method has extensively improved the accuracy of generated points cloud compared to the SFM/CMVS/PMVS algorithm. It is believed that the proposed method may present a novel and robust tool for automated progress monitoring in construction projects.
TL;DR: The aim of this paper was to briefly describe the recently used non-destructive and semi-destructives testing methods and the parameters useful for characterizing the adhesion between overlays and substrates in concrete floors, as well as the methods useful to characterize the functional properties of the overlays.
Abstract: Non-destructive testing (NDT) and semi-destructive testing (SDT) have recently been more frequently used for the evaluation and condition assessment of concrete floors in various types of buildings. The subject of the article is to briefly introduce the reader to the problem of adhesion between overlays and substrates in concrete floors and to illustrate the current state of knowledge on the subject. The aim of this paper was to briefly describe the recently used non-destructive and semi-destructive testing methods and the parameters useful for characterizing the adhesion between overlays and substrates in concrete floors, as well as the methods useful to characterize the functional properties of the overlays. A recent literature survey, related to the adhesion between the overlays and substrates in concrete floors, is thus shown. Special emphasis was placed on the critical review of the current research results. Based on the analysis of the literature review, research gaps have been presented in order to highlight future research directions.
TL;DR: In this article, the effect of different ventilation and airing strategies on both indoor air quality and energy consumptions in high energy-demanding naturally-ventilated classrooms was evaluated by means of experimental analyses and simulations through CO2 mass balance equation during the heating season.
Abstract: Most of the school buildings in Italy are high energy-demanding buildings with no ad-hoc ventilation systems (i.e., naturally-ventilated buildings). Therefore, reducing the heat losses of schools represent the main aspect to be dealt with. Nonetheless, the indoor air quality of the building should be simultaneously considered. Indeed, to date, energy consumptions and air quality are considered as incompatible aspects especially in naturally-ventilated buildings. The aim of the present paper is to evaluate the effect of different ventilation and airing strategies on both indoor air quality and energy consumptions in high energy-demanding naturally-ventilated classrooms. To this purpose, an Italian test-classroom, characterized in terms of air permeability and thermophysical parameters of the envelope, was investigated by means of experimental analyses and simulations through CO2 mass balance equation during the heating season. The air quality was assessed in terms of indoor CO2 concentrations whereas the energy consumptions were evaluated through the asset rating approach. Results clearly report that not adequate indoor CO2 concentrations are measured in the classroom for free-running ventilation scenarios even in low densely populated conditions (2.2 m2 person−1), whereas scheduled airing procedures can reduce the indoor CO2 levels at the cost of higher energy need for ventilation. In particular, when airing periods leading to the air exchange rate required by standards are adopted, the CO2 concentration can decrease to values lower than 1000 ppm, but the ventilation losses increase up to 36% of the overall energy need for space heating of the classroom. On the contrary, when the same air exchange rate is applied through mechanical ventilation systems equipped with heat recovery units, the ventilation energy loss contribution decreases to 5% and the overall energy saving results higher than 30%. Such energy-saving was found even higher for occupancy scenarios characterized by more densely populated conditions of the classroom typically occurring in Italian classrooms.
TL;DR: In this paper, the authors evaluated the impacts of hourly microclimate data in typical and extreme climate conditions on the energy performance of an office building in two different urban areas and found that the urban morphology can reduce the wind speed by 27% and amplify air temperature by more than 14%.
Abstract: Urbanization trends have changed the morphology of cities in the past decades. Complex urban areas with wide variations in built density, layout typology, and architectural form have resulted in more complicated microclimate conditions. Microclimate conditions affect the energy performance of buildings and bioclimatic design strategies as well as a high number of engineering applications. However, commercial energy simulation engines that utilize widely-available mesoscale weather data tend to underestimate these impacts. These weather files, which represent typical weather conditions at a location, are mostly based on long-term metrological observations and fail to consider extreme conditions in their calculation. This paper aims to evaluate the impacts of hourly microclimate data in typical and extreme climate conditions on the energy performance of an office building in two different urban areas. Results showed that the urban morphology can reduce the wind speed by 27% and amplify air temperature by more than 14%. Using microclimate data, the calculated outside surface temperature, operating temperature and total energy demand of buildings were notably different to those obtained using typical regional climate model (RCM)–climate data or available weather files (Typical Meteorological Year or TMY), i.e., by 61%, 7%, and 21%, respectively. The difference in the hourly peak demand during extreme weather conditions was around 13%. The impact of urban density and the final height of buildings on the results are discussed at the end of the paper.
TL;DR: In this paper, the authors investigated the challenges and enablers of utilizing an end-to-end BIM strategy for digital transformation of mega project delivery processes through a mega airport project case study, in order to contribute a solid strategic understanding in BIM implementation for mega infrastructure projects.
Abstract: The Architecture Engineering and Construction (AEC) sector has been working on an increasing number of mega projects having large scale investments worldwide. The majority of these mega projects are infrastructure projects that are comparatively more difficult to manage in terms of yielding an expected return of investments while increasing quality and productivity. Today’s construction technology landscape offers a wide variety of innovative digital solutions for optimizing the project constraints of scope, time, cost, quality, and resources. Despite being one of the least digitized sectors, the AEC sector is currently ripe for adopting innovative digital solutions. It is observed that Building Information Modeling (BIM) has been rapidly adopted to tackle the ever-evolving challenges of mega infrastructure projects. This study investigates the challenges and enablers of utilizing an end-to-end BIM strategy for digital transformation of mega project delivery processes through a mega airport project case study, in order to contribute a solid strategic understanding in BIM implementation for mega infrastructure projects. The case study is followed with two-phased semi-structured interviews. Based on the findings, major challenges are sustaining continuous monitoring and controlling in the project execution, engineering complexity and aligning stakeholders’ BIM learning curves whereas strategic control mechanisms, incentivizing the virtual collaborative environment, and continuous digital delivery are major enablers.
TL;DR: An ontology of IM for IM for adaptive reuse projects is defined based on the current barriers to adaptive reuse and the most common interface problems in construction projects, and suggestions on interface management systems (IMS) implementation are made.
Abstract: Adaptive reuse of buildings is considered a superior alternative for new construction in terms of sustainability and a disruptive practice in the current capital project delivery model for the renewal of today’s built environment. In comparison to green-field construction projects, adaptive reuse projects require distinct stages, definition of interfaces, decision gates, and planning methods in order to secure the success of the building project. Unfortunately, little research has been done regarding establishing feasible systems for the planning, assessment, and management of adaptive reuse projects, leading to underperforming building projects outcomes. Interface management (IM) can improve renovation projects outcomes by defining appropriate ways to identify, record, monitor, and track project interfaces. IM has the potential of bringing cost and time benefits during adaptive reuse projects execution. The aim of this study is to develop a reference framework for implementing IM for adaptive reuse projects. First, the inefficiencies of redevelopment projects are explained inside of a circular economy (CE) context. Second, an ontology of IM for adaptive reuse projects is defined based on the current barriers to adaptive reuse and the most common interface problems in construction projects. Third, the defined ontology is expanded through a case study by showing examples of adaptive reuse barriers on a case project, and how IM could have been part of the solution for these problems. Finally, this study concludes with the suggestions on interface management systems (IMS) implementation for future adaptive reuse projects.