A Holographic Future: Comparing an AR headset to traditional construction methods

<p>New Zealand’s construction industry has seen a profound uptake in the use of Building Information Modelling (BIM) in recent years. BIM has proven to be beneficial to individuals during moments of the lifecycle of a building, but it has yet to play a significant role in the actual construction stage of a project. In recent years, researchers have become increasingly interested in the use of Augmented Reality (AR) to provide support for BIM implementation and productivity on-site. However, current research has yet to prove the effectiveness of integrating the information from the BIM model into an AR environment. With international AR applications emerging and the improvement on AR and BIM software, it has now become feasible to test the integration of these two technologies dynamically. This paper utilises recent developments in technology to provide a comparison of the effectiveness of information retrieval methods. A three-phase, mixed method experiment was conducted and evaluated over a one-year time frame in Wellington, New Zealand. By using a mixed method approach, the research gained multiple forms of data drawing on all possibilities. One phase involved a focus group with a variety of construction industry professionals exploring the use of BIM and how their teams work together to solve problems and tasks on-site. The second phase had twenty-four construction industry tradesmen randomly assigned to three control groups to complete clash detection tasks using different visualisation mediums. The control groups used either two-dimensional paper drawings, a BIM model on a laptop, or a BIM model in a Microsoft HoloLens to complete the information retrieval tasks. Following the task-based experiment, the control groups participated in a focus group to understand tradesmen’s perceptions of the different visualisation mediums and how current processes could be improved for their understanding. Each group was assessed on a usability framework model of effectiveness, efficiency and satisfaction. Based on the results of the experiments and focus groups, this research can produce evidence for determining the most effective methods for information retrieval and clash detection on-site. Can AR provide a more powerful system for construction productivity and information retrieval than paper or computer-based systems? The research does not provide a detailed solution but instead demonstrates the potential marriage between AR and BIM technologies to help evolve future building processes.</p>

A Holographic Future: Comparing an AR headset to traditional construction methods

<p>New Zealand’s construction industry has seen a profound uptake in the use of Building Information Modelling (BIM) in recent years. BIM has proven to be beneficial to individuals during moments of the lifecycle of a building, but it has yet to play a significant role in the actual construction stage of a project. In recent years, researchers have become increasingly interested in the use of Augmented Reality (AR) to provide support for BIM implementation and productivity on-site. However, current research has yet to prove the effectiveness of integrating the information from the BIM model into an AR environment. With international AR applications emerging and the improvement on AR and BIM software, it has now become feasible to test the integration of these two technologies dynamically. This paper utilises recent developments in technology to provide a comparison of the effectiveness of information retrieval methods. A three-phase, mixed method experiment was conducted and evaluated over a one-year time frame in Wellington, New Zealand. By using a mixed method approach, the research gained multiple forms of data drawing on all possibilities. One phase involved a focus group with a variety of construction industry professionals exploring the use of BIM and how their teams work together to solve problems and tasks on-site. The second phase had twenty-four construction industry tradesmen randomly assigned to three control groups to complete clash detection tasks using different visualisation mediums. The control groups used either two-dimensional paper drawings, a BIM model on a laptop, or a BIM model in a Microsoft HoloLens to complete the information retrieval tasks. Following the task-based experiment, the control groups participated in a focus group to understand tradesmen’s perceptions of the different visualisation mediums and how current processes could be improved for their understanding. Each group was assessed on a usability framework model of effectiveness, efficiency and satisfaction. Based on the results of the experiments and focus groups, this research can produce evidence for determining the most effective methods for information retrieval and clash detection on-site. Can AR provide a more powerful system for construction productivity and information retrieval than paper or computer-based systems? The research does not provide a detailed solution but instead demonstrates the potential marriage between AR and BIM technologies to help evolve future building processes.</p>

Productivity Metrics and Its Implementations in Construction Projects: A Case Study of Singapore

Although some studies have used or developed different types of metrics to assess construction productivity in the existing literature, few of them investigated those metrics systematically and the differences between assessment results. This study examined the various types of metrics used in the assessment of the productivity of construction projects. First, a literature review was conducted first to identify prevailing productivity metrics at four levels, namely trade, project, company, and industry. Then, the questionnaire was developed and disseminated to 53 Singapore-based construction companies for data collection. Subsequently, non-parametric statistical tests were conducted to analyze the data collected by the questionnaire. Results showed that the top five metrics in terms of usage frequency and relative importance were “constructability score”, “buildable design score”, “square meter of built-up floor area per man-day”, “square meter per dollar”, and “output per worker.” In addition, results showed that differences existed in the assessment results when productivity metrics at different levels were used to conduct the same measurement. This is the first study to explore the most widely used metrics in productivity assessments of construction projects and investigate possible differences in assessment results. This study could help the authorities to review, evaluate, and modify the productivity metrics used in practice. Thus, this study is beneficial to the practice as well.

Implementation of lean practices facilitated by BIM functionalities in the construction phase: advances and opportunities

Over the past few decades, construction productivity has been at a standstill. Lean and Building Information Modelling (BIM) is attracting increasing interest in the construction industry as a way to increase construction productivity. This paper aims to contribute to the body of knowledge by identifying hitherto unexplored opportunities for the use of BIM functionalities as a support and as facilitators of the application of lean practices in the construction phase. A systematic literature review was adopted as the methodological approach in this research, and reported case studies related to the scope of this paper were searched. The results show that lean practices can be classified into four degrees of BIM support based on the level of current exploration. Just one lean practice (the last planner system) has been extensively explored, three have been reasonably explored, and five have just been preliminarily explored. Five practices have not been explored at all. This research summarises the already studied and the potential additional uses of BIM functionalities to support each lean practice, showing that lean practices supported by BIM functionalities are still underused and that further studies can explore additional ways to support these practices. This study holds great value for a broader practical application of lean practices, bringing faster and easier results with more extensive BIM support.

Monitoring the Work Cycles of Earthmoving Excavators in Earthmoving Projects Using UAV Remote Sensing

Monitoring the work cycles of earthmoving excavators is an important aspect of construction productivity assessment. Currently, the most advanced method for the recognition of work cycles is the “Stretching-Bending” Sequential Pattern (SBSP), which is based on fixed-carrier video monitoring (FC-SBSP). However, the application of this method presupposes the availability of preconstructed installation carriers to act as a surveillance camera as well as installed and commissioned surveillance systems that work in tandem with them. Obviously, this method is difficult to apply to projects with no conditions for a monitoring camera installation or which have a short construction time. This highlights the potential application of Unmanned Aerial Vehicle (UAV) remote sensing, which is flexible and mobile. Unfortunately, few studies have been conducted on the application of UAV remote sensing for the work cycle monitoring of earthmoving excavators. This research is necessary because the use of UAV remote sensing for monitoring the work cycles of earthmoving excavators can improve construction productivity and save time and costs, especially in post-disaster reconstruction projects involving harsh construction environments, and emergency projects with short construction periods. In addition, the challenges posed by UAV shaking may have to be taken into account when using the SBSP for UAV remote sensing. To this end, this study used application experiments in which stabilization processing of UAV video data was performed for UAV shaking. The application experimental results show that the work cycle performance of UAV remote-sensing-based SBSP (UAV-SBSP) for UAV video data was 2.45% and 5.36% lower in terms of precision and recall, respectively, without stabilization processing than after stabilization processing. Comparative experiments were also designed to investigate the applicability of the SBSP oriented toward UAV remote sensing. Comparative experimental results show that the same level of performance was obtained for the recognition of work cycles with the UAV-SBSP as compared with the FC-SBSP, demonstrating the good applicability of this method. Therefore, the results of this study show that UAV remote sensing enables effective monitoring of earthmoving excavator work cycles in construction sites where monitoring cameras are not available for installation, and it can be used as an alternative technology to fixed-carrier video monitoring for onsite proximity monitoring.

Effects of weather conditions on concrete work task productivity – a questionnaire survey

Purpose This paper aims to study the effects of different weather conditions on typical concrete work tasks’ productivity. Weather is one important factor that has a negative impact on construction productivity. Knowledge about how weather affects construction works is therefore important for the construction industry, e.g. during planning and execution of construction projects. Design/methodology/approach A questionnaire survey method is used involving means to perform pairwise comparisons of different weather factors according to the analytical hierarchical process (AHP). The survey also contains means to enable assessment of the loss in productivity for typical work tasks exposed to different weather types. The survey targets practitioners involved in Swedish concrete construction projects, and the results are compared with previous research findings. Findings The survey covers responses from 232 practitioners with long experience of concrete construction. The pairwise comparisons reveal that practitioners rank precipitation as the most important followed by wind and temperature. The loss in productivity varies significantly (from 0 to 100%) depending on the type of work and the type of weather factor considered. The results partly confirm findings reported in previous research but also reveal a more complex relationship between weather and productivity indicating several underlying influencing factors such as type of work, type of weather (e.g. rain or snow) and the intensity of each weather factor. Originality/value This paper presents new data about how 232 practitioners assess the effects of weather on construction productivity involving novel means to perform objective rankings such as the AHP methodology.

Subcontracting Strategy in Industrial Projects: Evidence from Saudi Arabia

Subcontracting is widely employed in the construction industry owing to the variation of methods, materials, magnitude, and function of the infrastructures. However, the rapport between parties in construction are mostly adversarial and plagued with hitches, which negatively impact construction productivity. This research investigates the problems associated with subcontracting strategies of contractors in industrial projects in the Eastern Province of Saudi Arabia via questionnaire survey. The questionnaire contains a list of thirty-three likely problems affecting subcontracting strategy of contractors organised under the three categories of planning, awarding, and contracting issues. The respondents matched the likely problems with the project value drivers (quality, cost, and time) with which they impact, and rated the magnitude of the problems on project performance. The survey identified incompatibility of the subcontractor/supplier’s time schedule with the project’s time schedule as the topmost problem related to planning issues. Unethical practices is ranked highest among problems related to awarding issues, while incompatibility of subcontracts’ terms and conditions with the main contract’s terms and conditions is rated top among the topmost problems related to contracting issues. The findings revealed that the three problem categories have negative impacts on all the project value drivers in different combinations and are almost equally significant in the view of contractors while making subcontracting decisions. Contractors are therefore advised to critically evaluate the schedule, cost, and quality performance of industrial projects during the planning, awarding, and contracting phase of subcontracting in industrial projects.

THE INFLUENCE OF CHANGES IN CONSTRUCTION PRODUCTIVITY: A STATE OF THE ART REVIEW

Multiple studies have found that productivity in Chilean construction has been stagnated during recent decades; thus, creating the need to understand better what factors have led to these results in the construction sector. In the international literature, studies have found that changes are the leading cause of productivity losses in construction projects; however, limited studies have been done in Chile in this regard. This context is understood as an opportunity to learn from the existing literature about the impact of changes in construction productivity, more importantly, such learning can contribute to the discussion of productivity improvement in the Chilean construction sector. This study recommends that more studies are necessary to be done in Chile regarding the impact of changes in construction projects. Namely, future studies should be based on an extensive database of projects so that generalization can be drawn for the construction industry. Additionally, the data collection process of changes in construction should be improved, paying specific attention to the size of changes, the timing of changes, and the scale of assessment—namely activity, project, and industry levels. Ultimately, this study aims to contribute to the discussion about productivity improvement in Chilean construction as this remains one of the main challenges in the industry

Improving Marine Concrete Performance Based on Multiple Criteria Using Early Portland Cement and Chemical Superplasticizer Admixture

This study sought to examine the performance design of concrete mix proportions to ensure chloride resistance and early strength with respect to C35 (35 MPa), which is the minimum compressive strength class of concrete used in a marine environment. For the proposed concrete mixture, C24 (24 MPa) was selected and binders for concrete were manufactured using a blend of OPC (ordinary Portland cement), EPC (early Portland cement), and GGBS (ground granulated blast-furnace slag). The results of the experiment confirmed that the combined use of EPC and GGBS greatly improve the early-strength development and chloride resistance of concrete. An analysis revealed that the time for removal of forms can be reduced by 5–9 h from the aspect of early concrete strength. Moreover, in terms of construction productivity, EPC and GGBS were reduced by up to 16.39 h/cycle compared to other concretes. Regarding economic and environmental impacts, EPC and GGBS were more effective than C35 concrete. This study is significant as its findings help make it possible to examine the most economical concrete mix design in relation to strength development according to the application of EPC, GGBS, and PC-based admixtures.