On-site Construction Activities Research Articles

Automated component delivery management under uncertainty for prefabricated buildings to minimize cost and harmful emissions

Effectively coordinating and managing onsite construction, offsite prefabrication, and component delivery activities in an ever-changing environment is crucial for prefabricated or modular construction. This study develops an automated component delivery management system to identify the optimal supplier portfolio and delivery strategy, balancing the trade-offs among time, costs, and carbon emissions before construction. The system incorporates onsite activity rescheduling and delivery re-planning strategies to manage progress uncertainty, thereby minimizing crash and overstock costs. It automatically extracts project design data from building information model (BIM) digital files, schedule data from scheduling programs, and logistic data from the Web Map Service. The outcomes generated are then fed back into BIM platforms for enhanced visualization. An illustrative example showcases the system's effectiveness, demonstrating its ability to support lean construction practices while offering economic and environmental advantages to stakeholders.

Construction Activity Analysis of Workers Based on Human Posture Estimation Information

Identifying workers’ construction activities or behaviors can enable managers to better monitor labor efficiency and construction progress. However, current activity analysis methods for construction workers rely solely on manual observations and recordings, which consumes considerable time and has high labor costs. Researchers have focused on monitoring on-site construction activities of workers. However, when multiple workers are working together, current research cannot accurately and automatically identify the construction activity. This research proposes a deep learning framework for the automated analysis of the construction activities of multiple workers. In this framework, multiple deep neural network models are designed and used to complete worker key point extraction, worker tracking, and worker construction activity analysis. The designed framework was tested at an actual construction site, and activity recognition for multiple workers was performed, indicating the feasibility of the framework for the automated monitoring of work efficiency.

Development of offsite construction skill profile prediction models using mixed-effect regression analysis

Offsite construction (OSC) transfers onsite construction activities to factory-based processes utilising technological advancements, resulting in new and emerging skills while causing some existing skills to be changed and others to be redundant. However, there are no established methods to systematically quantify these OSC skill requirements. This paper presents OSC skill prediction models while highlighting the process of model development for future research. The aim of these models is to predict skills using a comparable measure, manhours/m2. A skill classification with six skill categories was used to analyse OSC skills. Numerical model development methods were reviewed, and mixed-effect regression modelling was selected for model development. The skills data needed for regression modelling was collected using eight case studies. Predominantly panelised and modular OSC projects were used to collect skills data. The skill prediction models were validated using further case study data and an expert forum. Comparatively, modules OSC type requires higher skill quantities than panels, for all the six skill categories analysed. Onsite and offsite skill requirements vary for different OSC types. Additionally, complex, non-linear relationships were recognised between OSC types and the utilisation of their skills. This research presents unique OSC skill prediction models that can provide early-stage advice to policymakers, project planners and manufacturers on OSC skill requirements. It also provides a novel methodology to develop predictive models for specific industry scenarios that have non-linear and complex relationships.

Automated PPE-Tool pair check system for construction safety using smart IoT

Construction hand tools have been widely used in the construction industry. These tools have changed the building methods and improved the construction productivity significantly, but they have also been recognized as one of the hazardous factors leading to occupational diseases and workplace injuries if they are used without proper personal protective equipment (PPE). This paper aims to develop an automated PPE-Tool pair checking system using the internet of things (IoT) with wireless Wi-Fi modules tagged on the PPE. The distributed system warns the user and safety officer if the tool user does not wear the required PPE items. The sensors used in PPE contain photoresistors, optical sensors, force stretchable resistors, and touch sensors, which are embedded with near real time data processing algorithms for proper wearing detection. The wearing states are then transmitted wireless to an online website and updated real-time in a cloud database in a way that multiple users can get access and visit the states. Simultaneously, alerts with sound and vibration and emergency stops are also sent to the workers through the construction hand tools they hold. The proposed system in this paper has been implemented and tested in a lab experiment. The results show that the average time lag between actual non-wearing actions and corrective warning actions was 1.229 s, which is acceptable and the authors believe that the proposed system is efficient and effective to enhance the safety management of on-site construction activities with hand tools.

A model for investigating construction workers’ waste reduction behaviors

Construction workers’ waste reduction behaviors (CWWRBs) have been critical given that workers directly use building materials and carry out on-site construction activities. However, to date, the underlying causations of CWWRBs have not yet been well revealed. This paper thus aims to identify major factors affecting CWWRBs based on the Theory of Planned Behavior (TPB) and develop a simulation model to explore the causation of CWWRBs through a system dynamics (SD) approach. Based on simulation results of three typical groups of management measures, namely, reactive actions (RAs), prioritization (P) and preventive actions (PAs), it is found that overall RAs and P are more effective in improving CWWRBs, while the effect of RAs is the most significant. Besides, RAs would be more effective in the early period of construction processes while PAs more effective in the later period. This study not only, for the first time, presents a deeper explanation of causations of CWWRBs, but also provides a model through which construction waste management policies and measures can be simulated in advance to effectively improve CWWRBs.

Applications and requirements of unmanned aerial systems (UASs) for construction safety

The unmanned aerial system (UAS), as an emerging technology that can be used as a vehicle in a variety of settings, has the potential to strongly affect safety performance. UASs can move faster than humans into inaccessible, hard-to-reach, and unsafe areas of jobsites and can be equipped with various types of sensors to transfer valuable data to safety managers and assist with onsite safety monitoring. UASs can improve safety performance in general; however, little is known about safety managers’ perceptions regarding specific safety operations or hazardous situations that can be improved through UAS use. Prompted by the growing interest in industry and academia to better understand safety managers’ opinions on using UASs in various safety-related operations, a survey study was conducted to determine (1) the effectiveness and frequency of using UASs in improving safety operations or hazardous situations, (2) ideal UAS technical features, and (3) enablers and barriers for using UASs to monitor and control onsite construction activities. The results indicated that the most important safety activities that can be improved using UASs were monitoring boom vehicles or cranes in the proximity of overhead power lines, monitoring activities in the proximity of boom vehicles or cranes, and monitoring unprotected edges or openings. In terms of the UAS technical features required for safety inspection applications, the most important features were camera movability, sense-and-avoid capability, and a real-time video communications feed. Liability and legal concerns and safety challenges were rated as the most important barriers to using UASs for construction safety applications.

THE ECONOMIC RELEVANCE OF ON-SITE CONSTRUCTION ACTIVITIES WITH THE EXTERNAL THERMAL INSULATION COMPOSITE SYSTEM (ETICS)

The systematic inadequacies of the External Thermal Insulation Composite System (ETICS), which occur during the construction phase, increase the financial risk for stakeholders, while reducing the long-term durability of the facade. The economic effect of on-site shortcomings can be reduced if the most significant on-site activities are recognised. The current paper develops an economic relevance assessment model for on-site construction activities of ETICS to increase economic rationality of resource allocation and emphasise the high-risk systematic shortcomings. The economic assessment model quantifies the financial risk of the on-site degradation factors with the method of modified Failure Mode Effects Analysis (FMEA). The data collection is followed by experts’ judgments and is validated with the Delphi technique. The study reveals that degradation factors in the early phases of construction have the highest relevance due to high costs of repair as well as high occurrence possibility and higher detection difficulty due to rapid coverage. Ninety percent of the shortcomings appear during the first five years of completion of the construction. The on-site failures occurring during the application of mechanical anchors and finishing layer cause the lowest financial risk. The model enables the economic effect of the on-site activities to be prioritised for better resource allocation.

Construction Process Technical Impact Factors on Degradation of the External Thermal Insulation Composite System

The European climate strategy has encouraged the usage of the External Thermal Insulation Composite System (ETICS) to increase the energy efficiency of external building envelopes. This externally and relatively easily applicable façade solution must meet various technical requirements. This paper develops a technical severity evaluation model of on-site construction activities of ETICS to prioritize the risks of the construction process. The model can be used independently by any stakeholder of the construction process. The relevance of the activities is assessed with the Failure Mode Effects Analysis method. The model weights the impact of the essential technical requirements and simulates an integrated weighted technical severity value, which is derived from the analysis of experts’ judgments validated with the non-parametric Friedman’s test. The data collection for probability of occurrence and difficulty of detectability follows the Delphi technique to quantify the opinions of a group. The simulation, conducted on 103 degradation factors, shows that the on-site construction activities of ETICS strongly influence the decrease in the technical resilience of long-term durability, mechanical resistance, and stability, as well as the ability to bypass tensions. The highest risk is detected by the shortcomings in the layers of substrate, reinforcement, adhesive, and additional details.

New Connection Detail to Connect Precast Column to Cap Beam using Ultra-High-Performance Concrete in Accelerated Bridge Construction Applications

Accelerated bridge construction (ABC) is a paradigm change in delivery of bridges. ABC minimizes the traffic interruption, enhances safety to public and workers by significantly reducing on-site construction activities, and results in longer-lasting bridges. The use of precast elements is gaining attention owing to inherent benefits of accelerated construction. Designing an economical connection is one of the main concerns for these structures. New improved materials such as ultra-high-performance concrete (UHPC) with superior characteristics can provide solutions for joining precast concrete elements. In this paper two types of column to cap beam connection using UHPC are proposed for seismic and non-seismic regions. Among the merits of the proposed details, large tolerances in construction and simplicity of the connection can be highlighted which facilitates and accelerates the on-site construction time. The experimental program was carried out to evaluate the performance and structural behavior of the proposed connections. Four specimens were subjected to constant axial compressive loads and cyclic lateral loading. Results of the experiment showed that the displacement ductility of the specimens, incorporating suggested details, demonstrated adequate levels of displacement ductility. More importantly, the proposed connections prevented the damage into capacity protected element—in this case the cap beam. Analytical and nonlinear finite element analysis on the specimens was carried out to better comprehend the behavior of the proposed connections.

Labour productivity statistics: a reality check for the Norwegian construction industry

ABSTRACTConstruction is one of the largest sectors that drive the global economy, yet it has failed to receive the necessary attention from the policymakers and investors. The existing construction statistics report the declining state of labour productivity. However, existing statistics often fail to reflect the true scope and economic impact of construction. They mainly account for on-site construction activities, but overlook the manufacturing of construction products and services in construction labour productivity statistics. The aim of this research is to investigate macro-economic labour productivity and identify the methodological problems inhibiting the effective measurement of construction labour productivity. The paper opted for academic literature review and a case study strategy for data collection. The findings reveal that many productive construction activities related to construction products and services are excluded from the construction labour productivity statistics. The results suggest that Norwegian construction labour productivity is not declining and is actually a productive industry in terms of value added per working hour. Although special reference has been made to the Norwegian construction industry, the same approach holds validity at the international arena of construction statistics. The study offers insights and lessons to construction industries of other countries facing similar productivity related issues.

Household construction knowledge acquisition in post-disaster shelter training

The incorporation of safer building practices into shelter after disasters continues to plague recovery efforts. While limited resources are one potential cause, evidence from case studies suggests that poor adoption of safer construction may stem from a knowledge deficit. Despite these shortcomings, previous research has done little to examine the current state of construction education and training in post-disaster shelter and housing, and there is lacking evidence to support how households acquire new knowledge of construction practice. Examining nineteen shelter projects in the Philippines following Typhoon Haiyan, training methods were categorized using Kolb's experiential learning theory poles. Fuzzy-set qualitative comparative analysis (fsQCA) was then used to analyze the impact of these methods on community construction knowledge. Findings reveal that households acquired knowledge either through a combination of formal training methods that encompassed reflective observation, active experimentation, and concrete experiences or alternatively through observation of on-site construction activities.

Off-site construction optimization: Sequencing multiple job classes with time constraints

Off-site construction is a unique hybrid of manufacturing operations and on-site construction activities. Maximizing the production output has long been the main challenge for off-site manufacturers. Among other responses to this challenge, the use of multi-task shared resources has proved its effectiveness in improving tangible performance measures of production. However, multi-skilled resources often become bottlenecks (overloaded) when producing multiple classes of products and prevent the production network from meeting due dates. This paper analytically models the problem of defining the optimal product sequencing using optimization-based metaheuristics with the aim of minimizing changeover time, which is wasted switching from a product class to another. Production data of two Australian off-site manufacturers are used in the subsequent empirical analysis resulting in advancement of five research propositions. This research contributes to the scheduling theory by expanding the insight into dynamics of resource sharing and job sequencing. The developed models and propositions are of practical value for off-site manufacturers of building elements to maximize their production output.

A methodology for the optimal modularization of building design

Abstract The use of prefabricated modules has the potential to increase the efficiency of onsite construction activities, as well as the adaptability of buildings. However, such modules currently require a degree of repetitiveness to which many clients object. To resolve this conflict, a graph-based methodology is proposed that decomposes the design into non-repetitive modules that can be preassembled offsite, without restricting the design in advance. Such modules contain components that have similar future replacement rates, and a limited number of connections to other components. A clustering algorithm is applied on data from BIM tools for an optimal definition of the modules and their interfaces. A computer program is developed to allow the automated application of the methodology in large and complex projects. The research demonstrates that graph-based models can be useful for representing and analyzing construction projects. A graph-based approach has the potential to be successfully applied in additional areas, in order to provide project management tools.

A social life cycle assessment model for building construction in Hong Kong

Social life cycle assessment (S-LCA) is a relatively new technique that is under rapid development. To further improve the reliability of S-LCA, more case studies and methodologies are of paramount importance. This study aims to develop a S-LCA model for building construction projects in Hong Kong, namely, the Social-impact Model of Construction (SMoC). In this paper, a social life cycle impact assessment (sLCIA) method is developed and a case study of a building construction project in Hong Kong is performed. The development of SMoC is composed of three stages. Stage one strives to establish the sLCIA method which includes the characterization, normalization and weighting. In stage two, a questionnaire survey is conducted to collect the weighting factors and to unveil the social impacts of on-site construction practices. Based on that, the SMoC model which consists of a set of functional worksheets is built. In stage three, a case study following the four-phase structure of S-LCA suggested by the UNEP/SETAC guidelines is conducted. Of the selected subcategories, local experts believed that health and safety (worker) is the most important social aspect. The questionnaire survey also suggests that the environmental-friendly on-site construction activities as identified in this research are beneficial to the society in general. However, adoption of precast concrete components can lead to negative impacts on fair salary and local employment, since the precast concrete is normally produced outside Hong Kong. The case study demonstrates that the studied project has positive social impacts in general, while the construction stage performs better than the material stage. The sensitivity analysis indicates that inclusion of environmental-friendly construction practices can significantly improve the social performance of the studied building construction project. The developed SMoC model and the case study should provide a comprehensive framework of S-LCA for building construction in Hong Kong. Despite being the first attempt of S-LCA in Hong Kong, the results help inform the local industry the social performance of their construction projects from a life cycle perspective.

Crowdsourcing Construction Activity Analysis from Jobsite Video Streams

AbstractThe advent of affordable jobsite cameras is reshaping the way on-site construction activities are monitored. To facilitate the analysis of large collections of videos, research has focused on addressing the problem of manual workface assessment by recognizing worker and equipment activities using computer-vision algorithms. Despite the explosion of these methods, the ability to automatically recognize and understand worker and equipment activities from videos is still rather limited. The current algorithms require large-scale annotated workface assessment video data to learn models that can deal with the high degree of intraclass variability among activity categories. To address current limitations, this study proposes crowdsourcing the task of workface assessment from jobsite video streams. By introducing an intuitive web-based platform for massive marketplaces such as Amazon Mechanical Turk (AMT) and several automated methods, the intelligence of the crowd is engaged for interpreting jobsite vid...

Productivity-Based Management System for Offsite Manufacturing: Case Study of Noralta Lodge

Large-scale projects entail a zero-tolerance policy in regards to on-time project delivery and project quality. Severe winter conditions in Canada challenge conventional on-site construction activities and raise the risk of project delays and deficiencies. Industrialized (modularized) construction stands as an alternative that provides high quality products in a timely manner. Moreover, modular construction offers manufactured building components in a controlled environment, which ensures that quality standards remain consistent regardless of weather conditions. Once manufactured, modular units are then shipped to the site to be assembled. Two major geographical phases are common in offsite construction: the manufacturing phase, and the on-site installation phase. Consequently, management teams face challenges related to productivity and optimum work sequence in both phases. Traditional project planning and control methods consider the duration of a task as a static entity resulting from the direct relationship between the sizes of the crews on-site and labour productivity. Learning curves, skill-based tasklabour matrices, and resource levelling techniques are factors that imply the dynamic nature of construction tasks; delays in one task may affect other subsequent tasks both directly and indirectly. The Productivity-Based Management System (PBMS) provides opportunities to increase the production rates of task duration, and decrease actual task duration. The proposed research introduces a framework for a PBMS to manage and control the on-site phase of modular construction. In this research, the PBMS is developed, implemented, and then applied to a 1,700- bedroom workforce camp in Fort McMurray, Alberta, Canada.

Application of AV-ERP system for on-site project monitoring

Purpose – The purpose of this paper is to report the results of a techno-economic feasibility study on the application of Audio Visual Enterprise Resource Planning (AV-ERP). Due to rapid urbanisation and economic growth in developing countries (DCs) like India, there has been tremendous development in infrastructural projects. To maintain the quality and competitive commercial pricing of the projects, stakeholders are working together from different geographic locations. Due to lack of culture in adopting the technological advancements, the on-site construction activities lack coordination among the stakeholders. Design/methodology/approach – In the present case, it is observed that the site and various stakeholders like consultants are physically monitoring and controlling the ongoing construction activity from different geographic locations. To manage the effective communication and information exchanges, an integrated tool for surveillance and AV-ERP is proposed in the present paper. These equipment and technologies play a very vital role in the construction industry, which, in turn, significantly affects the progress, cost and time of the project. The techno-economic feasibility of proposed AV-ERP system was evaluated for the ongoing township project over the study area. Findings – For the considered case study, 75 per cent cost of the project overhead incurred for site monitoring can be saved by implementing the proposed technology of AV-ERP system. Practical implications – The proposed AV-ERP system is a techno-economically viable solution for the effective project management. Originality/value – In the DCs like India, to develop the culture for adopting the technological advancements (AV-ERP system) for monitoring the on-site construction activities, the presented case becomes an innovative solution for upcoming medium as well as large-scale construction projects.

Major Challenges to the Sustainable Operations of Construction Equipment in Malaysia

The growing considerations of people, profit and planet have emphasized the integration of sustainable concepts in the construction processes. The previous research in sustainable construction has underlined the issues pertaining to raw material and its manufacturing; design aspects along with the occupancy phase of a building life cycle. However, concerned over GHG emissions from the operation of non-road diesel equipment are still being ignored in the established literature. These non-road construction equipment consume fossil fuel and a serious threat for green environment. In addition to this, health and safety issues are also important concerns for the human well-being. Thus, mitigating these impacts are the important aspects of sustainable planning for onsite construction activities. A questionnaire survey was carried out to explore the contractors views towards potential challenges that are relevant with the growing attention of sustainability in construction sector. A group of large civil contractors of Malaysian construction industry were solicited through online survey to prioritize the potential barriers. The research findings presents a broader view and a number of challenges that inhibits the contractors for acquiring, adopting and implementing sustainable practices for onsite mechanized construction activities.

Challenges for capturing and assessing initial embodied energy: a contractor’s perspective

Initial embodied energy includes energy use during material, transportation, and construction life cycle phases up to project practical completion. Contractors have an important role to play in reducing initial embodied energy levels due to their significant involvement in preconstruction and onsite construction activities. Following an extensive literature review a comprehensive framework was designed to highlight the significance of initial embodied energy levels relative to specific construction packages, activities and subcontractors. This framework was then applied to a new UK industrial warehouse project using a case study approach. Capturing information from a live project during the entire construction phase helped highlight the practical challenges inherent when capturing and assessing initial embodied energy levels. A series of contractor current practices was reviewed to determine their compliance with the framework requirements. The findings revealed that the ground and upper floor, external slab and frame were the most significant construction packages in terms of embodied impacts. Many challenges embedded within the contractor’s current practices in terms of data detail, legibility, and terminology were also revealed. The framework provides a practical approach for initial embodied energy assessment which can readily be adopted by contractors to help highlight opportunities to increase efficiency.

Integrated Framework for Estimating, Benchmarking, and Monitoring Pollutant Emissions of Construction Operations

AbstractConstruction operations are highly energy-intensive and account for significant environmental impacts, including greenhouse gases (GHG) and other engine exhaust associated with material procurement/delivery and on-site construction activities. The opportunities for mitigating air pollutant emissions from construction operations can be captured by estimating and benchmarking during the preconstruction phase and then monitoring during the construction phase. However, a formal process model to manage the environmental aspects of on-site construction activities has yet to be clearly delineated, although recently several research efforts have appeared in relevant areas such as the development of in-use emission factors of construction equipment, methods for reliably estimating emissions at the project level, embodied carbon footprint benchmarking methods, and practical monitoring tools. Such a lack of a formal process model causes the misinterpretation of the benefits from recent research efforts in ea...