Modular and Offsite Construction (MOC) Summit Proceedings
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A Pilot Study of Identifying Execution Plan Differences for Accelerated Bridge Construction
Get PDFAccelerated bridge construction (ABC) is an innovative construction technique used to accelerate the construction of new bridges, as well as the renovation/replacement of existing bridges. Due to the benefits offered by ABC, transportation authorities have a higher preference in executing an accelerated approach over conventional bridge construction. The execution of an accelerated approach has differences when compared to the conventional approach, and it is important to identify such differences for the successful implementation of ABC projects. However, there have been no studies to identify such execution differences. Therefore, this study was conducted to identify execution plan differences relevant to ABC. For this purpose, an extensive literature review was conducted to prepare a preliminary list of execution plan differences. Then, a questionnaire survey was administered with the industry experts, who were previously involved in the execution of ABC projects, to validate the preliminary list. Based on the literature review and the responses from questionnaire survey, this study identified 61 execution plan differences relevant to ABC in different phases of execution. This study is expected to benefit owners, contractors, and road/bridge users for successful execution of ABC projects
Lean Construction Supply Chain: A Bibliometric Analysis of the Knowledge Base
Get PDFThe construction industry known for its adoption of ideas from other industries has also adopted lean thinking from the manufacturing sector for managing construction supply chains. Towards the successful adoption of this concept, there is a need to establish the philosophy surrounding is application within the construction industry. Thus, this study conducts a bibliometric analysis with the intention of discovering intellectual progress within lean concepts, relevant authors and philosophies surrounding lean construction supply chain concepts. The study adopted VOSviewer software through the assistance of citation, co-citation and keywords analysis to present a bibliometric and network analysis. A total of eight hundred and fifty Scopus indexed articles were extracted and used for the analysis. Through the analysis we have revealed the most important authors, journals and articles supporting lean concept. Also discovered are the major school of thought related to lean construction supply chain which are; waste reduction, just in time, integration and pre-fabrication. This review points to the benefits of using bibliometric network analysis for unearthing the practices of lean construction supply chain. These findings contribute to using a new research methodology for analysing the contribution of lean concept to the construction supply chain
Appraisal of the Challenges to Ensuring Occupational Health and Safety Compliance within the Nigerian Construction Industry
Get PDFThe construction industry is known for the high number of accidents occurring within the industry. This is due to the hazardous working processes which have led to severe injuries, disabilities and fatalities. Towards reducing this hazards numerous health and safety regulations have been provided by construction firms in Nigeria. Despite the provision of the regulations hazards and accidents is still experienced on construction sites. Thus, this study appraised the challenges of ensuring compliance with health and safety regulations by construction workers in the Nigeria construction industry. Data were obtained from safety personnel and construction professionals using questionnaires through a convenience sampling method. One hundred and thirty-eight were used for the analysis out of one hundred and sixty-eight that was distributed to the respondents. The questionnaire was analysed using SPSS V 24 adopting Factor analysis and mean item score. The findings clearly show that construction workers compliance to health and safety requirements is below average while the factor analysis shows inadequate safety equipment, low awareness to occupational health and poor compliance to health and safety requirements are the major challenges hindering the compliance rate. The study recommends that implementation of the use of innovative measures and hi-tech devices such as radio frequency identification for effective monitoring of construction workers. It also recommends the involvement of construction workers when making the health and safety policies. This study contributes towards improving the occupational safety experienced on construction sites within the country
Canadian Mass Timber Demonstration Projects Initiatives
Get PDFIn order to expedite market acceptance and facilitate the commercial uptake of wood products and systems in Canada, it is necessary to showcase such applications through high-rise and non-residential building demonstration projects. This paper presents recent initiatives by the Government of Canada focused on increasing use of wood as a green building material in infrastructure projects by supporting such demonstration projects. The objective of Green Construction through Wood (GCWood) program (launched in 2017) is to support the design and construction of several high-rise and non-residential timber demonstration buildings and bridges in Canada through expression of interest (EOI) calls. The program is also supporting research and development activities to facilitate acceptance of provisions that would allow for the construction of tall wood buildings in Canadian building codes and advanced wood education at engineering and architectural colleges and universities to help develop the future design capacity in Canada
Applying Virtual Reality to Improve the Construction Logistics of High-rise Modular Integrated Construction
Get PDFModular and offsite construction is becoming increasingly popular around the world. In Hong Kong, a modular integration construction (MiC) method is identified as a pragmatic approach to speed up the housing construction program and to solve the productivity and manpower problems of the industry. Using the MiC, virtually all the construction works including the finishing as well as the mechanical and electrical installation are completed offsite. The MiC units are then delivered to and installed on site. While the MiC can shift the risks of construction projects to the factories, this construction method is not without challenges. This is particularly the case for Hong Kong as most of the construction sites in the city are cramped due to the high-density urban environment. The problem is aggravated when every modular unit is unique and they are time consuming to produce. Any damages to the MiC components during the lifting process could seriously affect the entire construction sequence under a just-in-time management philosophy. Therefore, it is imperative to plan and monitor the logistics carefully when the MiC technique is used. To reduce any human errors and increase the efficiency and accuracy of the lifting process, a virtual reality (VR) approach may be adopted to simulate the construction logistics of MiC construction and train the crane operators. In this paper, a VR model is developed to simulate the construction of a high-rise residential building in a confined site. Various functions are built into the VR model to support the decisions pertinent to lifting logistics planning. In this paper, the design considerations and functions of the VR model are identified through a series of interviews. Moreover, the validation interviews help unveil the potentials and pitfalls of the developed VR model
Drywall Waste Blocks: A Novel Masonry Material Utilizing Recycled Construction & Demolition Waste
Get PDFThis paper describes patent-pending mixtures and methods for producing masonry blocks using gypsum drywall waste and preliminary investigation of Drywall Waste Block (DWB) engineering properties. Recycling waste from building construction and demolition (C&D) provides many environmental and economic benefits. However, challenges remain for recycling certain low-value C&D materials, such as gypsum drywall waste, and there are few uses for drywall waste from demolition, which constitutes the majority of the drywall waste stream. Recycling drywall waste is desirable as this waste produces noxious hydrogen sulphide gas in landfill conditions, resulting in bans on landfilled drywall waste in some localities. Investigation of compressive strength, water absorption, and thermal performance of DWB specimens is described, and results are compared to specifications for concrete masonry units (CMU), and other comparable masonry blocks. Technical gaps for DWB to be recognized as a CMU alternative are also discussed
Toward Community Generation: Energy Simulation and Performance Evaluation of Multi-family Solar PV Settings for Energy-efficient Homes in Edmonton, Canada
Get PDFThe integration of renewable micro-generation systems into residential buildings, particularly solar photovoltaic (PV) distributed energy generation, is emerging rapidly as an effective method of mitigating the housing impact on greenhouse gas emissions. However, the application of solar PV micro-generation is confronted with several challenges: (a) the average system self-consumption does not exceed 25% in cold-climate regions; (b) most of the energy generated during daytime, peaking in the summer, is exported to the grid; and (c) rebates from the surplus generated energy exported to the grid are at a lesser rate than that of the imported energy. Due to relatively poor economics paralleled with the solar PV application, governments and policy makers envision the value of considering the integration of renewable energy sources at the community level rather than individual behind-the-meter applications, since this strategy can leverage the system self-consumption and increase its social impacts and economics. In this regard, this research aims to simulate and compare the overall performance of two scenarios of a sustainable community of 42 townhouse units. In the first scenario, each unit is connected to a behind-the-meter solar PV system of 3.3-kWp. In the second scenario, all units are connected to a large 140-kWp solar PV system. Historical data from one typical house has been collected (ongoing since 2015). Monte Carlo simulation technique is applied to ensure the stochasticity of the diverse household users. The hourly energy consumption and generation data is simulated using Simphony.NET® simulation engine based on the real-time data collected in Edmonton, Canada. Then, the load-match is identified as well as grid interaction indicators and system economics resulting from both scenarios. Results indicate that the application of community generation can significantly mitigate the imported and exported energy compared with individual behind-the-meter system generation due to the improved system self-consumption
Cross-Laminated Timber Shear Walls in Balloon Construction: Seismic Performance of Steel Connections
Get PDFIn the context of the global trend of designing sustainable structures, the attention towards high-rise timber buildings of 8 to 25 storeys has been increasing in recent years. Balloon construction technique using a relatively new heavy timber material, cross-laminated timber (CLT), has been shown to be promising for high-rise building applications, given its compatibility with off-site construction techniques and its desirable mechanical characteristics. To date, tall timber buildings using CLT have been built mainly in non-seismic or low-seismic locations around the world, whereas their application in high seismic regions has been limited to platform construction. More research on the behaviour of CLT structures during seismic events in terms of system behaviour as well as the behaviour of components, particularly connections, is required. The research presented in this paper seeks to initiate the process of seismic design of tall wood buildings using a balloon construction technique. Two buildings, one three-storey fictitious building and one to-be-constructed ten-storey building, both located on the west coast of Canada, were considered and designed based on the NBCC 2015 seismic provisions. The loads on the shear walls, which span over three storeys, were extracted in order to estimate realistic demands on lateral load resisting systems (LLRS) in the balloon construction. Different connections, including base shear connections, panel-to-panel shear connections, as well as high-capacity hold-downs, were designed accordingly. An experimental program was developed to investigate the behaviour of these connections, focusing on yielding and failure mechanisms in each connection category. This paper explains different phases of the experimental program and introduces connection details designed to achieve the research goals. The results of this study will contribute to the body of knowledge on seismic behaviour of prefabricated mass timber buildings, and will benefit engineers and practitioners using timber to design high-rise structures
Site-specific Modular Design Optimization for High-rise Residential Buildings
Get PDFModular design refers to a design approach whereby customized modules or components are assembled to form the layout plan of a building. Previous researches have attempted to optimize the layout plan design of low-rise houses for maximizing the natural daylighting, ventilation performance, and energy efficiency. Engineers have also studied the modular design of high-rise residential buildings to meet site constraints and to optimize site development potentials. However, the previous studies on modular building design were based on empirical trial-and-error approaches, efficient methods for identifying the optimal combination of different modules and components were still lacking in literature. Therefore, this study attempts to develop an innovative approach for optimizing the modular design of high-rise residential buildings, with the aim of maximizing the building energy performance while fulfilling the site constraints and design code requirements. The design optimization problem, including the design variables and objective functions, is properly formulated to guarantee the quality of final optimized deign. Provided a set of well-defined modules and components, evolutionary genetic algorithm (GA) is then utilized for the wide-ranging exploration of the building layout plans, taking into consideration the site conditions and building design requirements. A computer program is developed, coupling the GA optimization and energy modeling, to systematically evaluate the candidate layout plans. The energy simulation results are subsequently used to guide the GA towards finding the optimal design solution. The proposed optimization method is utilized to generate the optimal layout design for a 40-story high-rise residential building, using a set of pre-defined modular flat units. The optimal design maximizes the use of natural ventilation and daylighting to save 30-40% of the energy consumption without compromising the site constraints and design requirements. The findings of this study serve as the decision support basis to enhance modular design of high-rise residential buildings (such as energy conservation in this study), thereby improving the sustainability and cost-effectiveness of the built environment
A Collaborative Scheme for DFX Techniques in Concurrent Engineering Mitigated with Total Design Activity Model
Get PDFIndustry 4.0 has sparked rapid changes in the manufacturing and construction sectors, leading to a significant shift in how off-site factory-based panelized construction machines are designed and manufactured. Concurrent engineering which seeks to close the gap between design and manufacturing sectors provides an ideal environment for machine development. It is a systematic methodology to integrate machines holistic concurrent design activities and their related processes. Competition arising in the marketplace for newly developed machines is driving modifications in the way machine designers develop production machines. Thus, to boost the efficiency in concurrent machine development, appropriate evaluation, and decision analysis tools required to be developed and utilized. Currently, there is no DFX selection tool available to aid the designer in concurrent machine design applications. In this paper, these challenges are addressed through a comprehensive qualitative literature review of DFX techniques with their implementation in Stuart Pugh: Total Design Activity Model. Various DFX techniques are mapped and clustered in a collaborative scheme, interactions and links between them are identified, and the relative importance weight of each is calculated. A description of a functional DFX scheme is proposed in this paper that can aid designers in establishing lean design processes for machine development and reveals its potential application in Multi-DFX fuzzy multi-criteria decision-support system