The NISPAcee journal of public administration and policy

This paper introduces a new approach for conducting project feasibility study by embracing the principles of sustainable development. Construction projects, in particular, infrastructures have major influence on the attainment of sustainable development, thus project sustainability needs to be considered. This becomes a pressing issue particularly in those developing countries or regions, such as China where a huge amount of construction works are currently performed and remain to happen in the future. Previous study has addressed little on the relevance of project feasibility study to project sustainability performance. The importance of incorporating sustainable development principles in conducting project feasibility study is not effectively understood by project stakeholders. This paper addresses major challenges of undertaking project feasibility study in line with sustainable construction practice with reference to the Chinese construction industry. A case study approach is the major research method in this study. The research team collected 87 feasibility study reports from various projects. Attributes are used for measuring project performance, including 18 economic performance attributes, nine social performance attributes, and eight environmental performance attributes. Research results show that economic performance is given the most concern in the current practice of project feasibility study, whilst less attention is given to the social and environmental performance. The study reveals the insufficiency of examining the performance of implementing a construction project from the perspective of sustainable development. The results also suggest the need for shifting the traditional approach of project feasibility study to a new approach that embraces the principles of sustainable development

Wireless secrecy under multivariate correlated Nakagami-m fading

Current wireless secrecy research in the literature has mainly been performed for one wiretapper under correlated fading. In this paper, a new wireless secrecy framework for multiple wiretappers under multivariate exponentially-correlated (exp.c.) Nakagami-m fading is proposed. Using the distribution of multivariate exp.c. Nakagami-m fading, new, exact, and compact expressions for the ergodic secrecy capacity, and secrecy outage probability (SOP) under multiple wiretappers are obtained for an integer fading parameter m. A secrecy analysis is also performed for the first time in this paper using an adaptive on/off transmission encoder under multivariate exp.c. Nakagami-m fading. A secrecy analysis with three wiretappers under quadrivariate exp.c. Nakagami-m fading is also given, which shows the effectiveness of the new framework. Simulation results are shown to exactly match theoretical predictions

Comparative response spectrum analysis on 15- and 50-story reinforced concrete buildings having shear walls with and without openings as per EN1998-1 Seismic Code

Medium-rise reinforced concrete (RC) framed apartment complexes with stories ranging from 15 to 50 are becoming more common in Ethiopia’s main cities. In these RC-framed structures, shear walls are included for lateral load resistance. As apertures are frequently provided in shear walls, it is critical to evaluate their influence on story drift, stiffness, shear and moments, and stress within the shear walls. A 3D study with five different cases was carried out with ETABS version 19.00 software to investigate the influence of apertures in a building’s shear wall. This study looks at the effects of changing the size and location of these apertures. Based on this analysis, extensive data were acquired, and useful conclusions were formed that will be useful to practicing engineers. The seismic parameter utilized for the response spectrum study was Building Code of Ethiopia ES8-15, which conforms to Eurocode 8-2004 seismic code guidelines (based on EN1998-1) with target response spectrum type-I. The following parameters were used: ground acceleration, ag/g = 0.1, spectrum type = I, ground type = B, soil factor, S = 1.35, spectrum period, Tb, = 0.05 s, spectrum period, Tc = 0.25 s, spectrum period, Td = 1.2 s, lower bound factor, beta = 0.2, behavior factor = 1, and damping ratio = 5%. The outcomes are compared using various parameters such as displacement, story drift, story stiffness, story shear, and story moment both with and without shear wall opening cases. This study will give tremendous insight into the effect of shear wall openings on the performance of the structure. The analysis in this work was carried out on a linear model, which may not represent the complete local response of the structure; thus, future researchers should perform nonlinear analysis based on a performance-based design. It was concluded from this investigation that incorporating shear walls considerably enhanced the performance of the building over framed structures. Shear wall openings in a structure have a significant influence on the building’s performance. Due to their significant resistance to earthquake forces, shear wall structures are highly recommended for seismic hazard zones

Advanced progress in recycling municipal and construction solid wastes for manufacturing sustainable construction materials

The sharply increasing solid waste generation has raised the environmental concerns worldwide which currently have been escalated to a worrying level. Intending to eliminate the negative environmental impacts of solid waste and meanwhile promote sustainability on the energy- and resource-intensive construction and building sector, considerable efforts have been devoted to recycling solid waste for the possible use in sustainable construction material products. This paper reviews the existing studies on recycling municipal and construction solid waste for the manufacture of geopolymer composites. Special attention is paid to the predominate performance of these geopolymer composite products. The principal findings of this work reveal that municipal and construction solid waste could be successfully incorporated into geopolymer composites in the forms of precursor, aggregate, additive, reinforcement fiber, or filling material. Additionally, the results indicate that although the inclusion of such waste might depress some of the attributes of geopolymer composites, proper proportion design and suitable treatment technique could alleviate these detrimental effects and further smooth the recycling progress. Finally, a brief discussion is provided to identify the important needs in the future research and development for promoting the utilization of solid waste materials in the forthcoming sustainable geopolymer industry. In summary, this work offers guidance for the better ecological choice to municipal and construction solid waste through developing waste materials into highly environmental-friendly construction materials

Insulated Wall Systems to Tackle Global Warming

Brief introduction to the problem: the growing awareness of climate change and its link to carbon dioxide emissions have caused concerns in the community. A substantial amount of carbon dioxide emitted is due to the energy consumed by residential households. Heating/cooling of a residential house consumes a large proportion of the total household energy. Purpose: This paper explores the concept by comparing thermal efficiency of the four most common external wall structures, with varying amounts of insulation added in the context of Sydney, Australia. Design/methodology/approach: Cost and thermal analysis for each wall type are calculated. Life cycle cost saving and payback period are then evaluated. Findings: It is found that up to 95.7% cost saving can be achieved in heating/cooling in comparing the use of insulated wall systems and air film. Cement sheet wall system is found to be the most cost effective wall system for insulation with minimum 50% of cost saving can be achieved. The results also identify substantial energy cost required for heating/cooling a house without insulation when the climate gets extreme. The payback period for the installation of the insulated wall systems can be achieved in 4.98 years for normal climate condition or 2.58 years for extreme climate condition. Practical implications: The community is currently at great risk of being unable to deal with climate change issue as not clear the effective use of insulated wall systems. This paper can help provide insight and suggestions for residential households in tackling global warming issue

Users' building optimal performance manual

Occupant behaviour has a significant impact on the overall energy performance of a building. The lack of awareness, misinformation and misunderstanding of the buildings’ systems and features are some of the key elements that impact the use of energy in buildings. This paper presents the results of a workshop performed to increase the awareness of the occupants of two university buildings, in Sydney Australia. The occupants were asked to provide their opinions on their interactions with the lighting, cooling, heating, equipment, windows opening and shading. Then, the behaviours collected in the surveys were converted into energy use, through building simulations, and the results presented in a workshop. After presenting the results, a brainstorming was promoted to collect occupants’ new perceptions based on the previous results. Occupants highlighted as one of the key impacting factors to high levels of energy use the lack of awareness. To answer to the outcome from the workshop, this paper suggested then the incorporation of a users’ building performance (U-BOP) manual as a tool to be used to increase occupant’s awareness and increase the overall performance of a building. It was used as an example and baseline for the manual the building user guideline (BUG) from Green Star and BREEAM, as well as exiting O&M reports. The results of this study and workshop should not be extended to other occupant behavioural situations and patterns. The results should be maintained within the present study and context

A critical review and comparative analysis of cost management on prefabricated construction research (2000–2022)

Prefabrication construction has gained attention in the construction industry. The cost of prefabrication has got mixed reviews. Cost management in prefabricated construction (CMPC) includes many cost considerations such as initial design costs, supply chain cost considerations, maintenance costs and assembly costs. These costs are inter-linked and thorough understanding on cost management is essential. It is important to develop a holistic cost management system to capture all the economic, social and environmental aspects of prefabricated construction. The aim of this research is to conduct as a critical review and analysis of cost management in prefabricated construction holistically. The literature review selected 63 articles for this research study from 2000 to 2022. The research showed that there is an uptake in research on this research area since 2005. The study identified four main research categories in CMPC namely 1) cost estimating, 2) cost optimization, 3) economic performance and 4) cost management models. Previous studies mostly focused on estimating costs and comparison studies with conventional construction. Recently studies focused more on developing cost model to integrate supply chains and other considerations into cost evaluation. Based on the literature review, there are several future directions in CMPC. Cost estimating should now focus on identifying the effect of each cost determinant in project scenarios to provide more accurate results. Future studies are also expected to focus on BIM and big-data based optimization models. © 2023 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group

A BIM-LCA approach for estimating the greenhouse gas emissions of large-scale public buildings : a case study

Exiting green building assessment standards sometimes cannot work well for large-scale public buildings due to insufficient attention to the operation and maintenance stage. This paper combines the theory of life cycle assessment (LCA) and building information modeling (BIM) technology, thereby proposing a green building assessment method by calculating the greenhouse gas emissions (GGE) of buildings from cradle to grave. Life cycle GGE (LCGGE) can be divided into three parts, including the materialization stage, the operation and maintenance stage, and the demolition stage. Two pieces of BIM software (Revit and Designbuilder) are applied in this study. A museum in Guangdong, China, with a hot summer and warm winter is selected for a case study. The results show that BIM can provide a rich source of needed engineering information for LCA. In addition, the operation and maintenance stage plays the most important role in the GGE reduction of a building throughout the whole life cycle. This research contributes to the knowledge body concerning green buildings and sustainable construction. It helps to achieve the reduction of GGE over the whole life cycle of a building. This is pertinent to contractors, homebuyers, and governments who are constantly seeking ways to achieve a low-carbon econom

Synergistic effects of polypropylene and glass fiber on mechanical properties and durability of recycled aggregate concrete

To better understand the synergistic effects of combined fibers on mechanical properties and durability of recycled aggregate concrete (RAC), different types of fibers with various lengths and mass ratios were adopted in this study. Experimental investigations were conducted to study the 28-day compressive strength and strength loss after exposed to salt-solution freeze–thaw cycles and the coupled action of mechanical loading and salt-solution freeze–thaw cycles. The microstructure was also characterized to evaluate the mechanism of this synergistic effect. To determine the effectiveness of the combined fibers on improving the mechanical properties and durability of RAC, the synergistic coefficient was proposed and applied for various combinations of fibers. The results indicate that the incorporation of fibers slightly decreased the 28-day compressive strength of RAC, but combining different sizes and types of fibers can mitigate this negative effect. Moreover, the incorporation of fibers greatly improves the freeze–thaw resistance of RAC. The combining different fibers exhibited a synergistic effect on the enhancement in properties of RAC, which could not be predicted with only one simplistic rule of fibre mixtures. In addition, microstructural characterization shows that the bonding strength of the interfacial transition zone (ITZ) between the fiber and cement matrix is mainly determined by the chemical bonding force which is due to the hydration reaction between fiber surface and cement matrix

Leagile strategies for optimizing the delivery of prefabricated house building projects

Australian housing supply has not been responded at a rate commensurate with its growing demand. Residential housing sector is facing this serious shortage issue by actively developing and effectively using new construction material, processes and practices for sustaining its competitive advantage over other construction sectors in the Australian context. The Construction 2020 report confirmed prefabrication/off-site manufacturing (OSM) as a critical vision for the Australian construction industry’s future, as OSM provides opportunities for not only increased productivity and safety, but also decreased cost. It also has the capability of meeting the growing housing demand within the extant level of skilled labour. By combining lean and agile concepts, OSM’s supply responsiveness and efficiency can be intensified. The current research studies the association between demand–supply housing imbalance factors using mixed methods from literature and interviews. Literature has documented four main factors that drive this imbalance: (1) housing completion time; (2) cost of a finished house; (3) customer preferences and (4) level of skilled labour. Interviews with 13 industry professionals identified the four main leagile strategies used to deliver prefabricated building projects. Literature and interview findings supported the development and validation of multicriteria decision-making (MCDM) model comprising and incorporating these factors (and subfactors) and the four leagile strategies. The choice of the appropriate strategy to address the studied factors within the Australian context was optimized using analytic hierarchy process (AHP). The results from the AHP model show the suitability of applying each strategy at different degrees as influenced by the tested factors