• Energy Research

Rehabilitation using Glass Fibre Reinforced Polymer (GFRP) wrapping system is an innovative technique for rehabilitation of deteriorated timber structures exposed to severe environmental conditions. This paper investigates the effectiveness of rehabilitation using GFRP wrapping system for deteriorated timber piles due to splitting. An experimental investigation was conducted on undamaged and damaged short timber columns with three levels of splitting. Crane rail epoxy and underwater cementitious grout were used to fill the annulus between columns and GFRP jackets in the rehabilitated samples. All the samples were tested under axial compression loading. Axial peak and yield loads, ductility and energy absorption were discussed to assess the overall behaviour of timber columns. In addition, a finite element analysis was established to investigate the overall load-deformation performance of the tested samples and to validate the experimental results. Furthermore, an analytical prediction was performed based on Australian Standards along with an existing GFRP wrapped stress- strain model to determine the peak load capacity of the unwrapped and GFRP wrapped samples. The experimental results indicated that the GFRP wrapping system can restore the axial capacity and energy absorption of the damaged samples with high effectiveness was observed for samples infilled by the crane rail epoxy. Also, the results of numerical and analytical analysis showed a reasonable correlation with the experimental results.

3D Printed Concrete (3DPC) technology is currently evolving with high demand amongst researches and the integration of modular building system (MBS) with this technology would provide a sustainable solution to modern construction challenges. The use of lightweight concrete in such innovative construction methods offers lightweight structures with better heat and sound insulation compared to normal weight concrete. It is worth noting that fire and energy performance has become central to building design. However, there are limited research studies on the combined thermal energy and fire performance of 3DPC walls. Therefore, this study investigates fire performance of 20 numbers of varying 3DPC wall configurations using validated finite element models under standard fire conditions. The fire performance analysis demonstrated that 3DPC non-load bearing cavity walls have substantial resistance under standard fire load and its performance can be further improved with Rockwool insulation. There is significant improvement in terms of fire performance when the thickness of the walls increases in a parallel row manner. Previous thermal energy investigation also showed a lower U-value for increased thickness of similar 3DPC walls. This research concludes with a proposal of using 3DPC wall with Rockwool insulation for amplified combined thermal energy and fire performance to be used in MBS.

The evolution of innovative construction technology and automation has rapidly transformed the construction industry over the last few decades. However, selecting the most efficient and sustainable construction technology for high-rise building construction is a critical factor in completing the project successfully. This requires a multiple-judgment-decision process relevant to cost, time, environment, sustainability, quality, etc. Thus, this research aims to identify the most suitable sustainable construction method for high-rise building construction in Australia. Three construction methods (i.e., automated building construction, aluminium formwork construction, and off-site construction) and robotic construction technology are reviewed in terms of economic, equity and environmental performance. A detailed multi-criteria analysis is conducted concerning the weighting calculated for each construction method, which aids in recommending a sustainable and cost-effective method. The analytical hierarchy process (AHP) is used as a multi-attribute decision-making tool to determine the weighting factors. The results show that the off-site construction method and robotic construction technique significantly improve the construction performance of high-rise construction in Australia. However, the finding is based on data obtained from a limited number of experts. Thus, a detailed case study with a greater number of expert opinions is needed to ensure the significance of the finding. However, the AHP-based approach method can be used to select sustainable construction alternatives for high-rise buildings.

Wall plaster production induces significant environmental impacts during its entire life as it consumes a high amount of cement and natural resources. Therefore, in sustainable development, industrial wastes are partially replaced to produce cementitious material to reduce environmental impacts. This study aims to identify the optimal environmental benefits from the waste-based cementitious materials that are used to produce wall plaster. Thus, this study involved conducting a comprehensive review of the mechanical and sustainable performance of industrial waste-based cementitious materials focused on wall construction. Then, an experimental test was conducted to ensure the appropriate mix design to enable the required compressive strength. A comparative analysis of mortar showed that it contained 15% (by weight) of fly ash, blast furnace slag, bottom ash, recycled glass, ferronickel slag, expanded polystyrene and wood ash using life-cycle assessment. The results show that mortar containing fly ash has lower environmental impacts in almost all impact categories (i.e., human health, the ecosystem and natural resources). Endpoint damage assessment of mortar mixtures expresses resource extraction cost as the most affected impact criteria. The replacement of globally consumed cement with 15% fly ash can contribute to monetary savings of up to USD 87.74 billion. The assessment clarifies the advantage of incorporating waste products in cement mortar, which allows policymakers to interpret the analysis for decision making. This study also found that the production of industrial wastes for mortar mixes has a significant impact on the environment.

This study aims to comprehensively depict a thematic evaluation within the context of carbon-neutral buildings over this century at variable time phases (2000–2008, 2009–2016, and 2017–2023). The overarching objectives of this study are delineated into three (3) contexts. Firstly, a bibliometric network encompassing influential research documents, authors, prominent journals, organisations, and countries is erected in pertinent fields. Secondly, significant terms are extracted from the scientific literature to exhibit co-occurrence patterns. Finally, an analysis of the evaluative clusters across variable phases was conducted to ascertain their intricate interrelations. The software tool VOSviewer Version 1.6.19 successfully achieves the initial objectives by visualising networks based on co-authorship, citations, co-citations, and bibliographic coupling. The ultimate goal of this research is fully realised through the application of the Science Mapping Analysis Tool (SciMAT), Version 3, which facilitated the evaluation of diverse clusters, phases, and thematic domains. The findings from the initial stages of research conducted on carbon-neutral buildings primarily revolve around energy-savings measures, environmental impacts, and the pursuit of energy-efficient design. As the research progressed into subsequent phases, the scope of inquiry broadened into specific themes, such as (1) optimisation, (2) retrofitting, (3) transitioning, and exploring (4) phase change materials (PCMs). Moreover, the areas of study continued to expand by developing diverse scenarios, algorithms, and digital twin technologies. The graphical representations of the strategic diagrams, evaluation areas, and cluster networks are a valuable resource for practitioners and policymakers, offering valuable insight and understanding of the multifaceted landscape of thematic evaluation in carbon-neutral buildings, thus facilitating further investigations and informed decision making.

Effective waste management has become a crucial factor in Australia because, from 1996 to 2015, the population increased by 28%, while Australia’s annual waste increased by 170%. In the period 2018–2019, Australia generated 27 Mt of construction demolition waste (44% of all waste). Although 76% of this waste is recycled, there has been a 61% increase in the rate of waste since 2006–2007. Therefore, minimising waste and prioritising waste management are necessary to build a circular economy. This study aims to identify the current waste minimisation perceptions in the Australian construction industry. A semi-structured interview was conducted with 50 industry experts focusing on four sectors (design/planning, building information modelling (BIM), material logistics, and prefabrication). The data were analysed qualitatively and quantitatively (Severity index). The result disclosed that the designers are the first contributor to waste minimisation, followed by the material suppliers/manufacturers. It is revealed that subjective attitude and the personal reluctance to exercise waste mitigation strategies are crucial. The outcome also indicated that BIM has the potential to minimise waste significantly. Overall, 15 key points were highlighted to consider for waste minimisation, and a conceptual framework was proposed. Therefore, identifying waste management’s current practices and the responsibility of industry personnel will help minimise waste and bring sustainable development.

The concept of sustainability and the utilization of renewable bio-based sources have gained prominent attention in the construction industry. Material selection in construction plays a significant role in design and manufacturing process of sustainable building construction. Several studies are being carried out worldwide to investigate the potential use of natural fibres as reinforcement in concrete with its noticeable environmental benefits and mechanical properties. 3D printed concrete (3DPC) is another emerging technology, which has been under-developed for the past decade. The integration of reinforcement is one of the major challenges in the application of this new technology in real-life scenario. Presently, artificial fibres have been used as a reinforcement material for this special printable concrete mixture. However, natural fibre composites have received significant attention by many 3DPC constructions due to their lightweight energy conservation and environmentally friendly nature. These benchmarking characteristics unlock the wider area of natural fibres into the composite sector and challenge the substitution of artificial fibres. Hence, this paper presents a comprehensive review on the current practice and advantages of natural fibres in conventional concrete construction. Subsequently, with a view to the future efficient 3DPC construction, the potentials of natural fibres such as eco-friendly, higher impact, thermal, structural, and fire performance over the artificial fibres were highlighted, and their applicability in 3DPC as composites was recommended.

Circular-economy-based sustainability approaches in construction are gaining wide acceptance due to the volume of waste generation and increasing demand for natural materials. Propelled by the recent timber shortage in Australia and the issues of waste management of cardboard, this study aims to analyse the possibilities of using cardboard as a construction material, based on its initial strength and multiple recycling options. A systematic review of research papers published in the last 40 years has been undertaken using a single keyword search to select the database. The review is presented in terms of the characteristics of the cardboard, dimensional stability, durability, structural strength, design, and analysis of cardboard. Recurring themes are evaluated using a latent Dirichlet allocation approach to identify the factors that ascertain the suitability of cardboard. Analysis reveals that despite certain constraints, such as water absorption and fire resistance, cardboard can be used as a replacement for timber by overcoming such limitations. This observation has benefits for the construction industry and the recycling industry. This study found that cardboard adheres to the circular economy principles, which should inspire policymakers. The paper concludes by highlighting the current circumstances and scientific challenges that impede the usage of cardboard in construction and recommends potential works needed to address these challenges for the benefit of practitioners and researchers.