Assessing the environmental performance of construction materials testing using EMS: An Australian study

A study on the spatial network characteristics and effects of CDW generation in China.

This study presents the first application of the pressure-state-response (PSR) model in the comprehensive assessment of construction and demolition waste (CDW) recycling benefits. Unlike traditional methods, the PSR model provides a multi-dimensional analysis that integrates economic, environmental, and social factors, offering a more holistic approach to evaluating the impact of CDW recycling strategies. This model enables stakeholders to better understand the pressures, states, and responses involved in CDW management, providing actionable insights to optimize recycling efforts and support sustainable urban development. Using the pressure-state-response (PSR) logical framework of sustainable economics, this paper systematically analyzed the comprehensive benefit mechanism of the recycling of construction and demolition waste (CDW), and designed a comprehensive benefit evaluation model for CDW recycling. At the same time, taking Chongqing as an example, the management status of construction and demolition waste, the supply and demand matching of sustainable recycling products, and the impact of the input and output of CDW management were analyzed. The results were as follows: (1) The recovery rate of urban manure fluctuated between 0.13 and 0.17, mainly in temporary landfill. (2) Based on the latest market demand data of CDW recycled products, the supply–demand ratio of recycled products fluctuated between 0.11 and 0.21. This change in the supply–demand ratio reflects improvements in recycling technologies, such as the introduction of C2CA technology, which has greatly increased the supply of high-quality recycled materials. In addition, government policies encouraging the use of recycled products in public projects have contributed to this shift, further aligning supply with market demand. (3) The benefit–cost ratio of CDW management reflects new recycling technologies and the improved efficiency of CDW management. The benefit–cost ratio, which currently fluctuates between 0.32 and 0.39, more accurately reflects the current state of CDW management, which is increasingly adopting advanced technologies, resulting in increased efficiency and reduced costs. Based on this, this paper discusses the supply–demand relationship and benefit–cost ratio in CDW management from supply-side and demand-side perspectives, and puts forward corresponding countermeasures and suggestions. The research results provide a clear reference for improving the efficiency of building demolition waste resource utilization, especially in optimizing the balance of market supply and demand, and improving the economic benefits of recycled products. By analyzing the balance between the supply and demand ratio and the benefit–cost ratio, this study helps inform policy makers, businesses, and investors, to promote the sustainable development of CDW recycling projects to maximize resource efficiency, while reducing environmental pressures. These results not only provide practical guidelines for the implementation of CDW recycling projects, but also lay a foundation for future policy formulation and the setting of industry standards.

The Zambian Construction Industry (ZCI) is one of the fastest growing sectors in Zambia arising from increased infrastructure development. The ZCI, like elsewhere, is composed of many players including designers, contractors, regulators, manufacturers and suppliers of construction materials. The country has seen an upsurge in Construction and Demolition Waste (CDW) generation due to increased construction activities. However, opportunities for utilizing CDW for sustainable construction and management have been minimal. Most research in developing countries has focused on Municipal Waste Management (MWM) rather CDW. In Zambia, CDW is a challenge in the absence of legislation, guidelines and regulation. In the developed countries, guidelines, legislation and regulation, exist. Sustainable utilization of CDW in Zambia is limited due to inadequate policy guidelines and legislation. The research aimed at estimating the levels of CDW waste generation and utilization, and proposing a framework for sustainable utilization and management of CDW. The research required both qualitative and quantitative data. Primary data was collected through questionnaires, interviews and site visits whilst secondary data was obtained through literature review. The research, conducted in four provinces of Zambia, established that CDW generation rates were mainly in the 1-10% levels and utilization was low, regardless of the type of project. The main cause for such generation levels was poor skills and workmanship. Further, there are no specific policies dealing with CDW in Zambia. A frame work for estimating and quantifying CDW generation over the whole life cycle of a construction project is also proposed.

Urban development significantly increased construction activities, which led to the generation of Construction and Demolition Waste (CDW) and inefficient resource exploitation. Most of these CDWs end up in landfills, and most countries give little attention to sustainable practices in this area. "Circular Economy" (CE) is one of the best ways to reduce CDW and the use of resources. Even though CE is not a new idea, it is not fully used to reduce CDW because the construction industry is still based on a linear economy and building materials are designed to be used linearly. Hence, this paper aims to investigate how CE can contribute to minimising the CDW to achieve sustainable urban development. This study adopts a qualitative approach to examine the strategies used to minimise the CDW in Sri Lanka. Multiple holistic case studies with three large-scale construction projects in the Colombo district were selected, and semi-structured interviews were used to get first-hand information. Manual content analysis was used for data analysis. Findings noted that disposal is unavoidable for all 14 CDW types, and e-waste was counted as the 15th type. The 3Rs (reduce, reuse, and recycle) of CE are quite popular among the projects, and the other 8Rs of Cimen (2021) of the CE concept are challenging to put into practice. To increase the knowledge and application of CE principles among built environment experts, this research provides recommendations based on a desk study by gathering case studies from secondary sources where CE principles are extensively applied for CDW minimisation

Mexico City has experienced a rapid urbanization process, which has led to a socio-environmental crisis characterized by the generation of construction and demolition waste (CDW). The generation of CDW has been favored by the growth of the construction industry, the decrease in the useful life of buildings and an increase in the number of new buildings. To reduce the environmental impacts of CDW, recycling initiatives have been developed, offering alternatives for sustainable urban development. This study examines the use of recycled materials from CDW for urban park rehabilitation, focusing on the production of sustainable urban furniture. CDW as recycled material can be useful because it reduces the need for new resources, preserves land for future urbanization, protects the environment, and reduces transportation costs and energy needs A bibliographic analysis explored urban growth trends, CDW management methods, and the benefits of urban green spaces. As part of the project, urban furniture such as benches and planters was manufactured using recycled aggregates from CDW. The results demonstrate the functionality and sustainability of these elements, while providing recommendations on optimal aggregate sizes and compaction techniques. The urban furniture built using CDW (to manufacture benches, planters, jogging tracks and gabions), turned out to be totally functional, meeting the expectations of use This approach represents a viable alternative to natural fine aggregates, contributing to sustainable city development.

Construction and demolition waste management in China through the 3R principle

In Bangladesh, the minimisation of construction and demolition waste (CDW) generation is a demanding need to alleviate the environmental burden. Various barriers limit the effective CDW management strategies in this economy. Hence, this paper aims to explore the major obstacles to managing construction and demolition waste in Bangladesh. Major barriers identified in previous studies were selected through a literature review, and a tentative question list was prepared. Afterwards, by the suggestion of four experts, a structured questionnaire was designed to collect the respondents' knowledge on CDW, impacts of CDW and 19 barriers that hinder the effective implementation of CDW management. On-site visits and face-to-face interviews were to collect research data. The results of the questionnaire survey were analysed using ranking analysis. The findings show that waste generation in construction and demolition sites is different. Primary wastes generated in demolition sites are concrete and bricks, whereas in construction sites, the percentage of concrete, timber, brick, metal, sand, etc., is high. This study also evaluated that female respondent, mainly field workers, have more knowledge about CDW management than males. However, the number of female workers is few due to socio-cultural barriers. Based on the ranking analysis, the four most significant barriers that were identified hindering the effective CDW management are: 'Negligence and carefree attitude of workers', 'Poor supervision', 'Inadequate workers' skill', 'Space lacking for on-site storage'. The current study contributes to the field by identifying and highlighting the challenges to CDW management implementation in Bangladesh and providing remedial solutions to the identified barriers. Furthermore, the results could be helpful to provide information for developing strategies to improve CDW management strategies in Bangladesh.

Reasonable evaluating the economic benefits and social welfare of construction and demolition waste (CDW) recycling contributes to CDW investments and decision-making. The formation mechanism of comprehensive benefits on CDW recycling is analyzed by applying the pressure-state-response framework from the resource economics, and the article constructed the evaluation model of comprehensive benefits on CDW recycling. The context of CDW management, supply and demand of recycled products, and the input-output effectiveness of CDW management are determined and discussed in the case of Chongqing. These findings suggest that 1) the CDW recycling rate changed between 0.06 and 0.14, which indicated that construction and demolition waste are mostly in landfill; 2) the supply-demand ratio of CDW recycled products fluctuates between 0.1 and 0.25, which suggests that the supply-demand of recycled products is a serious mismatch, and then this mismatch is the pressure and driving force of CDW recycling development; 3) the benefit-cost ratio of CDW management varies between 0.16 and 0.35, which suggests that the input-output of CDW management is a significant disproportion, and the disproportion not only conforms to the economic man of the investor who do not participate in CDW recycling,but also reflects the stakeholders’ response to CDW management. Based on the previous study, the suggestion is discussed and studied on the CDW supply-demand side applying supply-demand ratio and benefit-cost ratio.

Improve the quality of construction and demolition waste by separation techniques

Construction and demolition waste (CDW) are commonly disposed of in unlined landfills or inappropriately at irregular sites. Civil construction materials may contain hazardous substances that, if solubilized or leached, can negatively impact the environment and human health. Understanding the leaching behavior of CDW is essential for assessing its environmental performance and ensuring its safe reintegration into the construction supply chain. This study aimed to investigate the impact of paint presence on the leachate contamination potential. The method involved the UNE-EN 12457-3 compliance leaching test and column percolation tests conducted under both saturated and unsaturated conditions, using columns filled with CDW, with and without paint. The samples, regardless of the presence of the paint layer, were classified as non-hazardous according to the criteria established by the European Council. The results indicate that the presence of paint mainly influenced the apparent color, turbidity, and concentrations of Na + and K + in the leachate. Although various heavy metals are used in paints, especially as pigments, the presence of paint in CDW did not significantly influence the release of these metals into the leachate. The CDW leachates, regardless of the presence of paint, exhibited potential for groundwater contamination due to elevated levels of sulphate and total dissolved solids. Notably, CDW also demonstrated the capacity to remove Zn and Fe and CDW without paint was found to reduce water turbidity.

BIM-based information system for econo-enviro-friendly end-of-life disposal of construction and demolition waste

Nowadays, the construction, remodelling and demolition operations can cause serious environment impacts. These activities produce materials defined as construction and demolition wastes (CDW). The CDW generated in Europe represents around 25–30 % of total waste. In EU 28 CDW production is about 821,160,000 t, but there is a significant difference among the European countries, mainly because of the variation of construction and demolition activity. In 2011, the total production of CDW in Portugal was around 930,000 t, but regional production is not homogeneous. The substantial inert fraction from the CDW makes them suitable for reuse. The present study aims to quantify and characterize CDW from residential recuperation of small constructions in Portugal and then propose mitigating measures to improve CDW management. The results obtained by bibliographic research revealed that the construction and demolition activity has decreased significantly in the last years and consequently CDW production. In addition, it was observed a big number of entities were involved in CDW management. Therefore, it was necessary to select a specific area from Portugal (Setubal region) which has thirteen City Halls. The surveys had scarce response. This can be explained by the lack of obligation of enterprises with less than ten employees to register CDW production and because in some regions the CDW are mixed with municipal solid waste. Most of the CDW collected from Setubal region was disposed in landfill. In order to reduce CDW production it is necessary to promote and make available recycled materials for small works at low cost.

Potential evaluation of the use of construction and demolition waste (CDW) in the recovery of degraded soils by mining in Brazil

The creep deformation of recycled construction and demolition waste (CDW) filler is an important factor affecting road performance. In this paper, a series of laboratory tests, including a compaction test, sieving test, California bearing ratio (CBR) test, creep test and unloading test are conducted on CDW filler. The engineering properties of different ratios of CDW mixture are systematically analyzed, the CBR value of CDW filler meets the requirements of an embankment. The creep type of CDW filler under a test load is stable creep, the results of the creep characteristics are analyzed from a microscopic point of view. The filler with a 7:2:1 ratio (brick slag: concrete: mortar) has the densest structure, which is dense and less porous, and the deformation is the smallest. Reasonable proportion control is the key to reducing embankment deformation. The improved Burgers model, which can better describe the creep characteristics of CDW filler, and the effects of load and ratio on the creep parameters are analyzed using the equivalent creep compliance. This study is of great significance for the promotion of CDW and meets the requirements of sustainable development.

Robotic automation is instrumental in the valorization of construction and demolition waste (CDW), facilitating scalable and efficient material recovery in response to rising waste volumes from accelerated urban development. AI-driven computer vision (CV) has advanced perception-focused tasks in CDW processing, such as classification, object detection, and segmentation. However, the subsequent action-focused task of robotic CDW grasp detection remains underexplored. Identifying optimal, collision-free gripper poses for CDW recyclables is particularly challenging in cluttered environments and is further limited by the need for large amounts of grasp-annotated training data. This paper therefore presents a robust CDW grasp detection method that leverages boundary features of CDW objects to guide grasp predictions via attentional feature fusion. Our approach builds upon recent advances in shape-aware CDW instance segmentation and takes advantage of the growing availability of high-quality segmentation data, enabled by automated labelling techniques using large language models (LLMs). To address the shortage of publicly available grasp-annotated CDW data, we also introduce ReCoDeWaste; the first RGB-D CDW instance segmentation and grasp detection dataset tailored for off-site AI-based sorting training and evaluation. Designed to capture the compositional complexity of CDW, ReCoDeWaste contains over 100,000 annotated waste object instances across diverse cluttered scenes. Experimental results demonstrate that our boundary-guided grasp detection model predicts collision-free grasps for detected recyclables in these cluttered streams, outperforming state-of-the-art methods in standard evaluation metrics and achieving up to 94.36% grasp detection accuracy. This research serves to enhance CDW valorization by transitioning efforts to action-focused CV tasks that go beyond recognition and classification.