Search Results (24)

The dramatic increase in global construction and demolition waste (CDW) is a considerable environmental challenge, but recycled building materials face serious marketing bottlenecks. Although existing studies have focused on the technological path and policy regulation of CDW management, they have not yet considered the impact of sales effort level under the dual-channel sales model. Considering the coexistence of price competition and bidirectional free-riding behavior, this paper constructs a Stackelberg game model, which includes a construction waste remanufacturer with both online and offline sales channels and a building materials retailer, to reveal the pricing decision-making mechanism under bidirectional free-riding behavior. The results of the study show that (1) in the decentralized decision-making model, offline free-riding has a negative effect on the online channel, and when the effort cost coefficient is high, it increases the retail price of recycled building materials in the offline channel; at the same time, under high cross-price sensitivity, both the manufacturer and the retailer are negatively affected by online free-riding behaviors; (2) in contrast to decentralized decision-making, centralized decision-making motivates the supply chain as a whole to significantly increase sales effort investment and develop a better pricing strategy under the condition of satisfying the threshold cross-price sensitivity, which ultimately improves the overall efficiency of the supply chain. The findings provide an important theoretical basis and management insights for the coordination of dual-channel supply chains, the governance of free-riding behavior, and the promotion of recycled building materials in the recycling economy. Full article

The waste management and recycling industry in Saudi Arabia is facing ongoing challenges in reducing the negative impact resulting from the recycling process. Different types of waste lack an efficient and accurate method for classification, especially in cases that require the rapid processing of materials. A deep learning prediction model based on a convolutional neural network algorithm was developed to classify and predict the types of construction and demolition waste (CDW). The CDW image dataset used contained 9273 images, including concrete, asphalt, ceramics, and autoclaved aerated concrete. The model obtained an overall accuracy of 97.12%. The Green Ground image prediction model is extremely useful in the construction and demolition industry for automating sorting processes. The model improves recycling rates by ensuring that materials are sorted correctly, thus reducing waste sent to landfills, by accurately identifying different types of materials in CDW images. As part of Saudi Arabia’s 2030 sustainability objectives, these steps contribute to achieving a greener future, complying with environmental regulations, and promoting sustainability. Full article

Construction and Demolition Waste (CDW) forecasting is essential for sustainable waste management and circular economy objectives. Traditional prediction models often face limitations when dealing with small datasets and extreme variability. This study introduces a robust statistical framework that employs the median and Median Absolute Deviation (MAD), applied to standardized CDW indicators: tons per day (t day⁻¹) and tons per square meter (t m⁻²). The method enables the detection of statistical anomalies using a ±2·MAD threshold, increasing the model’s resilience to outliers and enhancing its predictive reliability. The analysis is based on a dataset of 16 construction and rehabilitation projects, carried out under consistent technical methodologies, operational practices, and centralized data collection protocols. The results show that median-based predictions offer greater stability than mean-based estimators, particularly in skewed datasets. The framework successfully identifies projects with significant deviations, supporting targeted audits, performance monitoring, and iterative model refinement. Although the current model focuses on the duration and area as predictors, future enhancements should incorporate additional contextual variables. Furthermore, embedding the median–MAD logic within machine learning architectures (e.g., LSTM, ARIMAX) could improve scalability and support real-time CDW monitoring. These findings contribute to the development of data-driven forecasting tools that are aligned with operational efficiency and circularity goals in the construction sector. Full article

This study investigates the design and implementation of circular economy (CE) strategies for managing construction and demolition waste (CDW) in the Santiago Metropolitan Region of Chile (SMRC). The research aimed to identify key factors influencing the current and future adoption of CE practices for CDW management related to socio-environmental, technical, financial, and strategic-regulatory aspects, employing the Delphi method to gather expert insights. Findings reveal that the lack of knowledge about sustainable practices and the absence of regulatory frameworks for CDW disposal are the most critical barriers to effective CE implementation. The study recommends enhancing public awareness and environmental education through government and school programs, as well as enacting stricter legislation to combat illegal disposal and encourage sustainable practices and valorization of secondary raw materials within companies. Additionally, it emphasizes the importance of designing projects that prioritize waste avoidance and the development of infrastructure, technology, and processes for efficient material separation and recycling. The research also highlights potential challenges such as stagnation in the adoption of sustainable practices, skilled labor shortages, and limited research and innovation. It underscores the need for a comprehensive approach to CDW management that integrates socio-environmental, technical, financial, and regulatory dimensions to promote sustainability at both regional and global levels. Full article

Exploring the management efficiency of construction and demolition waste (CDW) and the spatial correlation network across regions in China is essential for promoting sustainable development and optimizing resource allocation. This study utilizes an improved three-stage SBM-DEA model and social network analysis to examine the management efficiency of CDW across 30 regions in China from 2010 to 2020. Research findings indicate that from 2010 to 2020, China’s CDW management efficiency improved, with a clear spatial gradient observed across regions. The eastern regions performed better than the western, northeastern, and central areas. Key factors affecting CDW management efficiency include economic development, infrastructure expansion, government policies, and technological progress. Economic growth was negatively associated with redundancy in labor and machinery, while infrastructure development correlated positively with labor, machinery, and capital redundancy. In some areas, government policies contributed to excessive capital investment, increasing redundancy. Technological progress helped reduce labor and machinery redundancy but had a minimal impact on capital redundancy. The spatial correlation network of CDW management demonstrated a “small-world” structure, maintaining stability in network density, relatedness, and hierarchy, though the network efficiency showed a downward trend. Beijing, Henan, and Xinjiang stood out as key nodes in the network, performing strongly in various centrality measures. Full article

This study investigates the feasibility of using mineralized collector-drainage water (CDW) for irrigating maize crops on light gray soils in the Syrdarya region of Uzbekistan, an area facing severe water scarcity and soil salinity challenges. The research is particularly novel as it explores maize production in marginalized soils, a subject previously unexamined in this context. The experiment was designed as a three-factor factorial study with three replications, following the guidelines of the Uzbekistan Cotton Scientific Research Institute. Five irrigation treatments (Fresh Water, Fresh Water 70% vs. CDW 30%, Complex Method (Mixing with Specific Rules), CDW 70% vs. Fresh Water 30% (Mixing) and only CDW) were evaluated using an Alternate Furrow Irrigation system, incorporating various mixtures of fresh water and CDW to determine their effects on soil salinity, crop health and yield. The amount of irrigation water required was determined using a soil moisture balance model, with soil samples collected at multiple depths (0–100 cm) to monitor changes in moisture content and salinity. Salinity levels and soil health parameters such as alkalinity, chloride, sulfate and cation/anion balances were measured at different stages of crop growth. Data were collected over three growing seasons (3 years). An analysis of the data revealed that using CDW, even in mixtures with fresh water, can sustain crop production while managing soil salinity. Notably, irrigation methods such as Mixing 70–30 and the Complex Mixing Method effectively reduced freshwater dependency and maintained the crop yield without significantly increasing salinity. The results suggest that CDW could be a viable alternative water source in regions where traditional water resources are limited. The findings have significant implications for improving water use efficiency and agricultural productivity in areas facing similar environmental challenges. This research not only contributes to the broader understanding of sustainable irrigation practices in arid regions but also provides a scientific basis for the wider adoption of CDW in Uzbekistan, potentially enhancing food security and supporting long-term agricultural sustainability in the region. Full article

The demolishing of concrete structures such as bridges, tunnels, buildings, and pavements has become a common activity due to reasons such as renovation, rehabilitation, retrofitting, or simply ending the service life of these structures. This upsurge has brought major challenges in managing construction demolition waste (CDW). Traditional demolition techniques are often characterized by high environmental impacts, inefficiency in waste management, and safety concerns. This paper critically reviews traditional and emerging concrete structure demolition technologies in terms of efficiency, safety, environmental impact, waste minimization, and material recyclability. A detailed review of manual demolition, mechanical demolition, implosion, and relatively new techniques such as static blasting, diamond wire sawing, soundless chemical demolition agents, hydro demolition, electrical discharge technology, demolition robots, and microwave heating is conducted. The key findings of this paper are that various alternative technologies have significant advantages over their traditional counterparts by offering minimum environmental pollution, improvements in on-site safety, and a possibility for materials to be reused and recycled. For instance, hydro demolition and diamond wire sawing are very efficient and accurate, meaning that actual waste management is highly improved. This paper underlines that the choice of demolition methods adapted to project needs is crucial for the development of sustainable CDW management. Such findings are useful to practitioners and policymakers who have to make fully informed decisions to promote environmental sustainability and resource conservation goals. Full article

The increasing concern about the environment has led to the necessity of ensuring efficient Construction and Demolition Waste Management (C&DWM) in the built environment. Despite the extensive research on C&DWM, the industry still faces significant challenges, including inefficiencies, high costs, and environmental impacts. Meanwhile, incorporating digital technologies (DTs) has emerged as a way to eradicate the challenges of C&DW. In response to the knowledge gap, in this research, we conducted a systematic literature review (SLR), incorporating bibliometric, text-mining, and content analysis to meet the research objectives. In total, 126 papers were retrieved from the Scopus database and transferred into VOSviewer to conduct the bibliometric analysis. The findings identified seven specific DTs, namely, blockchain, Internet of Things (IoT), Artificial Intelligence (AI), Machine Learning (ML), Robotics, Computer Vision (CV), and Building Information modeling (BIM). This study demonstrates that these technologies play a significant role in promoting efficient C&DWM in the construction industry. The study’s implication lies in its potential to guide industry stakeholders and policymakers in promoting the use of DTs and overcoming the barriers to their adoption, thereby facilitating more efficient and sustainable C&DWM practices. Finally, the findings of our research indicate possible future research directions for promoting DTs for C&DWM and eradicating the barriers to efficient implementation. Full article

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. Full article

How to efficiently and greenly dismantle abandoned buildings and reuse them is a dilemma facing the building material industry’s low-carbon objective. However, relevant studies ignore the influence mechanism of altruistic preferences of enterprises on green dismantling technology in supply chains. Driven by filling this theoretical gap, this paper firstly integrates reciprocal altruism theory and the Stackalberg game method and constructs a construction and demolition waste (CDW) recycling supply chain system consisting of a recycler and a remanufacturer, in which enterprises’ altruistic preferences are considered. The main theoretical outcomes of this paper are as follows. (1) In the case of unilateral altruism, enterprises’ altruistic preference behaviors help in increasing the green dismantling technological level and the amount of CDW recycling. Under the mutual altruism model, the influence of the recycler’s altruistic preference degree on the amount of CDW recycled hinges on the remanufacturer’s altruistic preference degree. (2) The utility of the enterprises and the green dismantling technological level are optimized under the mutual altruism model. (3) In a system of unequal power, unilateral “goodwill” by the follower will have a negative effect on their own interests; the leader plays a crucial role in facilitating equal cooperation and realizing win–win situations. This paper enriches the reciprocal altruism theory in waste management. It also helps in providing guidance for the recycler and remanufacturer in making operational decisions. Full article

With the rapid pace of global urbanisation, construction demolition waste (CDW) constitutes roughly 36% of the total solid waste deposited in landfill sites worldwide, thereby posing a significant challenge to the sustainability of the construction industry. To address this issue, circular economy strategies are proposed as a solution. This paper systematically analyses 55 research articles published in leading peer-reviewed English-language scholarly journals over the past decade. It aims to identify and categorise drivers for enhanced CDW management by synthesising findings from previous research to support the principles of a circular economy. Utilising a PESTLE model for classification and analysis provides valuable insights into disparities and distinctions among categories, regions, and countries. The resulting analysis yields valuable insights into enablers and trends, with the aim of making a substantial contribution to mitigating the impact of construction activities and thus fostering the establishment of an efficient circular economy within the sector. Full article

Resource consumption in the construction industry is expected to increase globally in the coming years. Additionally, construction and demolition waste (CDW) remains a significant priority within numerous global policies due to its vast volume and the inefficiencies in its management. This situation results in substantial environmental repercussions, primarily due to the low rates of material recovery in the manufacturing processes for new building materials. In response, the concept of the circular economy (CE) emerges as a promising solution across various sectors. CE promotes more resource- and energy-efficient practices, reducing waste generation and mitigating the environmental impacts associated with product life cycles while also unlocking potential economic opportunities. The primary aim of this study is to identify and assess the design practices influencing the adoption of CE principles within the Italian architectural, engineering, and construction (AEC) sector. The study’s main contribution lies in a survey of 77 Italian designers to explore the core strategies driving the development of comprehensive circular approaches. This investigation seeks to understand the constraints and opportunities for CE implementation. The findings will assist in decision-making, inform policy, promote literacy around the CE topic, enable new quality standards, and serve as a baseline reference for businesses regarding sustainability investment indexes and markets. Full article

The circular economy is one of the main strategies for mitigating the environmental impacts of civil construction due to the generation of construction and demolition waste (CDW). In this transition, evaluating alternatives for using buildings as material banks is a way to make the process of reusing construction components more efficient. Thus, the article aimed to evaluate the state of the art of publications on the relationship between the circular economy in civil construction and the conceptual model of buildings as material banks to mitigate the environmental impacts of CDW. The authors chose the methodological design of Systematic Literature Review, using the Scopus and Web of Science databases for research, with the following search strings: (“construction” or “civil construction” or “built environment” or “construction industry”) and (“circular economy” or “circular construction”) and (“material banks” or “BAMB” or “buildings as material banks” or “building stocks” or “building materials”) and (“construction waste” or “demolition waste” or “CDW” or “construction and demolition waste” or “environmental impacts”). After a screening in which only articles published in journals were selected, from 2013 to 2023, inclusion and exclusion criteria were applied, to evaluate only those that had a direct relationship with CDW management through circular economy strategies and buildings such as banks of material. As a result, 93 articles remained, which were analyzed using a quantitative and qualitative approach. The predominance of applied studies was also noted through case studies that evaluate the management of materials and waste in the urban environment. The qualitative analysis, carried out using a SWOT matrix, highlighted the strengths of the buildings, such as material banks, the potential reduction of resource extraction and urban mining, and promoting the circulation of construction products. However, the recycling of waste, such as aggregates, still stands out as the main end-of-life strategy adopted, even without occupying the top of the waste hierarchy. Full article

Accurately and rationally quantifying the environmental impact of construction and demolition waste (CDW) management is paramount, especially the environmental impact of different waste disposals, and more effective policies should be implemented to manage CDW. However, previous research on CDW disposal has typically ignored the potential for energy recovery and focused on a single environmental impact category. Therefore, this study aims to develop a conceptual framework to assess the environmental impacts under different CDW management scenarios (including reuse, recycling, energy recovery, and landfill), quantifying the global warming potential and resource consumption impacts under different scenarios. This framework incorporates Building Information Modeling to accurately collect data for feedback to the Life Cycle Assessment. The results indicate that Scenario 3, which considers the circular economy strategy, efficiently reuses metals, plastics, glass, and wood, generates recycled aggregate from concrete and cement, recycles bricks and tiles, and uses the remaining waste for energy recovery. This CDW management scenario, which prioritizes reuse and recycling, is the most effective in mitigating carbon emissions, resulting in a reduction of 6.641 × 10⁵ kg CO₂ eq. Moreover, it significantly conserves resources and prevents the energy consumption of 4.601 × 10⁷ MJ. Among them, metal reuse saves 42.35% of resources, and plastic reuse saves 31.19% of resources. In addition, increasing the reuse rate and recovery rate can directly avoid carbon emissions and cumulative exergy consumption, effectively alleviating environmental issues. This study can provide new ideas for the treatment of CDW, which can provide a basis for the relevant government departments to formulate CDW management policies. Full article

The rising concern for the environment and the need for a sustainable economic model has stimulated experimentation in the field of construction materials, notably in replacing certain components from cementitious materials with construction and demolition waste. The main objective of this study is to replace a significant proportion of natural aggregates with glass waste, in the composition of plastering mortars, and to observe the evolution of physical–mechanical characteristics in the fresh state: apparent density, consistency, and segregation tendency, and in the hardened state: apparent density, flexural strength, compression strength, and adhesion to the substrate, across time, at 3, 7, 14, and 28 days. SEM and EDX tests were also performed to observe the microscopical characteristics. The experimental program studied four types of plastering mortars: the reference mortar—CS IV, and three mortars in which aggregates have been replaced with glass waste in the following proportions, by mass: 15%, 30%, and 45%. Results obtained on fresh properties (apparent density and consistency) indicate a decrease in values as the percentage of glass increases, with the exception of the mortar with 30% aggregated glass replacement. The flexural strength and the compressive strength were improved by replacing 30% of the aggregates with glass waste and were not significantly impacted by a replacement of 15%. Mechanical properties decreased at a replacement level of 45%. All glass aggregate mortars had lower adhesion strength to the brick substrate than the reference mortar by up to 70%. SEM and EDX analyses showed the morphology of the studied mortars and the processes taking place to increase mechanical strength. Further research directions are proposed, including studying the glass particles, the occurrence of alkali–silica reactions, durability, and improvement of adhesion to the substrate, for progressing towards the most viable, locally sourced, waste-containing plastering mortar. Full article