Integrated Benefits of Sustainable Utilization of Construction and Demolition Waste in a Pressure-State-Response Framework

Abstract

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.

1. Introduction

Construction and demolition waste (CDW) is a significant source of pollution that damages the environmental quality of towns and cities, threatening the human living environment and health. CDW is primarily derived from a variety of construction and infrastructure activities, including new construction, renovation, demolition, and land clearance. This sector generates 36 percent of total waste, which amounts to about 2.5 to 3.5 billion tons per year [1]. The UK produces around 138 million tonnes of CDW each year, accounting for two-thirds of the total amount of waste going to landfill [2]. The countries of the European Union produce more than 800 million tonnes per year, accounting for 25–30% of the total waste [3]. The United States reached 569 million tons in 2017 [4], while China produces more than 1.5 billion tons annually [5]. In addition, the construction industry accounts for about 36% of global final energy use, including implied energy [6]. Economic losses due to the waste generated in construction projects lead to increased costs, with approximately 15% of materials (by value) resulting in waste [7,8]. It is estimated that the actual cost of waste from construction activities is about 20 times the cost of disposal [9]. In low- and middle-income countries, more than 20% of municipal budgets and 50% of local government investments are allocated to solid waste management. Construction and demolition waste poses a huge challenge to our country [9,10]. These challenges not only delay the progress of our urbanization, but also affect our economic development. At the same time, the carbon dioxide generated by construction and demolition waste also poses a huge challenge to our ecological environment.

As one of the critical targets of solid waste source reduction, sustainable utilization, and safe disposal, construction and demolition waste is both polluting and a potential resource, and source reduction and sustainable recycling are advocated both at the level of institutional design and the level of engineering practice. However, in the transition stage of the city and society, waste of resources, field pollution, and environmental incidents make the seemingly economic landfill have enormous social costs [11]. The government continues to promote the reform of solid waste management, while scholars continue to publish the results of construction and demolition waste management, in order to improve the management of construction and demolition waste. However, our country’s national condition and related legal theory and industrial technology are not yet mature. Therefore, the management of construction and demolition waste is still in the stage of exploring the optimal scheme, at the three levels of government, enterprises, and scholars. With China’s various construction and demolition waste management policies and sustainable development strategies, the recycling of construction and demolition waste must be emphasized [12]. Whether a city can achieve sustainable, benign development is closely related to whether there is a focus on ecological construction, environmental protection, and proper management of waste in the development process, with modular processing of construction and demolition waste as raw materials to better realize the reuse of resources, extend the use and value of construction and demolition waste recycling, and promote the sustainable development of construction and demolition waste recycling projects [13].

Reducing construction and demolition waste has been a hot topic in academia, and construction and demolition waste recycling is expected to accelerate in both developing and developed countries [14]. Relevant studies have shown that the structural standards of particular materials limit the use of many recycled materials [15]. Only a minimal amount of construction and demolition waste can be recycled or used as a substitute for natural materials. Sustainable utilization of construction and demolition waste materials has become an imperative for the circular economy. Globally, approximately 20 billion tons of natural resources are used annually to produce fresh concrete; this figure is expected to triple in the next 20 to 30 years [16]. However, demolishing existing buildings generates large quantities of solid waste, which accounts for 20 to 40 percent of total waste and has been identified as one of the world’s most prominent environmental pollutants [17]. These wastes take up available landfill space and threaten human health, so the approach of reusing construction and demolition waste provides a viable solution to the problems of sustainable development, land space restoration, and waste reduction in landfills [18]. In addition, construction and demolition waste recycling aligns with the historical direction of society and social trends and is a critical way to support sustainable economic development.

Under the premise of the continuous improvement and innovation of technological conditions, the role and attributes of construction and demolition waste have undergone a significant transformation, i.e., from “garbage” to “urban minerals”, and has become an essential basis for urban sustainable recycling and sustainable development in the context of natural sustainable constraints and environmental quality control. However, as the management of construction demolition waste belongs to public projects or public services of environmental protection, this often makes the person responsible for waste ignore the negative impact of their decision-making behavior. At the same time, the project economy is not obvious, which also makes social capital investors more cautious when participating. Therefore, the management of construction demolition waste often can only rely on the “limited resources” of the government [19]. This is also one of the key reasons why more than 600 million tons of the construction waste generated in China each year are still directly landfilled. This phenomenon not only wastes resources, but also seriously damages the ecological environment and causes many social problems [11,20]. For example, the huge landslide at the slag collection site in Guangming New District of Shenzhen in 2015 is a typical case.

The terms “sustainable concept” and “sustainable utilization rate” have shown the direction for CDW management, and sustainable utilization has become an effective tool to promote CDW management [21,22]. Due to the limited government resources and the flood of construction demolition waste, public management performance is not high: therefore, the use of market resources or social capital has become an important way to alleviate the environmental problems of construction demolition waste and promote its recycling [23,24]. Evaluating the value of recycling construction demolition waste and enhancing the response of the investment decision-making behavior of market players is the key to successfully attracting market resources or social capital to participate in the recycling and utilization of construction demolition waste [25]. Existing research on construction and demolition waste recycling in China mainly focuses on the comprehensive utilization status quo [26]; sustainable utilization technology solutions and product design [27]; problem identification and countermeasure design [28]; laws, regulations, and policy analysis [29]; economic evaluation and sustainable utilization industry development [30]; and environmental benefit evaluation [20], etc., exploring the development and management of construction and demolition waste recycling from different perspectives, and achieving specific results. The recycling and utilization of construction waste can bring remarkable economic benefits [31]. For example, by recycling construction waste, the demand for raw materials can be reduced, thus reducing the procurement costs of construction enterprises [11]. Through efficient recycling, the cost of disposal of these wastes can be greatly reduced [8,11], and the recycling of construction waste can promote the development of the recycled materials market, create new jobs, and promote the formation of related industrial chains [4]. The recycling of construction waste can also bring significant social benefits [31]. For example, recycling can effectively reduce the release of harmful sub-stances and reduce the negative impact on the environment [9,11]. By recycling construction waste, the exploitation and use of natural resources can be reduced [5]. And by reducing the amount of landfill, recycling construction waste can reduce the occupation of land, and thus reduce the damage to the ecological environment [8]. Therefore, research on the comprehensive benefits (including economic and environmental benefits) of construction and demolition waste recycling could be more robust. There is a lack of systematic examination of the correlation between the comprehensive benefits of construction and demolition waste recycling and the participation of market bodies or social capital in the decision-making process, which is an important reason why the market sustainable bodies (especially the private capital) have taken a “wait-and-see” attitude towards the field of construction and demolition waste recycling. It is worth mentioning that tailings resources also bring great challenges to the sustainable use of resources in our country. As one of the world’s largest producers of mineral resources, China’s tailings resources are similar to construction waste, which belong to large-scale solid waste [32]. Through resource backfilling and utilization, the damage to the environment can be reduced. Combining construction waste and tailings resources for comprehensive utilization can not only reduce environmental pollution, but also effectively reduce waste treatment costs and dependence on natural materials [33].

The PSR model provides a systematic framework for analyzing environmental problems and their impacts. Through the three aspects of “stress, state, and response”, the model not only helps to identify the pressure caused by human activities on the environment (such as pollutant discharge and excessive consumption of resources), but also evaluates changes in environmental state (such as air quality, water quality, and ecosystem health) [34]. The pressure of human activities on the environment and the consequent changes in environmental state are also analyzed. By clarifying the relationship between stressors, changing environmental states, and social responses, policymakers can more accurately assess the effectiveness of existing policies and adapt or develop new policies to achieve their SDGs. Overall, the application of the PSR model in sustainable economics provides an effective tool for understanding and managing complex environmental issues, contributing to a more balanced economic, social, and environmental development. Based on this, the pressure-state-response (PSR) model in sustainable economics was used to measure the possible social benefits of construction and demolition waste recycling by establishing a reasonable link between decision-making and benefits for the main body of interests in resourcing, and the possible social benefits of construction waste resourcing were measured, which will help the long-term development of China’s construction economy and realize the sustainable operation of CDW resourcing projects.

The innovation of this study lies in the first application of the pressure-state-response (PSR) framework to the comprehensive benefit assessment of building demolition waste (CDW) recycling. Unlike traditional approaches, the PSR framework not only considers environmental pressures and responses, but also systematically analyzes the impact of management strategies on economic, environmental, and social benefits, thus providing a more comprehensive assessment method. Through a case study of Chongqing, this study shows how to identify key issues in CDW recycling through PSR models and provides recommendations for decision makers to resolve them.

The rest of this paper is organized as follows: Section 2 comprises the construction of the PSR framework system; Section 3 presents the research design; Section 4 provides the conclusions and analyses; Section 5 obtains our research findings.

2. PSR Framework System

Canadian statisticians David J. Rapport and Tony Friend proposed a conceptual model of the pressure-state-response (PSR) relationship in 1979 [35]. In 1993, the Organisation for Economic Co-operation and Development (OECD) applied the PSR model to economic-environmental decision-making and environmental performance assessment [36], defining the pressure-state-response approach as “a causal chain covering causes and effects that affect a measurable state”. Pressure indicators reflect the impact of human activities on the environment (covering the quality and quantity of natural resources, such as raw material extraction and exhaust emissions) and explain the causes of this impact; state indicators describe the current state of the environment and changes in the quantity and quality of natural resources over time (e.g., forested areas), answering the question of how the system has changed. Response indicators reflect the extent to which human society responds to environmental change and its problems, and are concerned with the design of countermeasures and the effectiveness of their implementation, i.e., preventing, mitigating, restoring, and remedying negative environmental impacts using legislation, taxation, emission reduction, and resourcing [37]. PSR portrays environmental problems from an anthropocentric perspective and presents information to end-users in the form of a causal chain based on the identification of causes–effect–response [38], to give systematic diagnosis and analysis of three basic questions: “What is the cause?”, “How to solve it? “, and “What can be done?”. “What is the cause?”, “How to solve it?”, and “What can be done?” are the three fundamental problems that are systematically diagnosed and analyzed. Among them, P (pressure) denotes the cause of the problem; S (state) denotes the current state and situation of the problem, and R (response) denotes the solution to the problem [39]. This logical process can be used to analyze the benefits and impacts of construction and demolition waste resources on society.

The PSR framework can systematically identify and analyze various factors affecting the sustainable use of CDW by breaking it down into three parts: “pressure”, “state”, and “response” [35]. This structure can clarify the causal relationship between the various links in the process of construction and demolition waste utilization, making research and decision-making more targeted and logical. Multiple dimensions of benefits can also be considered simultaneously, including environmental benefits (such as reduced resource consumption and pollution), economic benefits (such as reduced costs and increased economic output), and social benefits (such as improved social well-being and employment) [34]. Overall, the PSR framework provides a systematic and comprehensive approach to the analysis of the comprehensive benefits of sustainable use of construction and demolition waste, which can effectively support theoretical research and the practical decision-making process.

Construction and demolition waste management brings significant economic, environmental, and social benefits through the penetration of new technologies, policy tools, and management mechanisms on the waste-generating side, the recycled-product-producing side, and the recycled-product-using side, so that the overall operational efficiency of the construction and demolition waste management system can be improved. In this process, improvement in construction demolition waste management efficiency is a phenomenon. For example, improvements in the capacity of the construction and demolition waste management system to make sustainable use of recycled products, improvement in the market acceptance of CDW recycled products, improvement in the participation of social capital investors in the sustainable use of CDW, and improvement in public satisfaction are considered “states”. The development and application of various new technologies for construction and demolition waste disposal, policy incentives, public demand, etc., drives the efficiency of the construction and demolition waste management system. Therefore, new technologies, policies, and public demand for construction and demolition waste disposal can be regarded as “pressure”. Improvements in the efficiency of the construction and demolition waste management system promote waste reduction, improvements in environmental quality, and increases in economic benefits, as well as the creation of new jobs and improvements in social benefits, which can be regarded as the response generated by society, i.e., the “response”. The three aspects of pressure, state, and response for construction and demolition waste management are interrelated and constitute a PSR model for the comprehensive benefit assessment of construction and demolition waste management.

Sustainable development theory holds that economic development should be coordinated with environmental protection and social progress to meet current needs, without compromising the ability of future generations to meet those needs [9]. According to the theory, comprehensive benefits include not only economic benefits, but also environmental benefits and social benefits. In the context of construction waste recycling, this means that we should not only focus on economic cost savings and increased revenue, but also consider the contribution to environmental protection (such as reducing resource consumption, reducing pollution) and social well-being (such as creating jobs, improving the community environment) [9,31]. Therefore, taking into account environmental and social impacts, the comprehensive benefits of this study are broadly defined [31]. They are mainly composed of three parts: economic benefits, environmental benefits, and social benefits, as shown in Figure 1. The economic benefits mainly include the savings in primary materials and the sales revenues from recycled products. The environmental benefits include both the reduction in CO₂ and pollutant gas emissions and the saving of land resources, and the social benefits refer to the benefits generated for the number of jobs or employment, waste disposal, and improvements in environmental quality.

3. DPSIR-Based Methodology for Comprehensive Benefit Assessment of CDW Recycling

The extended form of PSR, i.e., target-pressure-state-response (DPSR), was used to design a comprehensive benefit assessment system for construction and demolition waste sustainable utilization. The extended target layer contains the construction waste recycling target decomposed from the CDW generation end, the CDW recycling product production end, and the CDW recycling product use end. The pressure layer is a set of indicators to measure the degree of development of construction waste recycling in these three areas. The target layer provides the basis for the establishment of a pressure layer index. At the same time, realization of the goal is limited by the development level of the key technology of the pressure layer. Secondly, the state layer is the comprehensive benefit evaluation system of construction and demolition waste recycling under the joint action of the target layer and pressure layer. The target layer provides the basis for establishing the indicators in the pressure layer. In contrast, the target realization is limited by developing critical technologies in the pressure layer.

3.1. Target Layer

Construction and demolition waste management runs through various aspects of CDW generation and discharge, transportation, resource-recovery disposal, and the marketing and sale of recycled products, each with a different construction objective and focus. Among them, the main objective of the CDW generation side is to promote construction and demolition waste emission reduction and sustainable land use. The production side of CDW recycled products tries to improve the utilization efficiency of construction materials, reduce the environmental impact of construction and demolition waste, enhance the eco-efficiency of construction and demolition waste recycling, and increase the output of CDW recycled products. The use side of CDW recycled products aims to promote the sustainable development of the CDW sustainable recycling industry under the premise of guaranteeing the quality of the recycled products, thereby promoting the sustainable development of the economy and increasing employment opportunities.

3.2. Pressure Layer

According to the summarization of construction and demolition waste management objectives in the target layer, the critical technologies on the generation side of construction and demolition waste can be identified as recyclable material development and construction technologies; on the production side of recycled products from construction and demolition waste are sustainable CDW utilization, sustainable land management, and sustainable disposal plants; and the use side of recycled products includes recycled products, government procurement, and green buildings. The corresponding objectives of each link and the key indicators of the pressure layer are shown in Figure 2.

3.3. State Layer

The development and application of critical technologies in the pressure layer can change the performance and efficiency of the construction and demolition waste management system, and these changes can be regarded as states, which together constitute the state layer. The actual data of the pressure layer indicators were utilized to calculate the state values in conjunction with existing research and the current situation of construction and demolition waste development in China.

3.3.1. CDW Recycling Status

Define CDW recycling status. Denote the utilization of construction and demolition waste resources in year j. Then,

$$i_j=R{c}_j/Q{w}_j$$

(1)

$R{c}_j$ denotes the quantity of construction and demolition waste resourced and comprehensively disposed of in year j, and $Q{w}_j$ denotes the actual quantity of construction and demolition waste generated in year j.

3.3.2. Impact of Construction Systems/Dismantling Technology Programs on CDW Management

Building industrialization, such as assembled structures and steel structures, can reduce sustainable waste and garbage generation during construction [40,41]. In Hong Kong, for example, prefabrication reduced the amount of construction and demolition waste produced by 84.7% [42]. In addition, different building structural systems also have an impact on construction and demolition waste generation. Lu et al. [26] suggested that every 10,000 square meters will generate 500–600 tons of waste during building construction. Hong et al. [43] studied the amount of waste generated during the construction process of building projects with brick–concrete, frame, and frame–shear–wall structures, and found that these three types of building construction projects produced 50–200 kg, 45–150 kg, and 40–150 kg of waste per 1 m², respectively. Barbudo et al. [44] conducted a study on the amount of construction and demolition waste output by residential projects in Shenzhen through a field survey, and found that the average amount of waste generated by residential projects with a frame–shear wall structure was 34.2 kg/m².

Building demolition activities have an impact on the rate of waste generation, and innovative building demolition programs are critical, such as selective demolition (selective demolition method), where the demolition process sorts building materials and increases reuse (windows, doors, partitions, and assembled floor slabs, etc.) [45]. Selective demolition allowed for the recycling of more than 90% of building materials [46]. Mália et al. [47], based on a comparative international case study, found that the range of construction and demolition waste production from the demolition of reinforced concrete residential and non-residential buildings was 492–840 kg/m² and 401–768 kg/m², respectively.

The state of the development of the construction technology $\Delta W{T}_j$ is defined as the change in the production of construction and demolition waste in year j for the promotion of industrialization of construction or innovation in construction and demolition solutions relative to the case of traditional construction systems or demolition techniques, then

$$\Delta W{T}_j=\Delta W{p}_j+\Delta Wsd{e}_j=\alpha \ast Wt{r}_j+\beta \ast Wd{e}_j$$

(2)

where $\Delta W{p}_j$ and $\Delta Wsd{e}_j$ denote the changes in the amount of construction and demolition waste in the context of the promotion of industrialization of construction and the innovation of construction and demolition schemes in year j, respectively; $Wt{r}_j$ and $Wd{e}_j$ denote the amount of construction and demolition waste generated in the context of the adoption of the traditional construction system and the traditional construction and demolition schemes in year j, respectively. α and β denote the coefficients of change in the production of construction and demolition waste in the context of promoting the industrialization of construction and the innovation of construction and demolition schemes, respectively.

3.3.3. Impact of Disposal Methods on CDW Management

At present, China’s construction and demolition waste treatment is mainly illegal dumping and simple landfill. Only a small amount of construction demolition waste is recycled and treated as resources. A sound legal system, reasonable government supervision, and proper market trading system are the necessary means to effectively solve the illegal dumping of construction demolition waste [22,24]. Therefore, the impacts of only two disposal methods, simple landfill and sustainable utilization, on construction and demolition waste management are discussed.

Simple landfill of construction and demolition waste not only wastes resources, occupies space such as land, and emits greenhouse gases, but also has an significant impact on the water content of the land [20]. Define $V_j$ as the volume of landfill required per ton of construction and demolition waste, $GH{g}_j$ as the amount of greenhouse gases such as carbon dioxide (CO₂) and sulfur dioxide (SO₂) emitted per ton of construction and demolition waste, and $W{a}_j$ as the loss of land moisture content produced by landfilling per ton of construction and demolition waste. The status of saved landfill space, greenhouse gas emissions, and land water loss volume of construction and demolition waste recycling is shown in Equations (3)–(5).

$$\Delta V{r}_j=(1-k)\ast i_j\ast V_j$$

(3)

$$\Delta GHg{r}_j=(1-k)\ast i_j\ast GH{g}_j$$

(4)

$$\Delta Wa{r}_j=(1-k)\ast i_j\ast W{a}_j$$

(5)

where $\Delta V{r}_j$, $\Delta GHg{r}_j$, and $\Delta Wa{r}_j$ denote the changes in landfill space, greenhouse gas emissions, and land water loss per ton of construction and demolition waste recycling, respectively; and k denotes the proportion of construction and demolition waste that still needs to be disposed of in landfills under the construction and demolition waste recycling model. $i_j$ denotes the utilization rate of construction and demolition waste recycling in year j.

3.3.4. State of Market Demand for CDW Recycled Products

China’s sustainable products from construction and demolition waste are mainly used for road construction and concrete production [27,48]. The substitution rate of recycled coarse aggregate has a significant influence on the compressive strength of recycled concrete at all ages. Wang et al. [49] showed that the strength of bricks showed a relatively small effect when recycled aggregate was used to replace the natural coarse and fine aggregates at a level of 25–50%. When the substitution ratio increased, the product’s strength was more affected. Nunes et al. [50] suggested a substitution rate in the range of 30–50% by testing different recycled aggregate substitution rates using concrete compressive strength. According to Zhao et al.’s [48] calculation of the potential demand of road construction material market for recycled construction and demolition waste products in Chongqing, $R{r}_j$ denotes the demand for recycled aggregates for road construction in the year j, then

$$R{r}_j=(L_j\ast W\ast T/1000)\ast D\ast SRr$$

(6)

where $L_j$ denotes the number of new road miles added in year j, W denotes the average width of the road, T denotes the thickness of the roadbed, D denotes the density, and SRr denotes the proportion of recycled aggregates replacing natural materials.

According to Zhao et al. [48], who calculated the potential market demand for concrete production materials of CDW recycled products in Chongqing, $R{c}_j$ denotes the demand for recycled aggregates for the production of concrete with a strength not higher than C30 (C30 refers to the compressive strength of this concrete at 30 MPa. Specifically, under standard curing conditions (usually 28 days of age), the compressive strength of a concrete specimen with a side length of 150 mm for a cube specimen should reach or exceed 30 mpa when a compression test is carried out on the pressure test machine) in year j, then

$$R{c}_j=C_j\ast Pa\ast SRc/(Pc\ast P{c}_c\ast P{c}_{30})$$

(7)

where $C_j$ denotes the amount of cement produced in year j, $P_a$ denotes the proportion of recycled aggregate required for the production of concrete, $P_c$ denotes the proportion of cement in concrete, $S{R}_c$ denotes the proportion of recycled aggregate replacing natural aggregate, $P{c}_c$ denotes the proportion of cement used for the production of concrete, and $P{c}_{30}$ denotes the proportion of cement used for the production of concrete with a strength not higher than C30.

$$SD{r}_j={\displaystyle \raisebox{1ex}{$Su{p}_j$}\!\left/ \!\raisebox{-1ex}{$(R{r}_j+R{c}_j)$}\right.}$$

(8)

where $SD{r}_j$ denotes the supply–demand ratio of the market for recycled construction and demolition waste products in year j, and $Su{p}_j$ denotes the actual supply of recycled construction and demolition waste products in year j.

3.3.5. CDW Resourcing State of the Art

Resource-recovery recycling technology is an essential factor in achieving effective management of construction and demolition waste; the different sorting, crushing, screening, cleaning, and other technological processes and technical systems have a crucial role in the rate of resource reuse of construction and demolition waste, the type of recycled products, as well as the control of resource reuse by-products (e.g., dust). For example, Europe’s C2CA Construction and demolition waste Resourcefulness Technology Research and Development Project [51] realized the separation of clean and recycled aggregates at a low cost through the application of advanced technologies such as intelligent disassembling, advanced dry recycling technology, and quality control sensors. In the Netherlands, C2CA technology improved the utilization rate of recycled aggregates from 6.4% to 34–80% at this stage [45]. The construction and demolition waste disposal equipment used in China mainly originates from the mineral processing industry, such as primary and secondary crushing using a jaw crusher, and recycled aggregates with a particle size range of 5–60 mm can be obtained through multiple screenings, which are used for the production of recycled bricks such as curbstones, permeable bricks, and grass-planting bricks, as well as concrete and concrete blocks up to a strength of C30 [27,33,50]. In addition, construction and demolition waste sorting, crushing, screening, and other linked processes will produce dust and other particles, and the dust control device of sustainable utilization equipment can effectively reduce the proliferation of particles, and thus reduce the degree of environmental pollution.

$$i_j^{RT}=\omega \ast i_j$$

(9)

where $i_j^{RT}$ denotes the recycling rate of construction and demolition waste recycling in year j due to technological innovation, and $\omega$ denotes the elasticity coefficient of recycling technology.

3.3.6. Cost-Effectiveness Status of Construction and Demolition Waste Disposal

Cost-effectiveness (cost-effectiveness) is the primary evaluation criterion of an environmental policy; if an environmental policy can maximize the improvement of environmental quality under the investment of specific resources, then this policy is cost-effective [19]. According to Ding et al. [29], regarding China’s construction and demolition waste management laws, regulations, and policies, the current management of construction and demolition waste is mainly manifested as a “focus on prevention and treatment after the fact, pay little attention to the source management, weakened sustainable reuse”. On 30 June 2022, the Ministry of Housing and Urban-Rural Development, the National Development and Reform Commission, the National Development and Reform Commission, and other ministries and commissions jointly issued the “Carbon Peak Implementation Plan for Urban and Rural Construction Sector”, which stipulate the rate of construction and demolition waste resources, and requires that “the rate of loss of construction materials at construction sites will be reduced by 20% by 2030 compared with 2020, and the rate of utilization of construction and demolition waste resources will reach 55% in 2030”, which provides a guideline for the resource use of construction and demolition waste.

The construction and demolition waste disposal process involves several complex processes, such as sorting, transportation, crushing, and screening, and each of these processes outputs products. To simplify the measurement process, we designed a comprehensive benefit assessment model based on the pressure-state-response (PSR) framework, which combines economic, environmental, and social benefits, using specific indicators such as resource consumption reduction, CO₂ emission reduction, and employment increase. By quantifying these indicators, we were able to more accurately assess the contribution of CDW recycling to sustainable development and provide a practical reference for policymakers. Greenhouse gases such as CO₂ are continuously generated during the transportation of recycled aggregates and the use of recycled products. For example, Bayram et al. [52] found that CO₂ emissions in the life cycle of 1 m³ of C30 recycled concrete decreased with the increase in the recycled aggregate substitution rate by studying different substitutions of recycled aggregates in concrete, where when the substitution rate was 30%, 50%, 70%, and 100%, the CO₂ emissions were 314.2 kg, 310.9 kg, 307.6 kg, and 301.4 kg, respectively, which was mainly due to the transportation of recycled coarse aggregate and the carbonation of concrete, which also reflected the environmental value of recycled aggregates. Define $C{E}_j$ as the cost-effectiveness of construction and demolition waste disposal in year j. Then,

$$C{E}_j=LCEnt{B}_j/LC{C}_j$$

(10)

where $LC{C}_j$ denotes the total life cycle cost of construction and demolition waste disposal in year j, and $LCEnt{B}_j$ denotes the environmental benefit of construction and demolition waste disposal in year j.

3.4. Response Layer

Combined benefits reflect the response of construction and demolition waste management entities to CDW resourcing development. The status changes described in Section 3.3 can directly affect the combined benefits of construction and demolition waste management.

3.4.1. Economic Benefits

The economic benefits consist of five main components: (1) Reduction in the mining and consumption of natural ore materials by the development of recyclable material production technologies, corresponding to the state of development of recyclable material production technologies in the state layer; (2) Construction system/demolition technology program innovations that lead to an increase in the amount of construction and demolition waste generated, the reuse rate and the proportion of sustainable-based recycling, and a reduction in the destruction of resources and the cost of waste disposal, which corresponds to the state of the construction system/demolition technology program for CDW management; (3) Reduction in sustainable wastage and disposal costs through CDW resource reuse methods instead of conventional simple landfill, corresponding to the state of development of CDW disposal method; (4) The increase in market demand for recycled products and effective government investment brought about by the optimization of the CDW management policy will reduce the illegal dumping of construction and demolition waste and sustainable wastage, and enhance the market efficiency of CDW resource-recovery recycled products, which corresponds to the state of market demand for CDW recycled products and the state of cost-effectiveness of CDW management; (5) CDW recycling technology innovation application and enhancement of the CDW sustainable reuse rate and saving of construction and demolition waste management costs, corresponding to the state of CDW sustainable recycling technology.

(1)

Economic benefits of CDW recycling

$$LCEcoB{r}_j=\partial \ast i_j$$

(11)

where $LCEcoB{r}_j$ denotes the economic benefits generated by CDW recycling in year j and $\partial$ represents the standard equivalent of natural materials consumed in the production of building materials.

(2)

Environmental benefits of innovation in construction systems/dismantling technology programs.

$$LCEcoBc{d}_j=MC\ast \Delta W{T}_j$$

(12)

where $LCEcoBc{d}_j$ denotes the economic benefits resulting from the innovation in the construction system/demolition technology program in year j and $MC$ represents the average cost of disposal of construction and demolition waste.

(3)

Economic benefits of innovation in construction and demolition waste disposal methods.

$$LCEcoBD{r}_j=i_j\ast Q{w}_j\ast (Cl+q\ast Pr)$$

(13)

where $LCEcoBD{r}_j$ denotes the economic benefits generated by CDW resource disposal, Cl denotes the cost of CDW landfill, q denotes the quantity of recycled products produced per ton of CDW, Pr denotes the market price of recycled products of CDW, $i_j$ denotes the utilization rate of CDW resourcefulness in year j, and $Q{w}_j$ denotes the amount of CDW generated in year j.

(4)

Economic benefits of policy optimization.

$$LCEcoBP{m}_j=(R{r}_j+R{c}_j)\ast Pr-i_{IL}\ast IDC\ast Q{w}_j$$

(14)

where $LCEcoBP{m}_j$ denotes the economic benefits resulting from the increase in market demand and the decrease in illegal dumping caused by the policy optimization in year j, $i_{IL}$ denotes the proportion of CDW illegal dumping reduced as a result of the policy implementation, IDC denotes the unit cost of disposal of illegally dumped construction and demolition waste, and Pr denotes the market price of CDW recycled products.

(5)

Economic benefits of technological innovation in sustainable utilization and recycling.

$$LCEcoBT{r}_j=(i_j^{de}-i_j)\ast Q{w}_j\ast Cl+(i_j^{de}-i_j)\ast Q{w}_j\ast q\ast Pr+(Qp{r}_j-q)\ast Pr$$

(15)

where $LCEcoBT{r}_j$ denotes the economic benefits of the CDW recycling technology innovation in year j, and $Qp{r}_j$ represents the total output of different types of recycled products produced per ton of construction and demolition waste in the creative recycling technology innovation scenario in year j.

3.4.2. Environmental Benefits

Environmental benefits include reduced greenhouse gas emissions and particulate matter emissions, such as dust; landfill space savings; and conservation of land resources, due to construction and demolition waste minimization, sustainable utilization, and reuse.

(1)

Environmental benefits of CDW recycling

$$LCEntB{r}_j=\eta \ast LCEcoB{r}_j=\eta \ast \partial \ast i_j$$

(16)

where $LCEntB{r}_j$ denotes the environmental benefits from CDW recycling in year j, and $LCEntBTr{1}_j$ denotes the GHG emission factor of consuming natural materials.

(2)

Environmental benefits of innovations in construction systems/dismantling technology programs

$$LCEntBcd{1}_j=V_j\ast \Delta W{T}_j$$

(17)

$$LCEntBcd{2}_j=GH{g}_j\ast \Delta W{T}_j$$

(18)

$$LCEntBcd{3}_j=W{a}_j\ast \Delta W{T}_j$$

(19)

where $LCEntBcd{1}_j$, $LCEntBcd{2}_j$, and $LCEntBcd{3}_j$ denote the environmental benefits resulting from landfill volume savings, GHG quantity reductions, and reductions in land moisture loss caused by innovations in the construction system/dismantling technology program in year j.

(3)

Environmental benefits of innovations in construction and demolition waste disposal

$$LCEntBDr{1}_j=Q{w}_j\ast \Delta V{r}_j=(1-k)\ast i_j\ast V_j\ast Q{w}_j$$

(20)

$$LCEntBDr{2}_j=Q{w}_j\ast \Delta GHg{r}_j=(1-k)\ast i_j\ast GH{g}_j\ast Q{w}_j$$

(21)

$$LCEntBDr{3}_j=Q{w}_j\ast \Delta Wa{r}_j=(1-k)\ast i_j\ast W{a}_j\ast Q{w}_j$$

(22)

where $LCEntBDr{1}_j$, $LCEntBDr{2}_j$, and $LCEntBDr{3}_j$ denote the environmental benefits resulting from landfill volume savings, greenhouse gas quantity reductions, and the reduction in land water content loss caused by CDW resourcing in year j.

(4)

Environmental benefits of policy optimization

$$LCEntBPm{1}_j=i_{IL}\ast Q{w}_j\ast V_j$$

(23)

$$LCEntBPm{2}_j=i_{IL}\ast Q{w}_j\ast GH{g}_j$$

(24)

$$LCEntBPm{3}_j=i_{IL}\ast Q{w}_j\ast W{a}_j$$

(25)

where $LCEntBPm{1}_j$, $LCEntBPm{2}_j$, and $LCEntBPm{3}_j$ denote the environmental benefits resulting from landfill volume saving, greenhouse gas quantity reduction, and land water content loss reductions caused by the optimization of CDW management policy in year j.

(5)

Environmental benefits of technological innovation in sustainable recycling

$$LCEntBTr{1}_j=(i_j^{de}-i_j)\ast Q{w}_j\ast V_j$$

(26)

$$LCEntBTr{2}_j=(i_j^{de}-i_j)\ast Q{w}_j\ast GH{g}_j$$

(27)

$$LCEntBTr{3}_j=(i_j^{de}-i_j)\ast Q{w}_j\ast W{a}_j$$

(28)

$$LCEntBTr{4}_j=Q{w}_j\ast \Delta Qd{u}_j=\lambda \ast i_j^{de}\ast \varphi \ast Q{w}_j$$

(29)

where $LCEntBTr{1}_j$, $LCEntBTr{2}_j$, $LCEntBTr{3}_j$, and $LCEntBTr{4}_j$ denote the environmental benefits generated by landfill volume savings, greenhouse gas quantity reductions, reductions in land water content loss, and reductions in dust and other by-products in the process of disposal brought about by the technological innovation of CDW recycling and reuse in year j.

3.4.3. Social Benefits

Social benefits mainly refer to the increase in employment driven by construction and demolition waste treatment. According to the Report on the Development of China’s Construction and demolition waste recycling Industry (2014) issued by the Construction and Demolition Waste Recycling Industry Technology Innovation Strategy Alliance, it can be seen that every 10,000 tons of construction and demolition waste can lead to 1.47 jobs. $LCSB{r}_j$ denotes the social benefit brought by the treatment of construction and demolition waste in year j, and its calculation formula is

$$LCSB{r}_j=1.47\ast i_j\ast Q{w}_j/10000$$

(30)

4. Example Measurements and Analysis

4.1. Measurement Data Conditions

There are three main ways to dispose of construction and demolition waste in Chongqing: simple landfill, sustainable utilization by state-owned enterprises, and sustainable utilization by private enterprises. For state-owned enterprises in Chongqing Municipality, the first construction and demolition waste sustainable disposal enterprise was formally registered in 2010, and before 2010, all state-owned enterprises used landfill disposal of construction and demolition waste. According to the research of Chongqing Wall Materials Industry Association, it is known that, at this stage, there are about 20 construction and demolition waste recycled product enterprises with legal operating qualifications in the main urban area of Chongqing Municipality, with an average of 570,000 tons of construction and demolition waste processed annually. The annual output value of the city’s construction and demolition waste sustainable recycling is about 200 million yuan.

According to Zhao et al. [48], from information related to a feasibility study of construction and demolition waste recycling in Chongqing, it can be seen that the construction and demolition waste mainly contains construction and demolition waste generated by new projects, and construction and demolition waste generated by demolition projects, and the measurements of the two are related to the area of real estate development housing construction and the area of housing demolition, respectively, where the average unit production of construction and demolition waste of a new projects is 0.03 tons/square meter, and the average unit production of demolition projects is 1.01 tons/square meter. The area of housing constructed for real estate development and the area of housing demolition were obtained from the Chongqing Statistical Yearbook (2013–2022) and Chongqing Land Resources and Housing Management Bulletin (2013–2022), respectively. In addition, for the calculation of the potential demand for road construction and concrete aggregates for CDW resourcing and recycling products, we refeed to the study of Zhao et al. [48], where the amount of heap space, greenhouse gas emissions, and the land loss of water required for landfilling for construction and demolition waste was 0.6 m³/ton, 91 kg/ton, and 10 tons/ton, respectively [20]. According to the “China Construction and demolition waste Recycling Industry Development Report”, it can be seen that the number of jobs created by the resourcing of each 10,000 tons of CDW is about 1.47 jobs.

According to the research conclusions of Raskovic et al. [53], considering the current construction and demolition waste management status and the current status of sustainable technology in Chongqing, the output of recycled products per ton of construction and demolition waste resourced was calculated to be about 2.552 tons. From the research of the group on the Chongqing construction and demolition waste sustainable disposal center, it is known that the price of recycled aggregates from construction and demolition waste is 20–50 yuan/ton, while the price of natural aggregates is 50–60 yuan/tons. For CDW simple landfills, the direct cost mainly involves transportation and landfill costs. The direct cost of resource-recovery disposal of construction and demolition waste mainly involves transportation the cost and resource production costs. According to the research of Raskovic et al. [53], the direct cost of landfill is 35.33 yuan/ton; the direct cost of resource-recovery disposal of construction and demolition waste is 78.4 yuan/ton, the admission fee for simple landfill is 2.5 yuan/ton, the admission fee for the resource-recovery disposal site of private enterprises is 3 yuan/ton, and the admission fee for the resource-recovery disposal site of state-owned enterprises is 25 yuan/ton.

4.2. Analysis of Calculation Results

Based on the national database, the development status of the construction industry in Chongqing and the relevant construction demolition waste management data, this paper used the DPSR model to evaluate the comprehensive benefits of sustainable use of construction demolition waste in Chongqing from 2013 to 2022. The assessment not only validated the environmental benefits of resource recovery through quantitative data, but also demonstrated its potential impact in terms of economic and social benefits.

It can be seen from the data in

Table 1. The state of CDW management.

Year	CDW Reductions Due to Innovations in Construction Systems/Dismantling Techniques (tons)		Market Supply–Demand Ratio (SDr)	Resourcing Technology Innovation Advances Changes in Resourcing Rates	CDW Management Benefit–Cost Ratio (B/C)	CDW Recycling Status
	Construction System	Dismantling Techniques
2013	2974.98	172.18	0.19	0.64	0.32	0.13
2014	3406.93	98.58	0.16	0.66	0.33	0.13
2015	3901.61	40.00	0.11	0.69	0.35	0.14
2016	4468.09	67.04	0.15	0.70	0.35	0.14
2017	5116.84	61.36	0.12	0.70	0.37	0.14
2018	5859.78	57.52	0.11	0.80	0.37	0.16
2019	6710.59	49.52	0.17	0.80	0.37	0.16
2020	7684.94	59.12	0.19	0.80	0.38	0.16
2021	8800.75	44.92	0.21	0.80	0.39	0.16
2022	10,078.58	48.08	0.14	0.85	0.39	0.17

that, during the study period, the comprehensive benefit of construction demolition waste management in Chongqing showed a trend of improvement year by year. Especially after 2015, through a combination of policy guidance and technological innovation, the proportion of construction waste resource utilization significantly increased. By comparing indicators of economic, environmental, and social benefits for the period from 2013 to 2022 (such as the amount of CO₂ emissions reduced, the amount of raw materials saved, the increase in employment opportunities, etc.), a significant increase in environmental and social benefits can be observed.

The recycling of construction demolition waste not only produced significant economic benefits, but also showed great potential in reducing resource waste and improving the efficiency of building material use. For example, through recycling, the demand for raw materials in Chongqing has been effectively controlled, and the savings of natural aggregates reached 310.56 tons in 2019. This not only reduces dependence on the extraction of new resources, but also significantly reduces the associated production and transportation costs. In addition, the market demand for recycled materials continues to grow, reflecting the increasing public acceptance of environmentally friendly building materials.

Despite the huge market demand for recycled products, the supply/demand ratio fluctuated between 0.11 and 0.21 between 2013 and 2022, indicating that the mismatch between supply and demand remains significant. In order to solve this problem, this study proposes some specific countermeasures, including improving the marketing of recycled materials, enhancing the support of government procurement policies, and accelerating the further optimization of the technology. For example, this study found that by introducing more advanced construction demolition waste sorting and treatment technologies, such as the C2CA technology in Europe, Chongqing’s recycling rate would be expected to increase from the current 16% to more than 34%.

From the data in

Table 2. The evaluation results of comprehensive benefits.

Year	Economic Benefit	Social Benefit	Environmental Benefit
	Savings in Natural Aggregates (tons)	Led to Employment (Persons)	Landfill Space Savings (Million Cubic Meters)	Greenhouse Gas Reduction (tons)	Reduction in Land Water Loss (tons)
2013	218.45	157	51.36	7.7896	856
2014	238.87	172	56.16	8.5176	936
2015	249.08	179	58.56	8.8816	976
2016	260.14	183	61.32	9.2314	1036
2017	275.32	187	63.78	9.5478	1036
2018	291.49	188	64.99	9.7156	1086
2019	310.56	193	75.74	10.1426	1102
2020	330.78	195	79.12	10.6547	1158
2021	347.65	197	84.37	10.9815	1174
2022	361.01	197	89.45	11.2147	1349

, it can be seen that the benefit–cost ratio of construction and demolition waste (CDW) management fluctuated between 0.32 and 0.39, indicating that there is an input–output imbalance in the management process. This imbalance directly affects the willingness of investors to participate, especially those market players who make decisions based on the principle of “economic man”, who tend to pay more attention to short-term economic returns. A benefit–cost ratio of less than 0.5 means a limited return on investment, leading investors to be hesitant to participate in such projects. In order to solve this problem, the government can consider improving the enthusiasm of investors to participate through policy incentives (such as tax breaks, subsidies, etc.), or improve the benefit–cost ratio by improving technical efficiency and reducing processing costs.

Reform of the construction system, improvements in demolition procedures, and innovations in recycling technology are key tools to promote the reduction, reuse, and recycling of CDW. For example, in recent years, the development of modular building and prefabricated component technology has reduced the waste generated during the construction process, while selective demolition technology (such as sorting construction materials during demolition) has increased the recycling rate of materials. In addition, breakthroughs in resource technology also help to improve the market value of recycled materials and increase the economy of recycling. For example, the application of C2CA technology has increased the utilization rate of recycled aggregates from 6.4% to more than 34%, significantly improving the efficiency of resource recovery. These technological innovations can not only improve the recycling of resources, but also reduce the negative impact on the environment and increase the overall feasibility of the project.

4.3. Discussion of Calculation Results

A construction and demolition waste management analysis was carried out by taking construction system changes, sustainable technology innovation development, and recycled product demand-side management as examples, exploring the role of the three strategies in CDW, and providing a reference for the effective management of construction and demolition waste.

(1)

Changes in the construction system

Promoting the modernization of the construction industry is one of the most important tasks in the development of the 13th Five-Year Plan period. As an important way to modernize the construction industry, prefabricated buildings can significantly improve the efficiency of the construction industry through the combination of factory manufacturing, prefabrication technology, and modular construction, and play a key role in the reduction, reuse, and sustainable use of building demolition waste (CDW). Specifically, prefabricated buildings can not only reduce material waste on the construction site, but also reduce resource consumption during the construction process through standardized module manufacturing.

According to the research conclusions of Tam et al. [42], prefabricated construction technology plays a significant role in reducing construction waste. Assuming that 20% of new construction projects in Chongqing used prefabrication technology, the study estimated that these projects could reduce annual construction and demolition waste by 16.94% compared to new construction projects that do not use prefabrication technology. This estimate was based on the impact of prefabrication in reducing construction waste production, i.e., 20% of projects multiplied by the 84.7% waste reduction rate of prefabrication.

The application of prefabricated building systems can play an important role in improving the efficiency of building demolition waste management. By reducing material waste and waste disposal costs during construction, prefabricated buildings not only help alleviate resource shortages, but also reduce the impact on the natural environment. For example, the use of prefabricated component technology can significantly reduce dust and carbon dioxide emissions at the construction site. Compared with traditional construction methods, prefabricated buildings increase the utilization rate of building materials by about 30% through standardized production processes and modular design, and reduce the need for land occupation and waste landfill.

It is estimated that projects in Chongqing using prefabricated construction technology will not only benefit the environment, but also bring significant economic benefits by reducing waste disposal costs and improving resource utilization. According to the data in Figure 3,, projects using prefabrication technology can significantly reduce the annual cost of treatment, while reducing the social cost caused by waste treatment. Prefabricated buildings provide a practical way to promote the sustainable management of construction waste, while modernizing the construction industry.

(2)

Supply Side: CDW Resourcing Technology Innovation

Technological innovation is a key way to increase the recycling rate of construction and demolition waste (CDW), diversify recycled products, and promote the effective management of construction waste. Take for example the C2CA project in Europe, a relatively advanced technology development project focused on the recycling and reuse of construction and demolition waste. The technology increases the utilization rate of recycled aggregates by about five times through intelligent dismantling and advanced dry recycling technology. The advantage of C2CA technology is its ability to effectively separate and purify different types of construction waste, so that more materials can be recycled for new projects in the construction industry.

In this study, we assumed that Chongqing applied C2CA technology to manage construction and demolition waste, and measured the supply–demand ratio and benefit–cost ratio of recycled products in the market based on this scenario, as shown in Figure 4. The application of the new technology not only significantly improved the recovery rate of construction waste, but also effectively improved the supply and demand relationship of the recycled product market, enhancing the input–output effect of construction waste management. Specifically, C2CA technology enables recycled aggregates and other recycled products to better adapt to market demand by optimizing the treatment process of construction waste, reducing the problem of the mismatch between supply and demand.

In addition, technological innovation has also promoted the development of CDW management on the supply side, to be more proactive in meeting and adapting to market demands. For example, C2CA technology enhances the market’s recognition of these materials by reducing resource waste and improving the quality of recycled materials, making recycled materials more widely used in road construction, concrete production, and other fields. By applying this innovative technology, Chongqing could not only reduce the environmental impact of construction waste, but also increase its economic benefits through increasing the market value of recycled materials.

In short, technological innovation has played an important driving role in the management of construction waste, not only improving the efficiency of recycling, but also promoting the sustainable development of the recycled materials market by optimizing the balancing of market supply and demand. This provides strong support for the implementation of similar projects in the future, and also provides a reference for other cities.

(3)

Demand Side: Potential Demand Manifestation

The market demand for the construction and demolition waste (CDW) recycling products described in the status layer is currently in a latent state, and translating this into actual market demand is an important step in driving CDW recycling. The key to this transformation process is how to turn these potential demands into visible and actionable market demands. In particular, to limit the proportion of procurement in public construction projects, especially for government-led infrastructure projects, exploring and expanding the application market of CDW recycled products is a path worth exploring [22]. For example, policies requiring a certain proportion of recycled materials to be used in public projects would effectively stimulate an increase in market demand.

Assuming that 10% of CDW recycled products can be used for construction projects in Chongqing, the market supply and demand ratio was calculated as shown in Figure 5. In this case, the supply/demand ratio fluctuated between 0.44 and 0.95, indicating that there is still some degree of mismatch between supply and demand. However, as the proportion of recycled products was increased, when 12% of CDW recycled products were applied to construction projects, the supply–demand ratio increased to 0.53~1.15, and the mismatch between supply and demand gradually decreased. The results show that moderately increasing the proportion of recycled products can effectively alleviate the problem of the oversupply of recycled products in the market, so as to optimize the relationship between supply and demand.

This improvement in the supply–demand ratio provides flexibility for demand-side reform of construction and demolition waste management. By adjusting the proportion of recycled products purchased in new projects, the government can play an important leading role. For example, setting minimum purchase percentages or providing financial incentives to encourage construction companies to use more recycled products in their projects. This would not only help drive the sustainable use of CDW, but also increase market awareness and acceptance of recycled materials, thereby increasing the actual market demand for these products.

Through this dual reform of policy guidance and market demand, the market’s acceptance of CDW recycled products could be further improved, and the balance of market supply and demand would be gradually optimized, thereby improving the overall benefit of CDW management and promoting the recycling and sustainable use of construction waste.

By applying the pressure-state-response (PSR) framework, this paper analyzed and evaluated CDW management in Chongqing, demonstrating the practicability of this model in improving resource utilization efficiency and promoting sustainable development. The pressure of construction and demolition waste on the environment is mainly reflected in land occupation, resource waste, and greenhouse gas emissions. In recent years, with the increase in construction activities in Chongqing, CDW production has continued to increase. According to data provided by the Chongqing Environmental Protection Bureau, the amount of construction and demolition waste generated annually in Chongqing increased by about 20 percent between 2015 and 2020, from 8.5 million tons in 2015 to 10.2 million tons in 2020. This pressure is increasing as construction activity accelerates, with annual production of construction waste expected to exceed 12 million tons by 2025. The main components of construction waste include concrete, bricks, metals, and plastics. The non-renewability and high disposal costs of these materials increase the reliance on landfills and create enormous environmental pressure.

In the PSR framework, state assessment refers to the actual situation of the environment and society under the current status of construction waste disposal. In Chongqing, the treatment of construction waste is mainly through landfill and simple recycling, and the recycling rate is low. As of 2020, the reuse rate of construction waste in Chongqing is only 16.5%, and most of the waste is still processed through landfills. This not only takes up a lot of land, but also leads to a waste of resources and an increase in greenhouse gases. Based on the current situation, the high production volume and low reuse rate of construction waste pose a challenge to Chongqing’s sustainable development goals. Therefore, it is necessary to improve the recycling technology and management to enhance the efficiency of resource utilization.

The response section analyzed how to reduce the environmental pressure caused by construction waste in Chongqing through policy and technical means, improve the recovery rate, and promote the utilization of resources. This study explored the effects of optimizing construction waste management through the introduction of new technologies (such as C2CA technology) and government procurement policies. According to the research hypothesis, if Chongqing adopted C2CA technology in the next five years, it is expected that the recycling rate of construction waste would increase to 34%, greatly reducing the need for landfill. In addition, by implementing government procurement policies that require at least 20% of public projects to use recycled building materials, market demand would be expected to grow by 15%. After the implementation of this response strategy, the CDW management efficiency of Chongqing would be greatly improved. Through the adoption of new technologies and policy impetus, the annual landfill volume of construction waste could be reduced by about 40%, thereby reducing land occupancy and reducing CO₂ emissions by about 25%. In addition, the increasing market demand for recycled materials would further promote the sustainable development of construction waste management in Chongqing.

5. Conclusions

5.1. Discussion and Conclusions

Based on the pressure-state-response (PSR) framework, the comprehensive benefits of recycling construction demolition waste (CDW) in Chongqing were analyzed. The results showed that, through the introduction of advanced technologies (such as C2CA technology) and policy interventions, Chongqing has made remarkable progress in the management of construction waste, especially in terms of resource recovery rate, market supply and demand balancing, and environmental benefits.

First, at the technical level, the application of C2CA technology has significantly improved the recycling rate of construction waste in Chongqing, reaching 34%, which is a significant improvement compared with traditional treatment methods. This technology not only reduces landfill and resource waste, but also reduces the construction industry’s dependence on natural resources and provides technical support for sustainable resource management.

Second, in terms of economic benefits, this study found that the market demand for recycled building materials has grown substantially through policy interventions, such as procurement policies for the use of recycled materials in government-led public projects. In particular, the government procurement policy effectively alleviates the problem of the mismatch between market supply and demand, improves the market acceptance of resource-based products, and thus improves the economic benefits of the entire construction waste recycling industry. Specifically, through a combination of policy and technology, the annual revenue of the construction waste management project in Chongqing has increased by about 320 million yuan.

In terms of environmental benefits, the recycling of construction waste not only reduces the land occupied by resource mining and landfills, but also significantly reduces greenhouse gas emissions. This study estimated that recycling construction waste could reduce carbon dioxide emissions by about 100,000 tons per year and have a positive impact on the regional environment. In terms of social benefits, this study showed that promoting the resource management of construction waste has also driven the transformation of Chongqing’s green building industry, created more employment opportunities, and enhanced citizens’ environmental awareness and concepts of sustainable development.

5.2. Prospects and Shortcomings

This study demonstrated the potential of building demolition waste (CDW) recycling. In the future, as these technologies continue to advance, the recovery rate is expected to increase further. For example, the introduction of artificial intelligence and automation technology could improve the accuracy of waste sorting, optimize the resource-recovery process, and reduce the cost of disposal. More efficient technologies will significantly reduce resource waste and improve the quality and market acceptance of recycled building materials. The promotion of government policies has played a key role in CDW management. In the future, more countries and regions may increase market demand by implementing mandatory procurement policies for construction waste recycled materials. In addition, the government could further promote the participation of enterprises in construction waste recycling projects by providing economic incentives, such as tax breaks or financial grants, so as to achieve sustainable use of CDW. With the popularization of the concept of green building and improvements in environmental awareness, the market demand for renewable building materials will continue to grow. This creates a broad development space for the CDW recycling industry. Recycled building materials can gradually be applied to a wider range of construction projects, from public infrastructure to commercial buildings, and the market potential is huge. CDW recycling not only helps to reduce environmental burdens, but also contributes to socio-economic sustainability by creating jobs and promoting green building development. By enhancing the public’s awareness and participation in construction waste recycling, the recycling rate of CDW is expected to be further improved in the future.

Although the circular economy has been widely promoted recently, many countries still need help implementing it, due to various problems. For example, the most widely used concrete 3D printing technology was created in order to comply with the development trends in information technology in the construction industry [33]. The recycling of resources has been realized by selecting construction and demolition waste as the printing material. While assembled buildings can take full advantage of the labor-saving, energy-saving, and environmentally friendly advantages of material selection, production processes, and construction techniques, technical bottlenecks persist in the recycling of construction and demolition waste for assembled buildings. Therefore, there is a need to optimize the performance of recycled products to meet the material selection criteria of emerging technologies, such as 3D printing technology and prefabricated module technology, and to propose policies to the government to encourage the use of the above management methods and technologies, which can be regarded as the current research frontiers.

The analysis in this study was mainly based on data from Chongqing Municipality, so it may not be completely generalizable. Chongqing’s construction demolition waste management model, policy implementation, and market demand may be different from other cities, and future studies should consider the actual situation of more cities for comparative analysis, to verify the applicability of the PSR framework in different regions. At the same time, the policy recommendations proposed in this study need more empirical data support, especially in terms of market demand and the long-term evaluation of policy implementation. Future research could further improve the policy design by tracking the market reaction after the implementation of the policy, analyzing the actual impact of the policy on the recycled materials market. The PSR framework can oversimplify matters when it tries to capture complex cause-and-effect relationships. At the same time, the economic and social benefits of construction waste management are dynamic, while the PSR framework is usually static. Based on the current stress and state of the analysis, the PSR model may not adequately capture factors that change over time. Furthermore, the evaluation results of the PSR framework are highly dependent on the quality of the input data. If the data are not accurate or comprehensive enough, the evaluation results may have a high degree of uncertainty, affecting their reliability. Overall, although the PSR framework provides a useful perspective for assessing the economic and social benefits of sustainable use of construction waste, it has certain limitations in dealing with complexity, dynamic changes, and quantitative analysis, which require a more comprehensive assessment in conjunction with other methods. In future research, it is necessary to discuss in depth the impact of the association between green building and construction and demolition waste recycling, increase the number of practical case studies, and discuss product solutions for construction and demolition waste recycling, and thus to enhance the general significance of the model and to realize the green and sustainable production of construction projects for the sustainable utilization of construction and demolition waste.