Recycling Of Construction Waste Research Articles

Spatial Distribution of Construction Waste Recycling Facilities

Spatial Distribution of Construction Waste Recycling Facilities

Using Recycled Construction and Demolition Waste Products: A Review of Stakeholders’ Perceptions, Decisions, and Motivations

While the increasing rate of urbanisation is a critical concern for socio-environmental reasons, this also leads to more extraction of natural raw materials and the generation of significant quantities of construction and demolition (C&D) waste. Although the use of recycled C&D waste products is technically feasible and regulated, and positive application examples are evident, it is still unclear how to engage key stakeholders to leverage this opportunity in construction projects. Previous research has shown that there is some level of resistance to the reuse of recycled C&D waste products in construction projects. This highlights a critical need to identify the roles of key stakeholders and the barriers they face when using recycled C&D materials. This paper therefore investigates the type of stakeholders influencing the use of recycled C&D waste products and the main factors affecting stakeholders’ decisions to use recycled C&D waste products through a systematic literature review. The authors present an emergent enablers and barriers for recycled C&D waste products model and provide commentary on how stakeholders’ perceptions, decision and behaviour influence the use of recycled C&D waste products. The authors also contribute to the body of knowledge with insights into the factors that various stakeholders believe influence the market for recycled C&D waste products and provides a reference point for authorities to consider these behavioural insights for policy reform.

Flexural behaviour and efficiency of CFRP-laminate reinforced recycled concrete beams: Optimization using linear weighted sum method

The increased demand for lightweight high-performance composites has led to search for alternative reinforcement to improve the mechanical performance of conventional structures. Likewise, various research initiatives have advocated recycling of construction and demolition wastes and novel technologies to avert their generation. Owing to disadvantages of steel rebar, carbon fibre reinforced polymer (CFRP) was utilized as potential internal reinforcement in recycled concrete beam owing to its lightweight, non-corrosiveness, high-stiffness-to-weight ratio and flexibility. Our study revealed significant improvement in the mechanical performance and efficiency which is controlled by the fibre architecture. The improved mechanical properties was attributed to the Bauschinger strain-reversal effect, made possible by the effective CFRP tensile strength mobilization, its high bonded surface area and interfacial energy as well as the composite action of the multi-layered CFRP reinforcements. The best configuration (N4) revealed by the simplified linear weighted sum optimization method achieved strengthening (load) efficiency of 402.7%, ductility efficiency of 299.7%, fracture toughness efficiency of 567.1% and fracture energy efficiency of 5713.9% compared to the unreinforced control. In addition, CFRP laminate was 3.67–4.9 times more cost-effective than steel rebar in terms of fracture toughness. Therefore, CFRP-reinforced recycled concrete is recommended for cost-effective and sustainable prefabricated concrete structures.

Architectural and landscape organization of Norra Djurgårdsstaden in Stockholm

The article discusses the architectural and landscape organization of the district of energy-efficient houses Norra Djurgårdsstaden in Stockholm. Since the end of the 19th century, the Norra Djurgårdsstaden district, with an area of more than 2 thousand hectares, has been part of the industrial area of the Royal Seaport. At the beginning of the 21st century, it was decided to modernize this area and destroy previous industries. Construction began in 2011 as part of the Living City strategy, which envisaged a balanced integrated design and construction of housing, trade, offices, services and public places. The strategy of resource management and responsibility for the climate meant that the city should develop in the direction of a resource-efficient and non-toxic future free of fossil fuels. Using the energy characteristics of buildings, monitoring the amount and recycling of construction and household waste, as well as soil restoration, has significantly reduced the impact on the environment. It was revealed that the architectural and landscape organization, based on the principles of individualization of “spaces of movement” and “spaces of being”, ensured maximum contact with nature, conservation of biodiversity, ecological, visual and social value of streets and courtyards.

COMPACTION CHARACTERISTICS AND CBR OF SLUDGE BLENDED WITH RECYCLED CLAY BRICKS FOR ROAD SUBGRADE APPLICATION

Reuse and recycling of non-hazardous construction and demolition waste and industrial byproducts in the construction industry is vital to promote environmentally sound waste management. In particular, the effective utilization of sludge and waste clay bricks is greatly required in developing countries. This paper studied compaction characteristics and the California bearing ratio (CBR) of water treatment sludge (WTS) blended with clay brick aggregates for the road subgrade application. Raw and waste clay bricks from Vietnam were used for preparing clay brick (CB) and recycled clay brick (RCB) aggregates of three different particle sizes, Coarse 10–30 mm, Graded 2–30 mm, and Fine 2–10 mm. In addition, fine residues of clay bricks with a size of 100%). Due to its limited particle breakage and high CBR, the WTS blended with graded CB/RCB aggregates was preferable for the road subgrade application.

Digital Twin in Circular Economy: Remanufacturing in Construction

Global warming attracts increasing public attention. However, in the past few decades, the contribution of construction to greenhouse gas emissions is around 40% of total emissions. The promotion of construction waste remanufacturing faces challenges. The application of digital twins in the remanufacturing of construction waste contributes to the tracking, recycling and management of construction waste. This article reviews the current research on construction waste remanufacturing and the application of Digital Twin in construction and remanufacturing, aiming at finding the current challenge of construction waste remanufacturing and the opportunity of Digital Twin to solve it. Then, the Digital Twin platform concept for construction waste remanufacturing is provided as a solution for the current challenges. Theoretically, this paper points out the shortcomings of the current research in construction waste remanufacturing based on literature review. Meanwhile, this article proposes the application of Digital Twin in construction waste remanufacturing, which expands the research scope of circular economy in construction. In fact, this research has driven the Digital Twin application in more industries. Besides, this research proposes a concept of potential solutions for the current challenges of construction waste in circular economy.

Experiment on Recycled Construction Waste Mixture Used in Subbase

In order to improve the recycling efficiency of construction waste and make rational use of the concrete and brick demolished in the process of urban construction, the application of construction waste recycling mixture in road engineering was studied in this paper. Test results showed that the reasonable combination of recycled concrete and brick slag could achieve the purpose of reasonable utilization of construction waste and meet the strength of municipal road base mixture.

Бетоны с нанодобавкой из обожженного вторичного бетона

The practice of using recycled concrete from the broken concrete of substandard reinforced concrete products can become widespread in practice. The undoubted relevance of this topic is explained by the program for the renovation of the housing stock in the city of Moscow, which provides for the demolition of 5-storey residential buildings until 2032. The problem of recycling and reuse of construction waste becomes obvious to improve the environmental situation, as well as to reduce the cost of materials in construction and preserve natural resources. The article deals with the nanostructuring of cement systems by means of introduction of ultra- and nanodispersed mineral additives. In this case, additional grinding of mineral additives is carried out in cavitation units. Nanostructuring provides the compaction of concrete structures and an increase in the strength properties of concrete.

A critical literature review on reuse and recycling of construction waste in construction industry

Development squander material is a significant issues of development field. This paper says that, detailed study on literatures, list of materials used, reuse of materials, sources of wastes and the places where the materials can be reused. Finally, comparison of percentage on waste materials (Standard waste and Actual waste at site through interview), Table for the sources and reuse of waste as per literature study, suggestion have been given to reuse the waste and suggestion given to manage the materials.

Recycling of concrete construction and demolition waste in alternative binders: Part 2 – Environmental footprint

The concrete demolition and construction waste (CDW) is usually recycled as aggregate. The fine fraction (crushed sand and powder) obtained from the recycling process remains less recovered – for downcycling purposes such as backfilling, if recovered at all. The feasibility study on the recycling of concrete waste as a component of a blended binder is presented in Part 1 of the study. Part 2 is dedicated to a preliminary assessment of the environmental impacts of the partial replacement of Portland cement binder by a waste concrete powder (WCP). The assessment is focused on the binder production stage as per BDS EN 15804 and does not consider any further scenarios. The environmental impacts of alternative binders with a different amount of WCP is compared to the impacts of conventional cement types CEM I, CEM II/A and CEM II/B. The results confirm that there is a significant reduction of the environmental impacts when WCP is used for cement replacement, because of the more efficient use of material resources and energy. The effect is more pronounced with the higher replacement rate. Therefore, the use of WCP in cements leads to more eco-friendly binders and can contribute to closing the concrete loop.

Recycling of concrete construction and demolition waste in alternative binders: Part 1 – Technical study

The concrete construction and demolition waste (CDW) is usually recycled as coarse aggregate. The fine fraction remains unused – if recovered at all, it is for downcycling in backfilling. Part 1 of this article is dedicated to a technical study on recycling of the waste concrete powder (WCP) as supplement in blended cements. Part 2 presents assessment of the environmental impacts of those binders. XRD and DTA/TG analyses of WCP are performed. WCP from two types of concrete CDW is used. The behaviour of fresh and hardened pastes with replacement of CEM I 52,5 by WCP (15%, 30% and 45%) is investigated. Standard methods of testing with some modifications are used. The influence of WCP content on the setting, consistency, strength and water absorption is evaluated. Four different curing regimes are applied. The results confirm the initial assumption that WCP can be consider as cementitious supplement. The replacement rate up to 15% practically does not change the behaviour of the binder, while 45% seems to be the maximum, because of binders performances degradation. The replacement up to 30% allows to keep satisfactory technical properties, but offers greater economic and environmental advantages.

Challenges in current construction and demolition waste recycling: A China study

China produced a large amount of construction and demolition (C&D) waste, owing to the rapid development of construction industry. Although a set of policies and regulations are being drafted in China for promoting C&D waste recycling, execution of these policies in practice seems to be far from effective. Currently, approximately 75% of Chinese cities are still surrounded by large volumes of C&D waste. Therefore, identification of challenges in the development of C&D waste management, specially recycling, is essential. This paper employs site visits to 10 recycling plants in 10 Chinese cities (Shanghai, Hangzhou, Suzhou, Chongqing, Chengdu, Xi’an, Changsha, Shenzhen, Nanjing, and Zhoukou) and interviews with 25 industry practitioners for examining the challenges. Eight challenges are identified: (1) unstable source of C&D waste for recycling, (2) absence of subsidies for recycling activities and high cost for land use, (3) insufficient attention paid to design for waste minimisation, (4) absence of regulations on on-site sorting, (5) unregulated landfill activities, (6) a lack of coordination among different government administration departments, (7) a lack of accurate estimation of waste quantity and distribution, and (8) a lack of an effective waste tracing system. Recommendations to address these challenges are presented. The results of this study are expected to aid policy makers in formulation of proper C&D waste management in China and provide a useful reference for researchers who are interested in C&D waste recycling industry.

A novel humidity regulating material hydrothermally synthetized from concrete waste

To promote the recycling of construction wastes, a low temperature (≤ 200 ℃) hydrothermal technology for solidifying construction (concrete) waste into a tough and humidity self-regulating material has been developed, in which more than 60% of concrete waste could be recycled. During the process, the whole concrete waste including aggregates could be converted hydrothermally into tobermorite or C–S–H. The formed tobermorite could not only enhance the strength but also improve the porosity and thus enhance the humidity regulating capability. The maximum flexural strength reached up to 22 MPa, and the increased porosity could provide a good moisture adsorption/desorption performance (170 g/m2). With the addition of sepiolite, the performance could be further improved (250 g/m2) due to the coexistence of the formed tobermorite and remained sepiolite. The materials also exerted a remarkable damping effect on relative humidity (RH) variation indoors, e.g., the RH variation even could be decreased to 1/3 compared to that of empty reference (no humidity regulating materials were used).

Tentative Ideas on Application of Prefabricated Environmentally-friendly Canals in Canal System of Farmland Irrigation District

This paper analyses the shortcomings of the reconstruction method of the current farmland irrigation canal and proposes a new type of environment-friendly prefabricated canal which is made of the new high-strength anti-seepage material produced by recycled construction waste. The new type of canal has the advantages of convenient transportation, low cost, high strength, short construction period, etc.

An Evolutionary Game Theory Study for Construction and Demolition Waste Recycling Considering Green Development Performance under the Chinese Government's Reward-Penalty Mechanism.

The low efficiency of the closed-loop supply chain in construction and demolition waste (CDW) recycling has restricted the green development of China’s construction industry. Additionally, the government’s reward–penalty mechanism has a huge influence on green development. This study aimed to investigate the effect of green development performance (GDP) and the government’s reward–penalty mechanism on the decision-making process of production and recycling units, as well as to reveal the optimal strategies under different conditions. Therefore, the strategies’ evolutionary paths of production and recycling units were investigated by using evolutionary game theory. Firstly, an evolutionary game model between production units and recycling units was proposed under the government’s reward–penalty mechanism. Then, the evolutionary stability strategies in different scenarios were discussed. Finally, the effects of the relevant parameters on the evolutionary paths of the game model were analyzed using numerical simulations. The main conclusions are as follows. (1) When the range of GDP changes, the evolutionary stable strategy changes accordingly. GDP plays a positive role in promoting the high-quality development of the CDW recycling supply chain, but an increase in GDP can easily lead to the simultaneous motivation of free-riding. (2) The government’s reward–penalty mechanism effectively regulates the decision-making process of production and recycling units. An increase in the subsidy rate and supervision probability helps to reduce free-riding behavior. Moreover, the incentive effect of the subsidy probability on recycling units is more obvious, while the effect of the supervision probability on improving the motivation of active participation for production units is more remarkable. This paper not only provides a decision-making basis to ensure production and recycling units to make optimal strategy choices under different conditions but also provides a reference for the government to formulate a reasonable reward–penalty mechanism that is conducive to a macro-control market.

Vision-based robotic system for on-site construction and demolition waste sorting and recycling

Construction and demolition waste (CDW) causes severe pollution on a global scale, as we can see from western countries' as well as Chinese statistics. CDW accounts over 25% of Hong Kong’s solid waste and about 40% for Australia and EU. The classification and recycling of CDW on construction sites make a vital contribution to the successful recycling of CDW. Currently, recycling of onsite construction waste is very time consuming and labor-intensive, which is probably one of the most critical reasons for inefficient CDW management. Previous experiences found that computer vision performed well in CDW recycling, but in special cases, the accuracy of the patrol and the picking method may cause failure. To reduce the occurrence of failure, this research adopts the Simultaneous Localization and Mapping (SLAM) technology and the instance segmentation method to enable the robot to cope with complex site situations. A database of CDW was developed and used to train a computer vision model for recognizing residual pipes and cables. The feasibility of developed methods and algorithms was evaluated through both lab and site experiments. The system can be improved and applied to other objects, which is useful for researchers and practitioners engaged in similar tasks.

Technological paradigm-based construction and demolition waste supply chain optimization with carbon policy

The shortage of landfill space and the environmental pollution from urbanization and industrialization have led to an increase in the recycling and reuse of construction and demolition waste (CDW). Based on the technological paradigm, this paper proposes a closed-loop supply chain (CLSC) that integrates forward and reverse logistics and has multiple centers that regulate end-of-life CDW recycling and promote new product remanufacturing. Carbon price (CP) and carbon trading (CT) policies are then innovatively applied to manage the proposed supply chain, incentivize technological CDW disposal improvements, encourage policy adherence, and ensure that the economic and environmental benefits are built into the proposed CLSC. A mixed integer nonlinear programming model (MINLP) is developed to optimize the proposed CLSC by minimizing the total costs under the two carbon policies, and a real case study from China is given. Scenario analyses under the two carbon polices and practical policy suggestions are given, and comprehensive conclusions are provided in the conclusions. It was found that with the adjustment of recycling ratio, the proposed CDW CLSC was able to minimize total costs and overall carbon emissions. Moreover, the CP policy could improve the CDW recycling ratio from 19.4% to 85.3% and reduced carbon emissions by 6393 tonnes, and the CT policy should be an incentive policy to further encourage a higher recycling ratio and lower carbon emissions.

4D-BIM to enhance construction waste reuse and recycle planning: Case studies on concrete and drywall waste streams

Despite pressing attention on construction waste management (CWM) issues, low rates of construction waste (CW) reuse and recycling (R&R) remain a limitation in construction projects. In recent years, Building Information Modeling (BIM) has gained momentum for CWM purposes; its data-richness, visualization, and simulation capabilities provide an opportunity to enhance CW R&R planning at the project level. In this context, this study proposes temporal-based algorithms integrated with 4D-BIM for the planning of concrete and drywall waste R&R throughout construction projects. Two case studies from Central Texas were used for the demonstration of the algorithms, and estimates were validated with ground truth data and literature values from different projects in North America. The overarching objective of the proposed algorithms is to streamline estimation and visual planning of CW for on-site reuse, and off-site recycling – therefore promoting a more proactive and schedule-based CWM plan. In addition, the approach improves team communication around CWM goals of the project. Moreover, through the use of 4D-BIM, on-site waste reuse opportunities are planned in advance, thus, improving resource recovery and minimizing waste disposal in landfills.

Modern biopositive technologies of waste processing in the utilities and construction industries

Introduction. In this article the analysis of certain biopositive technologies applied to processing or recycling of construction waste, municipal sewage, and paste-like slurries of organo-mineral nature is performed. The relevance of this research is confirmed by the steadily growing number of publications and currently implemented government programmes aimed at solving such problems. The paper summarizes the results of research into the treatment of wastes having different origin.
 Materials and methods. The analysis of the research literature and patents for inventions, as well as publicly available technologies used in waste processing and recycling is performed. Selection of biopositive technologies based on the chemical nature of materials and their groups is described. Biopositive technologies, most effectively applied to construction materials, are identified for the purpose of converting engineering structures into secondary raw components. The co-authors demonstrate the application of a biopositive technology to sludge decontaminated at municipal waste water treatment plants and to hot waste generated by the hydrolysis industry, as well as technologies used to process special thermal insulation and waterproofing materials.
 Results. The use of water-organic emulsions as active components in effective regeneration of asphalt granulated concrete mixtures is considered. Сompositions, concentrations and sedimentation stability of such emulsions have been identified. The results of the study of physical, mechanical and hydro-physical properties of the asphalt-concrete granulate treated with water-organic emulsions are described. This regeneration technology helps bitumen to restore binding properties on the surface of the asphalt-concrete granulate and makes this composite applicable as a material designated for the bottom layers of the road pavement.
 Conclusions. These biopositive technologies make it possible to efficiently and rationally process or recycle a wide range of municipal and construction waste into structures and products having various applications. Recycling, composting and plasma technologies are considered in this case.

Study on the Characteristics and Reduction Measures of Construction Waste Generated in Subway Engineering

In the process of urban modernization and rapid construction, the construction and reconstruction of large-scale construction projects such as subways, underground pipe corridors, and housing construction facilities are accompanied by a large amount of construction waste. A huge amount of construction waste not only occupies a large number of land resources, but also affects air quality, pollutes waters, destroys city appearance and environmental sanitation, and has potential safety hazards. In the long run, it also affects urban development space and shortens the city life cycle. At present, there are many shortcomings in China’s policy management, classification and measurement, reduction technology, transportation recovery, recycling and other aspects of construction waste. Especially from the source, there is a lack of research on the source characteristics of construction waste, which makes the quantitative quantification of various construction wastes impossible to achieve construction, accurate management, and control of waste. This study takes the urban subway construction project as the research object, through the field investigation, literature review and other methods, analyses the classification and source of underground construction waste by the project unit construction process as the framework, and analyses the corresponding construction waste according to the investigation and data collection. The reduction measures implemented.