Sustainable construction: construction and demolition waste reconsidered

Decision support model for selecting construction and demolition waste management alternatives: A life cycle-based approach

Construction and demolition waste (C&DW) represents a pressing concern within the European Union, underscoring the urgent need for effective waste management strategies. The selection of these solutions constitutes a complex task, entailing the identification of efficient C&DW management strategies that balance appropriate practices, regulatory compliance, resource conservation, economic feasibility, and environmental considerations. LCA is widely utilized to assess environmental impact, yet the economic aspect has not been adequately incorporated into the LCA process in the field of C&DW management. The life cycle costing (LCC) methodology has been tailored to assess economic performance in conjunction with LCA. The selection of an appropriate multi-criteria decision-making (MCDM) method is vital for the C&DW system. This study proposes a novel framework for C&DW management by integrating LCA and LCC outcomes into MCDM, using AHP for weight determination, and applying TOPSIS to identify the favorable alternative. Four waste management alternatives were examined in the Lombardy region of Italy, namely (i) landfill; (ii) recycling for concrete production and road construction, incineration with energy recovery; (iii) recycling for road construction; (iv) recycling for concrete production and road construction. We determine that, with the implementation of various scenarios, the most suitable scenario emerges to be recycled for concrete production and road construction, with a score of 0.711/1; recycling for road construction with final score 0.291/1, ranks second; recycling for concrete production and road construction, incineration with energy recovery scores 0.002/1, ranks third; and landfill (scores: 0/1) is the worst choice, signifying it has the highest environmental impacts and the least economic benefits. Lastly, recommendations were formulated to enhance the environmental performance of the system.

A review of extant literature and recent trends in residential construction waste reduction

The residential construction sector in New Zealand and worldwide is experiencing increased criticism for generating substantial waste that poses environmental concerns. Accordingly, researchers have advocated implementing residential construction waste reduction (RCWR) strategies as a sustainable solution to managing construction waste (CW). This article aims to provide a comprehensive overview of RCWR by analysing 87 articles from the Scopus database using bibliometric and critical review methods. The co-occurrence analysis of keywords revealed five clusters, in which five main themes emerged: (i) waste generation and management performance, (ii) prefabrication and life cycle assessment concepts, (iii) design concepts, (iv) circular economy and (v) decision-making concepts. The findings suggest that sustainable practices such as designing for waste reduction, prefabrication, waste quantification, three-dimensional printing and building information modelling can effectively achieve RCWR. The study also highlights the benefits of RCWR, including reducing environmental impacts, and identifies management, economic, legislative, technology and cultural barriers that affect the implementation of RCWR strategies. These results provide valuable insights to support future policy formulation and research direction for RCWR in New Zealand.

A multi-stakeholder digital platform for regional construction and demolition waste management

Little attention has been paid to the interaction or synergy among construction and demolition (C&D) waste management stakeholders. A framework allowing for interaction among the various C&D waste players is especially important in regions with mature C&D waste infrastructure, where various recycling, reuse and disposal facilities are present. In such an expanded infrastructure, these facilities differ in terms of the C&D waste materials they accept, the nature of the waste accepted (sorted/unsorted), as well as the services they provide. This makes developing the optimal C&D waste management plan (WMP) more cumbersome for contractors. To address the challenges arising from the poor dynamics associated with the overarching waste management infrastructure, this paper proposes a novel digital platform, namely the 'Construction and Demolition Waste Management Kernel' (C&D WMK). The C&D WMK has three main objectives: it allows for data exchange between the different stakeholders, provides guidance to contractors when developing C&D WMPs and allows for governmental supervision and regulation. This paper introduces the concept behind the C&D WMK, presents the optimization model embedded in the system, and demonstrates its application in a case study leveraging real-world data. Finally, a scenario analysis is conducted to show how the C&D WMK can be used by governments to identify pitfalls in the state of practice at the regional scale, and to determine effective solutions to enhance the C&D waste management performance.

Industrial-scale extraction of high value-added kaolin from excavation waste: Demonstration from Xiamen, China

Excavation waste from the construction of subways and other underground infrastructures is mainly composed of gravel, sand and clay of minimal economic value, which commonly ends up in landfills. Although the coarse sand and gravel of the excavation waste are typically recycled on site, a large amount of the fine-grained residue must be disposed of due to the prohibition of marine land reclamation in Xiamen, China, leading to an increasingly severe shortage of landfills. In this contribution, a new strategy was successfully developed for industrial-scale extraction of high value-added kaolin from the excavation waste of Xiamen. This strategy can overcome the challenges of complex and variable chemical compositions, high iron contents, low industrial grade, and organic contaminants in the raw materials. Characterization using chemical analysis, powder X-ray diffraction, scanning electron microscopy, and infrared spectroscopy showed that the Xiamen excavation waste originated from granite weathering is mainly composed of kaolinite and quartz, along with high Fe contents and other impurities. The excavation waste was subjected to an intensive process of blunging, grinding, sieving, and classifying, as well as successive iron removal by magnetic separation. Subsequently, the extracted products meet commercial requirements, including those for high-quality kaolin with whiteness and plasticity larger than 90° and 17%, respectively. Moreover, an industrial-scale green production line with an annual treatment capacity of one million tonnes of excavation waste at the utilization rate of 100% was implemented. Hence, this work presents an effective approach for exploiting similar excavation waste around the world to promote sustainable development.

Reprocessed construction and demolition waste as an adsorbent: An appraisal

Construction and Demolition (C&D) waste is solid wastes generated from the construction, demolition, and renovation activities that constitute almost 30-40 % of globally generated solid wastes. Improper disposal and management of these materials can cause negative impacts on the environment, economy, and human health. Most research on C&D waste is limited to reduction, recycling, and reuse of the wastes. However, there is no systematic review dedicated entirely to the applicability of C&D wastes as adsorbent for waste management. This review presents the utilization of C&D wastes-based adsorbents for removing contaminants from environmental matrices covering triple edge benefits in the viewpoints of waste treatment, solid waste management, and disposal. The properties, the capability of C&D waste adsorbents on contaminant removal, and the influence of various factors on the adsorptive removal is detailed. Further, the mechanisms involved in contaminant removal by C&D waste are summarized. The review revealed that, chemisorption is the prominent mechanism of contaminant removal by most C&D wastes. Among the three types of C&D waste reviewed; concrete-based adsorbents were the most efficient for contaminant removal. Limited studies are avaiable in the literature on binary and multiple contaminant systems, reusability studies, and high dependence on solution pH, therefore further studies are warrated. As C&D waste contain trace concentration of heavy metals and contaminants, its leaching potential at different pH levels and adsorbate concentration need to be conducted, which has been hitherto neglected. Finally, the approaches, obstacles, and potential solutions to build an industrially and economically efficient C&D adsorbent are discussed.

Systematic review of drivers influencing building deconstructability: Towards a construct-based conceptual framework

Deconstruction is an innovative and sustainable option for building end-of-life. It can turn the negative impacts of demolition, including diverting valuable resources from the congested landfill into beneficial use through reuse and recycling. However, the feasibility of deconstruction has placed a massive limitation on the implementation of deconstruction. This research carried out a systematic literature review of 35 academic and 3 non-academic pieces of literature to develop a construct-based deconstructability framework. This framework - built around technical, economic, legal, operational, schedule and social construct - describes the condition under which deconstruction is likely to work and drivers influencing deconstructability. A total of 44 drivers influencing deconstructability were established and ranked from which design and building technology, cost including expense and revenues from the resale, supply and demand of the recovered component and material, the schedule for the deconstruction were identified as most influential. However, every identified driver should be considered during the deconstructability assessment of a building.

Environmental management criteria, aimed at public policymaking, for the removal and disposal of asbestos-containing building materials in Colombia

Asbestos is a carcinogenic mineral banned in Colombia since 1 January 2021; however, there is a considerable amount of asbestos-containing building materials (ACBM) installed across the country in products such as roof tiles, tanks, pipes, and downspouts. Installed ACBM represent an exposure risk when the mineral fibers are released into the air through deterioration, damage, or disturbance of the cement matrix within which the asbestos is contained. Due to potential detrimental impacts on human health, safe management and correct handling of ACBM is a matter of vital importance. This article proposes evidence-based environmental management guidelines, aimed at public policymaking, for the removal and final disposal of installed ACBM in Colombia. A descriptive study was carried out, with a qualitative approach, based on an integrative literature review of international practices applied in the removal and disposal of installed ACBM. Forty scientific publications were reviewed, as well as the regulations for removal, transport, and final disposal of installed asbestos-cement from Australia, the USA, Italy, Chile, the UK, and Canada. Guidelines for the removal and final disposal of installed ACBM are proposed, suggesting the following stages: (a) diagnosis and management plan of installed ACBM, (b) removal of installed ACBM, (c) transport of ACBM waste, and (d) final disposal of ACBM waste. Expert opinion was collected to assess the local feasibility of the proposed guidelines. These guidelines may help direct national and regional agencies to establish comprehensive strategies with clear, measurable, and achievable goals for future replacement of installed ACBM. Integr Environ Assess Manag 2023;00:1-10. © 2023 SETAC.

Improvement of consolidation properties of clay soil using fine-grained construction and demolition waste

As urbanization spreads rapidly, more structures are being built, and more construction and demolition waste (CDW) is produced, occupying about 36–40% of the total solid waste generation in the world; hence, CDW has become a burden nowadays. Moreover, the construction of low-rise buildings on weak soil is always challenging and costly due to the soil's high compressibility and low bearing capacity. Sand or other granular materials are commonly used to improve the compressibility behavior and associated settlement, drainage, and shear strength of weak soil. The massive use of natural sand for construction purposes of different civil engineering structures have lessened their reserves in recent times, increasing their price and destroying the balance in the environment. Among the several methods of improving soil, this research uses fine-grained CDW to improve the geotechnical behavior of weak soil under study. The main objective of this research is to observe the changes in soil properties after mixing with CDW. Recycled waste mortar powder has been selected as CDW mixed in different percentages in the soil. In addition, CDW powder was inserted into soil mass as a circular powder column in triangular and square grid patterns as an alternative to the sand column. CDW in the soil samples improved consolidation settlement, and reduced settlement time and compression index. Increments in the pre-consolidation pressure, consolidation rate, and permeability of the clay-CDW mixtures were also remarkable. Soil improvement through reusing CDW is a sustainable way to solve problems in solid waste management and the soft soil settlement issue under a shallow foundation, ultimately reducing the environmental footprints, saving natural resources, and supporting the circular economy concept.

Drawing a Path towards Circular Construction: An Approach to Engage Stakeholders

The activities conducted in the building and construction sector should be guided by circular economy principles, which will result in the implementation of greener practices fostering both the development of economy and protection of the environment. This work proposes and discusses an innovative approach based on a concerted strategy between stakeholders to accelerate the transition to a circular construction paradigm, which involves, as sustainable development, the definition of three dimensions to guide the process: (a) the assignment of key roles to the government and construction professionals; (b) the improvement of the industry to perform a proper management of construction and demolition waste; and (c) the development of sustainable practices at the construction site. In addition to the discussion about the different stakeholder partnerships that must exist, key ideas that should be adopted by industry to deliver recycled materials and products to the building and construction sector are proposed in this work. Moreover, measures to assist in the management of both the traditional and innovative materials and products incorporating recycled waste at the construction site are suggested targeting the implementation of more sustainable practices within this context. A broad use of the ideas proposed in this work in the building and construction sector may lead to encouraging outcomes in the next decade.

Diverting demolition waste toward secondary markets through integrated reverse logistics supply chains: A systematic literature review

Construction industry has adopted reverse logistics (RL) concept to manage high volumes of demolition waste (DW). However, DW RL supply chains (RLSCs) were found to be suffering from uncertainties, information deficiencies, and uncoordinated material flows. Improving supply chain integration (SCI), specifically external integration, across DW RLSCs was identified as a possible solution to overcome such problems. Despite this, studies that focus on external integration in DW RLSCs are limited. Using a systematic literature review (SLR), this study explores external integration in DW RLSCs. Sixty-six articles from three databases published between 2006 and 2020 were subjected to descriptive and content analysis. Arrangement of material, information, and financial flows across DW RLSCs, inhibitors of external integration, and potential measures for improving external integration were analyzed. Accordingly, material, information, and financial flows across DW RLSCs were mapped, and inhibitors of external integration, along with potential measures for improving external integration were identified. As the key outcome of this SLR, these findings were developed into a conceptual framework, which shows the main factors that inhibit and improve external integration in DW RLSCs. The framework will be useful in guiding further empirical research and informing industry practice. Several future research directions are also proposed to expand knowledge around the research domain.

Analysis of the socio-economic and environmental impacts of construction waste and management practices

This study aims to analyze the significant socioeconomic and environmental impacts of construction waste and to indicate management strategies. An extensive review of the literature and interviews with construction experts were used to identify waste impact factors. Then a questionnaire survey was conducted based on a five-point Likert scale and the data were analyzed by descriptive statistics. The result showed that construction waste becomes a challenge for almost 95.71% of ongoing construction projects. However, only 57.14% of the construction companies have recorded and measured the volume of material waste. From purchased materials, 6–10% is recorded as waste that lead to project cost overrun. In addition, there is no professional assigned to handle waste issues in 75.71% of construction companies. The study also indicates that project cost overrun, pollution of the environment, reduction in profit and failure of construction firms, excessive consumption of raw materials, and public health and safety risks are ranked as the five major impacts of construction waste, respectively. Employing a waste management officer, using prefabricated or off-site components, implementing strong onsite management practices, reusing and recycling materials leftover on the sites, and practicing green building codes and specifications are measures devised to mitigate construction waste and its impacts.

Machine Learning Framework for the Sustainable Maintenance of Building Facilities

The importance of sustainable building maintenance is growing as part of the Sustainable Building concept. The integration and implementation of new technologies such as the Internet of Things (IoT), smart sensors, and information and communication technology (ICT) into building facilities generate a large amount of data that will be utilized to better manage the sustainable building maintenance and staff. Anomaly prediction models assist facility managers in informing operators to perform scheduled maintenance and visualizing predicted facility anomalies on building information models (BIM). This study proposes a Machine Learning (ML) anomaly prediction model for sustainable building facility maintenance using an IoT sensor network and a BIM model. The suggested framework shows the data management technique of the anomaly prediction model in the 3D building model. The case study demonstrated the framework’s competence to predict anomalies in the heating ventilation air conditioning (HVAC) system. Furthermore, data collected from various simulated conditions of the building facilities was utilized to monitor and forecast anomalies in the 3D model of the fan coil. The faults were then predicted using a classification model, and the results of the models are introduced. Finally, the IoT data from the building facility and the predicted values of the ML models are visualized in the building facility’s BIM model and the real-time monitoring dashboard, respectively.

Barriers to Implementing the Circular Economy in the Construction Industry: A Critical Review

To facilitate the adoption of the circular economy (CE) in the architecture, engineering and construction (AEC) sector, some authors have demonstrated the potential of recent designs that take into account the sustainable management of an asset’s end-of-life (EOL), providing an alternative to the dominant designs that end with demolition. However, there is no review of the literature that encompasses a large range of sustainable designs in the current CE context. This paper provides a critical review of journal papers that deal with the barriers to implementing sustainable designs and approaches to the EOL management of assets that have the potential to fulfil the principles of the CE. Eighteen approaches related to prefabrication, design for change, design for deconstruction, reverse logistics, waste management and closed-loop systems were found. Through an analysis of the barriers that are common among these 18 approaches, we classified them into six different categories (organisational, economical, technical, social, political and environmental). Two Sankey diagrams illustrate the interrelation between the barriers, their categories and the 18 approaches. The diagrams clearly show that most of the barriers are common to multiple approaches and that most of the barriers relate to organisational concerns. The study gives a detailed map of the barriers that would help stakeholders from the AEC sector develop strategies to overcome the current obstacles in the shift to a CE.

A Synthesis of Express Analytic Hierarchy Process (EAHP) and Partial Least Squares-Structural Equations Modeling (PLS-SEM) for Sustainable Construction and Demolition Waste Management Assessment: The Case of Malaysia

Construction and demolition waste (CDW), as the main consequence of construction and demolition (C&D) activities, has severely affected our sustainability needs. However, construction and demolition waste management (CDWM) lacks the integration of sustainability concepts. Thus, there is a great need to include sustainability dimensions in CDWM to reach sustainable construction and demolition waste management (SCDWM). This study aims at empirically investigating SCDWM by analyzing the impacts of factors that contribute to sustainability aspects of CDWM on waste management hierarchy (WMH), including reduce, reuse, recycle, and disposal strategies. According to the literature, 26 factors were initially identified and grouped under four categories, namely environmental, economic, social, and administrative, that contribute to sustainability aspects of CDWM. Subsequently, a pilot test was performed to assess the significance and applicability of these factors in the Malaysian construction industry by implementing the express analytic hierarchy process (EAHP). Then, a questionnaire survey was performed to collect data from 132 construction companies involved in CDWM. Partial least squares-structural equation modeling (PLS-SEM) was used to test the hypothetical relationships by applying SmartPLS software. Results demonstrated that the economic aspect of CDWM (main category) and “public environment contamination due to illegal waste dumping” (sub-category) were the most influential factor in SCDWM in Malaysia.

Analysis of the Scientific Evolution of the Circular Economy Applied to Construction and Demolition Waste

The circular economy (CE) concept applied to construction and demolition waste (CDW) is a developing field of research that entails a large amount of complex and disjointed information; thus, a comprehensive review of scientific contributions could provide a completed perspective. This article aims to analyse the existing knowledge of CE research applied to CDW, using a double integrated analysis, a systematic literature review and a bibliometric analysis. For this purpose, Science Mapping Analysis Tool (SciMAT), a software for the analysis of performance indicators and visualisations of scientific maps, has been used, which offers a complete approach to the field and evaluates the most cited and productive authors and subject areas related to this discipline. The results obtained from the 1440 bibliographic records from 1993 to 2020 show a still-developing scientific field, evolving from concerns about economic aspects to the most recent progresses in the evaluation of sustainable deconstruction. This work will contribute to the existing body of knowledge by establishing connections, mapping networks of researchers and recommending new trends.

Life Cycle Economic and Environmental Impacts of CDW Recycled Aggregates in Roadway Construction and Rehabilitation

The use of recycled materials in roadway construction and rehabilitation can achieve significant benefits in saving natural resources, reducing energy, greenhouse gas emissions and costs. Construction and demolition waste (CDW) recycled aggregate as an alternative to natural one can enhance sustainability benefits in roadway infrastructure. The objective of this study was to quantitatively assess the life cycle economic and environmental benefits when alternative stabilized-CDW aggregates are used in pavement construction. Comparative analysis was conducted on a pavement project representative of typical construction practices in northern Italy so as to quantify such benefits. The proposed alternative sustainable construction strategies considered CDW aggregates stabilized with both cement and cement kiln dust (CKD) for the base layer of the roadway. The life cycle assessment results indicate that using CDW aggregate stabilized with CKD results in considerable cost savings and environmental benefits due to (i) lower energy consumption and emissions generation during material processing and (ii) reduction in landfill disposal. The benefits illustrated in this analysis should encourage the wider adoption of stabilized CDW aggregate in roadway construction and rehabilitation. In terms of transferability, the analysis approach suggested in this study can be used to assess the economic and environmental benefits of these and other recycled materials in roadway infrastructure elsewhere.

Simulation analysis of implementation effects of construction and demolition waste disposal policies

Urban development generates large amounts of construction and demolition waste, and the enactment of various policies is an important way to increase resource efficiency. It is urgent to analyse the choices and effects of construction and demolition waste disposal policies around the world. This study analyses and compares the implementation effects of various construction and demolition waste disposal policies and provides suggestions on the selection and formulation of different disposal method policies. A BP neural network and an agent-based model are used to construct a simulation model for the implementation effects of construction and demolition waste disposal policies. The average acceptance willingness is analysed for the three disposal methods of reduction, reuse and recycling under the different policies based on questionnaire survey data. Simulation results show that the implementation effect of the incentive policy as a single policy is superior, and the comprehensive implementation effect of the guidance-incentive-mandatory policy as a combined policy is superior. The implementation effect of combined policies is better than that of single policies. The policies suitable for different disposal methods are inconsistent. Information interaction can effectively improve the implementation effects of different construction and demolition waste disposal policies, especially for single policies. This study innovatively compares the various construction and demolition waste disposal policies and explain the interaction during their implementation. The findings can help the government formulate policies at different stages of construction and demolition waste management and provide a new approach to policy simulation research.

Stakeholder-Associated Factors Influencing Construction and Demolition Waste Management: A Systematic Review

Construction and demolition (C&D) activities generate a large amount of waste and have significant impacts on the environment. Thus, it is necessary to implement C&D waste management (WM), which requires the involvement of stakeholders and is influenced by a variety of factors. This study aims to undertake a systematic review of the stakeholder-associated factors influencing C&D WM. The Scopus search engine was used in a literature search, and two rounds of screening were performed. Only journal articles or reviews that were published in English after 2000 were used in this study. A total of 106 journal articles were reviewed. The review identified 35 stakeholder-associated factors influencing C&D WM and categorized them into six groups: regulatory environment, government and public supervision, advances in technologies, recycling market, knowledge, awareness, attitude, and behaviour of stakeholders, and project-specific factors. All the 35 factors are discussed in detail with considerations into relevant stakeholders. Although there have been studies focused on the factors influencing C&D WM, few have attempted to take stakeholders’ perspectives into consideration. This study expands the C&D WM literature by mapping the influential factors with relevant stakeholders and enables the practitioners to clearly understand their roles and responsibilities and make better informed decisions in the C&D WM process.

Thermoset Polymer Matrix Composites of Epoxy, Unsaturated Polyester, and Novolac Resin Embedding Construction and Demolition Wastes powder: A Comparative Study

Composite materials that consisted of a polymer resin as matrix (PMCs), filled using construction and demolition (C&D) wastes powder of different grain sizing in micro-scale were manufactured and studied. Three different kinds of resins were used as the matrix for the purposes of this study. More specifically, composites made of epoxy and unsaturated polyester resins purchased from the market and phenolic resin (novolac) laboratory synthesized, were produced. The morphological and elemental analysis of these materials was performed through scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). Additionally, mechanical performance and thermal insulating efficiency of these materials were examined through bending and shear strength tests according to the three-point method and via determination of the thermal conductivity coefficient λ. C&D wastes have undergone the appropriate processing in order to prepare filling products of the required granular size in pulverized form. In this research study, construction and demolition waste-based thermosetting polymer composites were produced with flexural strength in the range 20-60 MPa, shear strength in between 1-8 MPa, and thermal conductivity coefficients in the range of 0.27-1.20 W/ m K. The developed materials embedded 30-50% w/w C&D wastes, depending on the resin used as the matrix.

Current Sustainable Trends of Using Waste Materials in Concrete—A Decade Review

Concrete is the most used construction material in the world. Consequently, the mass extraction of virgin materials required for concrete production causes major environmental impacts. With a focus on promoting sustainability, numerous research studies on incorporating waste materials to replace virgin substances in concrete were undertaken. Despite this vast volume of published literature, systematic research studies on these sustainable concrete mixes that inform various stakeholders on current research trends, future research directions, and marketability options products are seldom conducted. This paper presents a decade review on sustainable concrete with a focus on virgin materials being replaced with waste materials. It aims to inform researchers of current research trends and gaps in the research area of waste material use in concrete. The review also identifies key parameters that restrict the marketability of these sustainable concrete products. The three-step research methodology involves a bibliometric assessment, a key review of selected waste materials, and an interview with a panel of experts focusing on impediments towards the transition of sustainable concrete products into the industry market. Bibliometric assessment was based on 1465 research publications in which five key materials (plastic, glass, fly ash, slag) and construction and demolition waste were selected for the review. The interview was conducted with ten industry experts to discuss the industry limitations in the commercial establishment of materials. The review of existing knowledge and the findings on sustainable concrete presented in this paper provide directions for both research academics and industry stakeholders to systematically focus on sustainable concrete products that are market-ready.

Decision Support Systems in Construction: A Bibliometric Analysis

In recent years, the use of decision support systems for selecting sustainable construction materials in the building and commercial construction projects has received a great deal of attention. This paper reports an in-depth and systematic bibliometric analysis of the literature using Decision Support Systems (DSSs) for its construction, based on the papers published during the period from 2000 to 2016. The data were collected from two major databases, Web of Science (WoS) and Scopus, which included 2185 and 3233 peer reviewed articles, respectively. The analysis includes a general bibliometric analysis (publications output, country-wise research output, authorship, and collaboration patterns of these published articles). It also includes a citation analysis (keywords, most cited keywords, organizations, most cited articles, and average citations per article) and a network analysis (authors and countries). Overall, this study provides bibliometric insights and future research directions for researchers and practitioners who use DSSs.

Chemical Characterisation of Construction and Demolition Waste in Skopje City and Its Surroundings (Republic of Macedonia)

In the Republic of Macedonia, construction and demolition (C&D) waste is often dumped, underestimating the potential recycling and re-use as raw materials for civil engineering works and/or cement/ceramic industries. SAMCODE (Sustainable Approach to Managing Construction and Demolition Waste) is a know-how exchange program, the focus of which is chemical characterisation in terms of major and trace elements in order to evaluate the possible Macedonian C&D waste recycling. Thirty-nine C&D waste samples were collected from different dumps in Skopje and surroundings. X-ray fluorescence analyses, carried out on powdered samples, show i) highly variable concentrations, indicative of the heterogenous nature of C&D waste, and ii) high concentration in Cr, Ni, and Zn with respect to Italian, Chinese, and Dutch tolerance limits, probably due to the presence of these elements in ophiolitic rocks and sulphide-bearing deposits, used as raw material in building activity. Inductively coupled plasma mass spectrometry analyses of leachates, performed to assess the mobility of heavy metals, show significant concentrations of Cr, and to a lesser extent, Ni. Results suggest that homogenisation processes of the recycled materials should be implemented and preliminary screening of C&D waste should be performed to eliminate heavy metals-bearing components.

What are we discarding during the life cycle of a building? Case studies of social housing in Andalusia, Spain

The paper evaluates for the first time the embodied impact in CDW during the buildings life cycle by means of the bill of quantities of construction projects. The main objective is to be able to predict the future CDW to be generated by a project in the design stage, by means of the bill of quantities of the urbanization, construction, renovation, rehabilitation and demolition projects. The tools already in place for cost control can be used as an instrument for the introduction of sustainability considerations in construction projects. The methodology proposes a connection between the different stages of a building's life cycle, more precisely its budget. The latter is linked to other future budgets for building renovations or retrofitting projects. The result shows that urbanization and demolition generate 90% of CDW, the former is caused by earthworks and the latter is due to the elimination of all building materials. The building is removed 1.3 times, in terms of material weight, energy and water. Finally, traditional models for economic control and waste management in construction projects can be the vector which introduce environmental assessment through the building life cycle.

How Individual’s Proactive Behavior Helps Construction Sustainability: Exploring the Effects of Project Citizenship Behavior on Project Performance

Sustainable development has been commonly identified as a vital target in the construction industry. Studies have examined different management strategies and procedures to promote resource utilization efficiency, while the human factors in sustainable construction have received far less attention. This paper investigates the influence of Project Citizenship Behavior (PCB) on project performance in the sustainable construction context. After introducing the concept of “relationship sustainability,” a moderating model is established. Data are collected from 152 experienced construction project managers in China. The results show positive relationships between most dimensions of Project Citizenship Behavior and construction sustainability performance, in spite of the negative effect of taking charge on relationship sustainability. Moreover, the degree of complexity of projects acts as a moderator in the relationship between Project Citizenship Behavior and construction sustainability performance. This paper endeavors to enrich the knowledge of sustainable construction by regarding human behavioral factors as important resources and explaining their effect on project sustainability, thus shedding light on the theory of sustainable construction by extending it to the micro-level analysis, as well as offering guidelines about how to raise the sustainability level of construction projects.

Analysis of Best Practices to Prevent and Manage the Waste Generated in Building Rehabilitation Works

This paper carries out a survey conducted among the construction agents in order to evaluate the effectiveness and viability of several best practice measures regarding construction and demolition waste (CDW) management in building rehabilitation works. This survey was developed considering that in rehabilitation works two well differentiated activities are carried out: those of the dismantling of the building (deconstruction activities) and those of the execution of the new construction (construction activities). Results of this survey show that among the highly rated best practices for the design phase “designing the building in order to help the recovery of the materials at the end of its use” can be highlighted, despite less than 25% of respondents usually implement this measure in their works. Moreover, according to BP during the construction phase, the results reveal that only 70% of respondents routinely implement the most valued measure “Hiring authorized companies for the management of CDW” and 60% the second “Respecting the manufacturer’s directions regarding the transport, collection and commissioning”.

Manejo de residuos de construcción y demolición en el municipio Guamo, Tolima

El municipio de Guamo, ubicado en el departamento de Tolima, se encuentra localizado según coordenadas a 4°.02´ de latitud norte y 74°.58´ de longitud oeste; a una altura sobre el nivel del mar (asnm) de 321 metros y con una población aproximada de 31866 habitantes. Al igual que la totalidad del territorio colombiano, este municipio debe responder a la normatividad establecida como marco jurídico para el desarrollo de la cotidianidad del ciudadano y las relaciones que establece entre sí y con su entorno natural. La resolución 472 de 28 de febrero de 2017, emitida por el Ministerio de Medio Ambiente y Desarrollo Sostenible, aplica para todas las personas naturales y jurídicas que generen, recolecten, transporten, almacenen, aprovechen y dispongan residuos de construcción y demolición (RCD) de las obras civiles o de otras actividades conexas en el territorio nacional, al igual que brinda lineamientos para el aprovechamiento y disposición final de los mismos. Con base en los principios regulativos contenidos en este acuerdo, se estructura un instrumento para ser respondido por los encargados de las obras de construcción, con la finalidad de identificar las prácticas con las cuales se manejan los RCD, información que podrá ser incorporada en programas educativos que permitan crear una cultura ambiental en torno a las actividades constructivas en procura de alcanzar un entorno sustentable.

Waste Mismanagement in Developing Countries: A Review of Global Issues

Environmental contamination due to solid waste mismanagement is a global issue. Open dumping and open burning are the main implemented waste treatment and final disposal systems, mainly visible in low-income countries. This paper reviews the main impacts due to waste mismanagement in developing countries, focusing on environmental contamination and social issues. The activity of the informal sector in developing cities was also reviewed, focusing on the main health risks due to waste scavenging. Results reported that the environmental impacts are pervasive worldwide: marine litter, air, soil and water contamination, and the direct interaction of waste pickers with hazardous waste are the most important issues. Many reviews were published in the scientific literature about specific waste streams, in order to quantify its effect on the environment. This narrative literature review assessed global issues due to different waste fractions showing how several sources of pollution are affecting the environment, population health, and sustainable development. The results and case studies presented can be of reference for scholars and stakeholders for quantifying the comprehensive impacts and for planning integrated solid waste collection and treatment systems, for improving sustainability at a global level.

Waste Management of Emergency Construction Work. Case Study: 40 Dwellings in Seville (Spain)

Eco-efficient rehabilitation of buildings and neighbourhoods should include strategies to reduce the potential environmental impact of buildings under consideration for demolishment. In this case, good construction and demolition (C&D) waste management can represent a doubly eco-efficient approach: advantage is taken of much of the building and the volume of waste is reduced during construction and demolition work.

Construction and demolition waste management in emergency situations is a subject yet to be studied in the construction sector. This kind of work, although not very common, involves major building damages and the need for punctual, partial or total demolitions. The amount of C&D waste can be a major problem to deal with, and its management during the critical first phases can determinate the progress of the rehabilitation.

Conditioned by a greater number of factors than normal construction works, the lack of time for the identification, quantification, and evaluation of C&D waste renders this type of extremely useful study.

In this work, from the case study of the emergency repair of a residential building of 40 dwellings in Seville (Spain) seriously affected by a soil displacement, Generated C&D waste are identified and the waste reduction techniques used are shown. These techniques contributed to achieve the planned objectives and to control in advance the cost.

Finally, the most important data, C&D waste quantification and the managing cost are presented in order to serve as reference for similar circumstances in the future because there areno clear references to be used.

Critical management practices influencing on-site waste minimization in construction projects

As a result of increasing recognition of effective site management as the strategic approach for achieving the required performance in construction projects, this study seeks to identify the key site management practices that are requisite for construction waste minimization. A mixed methods approach, involving field study and survey research were used as means of data collection. After confirmation of construct validity and reliability of scale, data analysis was carried out through a combination of Kruskal-Wallis test, descriptive statistics and exploratory factor analysis. The study suggests that site management functions could significantly reduce waste generation through strict adherence to project drawings, and by ensuring fewer or no design changes during construction process. Provision of waste skips for specific materials and maximisation of on-site reuse of materials are also found to be among the key factors for engendering waste minimization. The result of factor analysis suggests four factors underlying on-site waste management practices with 96.093% of total variance. These measures include contractual provisions for waste minimization, waste segregation, maximisation of materials reuse and effective logistic management. Strategies through which each of the underlying measures could be achieved are further discussed in the paper. Findings of this study would assist construction site managers and other site operatives in reducing waste generated by construction activities.

Development of a hybrid model to predict construction and demolition waste: China as a case study

Construction and demolition waste (C&DW) is currently a worldwide issue, and the situation is the worst in China due to a rapid increase in the construction industry and the short life span of China's buildings. To create an opportunity out of this problem, comprehensive prevention measures and effective management strategies are urgently needed. One major gap in the literature of waste management is a lack of estimations on future C&DW generation. Therefore, this paper presents a forecasting procedure for C&DW in China that can forecast the quantity of each component in such waste. The proposed approach is based on a GM-SVR model that improves the forecasting effectiveness of the gray model (GM), which is achieved by adjusting the residual series by a support vector regression (SVR) method and a transition matrix that aims to estimate the discharge of each component in the C&DW. Through the proposed method, future C&DW volume are listed and analyzed containing their potential components and distribution in different provinces in China. Besides, model testing process provides mathematical evidence to validate the proposed model is an effective way to give future information of C&DW for policy makers.

Mining the physical infrastructure: Opportunities, barriers and interventions in promoting structural components reuse

Construction is the most resource intensive sector in the world. It consumes more than half of the total global resources; it is responsible for more than a third of the total global energy use and associated emissions; and generates the greatest and most voluminous waste stream globally. Reuse is considered to be a material and carbon saving practice highly recommended in the construction sector as it can address both waste and carbon emission regulatory targets. This practice offers the possibility to conserve resources through the reclamation of structural components and the carbon embedded in them, as well as opportunities for the development of new business models and the creation of environmental, economic, technical and social value. This paper focuses on the identification and analysis of existing interventions that can promote the reuse of construction components, and outlines the barriers and opportunities arising from this practice as depicted from the global literature. The main conclusions that derive from this study are that the combination of incentives that promote reuse of construction components and recycling of the rest of the construction materials with the provision of specialised education, skills and training would transform the way construction sector currently operates and create opportunities for new business development. Moreover, a typology system developed based on the properties and lifetime of construction components is required in order to provide transparency and guidance in the way construction components are used and reused, in order to make them readily available to designers and contractors. Smart technologies carry the potential to aid the development and uptake of this system by enabling efficient tracking, storage and archiving, while providing information relevant to the environmental and economic savings that can be regained, enabling also better decision-making during construction and deconstruction works. However, further research is required in order to investigate the opportunities and constraints of the use of these technologies.

Analysis of chromium and sulphate origins in construction recycled materials based on leaching test results

Twenty samples of recycled aggregates from construction and demolition waste (CDW) with different compositions collected at six recycling plants in the Andalusia region (south of Spain) were characterised according to the Landfill Directive criteria. Chromium and sulphate were identified as the most critical compounds in the leachates. To detect the sources of these two pollutant constituents in recycled aggregate, environmental assessments were performed on eight construction materials (five unused ceramic materials, two old crushed concretes and one new mortar manufactured in the laboratory). The results confirmed that leached sulphate and Cr were mainly released by the ceramic materials (bricks and tiles). To predict the toxicological consequences, the oxidation states of Cr (III) and Cr (VI) were measured in the leachates of recycled aggregates and ceramic materials classified as non-hazardous. The bricks and tiles mainly released total Cr as Cr (III). However, the recycled aggregates classified as non-hazardous according to the Landfill Directive criteria mainly released Cr (VI), which is highly leachable and extremely toxic. The obtained results highlight the need for legislation that distinguishes the oxidative state in which chromium is released into the environment. Leaching level regulations must not be based solely on total Cr, which can lead to inaccurate predictions.

Development of construction materials using nano-silica and aggregates recycled from construction and demolition waste

The present work addresses the development of novel construction materials utilising commercial grade nano-silica and recycled aggregates retrieved from construction and demolition waste. For this, experimental work has been carried out to examine the influence of nano-silica and recycled aggregates on compressive strength, modulus of elasticity, water absorption, density and volume of voids of concrete. Fully natural and recycled aggregate concrete mixes are designed by replacing cement with three levels (0.75%, 1.5% and 3%) of nano-silica. The results of the present investigation depict that improvement in early days compressive strength is achieved with the incorporation of nano-silica in addition to the restoration of reduction in compressive strength of recycled aggregate concrete mixes caused owing to the replacement of natural aggregates by recycled aggregates. Moreover, the increase in water absorption and volume of voids with a reduction of bulk density was detected with the incorporation of recycled aggregates in place of natural aggregates. However, enhancement in density and reduction in water absorption and volume of voids of recycled aggregate concrete resulted from the addition of nano-silica. In addition, the results of the study reveal that nano-silica has no significant effect on elastic modulus of concrete.

Leaching assessment of concrete made of recycled coarse aggregate: physical and environmental characterisation of aggregates and hardened concrete

Each year, millions of tonnes of waste are generated worldwide, partially through the construction and demolition of buildings. Recycling the resulting waste could reduce the amount of materials that need to be manufactured. Accordingly, the present work has analysed the potential reuse of construction waste in concrete manufacturing by replacing the natural aggregate with recycled concrete coarse aggregate. However, incorporating alternative materials in concrete manufacturing may increase the pollutant potential of the product, presenting an environmental risk via ground water contamination. The present work has tested two types of concrete batches that were manufactured with different replacement percentages. The experimental procedure analyses not only the effect of the portion of recycled aggregate on the physical properties of concrete but also on the leaching behaviour as indicative of the contamination degree. Thus, parameters such as slump, density, porosity and absorption of hardened concrete, were studied. Leaching behaviour was evaluated based on the availability test performed to three aggregates (raw materials of the concrete batches) and on the diffusion test performed to all concrete. From an environmental point of view, the question of whether the cumulative amount of heavy metals that are released by diffusion reaches the availability threshold was answered. The analysis of concentration levels allowed the establishment of different groups of metals according to the observed behaviour, the analysis of the role of pH and the identification of the main release mechanisms. Finally, through a statistical analysis, physical parameters and diffusion data were interrelated. It allowed estimating the relevance of porosity, density and absorption of hardened concrete on diffusion release of the metals in study.

Pilot-based assessment of the economics of recycling construction demolition waste

The significant amount of waste generated from construction demolition has become a chronic problem in many developing countries. Using data obtained from demolition contractors and various other sources, this paper proposes a framework for proper handling of construction demolition waste (CDW) to serve as a decision support tool in countries suffering from the lack of national CDW management guidelines. The framework is then demonstrated through a case study in the city of Beirut, Lebanon, and a sensitivity analysis is carried out to examine the economic feasibility of developing a recycling facility. The analysis showed that in order for a facility to be feasible, a gate fee should be charged in the presence of a market for recycled aggregates. The results confirm the significance of instigating and implementing legislation to control illegal dumping, constructing, and managing engineered landfills, and establishing markets for recycled CDW.

Selective classification and quantification model of C&D waste from material resources consumed in residential building construction

The unfortunate economic situation involving Spain and the European Union is, among other factors, the result of intensive construction activity over recent years. The excessive consumption of natural resources, together with the impact caused by the uncontrolled dumping of untreated C&D waste in illegal landfills have caused environmental pollution and a deterioration of the landscape. The objective of this research was to generate a selective classification and quantification model of C&D waste based on the material resources consumed in the construction of residential buildings, either new or renovated, namely the Conventional Constructive Model (CCM). A practical example carried out on ten residential buildings in Seville, Spain, enabled the identification and quantification of the C&D waste generated in their construction and the origin of the waste, in terms of the building material from which it originated and its impact for every m(2) constructed. This model enables other researchers to establish comparisons between the various improvements proposed for the minimization of the environmental impact produced by building a CCM, new corrective measures to be proposed in future policies that regulate the production and management of C&D waste generated in construction from the design stage to the completion of the construction process, and the establishment of sustainable management for C&D waste and for the selection of materials for the construction on projected or renovated buildings.

Incorporating waste into an experimental school prototype: lessons regarding materials reclamation opportunities

This article presents lessons learned from a design project that explored the possibility of incorporating waste into the design of a school prototype. The authors worked with professional architects, a waste artist, environmental scientists and local waste operators to uncover new uses and applications for discarded items. As a result, bottles, aluminium cans, reclaimed doors, crushed concrete and second-hand bricks, etc. were identified, explored and integrated into the architectural design. This article serves as a catalyst that advocates the use of reclaimed materials in the field of design and planning. In particular, it highlights the challenges and issues that need to be addressed in carrying out design work with waste. Designers and practitioners interested in minimizing waste generation by proposing the use of reclaimed materials will find this article useful.

Construction and demolition waste as a source of PVC for recycling

Construction and demolition waste can contain considerable amounts of polyvinyl chloride (PVC). This paper describes a study of the recycling of PVC pipes collected from such waste materials. In a sorting facility for the specific disposal of construction and demolition waste, PVC was found to represent one-third of the plastics separated by workers. Pipes were sorted carefully to preclude any possible contamination by poly(ethylene terephthalate) (PET) found in the waste. The material was ground into two distinct particle sizes (final mesh of 12.7 and 8 mm), washed, dried and recycled. The average formulation of the pipes was determined based on ash content tests and used in the fabrication of a similar compound made mainly of virgin PVC. Samples of recycled pipes and of compound based on virgin material were subjected to tensile and impact tests and provided very similar results. These results are a good indication of the application potential of the recycled material and of the fact that longer grinding to obtain finer particles is not necessarily beneficial.

Estimation of construction and demolition waste volume generation in new residential buildings in Spain

The management planning of construction and demolition (C&D) waste uses a single indicator which does not provide enough detailed information. Therefore the determination and implementation of other innovative and precise indicators should be determined. The aim of this research work is to improve existing C&D waste quantification tools in the construction of new residential buildings in Spain. For this purpose, several housing projects were studied to determine an estimation of C&D waste generated during their construction process. This paper determines the values of three indicators to estimate the generation of C&D waste in new residential buildings in Spain, itemizing types of waste and construction stages. The inclusion of two more accurate indicators, in addition to the global one commonly in use, provides a significant improvement in C&D waste quantification tools and management planning.