Recycled lightweight concrete made from footwear industry waste and CDW

In this paper two types of recycled aggregate, originated from construction and demolition waste (CDW) and ethylene vinyl acetate (EVA) waste, were used in the production of concrete. The EVA waste results from cutting off the EVA expanded sheets used to produce insoles and innersoles of shoes in the footwear industry. The goal of this study was to evaluate the influence of the use of these recycled aggregates as replacements of the natural coarse aggregate, upon density, compressive strength, tensile splitting strength and flexural behavior of recycled concrete. The experimental program was developed with three w/c ratios: 0.49, 0.63 and 0.82. Fifteen mixtures were produced with different aggregate substitution rates (0%, 50% EVA, 50% CDW, 25% CDW–25% EVA and 50% CDW–50% EVA), by volume. The results showed that it is possible to use the EVA waste and CDW to produce lightweight concrete having semi-structural properties.     

A BIM-based system for demolition and renovation waste estimation and planning

Due to the rising worldwide awareness of green environment, both government and contractors have to consider effective construction and demolition (C&D) waste management practices. The last two decades have witnessed the growing importance of demolition and renovation (D&R) works and the growing amount of D&R waste disposed to landfills every day, especially in developed cities like Hong Kong. Quantitative waste prediction is crucial for waste management. It can enable contractors to pinpoint critical waste generation processes and to plan waste control strategies. In addition, waste estimation could also facilitate some government waste management policies, such as the waste disposal charging scheme in Hong Kong. Currently, tools that can accurately and conveniently estimate the amount of waste from construction, renovation, and demolition projects are lacking.In the light of this research gap, this paper presents a building information modeling (BIM) based system that we have developed for estimation and planning of D&R waste. BIM allows multi-disciplinary information to be superimposed within one digital building model. Our system can extract material and volume information through the BIM model and integrate the information for detailed waste estimation and planning. Waste recycling and reuse are also considered in our system. Extracted material information can be provided to recyclers before demolition or renovation to make recycling stage more cooperative and more efficient. Pick-up truck requirements and waste disposal charging fee for different waste facilities will also be predicted through our system. The results could provide alerts to contractors ahead of time at project planning stage. This paper also presents an example scenario with a 47-floor residential building in Hong Kong to demonstrate our D&R waste estimation and planning system. As the BIM technology has been increasingly adopted in the architectural, engineering and construction industry and digital building information models will likely to be available for most buildings (including historical buildings) in the future, our system can be used in various demolition and renovation projects and be extended to facilitate project control.     

Choosing a sustainable demolition waste management strategy using multicriteria decision analysis

This paper presents an application of the ELECTRE III decision-aid method in the context of choosing a sustainable demolition waste management strategy for a case study in the city of Lyon, France. This choice of waste management strategy takes into consideration the sustainable development objectives, i.e. economic aspects, environmental consequences, and social issues. Nine alternatives for demolition waste management were compared with the aid of eight criteria, taking into account energy consumption, depletion of abiotic resources, global warming, dispersion of dangerous substances in the environment, economic activity, employment, and quality of life of the local population. The case study concerned the demolition of 25 buildings of an old military camp. Each alternative was illustrated with different waste treatments, such as material recovery, recycling, landfilling, and energy recovery. The recommended solution for sustainable demolition waste management for the case study is a selective deconstruction of each building with local material recovery in road engineering of inert wastes, local energy recovery of wood wastes, and specific treatments for hazardous wastes.     

Architects' perspectives on construction waste reduction by design

The construction, demolition and excavation waste arising in England was estimated at 91 million tonnes in 2003. The current thinking on construction waste minimisation is heavily focussed on several issues relating to physical construction waste and recycling guides. Indeed, much had been published on ways to improve on-site waste management and recycling activities but very few attempts made to address the effect of design practices on waste generation. However, there is a consensus in the literature that the architect has a decisive role to play in helping to reduce waste by focussing on designing out waste. This paper examines previous studies on architects' approach towards construction waste minimisation; and by means of a postal questionnaire, investigates: the origins of waste; waste minimisation design practices in the UK; and responsibilities and barriers within the UK architectural profession. The findings reveal that waste management is not a priority in the design process. Additionally, the architects seemed to take the view that waste is mainly produced during site operations and rarely generated during the design stages; however, about one-third of construction waste could essentially arise from design decisions. Results also indicate that a number of constraints, namely: lack of interest from clients; attitudes towards waste minimisation; and training all act as disincentives to a proactive and sustainable implementation of waste reduction strategies during the design process.     

Managing post-conflict demolition wastes in Gaza Strip: a case study on May 2021 conflict

Gaza Strip is considered as one of the armed conflicts prone areas in Middle East. Several intensive conflicts occurred in Gaza Strip in 2008, 2012, 2014 and 2021. These conflicts caused massive destroying the infrastructures, facilities, and buildings, which affected all services and activities in Gaza Strip. One of the major post-conflict issues in Gaza strip is the management of resulted demolition waste including its removal, sorting, recycling, and material recovery. In May 2021, over than 370,000 tons of demolition waste composed of rubbles and debris was generated during 11 days of armed conflict. The accumulated previous experience of rubbles and debris removal and recycling in Gaza Strip supported to perform a quick management approach for safe removal of the post-conflict demolition waste and reuse/recycle the resulted waste materials in various applications. The sorting and transporting process of concreate and non-concreate rubble elements of the waste were carried out in cooperation between local and international agencies as emergency recovery-funded projects. The most proportion of rubbles are concrete aggregates, thus, the material recovery was conducted through crushing process for concrete rubbles and then reusing it for road rehabilitation or producing concrete building blocks. The large concrete blocks reused to be placed for shoreline protection for specific area along Gaza beach. The recycling of post-conflict demolition waste management projects in Gaza Strip brought economic and social benefits through the reuse and recycle of resources and creation of job opportunities. In conclusion, although the post-conflict demolition waste management is quite different from municipal/industrial waste management in Gaza Strip, it is conducted through applying similar techniques of disaster waste management in waste removal, and those of construction and demolition (C&D) waste management in sorting, crushing, and sieving for recycling.

     

A web-based Decision Support System for the optimal management of construction and demolition waste

Wastes from construction activities constitute nowadays the largest by quantity fraction of solid wastes in urban areas. In addition, it is widely accepted that the particular waste stream contains hazardous materials, such as insulating materials, plastic frames of doors, windows, etc. Their uncontrolled disposal result to long-term pollution costs, resource overuse and wasted energy. Within the framework of the DEWAM project, a web-based Decision Support System (DSS) application - namely DeconRCM - has been developed, aiming towards the identification of the optimal construction and demolition waste (CDW) management strategy that minimises end-of-life costs and maximises the recovery of salvaged building materials. This paper addresses both technical and functional structure of the developed web-based application. The web-based DSS provides an accurate estimation of the generated CDW quantities of twenty-one different waste streams (e.g. concrete, bricks, glass, etc.) for four different types of buildings (residential, office, commercial and industrial). With the use of mathematical programming, the DeconRCM provides also the user with the optimal end-of-life management alternative, taking into consideration both economic and environmental criteria. The DSS's capabilities are illustrated through a real world case study of a typical five floor apartment building in Thessaloniki, Greece.     

Deep learning of grasping detection for a robot used in sorting construction and demolition waste

Journal of Material Cycles and Waste Management - The traditional construction and demolition waste (CDW) treatment process adopts the method of crushing and screening after mixing and combines the...     

Reverse supply chain practices for construction and demolition waste in the Brazilian Amazon: a multi-stakeholder view

Journal of Material Cycles and Waste Management - Construction and demolition waste (CDW) is an environmental problem that affects all regions of the world. Particularly in the Brazilian Amazon...     

Preliminary study for the management of construction and demolition waste

This paper refers to the management of the construction and demolition (C&D) waste since, according to the EU Waste Strategy, C&D waste is considered to be one of the priority waste streams and appropriate actions need to be taken with respect to its effective management. Initially, the paper presents the state-of-the-art of the problem of C&D waste, including the amount and composition of C&D waste in EU countries, differences in the characteristics of this waste stream depending on its origin, as well as collection and management practices that are applied. A methodology is described for the estimation of the quantities of the waste stream under examination, since in most cases quantitative primary data is not available. Next, the fundamentals for the development of an integrated scheme for the management of C&D waste are presented and discussed, such as appropriate demolition procedures and location of waste management (off-site waste management, on-site waste management, direct on-site recovery, centralized on-site recovery). Finally, taking into consideration all relevant parameters, alternative systems that could be applied for the management of the C&D waste are suggested.     

Developing strategies for managing construction and demolition wastes in Malaysia based on the concept of circular economy

Construction and demolition (C&D) waste is a pressing issue not only in Malaysia, but it is also a worldwide concern including the developed countries as well. C&D waste should be managed throughout the construction cycle. The concept of circular economy (CE) is an emerging notion that has the potential to be utilized as waste minimization approach. This paper aims to assess the potentials of incorporating the CE concept as an approach to minimizing C&D wastes, by developing a CE-based theoretical framework for C&D waste management in Malaysia. In line with this objective, a systematic review has been conducted to determine how CE can be operationalised as a strategy to minimize wastes, while considering it as a key factor for mitigating the environmental impacts. Based on the literature review, a CE-based theoretical framework has been proposed using Malaysia as a case study. The framework has been developed following a three-layer approach namely micro-, meso-, and macro-levels. Waste minimization strategies have been identified for each level taking into account the main stages in the construction industry, i.e., planning, designing, procurement, construction, and demolition. The different stakeholders involved at each stage and their interactions in the stages have also been identified.     

Construction demolition wastes, Waelz slag and MSWI bottom ash: a comparative technical analysis as material for road construction

The objective of the study is to analyze the technical suitability of using secondary materials from three waste flows (construction and demolition waste (CDW), Waelz slag and municipal solid waste incineration (MSWI) bottom ash), under the regulations and standards governing the use of materials for road construction. A detailed technical characterization of the materials was carried out according to Spanish General Technical Specifications for Road Construction (PG3). The results show that Waelz slag can be adequate for using in granular structural layers, while CDW fits better as granular material in roadbeds. Likewise, fresh MSWI bottom ash can be used as roadbed material as long as it does not contain a high concentration of soluble salts. This paper also discusses the adequacy of using certain traditional test methods for natural soils when characterizing secondary materials for use as aggregates in road construction.     

Separability studies of construction and demolition waste recycled sand

The quality of recycled aggregates from construction and demolition waste (CDW) is strictly related to the content of porous and low strength phases, and specifically to the patches of cement that remain attached to the surface of natural aggregates. This phase increases water absorption and compromises the consistency and strength of concrete made from recycled aggregates. Mineral processing has been applied to CDW recycling to remove the patches of adhered cement paste on coarse recycled aggregates. The recycled fine fraction is usually disregarded due to its high content of porous phases despite representing around 50% of the total waste.This paper focus on laboratory mineral separability studies for removing particles with a high content of cement paste from natural fine aggregate particles (quartz/feldspars). The procedure achieved processing of CDW by tertiary impact crushing to produce sand, followed by sieving and density and magnetic separability studies. The attained results confirmed that both methods were effective in reducing cement paste content and producing significant mass recovery (80% for density concentration and 60% for magnetic separation). The production of recycled sand contributes to the sustainability of the construction environment by reducing both the consumption of raw materials and disposal of CDW, particularly in large Brazilian centers with a low quantity of sand and increasing costs of this material due to long transportation distances.     

A review of waste prevention through 3R under the concept of circular economy in China

The large waste generation has become one of the worldwide environmental problems. Circular economy has been seen as a way to tackle its urgent problems of environmental degradation and source scarcity. In recent years, under the concepts of circular economy, waste prevention through “Reduce, Reuse and Recycle” (3R) rules have attracted a broad concern in China. China has made some great achievements on waste management, and at the same time is facing many challenges. It is very necessary to share the management experiences and practices with the scholars and managers in other countries. This review covered the current situation and progress of circular economy development from the perspective of the legal regime and project practices, and the recycling practices of typical waste. The typical household wastes, including municipal solid wastes (MSW), e-waste, and end of life vehicles (ELV), were studied as the typical cases. Based on an examination of the statistical results, we also identified the potential problems and challenges for waste prevention through 3R in China. Finally, we provided some effective measures to further improve the waste management and recycling in China.     

Phosphorus recovery methods from secondary resources,assessment of overall benefits and barriers with focus on the Nordic countries

Phosphorus (P) recovery and recycling play a crucial role in improving resource efficiency, sustainable nutrient management and moving toward circular economy. Increasing demand for fertilizers, signs of geopolitical constraints, and high discharge of P to waterbodies are the other reasons to pursue the circularity of P. Various research have been carrying out and several processes have been developed for P-recovery from different resources. However, there is still a huge unexplored potential for P-recovery specially in the regional framework from the four main P-rich waste resources: food waste, manure, mining waste, and sewage sludge. This study reviews recovery methods of P from these secondary resources comprehensively. Additionally, it analyzes the Nordic viewpoint of P-cycle by evaluating Nordic reserves, demands, and secondary resources to gain a systematic assessment of how Nordic countries could move toward circular economy of P. Results of this study show that secondary resources of P in Nordic countries have the potential of replacing mineral fertilizer in these countries to a considerable extent. However, to overcome the challenges of P-recovery from studied resources, policymakers and researchers need to take decisions and make innovation along each other to open the new possibilities for Nordic economy.

     

Management of hazardous waste in Thailand: present situation and future prospects

 This paper deals with the present scenario of hazardous waste management practices in Thailand, and gives some insights into future prospects. Industrialization in Thailand has systematically increased the generation of hazardous waste. The total hazardous waste generated in 2001 was 1.65 million tons. It is estimated that over 300 million kg/year of hazardous waste is generated from nonindustrial, community sources (e.g., batteries, fluorescent lamps, cleansing chemicals, pesticides). No special facilities are available for handling these wastes. There are neither well-established systems for separation, storage, collection, and transportation, nor the effective enforcement of regulations related to hazardous wastes management generated from industrial or nonindustrial sectors. Therefore, because of a lack of treatment and disposal facilities, these wastes find their way into municipal wastewaters, public landfills, nearby dump sites, or waterways, raising serious environmental concern. Furthermore, Thailand does not have an integrated regulatory framework regarding the monitoring and management of hazardous materials and wastes. In addition to the absence of a national definition of hazardous wastes, limited funding has caused significant impediments to the effective management of hazardous waste. Thus, current waste management practices in Thailand present significant potential hazards to humans and the environment. The challenging issues of hazardous waste management in Thailand are not only related to a scarcity of financial resources (required for treatment and disposal facilities), but also to the fact that there has been no development of appropriate technology following the principles of waste minimization and sustainable development. A holistic approach to achieving effective hazardous waste management that integrates the efforts of all sectors, government, private, and community, is needed for the betterment of human health and the environment. Received: February 26, 2001 / Accepted: October 11, 2002     

Solid waste recycling within higher education in developing countries: a case study of the University of Lagos

To create a truly circular economy requires a shift from the traditional view of waste disposal to one of resource management. This is particularly important in developing countries, where municipal waste generation is increasing, and efficient recovery of economic value from waste is rarely achieved. Conducted in the University of Lagos (UoL), Nigeria, this study investigated the efficiency of a recycling scheme with the goal of making recommendations to improve the process. UoL’s recycling policy centers around source segregation of waste into color-coded bins. Waste audit was carried out using the output method and interviews were conducted with staff from the waste management team to understand practices on campus. Substantial contamination of colored bins with non-target material was observed. Organics (30%), mixed plastics (28%) and paper (24%) were the most abundant materials, hence have the greatest potential for recovery, and income generation, if segregation rates could be improved. Despite its recycling policy and infrastructure, 99% of UoL waste was going to landfill. Poor policy implementation results in low recovery rates. Targeted waste reduction and increased material recovery would enhance efficiency. Improved awareness of recycling benefits, in addition to policy enforcement, could serve as tools to increase stakeholder participation in recycling.

     

An empirical investigation of construction and demolition waste generation rates in Shenzhen city, South China

The construction and demolition waste generation rates (C&D WGRs) is an important factor in decision-making and management of material waste in any construction site. The present study investigated WGRs by conducting on-site waste sorting and weighing in four ongoing construction projects in Shenzhen city of South China. The results revealed that WGRs ranged from 3.275 to 8.791 kg/m² and miscellaneous waste, timber for formwork and falsework, and concrete were the three largest components amongst the generated waste. Based on the WGRs derived from the research, the paper also discussed the main causes of waste in the construction industry and attempted to connect waste generation with specific construction practices. It was recommended that measures mainly including performing waste sorting at source, employing skilful workers, uploading and storing materials properly, promoting waste management capacity, replacing current timber formwork with metal formwork and launching an incentive reward program to encourage waste reduction could be potential solutions to reducing current WGRs in Shenzhen. Although these results were derived from a relatively small sample and so cannot justifiably be generalized, they do however add to the body of knowledge that is currently available for understanding the status of the art of C&D waste management in China.     

Disaster waste management: a review article

Depending on their nature and severity, disasters can create large volumes of debris and waste. The waste can overwhelm existing solid waste management facilities and impact on other emergency response and recovery activities. If poorly managed, the waste can have significant environmental and public health impacts and can affect the overall recovery process.This paper presents a system overview of disaster waste management based on existing literature. The main literature available to date comprises disaster waste management plans or guidelines and isolated case studies. There is ample discussion on technical management options such as temporary storage sites, recycling, disposal, etc.; however, there is little or no guidance on how these various management options are selected post-disaster. The literature does not specifically address the impact or appropriateness of existing legislation, organisational structures and funding mechanisms on disaster waste management programmes, nor does it satisfactorily cover the social impact of disaster waste management programmes.It is envisaged that the discussion presented in this paper, and the literature gaps identified, will form a basis for future comprehensive and cohesive research on disaster waste management. In turn, research will lead to better preparedness and response to disaster waste management problems.     

Review of LCA studies of solid waste management systems – Part I: Lessons learned and perspectives

The continuously increasing solid waste generation worldwide calls for management strategies that integrate concerns for environmental sustainability. By quantifying environmental impacts of systems, life cycle assessment (LCA) is a tool, which can contribute to answer that call. But how, where and to which extent has it been applied to solid waste management systems (SWMSs) until now, and which lessons can be learnt from the findings of these LCA applications? To address these questions, we performed a critical review of 222 published LCA studies of SWMS. We first analysed the geographic distribution and found that the published studies have primarily been concentrated in Europe with little application in developing countries. In terms of technological coverage, they have largely overlooked application of LCA to waste prevention activities and to relevant waste types apart from household waste, e.g. construction and demolition waste. Waste management practitioners are thus encouraged to abridge these gaps in future applications of LCA. In addition to this contextual analysis, we also evaluated the findings of selected studies of good quality and found that there is little agreement in the conclusions among them. The strong dependence of each SWMS on local conditions, such as waste composition or energy system, prevents a meaningful generalisation of the LCA results as we find it in the waste hierarchy. We therefore recommend stakeholders in solid waste management to regard LCA as a tool, which, by its ability of capturing the local specific conditions in the modelling of environmental impacts and benefits of a SWMS, allows identifying critical problems and proposing improvement options adapted to the local specificities.     

A dynamic model for assessing the effects of management strategies on the reduction of construction and demolition waste

During the past few decades, construction and demolition (C&D) waste has received increasing attention from construction practitioners and researchers worldwide. A plethora of research regarding C&D waste management has been published in various academic journals. However, it has been determined that existing studies with respect to C&D waste reduction are mainly carried out from a static perspective, without considering the dynamic and interdependent nature of the whole waste reduction system. This might lead to misunderstanding about the actual effect of implementing any waste reduction strategies. Therefore, this research proposes a model that can serve as a decision support tool for projecting C&D waste reduction in line with the waste management situation of a given construction project, and more importantly, as a platform for simulating effects of various management strategies on C&D waste reduction. The research is conducted using system dynamics methodology, which is a systematic approach that deals with the complexity - interrelationships and dynamics - of any social, economic and managerial system. The dynamic model integrates major variables that affect C&D waste reduction. In this paper, seven causal loop diagrams that can deepen understanding about the feedback relationships underlying C&D waste reduction system are firstly presented. Then a stock-flow diagram is formulated by using software for system dynamics modeling. Finally, a case study is used to illustrate the validation and application of the proposed model. Results of the case study not only built confidence in the model so that it can be used for quantitative analysis, but also assessed and compared the effect of three designed policy scenarios on C&D waste reduction. One major contribution of this study is the development of a dynamic model for evaluating C&D waste reduction strategies under various scenarios, so that best management strategies could be identified before being implemented in practice.