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

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 study on the waste generation rates and recycling potential for the construction and demolition waste in Dhaka, Bangladesh

Construction and demolition waste has a high environmental and socio-economic impact due to its poor management infrastructure. In recent years, Dhaka, the capital city of Bangladesh, experienced significant growth in the real estate sector, which demands substantial construction and demolition activities within the city. Most of the construction and demolition waste finds its way to landfills, roadsides, and unapproved locations with a 2% recycling rate through local scrap vendors and unregulated recyclers. In an effort to assess the waste generation rates from ongoing construction and demolition activities, the current study employed the Site Visit method along with direct and indirect waste quantification methodologies for the investigated demolition and construction projects, respectively. The findings indicate that for per unit area (m2) of demolition and construction, the average WGR was found to be approximately 575.0 kg and 73.9 kg, respectively. Projection reveals that by 2025 and 2030, within Dhaka City, construction and demolition activities will generate roughly 1.15 MT and 1.69 MT of construction and demolition waste if no recycling actions are considered. Additionally, the results highlight the recycling potential of construction and demolition waste with respect to economic benefits through the maximum recycling rates for the relevant materials. Furthermore, to address the future of sustainable construction and demolition waste management infrastructure, this paper presents a detailed overview of the current onsite construction and demolition waste management practices as well as safety protocols for demolition and construction activities.

Circular economy strategies for waste management in Sri Lanka: A focus on demolitions and repurpose and material recovery and production stages

In Sri Lanka, the management of Construction & Demolition (C&D) waste poses a major problem, leading to environmental degradation and depletion of resources. This study aims to tackle these issues by examining the implementation of Circular Economy (CE) strategies within the construction industry of Sri Lanka. The focus is on reducing waste generation and maximizing resource utilization during the demolitions and repurpose, as well as material recovery and production stages of the building project life cycle. These stages are crucial in terms of waste generation and resource consumption. A qualitative approach was employed in this research, utilizing the Delphi technique to gather insights through a series of three rounds of expert interviews. In the first round, 17 experts were involved, followed by 15 in the second round, and 12 in the final round. The data collected from these interviews were analysed using manual content analysis methods. Based on the research findings, a total of 14 C&D Waste Management (WM) issues were identified specifically in the Demolitions and Repurpose Stage in Sri Lanka. For each issue, suitable strategies were proposed to overcome them effectively. Furthermore, the study examined the impact of CE strategies on minimizing these issues within the context of the project management iron triangle. Similarly, the Material Recovery and Production Stage of the building presented eight C&D WM issues, each accompanied by corresponding strategies to address them. The research also explored the influence of CE strategies in mitigating these issues, considering the project management iron triangle. During the demolitions and repurpose stage, CE strategies focus on reducing waste generation and optimizing resource utilization. This involves carefully deconstructing buildings to salvage and recover materials that can be reused or repurposed.

Waste Clay Bricks as a Geopolymer Binder for Pavement Construction

Geopolymer binders that combine aluminosilicate materials (i.e., precursors) with alkali activators are a viable and environmentally friendly alternative to ordinary Portland cement. While fly ash, slag, silica fume, and metakaolin are the most extensively investigated precursor materials, recent studies demonstrate the feasibility of using low amorphous aluminosilicates (LAA) for geopolymer synthesis. Waste clay bricks (WCB) make an excellent LAA material for producing geopolymer binders, considering their chemical and mineralogical properties. Geopolymer binders with enhanced mechanical properties can be produced either by blending WCB with other aluminosilicate materials or by using WCB as the sole precursor, while providing appropriate production conditions, such as high-temperature curing. Until now, in pavement construction, WCB has been investigated only as a subbase material or as an aggregate for concrete. Since WCB is a potential geopolymer source material, it can also function as an alternative cementitious material (ACM), and stabilizing material in pavement construction. This work reviews the recent studies on producing WCB-based geopolymers, with the focus particularly on the properties of raw materials, activator types and their concentrations, curing conditions, blended geopolymer systems, and the mechanical properties of WCB-based geopolymer binders. Simultaneously, different pavement design requirements and currently available specifications for the use of geopolymer concrete were correlated to evaluate their feasibility as an ACM in pavement construction. Based on the current literature, WCB can be proposed as a suitable ACM to develop pavement-grade concrete and more promising results can be obtained by blending WCB with high-calcium sources, such as slag. Therefore, comprehensive studies on geopolymer concrete development, durability, and field performance are recommended.

Life Cycle Assessment of Construction and Demolition Waste from Railway Engineering Projects

Railway engineering generates large amounts of construction and demolition waste (CDW). To quantify the amount of CDW generated from railway engineering projects throughout the whole life cycle, a process-based life cycle assessment model is proposed in this paper. The life-cycle CDW is divided into four parts: CDW from off-site transportation of construction materials (OSTCM), CDW from site operation wastage of construction materials (SOWCM), discard ballast from roadbeds, stationyard, bridges and tunnels (DB), and CDW from reparation and renewal of aging components (RRAC). Yun-Gui Railway is selected as a case study to validate the developed model, and an uncertainty analysis is conducted with Oracle Crystal Ball software. The results show that between 175 and 311 million tons of CDW is generated throughout the whole life cycle of Yun-Gui Railway. DB is the largest component of the life-cycle CDW from railway engineering projects. This indicates the negative environmental impacts of railway construction can be significantly mitigated by optimizing the location of ballast disposal sites and developing suitable landfill proposals. Also, the CDW generated by wastage of construction materials during off-site construction and site operation is important in waste management in railway engineering projects, in which rubble, sand, and cement have the high potential for waste reduction. Findings from this study can contribute to the knowledge body as well as the engineering practice in green railways.

Estimation of construction waste composition based on bulk density: A big data-probability (BD-P) model

Estimating the composition of construction waste is crucial to the efficient operation of various waste management facilities, such as landfills, public fills, and sorting plants. However, this estimating task is often challenged by the desire of quickness and accuracy in real-life scenarios. By harnessing a valuable data set in Hong Kong, this research develops a big data-probability (BD-P) model to estimate construction waste composition based on bulk density. Using a saturated data set of 4.27 million truckloads of construction waste, the probability distribution of construction waste bulk density is derived, and then, based on the Law of Joint Probability, the BD-P model is developed. A validation experiment using 604 ground truth data entries indicates a model accuracy of 90.2%, Area Under Curve (AUC) of 0.8775, and speed of around 52 s per load in estimating the composition of each incoming construction waste load. The BD-P model also informed a linear model which can perform the estimation with an accuracy of 88.8% but consuming 0.4 s per case. The major novelty of this research is to harmonize big data analytics and traditional probability theories in improving the classic challenge of predictive analyses. In the practical sphere, it satisfactorily solves the construction waste estimation problem faced by many waste management facility operators. In the academic sphere, this research provides a vivid example that big data and theories are not adversaries, but allies.

Construction Waste Reduction through Application of Different Structural Systems for the Slab in a Commercial Building: A South Korean Case

Construction waste generation along with the extensive consumption of natural resources has propelled researchers to investigate effective measures for minimising the waste. While several studies have shown that the structural design would be an influencing factor on the carbon dioxide emissions of a building, there is a lack of studies to corroborate the effect of different structural systems to generate waste during the construction stage. This article seeks to bridge some of the knowledge gaps regarding the waste generation from different structural systems during the construction phase in a building project in South Korea and demonstrate its potential for waste reduction. In this study, the amount of waste generation during the construction phase was calculated based on the quantities and the material loss rate of each building material to estimate the quantity of construction waste by the changes in the application of different structural systems for the slab of the studied model. The total waste generation during the construction phase of the different slab systems shows that the solid slab system produces the largest amount of construction waste, which is 101,361.385 kg. On the other hand, the void slab system generates 87,603.958 kg of the construction waste, which is the lowest amount among the four variables of this study. The additional purchasing costs due to the loss of construction materials indicate that the solid slab system would require 80,709.76 USD, which is the highest value of the four variables in this study. The void slab system would cost USD 50,054.12 for additional materials purchasing costs, which is approximately 38% lower than the solid slab system.

GHG Emissions Assessment of Civil Construction Waste Disposal and Transportation Process in the Eastern Amazon

The urbanization process represented by an increased supply of housing and transport infrastructure has taken place at an accelerated rate in several regions of Brazil, especially in the metropolitan areas of the Brazilian Amazon. Despite the existence of environmental policies that guide the proper disposal of civil construction waste (CCW) in Brazil, the impacts of these policies are still negligible, pointing to the need to establish other metrics such as the measurement of greenhouse gas (GHG) emissions in CO2eq associated with civil construction waste. This work aims to evaluate, in the second-largest city in the Brazilian Amazon, the environmental impact generated by the transportation of CCW to disposal sites, having as indicators the volume of this waste and the CO2 emissions produced during a whole year. A literature review on life cycle carbon emissions assessment in building construction and CO2 emissions in transportation are provided to establish the background of the research methodology. Data collection was carried out by searching large generators of construction waste, the companies responsible for transporting construction waste, and the types of vehicles used. Calculation of GHG emissions from CCW transportation was based on the method described in the 2006 IPCC Guidelines. The study identified a volume of waste of around 1244 m3/month, with a generation of 40,440 kgCO2/year, only from small and large generators. Besides the damage identified in this study, there is also the dumping of CCW into urban streams in the city which is causing negative impacts on sanitation and drainage systems. The results point to the need to strengthen local policies to mitigate the impacts of the existing CCW to contribute to a more sustainable city.

Waste generation, composition, and handling in building-related construction and demolition in Hanoi, Vietnam

This study conducted a survey at 15 building construction and demolition sites in Hanoi, Vietnam in order to identify waste generation rates (WGR), composition, and current handling practices of construction and demolition waste (CDW). Waste quantification based on CDW layout, image analysis to identify CDW components, and face-to-face interviews with construction and demolition contractors to reveal CDW flows were performed. WGRs of 79.3 kg/m² and 1,030 kg/m² were determined in small- and large-scale construction sites, respectively, whilst WGRs at small and large demolition sites were 610 kg/m² and 318 kg/m². The composition analysis identified soil, concrete, and brick as the major CDW components, consistent with building structures in Vietnam. The interviews discovered that merely 10% of total CDW flows was from recycled and reused CDW. Reuse and recycling rates were most significant for metal and were lower (in descending order) for brick, concrete, and soil. These findings raise a need for aggressive and integrated strategies to promote more sustainable CDW management in the country, including the development of recycled CDW product standards, policies that facilitate recycling, and more importantly, a sustainable business model for CDW recycling, for which future evaluations of economic feasibility are of great importance.

Modelling waste generated during construction of buildings using regression analysis

The building industry is responsible for a large amount of waste, and the measurement and modelling of this waste could be used to develop better waste management plans. Several theoretical models explain the relationships between waste and building characteristics, but local practices may result in different behaviours. This study aimed to measure and analyse the waste generated through construction. It was based on the analysis of 18 building sites located in the region of Porto Alegre, Brazil. Waste was measured at these sites, and the results showed an average waste generation rate of 0.151 m³ m^-2. A regression analysis of the collected data presented a satisfactory performance in two models. The first model was developed to explain total waste generation, including the effects of certain attributes, with an R² = 0.81. The changes in waste generated during construction were estimated. The second model considered time schedules and examined the effect of the construction stage on waste generation, and reached an R² = 0.91. The model with time indicated an S-shaped relationship. The models presented satisfactory statistical parameters and could be used to produce better waste management plans in the preconstruction stage.

Differences of methods to quantify construction and demolition waste for less-developed but fast-growing countries: China as a case study

As China and other developing countries continue to urbanize over the next decades, construction and demolition waste (CDW) management has been becoming a significant challenge for urban sustainability in terms of the environment, economy, and safety. However, accurate estimations or statistics of CDW generation are absent from the official national report in spite of their importance to devise sensible interventions to tackle CDW-related problems. This paper examines and compares the applications of three prevailing methods for estimating CDW, including the weight-per-construction-area method (WAM), buildings' life span-based method, and weight-per-capita method. Specifically, China has been chosen as the case study. This study implies that the weight-per-construction-area method is more appropriate because of the data availability and accuracy at a city or national level. The results of WAM indicate that a total of 4.1 billion metric tons (Bt) of CDW were generated in China in 2016, mainly from demolition waste (85%). Taking the changes of buildings' life span into account, a projection analysis reveals that the cumulative CDW generation will be 50 Bt between 2017 and 2040 in China (equal to approximately 38 years cumulative generation of global municipal solid waste). Overall, the findings provide some methodological options for scholars, practitioners, and decision-makers to more accurately estimate the amount of the CDW and to develop a more environmentally sound management strategy.

An empirical study of construction and demolition waste generation and implication of recycling

Associated with the continuing increase of construction activities such as infrastructure projects, commercial buildings and housing programs, Bangladesh has been experiencing a rapid increase of construction and demolition (C&D) waste. Till now, the generation rate of C&D waste has not been well understood or not explicitly documented in Bangladesh. This study aims to provide an approach to estimate C&D waste generation using waste generation rates (WGR) through regression analysis. Furthermore, analyses the economic benefit of recycling C&D waste. The results revealed that WGR 63.74 kg/m² and 1615 kg/m² for construction and demolition activities respectively. Approximately, in financial year (FY) 2016, 1.28 million tons (0.149 construction and 1.139 demolition) waste were generated in Dhaka city, of which the three largest proportions were concrete (60%), brick/block (21%) and mortar (9%). After collection they were dumped in either landfills or unauthorized places. Therefore, it can be summarized as: waste is a resource in wrong place. The results of this study indicate that rapid urbanization of Dhaka city would likely experience the peak in the generation of C&D waste. This paper thus designates that C&D waste recycling is an entrepreneurial activity worth venturing into and an opportunity for extracting economic and environmental benefits from waste. The research findings also show that recycling of concrete and brick waste can add economic value of around 44.96 million USD. In addition, recycling of C&D waste leads to important reductions in CO₂ emissions, energy use, natural resources and illegal landfills. Therefore, the findings of WGR and economic values provide valuable quantitative information for the future C&D waste management exercises of various stakeholders such as government, industry and academy.

Construction and Demolition Waste in Romania: The Route from Illegal Dumping to Building Materials

The paper performs a critical overview concerning the construction and demolition waste (C&DW) management issues in Romania. Five main stages related to C&DW management are highlighted such as: (i) illegal dumping on public lands; (ii) C&DW collection and disposal in urban landfills; (iii) C&DW treatment and reuse in civil constructions (roads, coating material for landfills); (iv) regional integrated waste management systems; (v) recycling of building materials (e.g., cement industry and recycled aggregates). The paper reveals the poor monitoring of C&DW flows across Romanian counties and the geographical dimension of this waste stream collected by waste operators. The paper examines the current challenges in Romania and it reveals the future prospects to provide a reliable transition towards sustainable C&DW management activities. The targeted route: waste fractions can be recycled and/or reused as building materials via integrated waste management systems, which enable a circular economy in urban and rural municipalities.

Investigation of construction wastes generated in the Malaysian residential sector

The construction sector is among the fastest growing sectors in Malaysia; it consumes a vast amount of natural resources and produces a massive volume of construction and demolition waste. The waste is collected in a decentralised manner by sub-contracted companies. It is challenging to obtain reliable information on the amount of construction waste generated, because it is hard to determine its exact quantity and composition. Therefore, this study proposes a quantitative construction waste estimation model for residential buildings according to available data collected from the Construction Industry Development Board, Malaysia. In the development of this model, a theoretical investigation of the construction procedure and the construction waste generation process was conducted. The waste generated rate was determined as 25.79 kg m^-2 for new residential constructions, which translates into about 553,406 t of anticipated waste annually.

Factors influencing temporary wood waste generation in high-rise building construction

In Brazil, the use of wood in construction is primarily temporary, and it can represent a great percentage of construction waste. It is typically discarded with minimal reuse or recycling. As landfill wood disposal could result in methane emissions and/or leaching of hazardous constituents polluting water or soil, the implementation of temporary wood waste reduction strategies must be a critical issue for local construction companies. To manage and control wood waste generation, including setting some reduction goals, it is necessary to identify the influencing factors and ways to quantitatively predict their relative contributions. This study uses a multiple regression statistical model to estimate the amount of temporary wood waste generated in the construction of high-rise buildings by considering the influencing factors related to the design/construction as well as site and safety installations. The case study includes 22 high-rise residential buildings. The regression model predicted approximately 89% of the factors involved in the generation of wood waste in similar constructions. The dependent variables that had an influence on the amount of wood waste are related to design features ('number of floors'), structural construction system ('in situ moulded concrete volume'), and site and safety installations ('site wood fence' and 'wood use rate'). Ways of minimising wood waste generation and the contributions of each type of temporary wood use were discussed.

An estimation framework for building information modeling (BIM)-based demolition waste by type

Most existing studies on demolition waste (DW) quantification do not have an official standard to estimate the amount and type of DW. Therefore, there are limitations in the existing literature for estimating DW with a consistent classification system. Building information modeling (BIM) is a technology that can generate and manage all the information required during the life cycle of a building, from design to demolition. Nevertheless, there has been a lack of research regarding its application to the demolition stage of a building. For an effective waste management plan, the estimation of the type and volume of DW should begin from the building design stage. However, the lack of tools hinders an early estimation. This study proposes a BIM-based framework that estimates DW in the early design stages, to achieve an effective and streamlined planning, processing, and management. Specifically, the input of construction materials in the Korean construction classification system and those in the BIM library were matched. Based on this matching integration, the estimates of DW by type were calculated by applying the weight/unit volume factors and the rates of DW volume change. To verify the framework, its operation was demonstrated by means of an actual BIM modeling and by comparing its results with those available in the literature. This study is expected to contribute not only to the estimation of DW at the building level, but also to the automated estimation of DW at the district level.

Evaluating the performance and intellectual structure of construction and demolition waste research during 2000-2016

Construction and demolition (C&D) waste diminishes scarce land resources and endangers human health and the surrounding environment. Quantitative and visualized analysis was conducted to evaluate worldwide scientific research output on C&D waste from 2000 to 2016. The related information of 857 publications was collected from SCI-Expanded database and statistically analyzed. The number of documents about C&D waste presented a general growth during the last 17 years. Construction and Building Materials publication ranked first in the most productive journals. China and Spain acted as dominated roles comparing to other countries, and Hong Kong Polytechnic University was the institution with the largest amount of C&D waste research. Recycled aggregates, sustainable C&D waste management, and the rewarding program and commerce system were the hottest topics during 2000-2016 and in the near future according to the intellectual structure analysis.

Estimation of construction and demolition waste using waste generation rates in Chennai, India

A large amount of construction and demolition waste is being generated owing to rapid urbanisation in Indian cities. A reliable estimate of construction and demolition waste generation is essential to create awareness about this stream of solid waste among the government bodies in India. However, the required data to estimate construction and demolition waste generation in India are unavailable or not explicitly documented. This study proposed an approach to estimate construction and demolition waste generation using waste generation rates and demonstrated it by estimating construction and demolition waste generation in Chennai city. The demolition waste generation rates of primary materials were determined through regression analysis using waste generation data from 45 case studies. Materials, such as wood, electrical wires, doors, windows and reinforcement steel, were found to be salvaged and sold on the secondary market. Concrete and masonry debris were dumped in either landfills or unauthorised places. The total quantity of construction and demolition debris generated in Chennai city in 2013 was estimated to be 1.14 million tonnes. The proportion of masonry debris was found to be 76% of the total quantity of demolition debris. Construction and demolition debris forms about 36% of the total solid waste generated in Chennai city. A gross underestimation of construction and demolition waste generation in some earlier studies in India has also been shown. The methodology proposed could be utilised by government bodies, policymakers and researchers to generate reliable estimates of construction and demolition waste in other developing countries facing similar challenges of limited data availability.

Forecasting of construction and demolition waste in Brazil

The objective of this article is to develop a computerised tool (software) that facilitates the analysis of strategies for waste management on construction sites through the use of indicators of construction and demolition waste generation. The development involved the following steps: knowledge acquisition, structuring the system, coding and system evaluation. The step of knowledge acquisition aims to provide subsidies for the representation of them through models. In the step of structuring the system, it was presented the structuring and formalisation of knowledge for the development of the system, and has two stages: the construction of the conceptual model and the subsequent instantiation of the model. The coding system aims to implement (code) the conceptual model developed in a model played by computer (digital). The results showed that the system is very useful and applicable in construction sites, helping to improve the quality of waste management, and creating a database that will support new research.

Waste generated in high-rise buildings construction: a quantification model based on statistical multiple regression

Reducing construction waste is becoming a key environmental issue in the construction industry. The quantification of waste generation rates in the construction sector is an invaluable management tool in supporting mitigation actions. However, the quantification of waste can be a difficult process because of the specific characteristics and the wide range of materials used in different construction projects. Large variations are observed in the methods used to predict the amount of waste generated because of the range of variables involved in construction processes and the different contexts in which these methods are employed. This paper proposes a statistical model to determine the amount of waste generated in the construction of high-rise buildings by assessing the influence of design process and production system, often mentioned as the major culprits behind the generation of waste in construction. Multiple regression was used to conduct a case study based on multiple sources of data of eighteen residential buildings. The resulting statistical model produced dependent (i.e. amount of waste generated) and independent variables associated with the design and the production system used. The best regression model obtained from the sample data resulted in an adjusted R(2) value of 0.694, which means that it predicts approximately 69% of the factors involved in the generation of waste in similar constructions. Most independent variables showed a low determination coefficient when assessed in isolation, which emphasizes the importance of assessing their joint influence on the response (dependent) variable.

Estimation of building-related construction and demolition waste in Shanghai

One methodology is proposed to estimate the quantification and composition of building-related construction and demolition (C&D) waste in a fast developing region like Shanghai, PR China. The varieties of structure types and building waste intensities due to the requirement of progressive building design and structure codes in different decades are considered in this regional C&D waste estimation study. It is concluded that approximately 13.71 million tons of C&D waste was generated in 2012 in Shanghai, of which more than 80% of this C&D waste was concrete, bricks and blocks. Analysis from this study can be applied to facilitate C&D waste governors and researchers the duty of formulating precise policies and specifications. As a matter of fact, at least a half of the enormous amount of C&D waste could be recycled if implementing proper recycling technologies and measures. The appropriate managements would be economically and environmentally beneficial to Shanghai where the per capita per year output of C&D waste has been as high as 842 kg in 2010.

Production patterns of packaging waste categories generated at typical Mediterranean residential building worksites

The construction sector is responsible for around 28% of the total waste volume generated in Europe, which exceeds the amount of household waste. This has led to an increase of different research studies focusing on construction waste quantification. However, within the research studies made, packaging waste has been analyzed to a limited extent. This article focuses on the packaging waste stream generated in the construction sector. To this purpose current on-site waste packaging management has been assessed by monitoring ten Mediterranean residential building works. The findings of the experimental data collection revealed that the incentive measures implemented by the construction company to improve on-site waste sorting failed to achieve the intended purpose, showing low segregation ratios. Subsequently, through an analytical study the generation patterns for packaging waste are established, leading to the identification of the prevailing kinds of packaging and the products responsible for their generation. Results indicate that plastic waste generation maintains a constant trend throughout the whole construction process, while cardboard becomes predominant towards the end of the construction works with switches and sockets from the electricity stage. Understanding the production patterns of packaging waste will be beneficial for adapting waste management strategies to the identified patterns for the specific nature of packaging waste within the context of construction worksites.

Overview regarding construction and demolition waste in Spain

The construction sector comprises a number of activities that may result in environmental impacts of considerable magnitude, waste generation being one of the major negative effects of this industry due to the large streams generated. Proper knowledge of the environmental problem caused by the sector is of great importance in order to achieve an effective waste management. Thus, this paper analyse the Spanish situation regarding construction and demolition waste (CDW) compared with other European Union countries; which sets out the current figures of the CDW scenario (legislation, generation, composition, treatment and market) as well as the difficulties encountered when handling this residue.

Quantifying construction and demolition waste: an analytical review

Quantifying construction and demolition (C&D) waste generation is regarded as a prerequisite for the implementation of successful waste management. In literature, various methods have been employed to quantify the C&D waste generation at both regional and project levels. However, an integrated review that systemically describes and analyses all the existing methods has yet to be conducted. To bridge this research gap, an analytical review is conducted. Fifty-seven papers are retrieved based on a set of rigorous procedures. The characteristics of the selected papers are classified according to the following criteria - waste generation activity, estimation level and quantification methodology. Six categories of existing C&D waste quantification methodologies are identified, including site visit method, waste generation rate method, lifetime analysis method, classification system accumulation method, variables modelling method and other particular methods. A critical comparison of the identified methods is given according to their characteristics and implementation constraints. Moreover, a decision tree is proposed for aiding the selection of the most appropriate quantification method in different scenarios. Based on the analytical review, limitations of previous studies and recommendations of potential future research directions are further suggested.

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.