Construction Waste Generation Research Articles

Rendering mortars with incorporation of very fine aggregates from construction and demolition waste

The intense rate of construction and demolition waste generation (CDW) over the years should boost recycling. The use of CDW as constituents of cementitious composites has been considered a feasible alternative to dumping. This paper presents a study of the behaviour of cementitious renderings incorporating very fine recycled aggregates from two types of CDW. Only particles of recycled aggregates below 0.149 mm were used as filler, hereinafter referred as recycled concrete aggregate (RCA) and mixed recycled aggregate (MRA). The incorporation’ percentages used were 0%, 10%, 15% and 20% of natural aggregates’ volume. Several tests have been carried out, in order to evaluate the mortars in terms of mechanical strength, workability, water absorption, dimensional instability and water vapour permeability. The experimental programme consisted in three consecutive phases, in which the mortars that presented the best performances were selected for a deeper analysis of their features. The test results showed that modified mortars had a better behaviour in most of tests compared with the reference mortar (with no CDW). Mortars with incorporation of 20% of RCA and 15% of MRA presented the best performance.

Analysis of Waste Generation Characteristics during New Apartment Construction—Considering the Construction Phase

The waste generation rate (WGR) is used to predict the generation of construction and demolition waste (C&DW) and has become a prevalent tool for efficient waste management systems. Many studies have focused on deriving the WGR, but most focused on demolition waste rather than construction waste (CW). Moreover, previous studies have used theoretical databases and thus were limited in showing changes in the generated CW during the construction period of actual sites. In this study, CW data were collected for recently completed apartment building sites through direct measurement, and the WGR was calculated by CW type for the construction period. The CW generation characteristics by type were analyzed, and the results were compared with those of previous studies. In this study, CW was classified into six types: Waste concrete, waste asphalt concrete, waste wood, waste synthetic resin, waste board, and mixed waste. The amount of CW generated was lowest at the beginning of the construction period. It slowly increased over time and then decreased again at the end. In particular, waste concrete and mixed waste were generated throughout the construction period, while other CWs were generated in the middle of the construction period or towards the end. The research method and results of this study are significant in that the construction period was considered, which has been neglected in previous studies on the WGR. These findings are expected to contribute to the development of efficient CW management systems.

Identification of Construction Waste Generated at Precast Concrete Plants: Case study

The government of Malaysia has introduced Industrialised Building System (IBS) or commonly termed offsite construction in other countries to replace the conventional method of construction, as one of the initiatives to overcome the problems related to waste generation and negative environmental impact in the construction industry. There are few studies of the construction waste generation focus on the offsite, particularly at precast production plant as compared to the construction site. This study aims to investigate the significant type of construction waste generated at precast concrete plants in Johor. In order to identify the type of waste generated in the process of manufacturing the precast concrete component, this study involved field observation to three precast concrete plants in Johor, together with analysing the selected organisation’s document on the waste generation and management record. Interviews were also conducted with the production man-ager/engineer to support the data collection process. The findings revealed that, the types of construction waste that commonly found in the precast concrete plants are concrete and steel. The most significant type of waste generated at precast concrete factory is concrete (total 1,298.56 tonnes for 3 factories, followed by 820 tonnes, 350 tonnes and 128.56 tonnes). This study provides useful information concerning waste assessment data to achieve a better understanding of construction waste in the precast concrete manufacturing industry.

Factors Influencing Construction Waste Generation in Building Construction: Thailand’s Perspective

Rapid growth in construction activities as a result of a growing population and urbanization in many parts of the world generates a large amount of waste from construction. To reduce and manage these wastes, a comprehensive understanding of the construction waste generation factors is needed. The purpose of this study is to identify the contributing factors of construction waste in Thailand’s construction industry. The causes of construction waste were identified through an extensive literature review. A total of 28 causes of construction waste were identified and grouped into the four categories: design and documentation, material and procurement, construction method and planning, and human resources. To determine the significant level of each factor, a structured questionnaire survey was carried out to gather information from contractors about causes of construction material waste. The results show that the categories contributing to construction waste ranks as design and documentation, human resources, construction methods and planning, and material and procurement, respectively. Meanwhile, factors from each category were also determined and ranked. Design change, inattentive working attitudes and behaviors, ineffective planning and scheduling, and material storage were among the highest impact factors on construction waste generation in each category. Identifying the significance levels of waste generation factors will help the industry’s stakeholders build suitable strategies to manage construction waste more effectively.

PROPIEDADES FÍSICO-MECÁNICAS DE CONCRETOS AUTOCOMPACTANTES PRODUCIDOS CON POLVO DE RESIDUO DE CONCRETO

The high demand of Ordinary Portland Cement (CPO) due to the increase in new civil works, in addition to the generation of demolition and construction waste (RCD), cause a negative environmental impact, so a solution to this problem is the recycling of these materials to produce new concrete. The partial replacement of Portland cement by concrete waste powder (CWP) from the concrete recycling process has been highlighted as a sustainable approach. This paper present the chemical and pozzolanic characterization of CWP through X-ray fluorescence (FRX) and Frattini and resistance activity index test respectively. Also, it was evaluated the feasibility of producing self-prepared concretes (SCC) prepared with CWP. The performance of SCC prepared with various replacement ratios of CWP to CPO (i.e., 0 %, 10 %, 20 %, and 30 %) from RCD, has been evaluated experimentally. The workability properties were performed regarding the slump flow test, V-funnel, and L-box. The hardened properties of SCCs including compressive strength, splitting tensile strength and flexural strength, porosity and Capillary suction were studied. The experimental results of this work are showed that the CWP can be used successfully as a filler in self-compacting concrete, although decreasing workability and mechanical resistance.

Value stream mapping for identification and assessment of material waste in construction: A case study.

Construction sites are plagued with numerous problems, such as improper planning and management, high amounts of waste generation and low awareness of waste reduction. Construction and demolition waste literature provides several best practises and prescriptive strategies that help minimise waste during construction. However, it lacks in the systematic identification and minimisation approach of all possibilities of waste. Therefore, studies focusing on principles and tools that help systematically analyse the inefficiencies of on-site processes leading to waste generation and philosophies addressing waste minimisation are necessary. As eliminating waste is one of the key lean principles, this article discusses the need and importance of integrating the lean construction with the construction and demolition waste management. This article aims to estimate and assess the causes of waste generation in a high-rise building construction through a case study in Chennai city (India) using value stream mapping, a key lean construction tool. Onsite monitoring and measurement were performed to quantify the amount of waste generated. A waste generation rate of 66.26 kg m-2 was identified, of which concrete, cement mortar and brick waste represented almost 90% of the total construction waste. Direct observation and interviews of site personnel were conducted to understand the causes of waste generation. A strategic framework has been proposed to improve construction and demolition waste minimisation depicting the synergy of combining lean construction principles with construction and demolition waste management strategies. The proposed framework helps in the systematic identification, assessment and minimisation of on-site construction waste generation.

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 Waste Generation in the Iranian Building Industry

Building industry as one of the greatest industries in Iran comprises a significant share of waste generation in the country. Since a large quantity of the generated construction waste is buried due to the lack of a recycling protocol, it leads to an undesired waste of resources and causes severe environmental issues. This paper provides a study on the problem of material loss/construction waste in the Iranian Building Industry regarding the impact of relevant shortcomings in the stages of design, construction and supervision as the main phases of construction process. This paper includes the case studies from Isfahan, Mazandaran, Qazvin and Zanjan provinces, with a focus on the most important elements underlying construction waste generation. It also presents the experts points of view on prefab and conventional construction methods considering construction waste generation through a questionnaire-based survey. In general, the results show that Iranian project managers, engineers, contractors and workers believe that from 40 to 100 percent of construction wastes can be reduced via application of prefab construction methods. The results indicate that prefabrication can be considered as a solution to waste reduction in the Iranian Building Industry, whereas there is a dominant conventional method application in the industry.

Risks Identification and Allocation in the Supply Chain of Modular Integrated Construction (MiC)

Modular integrated construction (MiC) is an offsite construction technique which can improve construction quality, the certainty of the project cost, provide value for money and reduce construction time, waste generation, and carbon emissions. However, MiC is associated with a unique business model, engineering, supply chain, and stakeholder composition, resulting in bespoke uncertainties and risks. Prominent among them is the uncertainties and risk events in its linked supply chain segments. However, risks identification and allocation in the MiC supply chain segments is not well-established. This research identified and assessed 28 risk events (REs) across the manufacturing, logistics and on-site assembly segments of the MiC supply chain. A principal component analysis generated 10, 6 and 12 REs within the modular manufacturing, logistics, and on-site assembly segments, respectively. A fuzzy synthetic evaluation (FSE) modeling revealed that the on-site assembly REs are the most critical set of risk events with a criticality index of 5.58, followed by the modular manufacturing risk events (5.28) and logistics risk events (5.08). These rankings and criticality assessment have profound implications for the practice and praxis MiC risks management. It is a source of relevant information to stakeholders and practitioners in understanding the MiC supply chain risk events and may prioritize the riskiest events to improve the performance of MiC projects. Again, the assessed REs contributes to the checklists of MiC risk events and may form the basis for future studies on the risk of MiC. Future studies may examine the assessed risk events in different countries using larger samples.

Dynamic Incentive Mechanism Design for Recycling Construction and Demolition Waste under Dual Information Asymmetry

The generation of construction and demolition waste (CDW) is a problem for societies aspiring to sustainability. In this regard, governments have the responsibility to support the CDW recycling through subsidies. However, the information asymmetry, as well as the “dynamic nature” of the CDW recycling market, results in a number of barriers for the government to promote CDW recycling. In this paper, we establish a mathematical model that includes the government and the recycling enterprise in the presence of dual information asymmetry including the unknown recycling technology level and unobservable recycling efforts in one-stage and two-stage cooperation. Using the incentive theory, the static and dynamic optimal recycling incentive contracts of the government were designed, and the optimal decisions of the recycler were identified. A numerical simulation revealed that by designing reasonable contracts, the government can encourage the recycler to report the true technical level and achieve information screening. Furthermore, the subsidy of the high-tech recycler remained unchanged under different circumstances. However, the subsidy of the low-tech recycler was closely related to the probability of misreporting and the proportion of technology types. This finding suggests that the government and recycler are inclined towards long-term dynamic cooperation.

Construction and demolition waste generation in cities in India: an integrated approach

ABSTRACTThis paper quantifies construction and demolition waste (C&DW) generation rate in Indian cities using bottom-up material flow analysis approach. A dynamic model was applied to different classes of cities in India to investigate how C&DW generation rate varies across different classes of cities. The data on construction and demolition activities in different classes of cities were estimated from information reported in secondary literature. The results show that urban areas in India generated over 150 million tonnes of C&DW in 2016, and almost 50% of waste was generated in small to medium towns. The paper concludes with discussion on opportunities for recycling of C&DW and closing the material loops in Indian cities.

Construction Waste and its Distribution in Iraq: An Ample Review

Because of the economic evolution and advancement of the construction industry observed by many countries, the critical requirement for utilizing contemporary potentials in it is to construct taller and deeper buildings. On the other hand, the problems that rise with the similar capacity is the generation of millions of tons of construction waste each year. Such generation of construction waste causing many landfilling and environment problems in the world. Through the last few decades, the rapid development of construction industry has been also observed in Iraq. Such rapid development causes huge amount of construction waste also and causing not only landfilling problems but also effects to environment. In this research work, review has been taken to emphasize on construction waste. Almost 51 latest and critical research papers and web blogs has been reviewed. On the basis of reviewed literature in this research work, it is observed that no any standards have been set for disposing off the construction waste at Government level. Also, many non-government companies are working to construct proper lands for disposing off the construction waste. But still, the union of Iraqi Contractors and Engineer League must symposium on construction waste and designed better plans to manage waste and disposing off construction debris. Keywords: Amount and Distribution, Construction Waste, Construction Waste Management, Construction Waste types, Sources

Methodology for upstream estimation of construction waste for new building projects

Construction waste includes waste arising from construction works such as new build, renovation, demolition and road works. Through waste sorting and separation, inert material can be used to fill in reclamation sites; however, the non-inert portion of the construction waste still goes to landfills. However, Hong Kong is running out of landfill space. When determining reduction and management strategies for construction waste, the Government's objectives are to reduce waste generation, maximize reusing and recycling and reduce the intake of mixed construction waste at landfills. In order to develop and implement the waste reduction and management strategies at project level, proper quantification of construction waste generation is a prerequisite. Our research reveals that limited information is currently available for understanding the magnitude and composition of construction waste and for preparing an appropriate construction waste management plan for a project on new or existing facilities. To bridge the gap, the aim of this research is to present a comprehensive and practical approach for estimating the construction waste for building projects once detail design is carried out for new build or major retrofitting works. The estimation of waste quantities is based on the actual design information available from tender or contract documentation for a project at the upstream stage (a full set of bills of quantities classified under standard format). The proposed methodology of aggregating wastages accruing to quantified elements for a complete building has its advantages over a ball park figure established through indexing or other methods as proposed in existing literature, in terms of ensuring accuracy and maximizing the use of available design information whilst the workflow is uninterrupted.Three representative case studies with different formwork and façade systems are depicted to highlight the significant effects on waste generation in otherwise similar construction projects.

Evaluation of the self-cemeting effect of Construction and Demotion Waste (CDW) on mechanical performance over time for pavement support layers purpose

Abstract The problem related to the generation of construction and demolition waste (CDW) is directly associated with its high volume and irregular disposal, especially when such waste is disposed of in landfills. Therefore, it is increasingly important to encourage the reuse of this material, especially in large-scale projects. However, the use of this waste depends on the different constituent materials, which show a wide variability. Within this context, the objective of this work was to study the mechanical performance of construction and demolition waste over time aiming at the use in pavement support layers. Two samples were evaluated, one composed exclusively of construction waste (CDW_1) and the other composed of a soil-waste mixture (S_CDW), with 50% of each material. The tests evaluated the strength of the materials over a curing period from 0 to 224 days. The results clearly indicate an increase in strength and stiffness over time. The CDW_1 samples indicated a more significant increase. The analyses indicated that this behavior occurs due to the effect of self-cementing properties that occur in this type of waste. The results indicate a benefit in terms of strength when using this type of waste either alone or mixed with soil.

Implementation of eco-costs per value ratio (EVR) on construction waste management in Shah Alam, Malaysia

The construction industry in Malaysia which is rapidly growing is indirectly contributing towards the economic influx to the country. However, the waste generation in construction is increasing proportionally with new construction developments. The current construction methods focus on minimal recycling process where most construction wastes are dumped at landfills because construction companies are required to set aside a higher preliminary cost for proper waste disposal. This study focuses on creating a more potential outcome in decreasing the construction waste by implementing eco-costing in development for the construction waste generated from the beginning stages of a project. Therefore, this study discusses the construction waste management using the eco-costing per value ratio (EVR) assessment. The EVR assessment for eco-costing were targeted to the construction waste products from Shah Alam. The analysis included 5 selected sample sites in Shah Alam conducted within the year 2013 to 2017. The findings indicated that EVR index ranged between 0.054-0.1225 for conventional and semi industrialised building system (IBS) method based on five-selected sample of sites. This range signify on current EVR index which will be compared with Malaysian EVR benchmarking in result and discussion. Furthermore this result is useful to evaluate EVR index between residential for construction waste management towards sustainable development.

BIM-based automated construction waste estimation algorithms: The case of concrete and drywall waste streams

Globally, the growth of construction activities over the past years has resulted in large quantities of waste generation. Much of this waste is not reused or recycled and is subsequently redirected to landfills. The environmental impact of construction waste (CW) generation and the shortage of land resources for the creation of new landfills have reinforced the need to adopt more innovative CW management practices. Estimation of CW is a necessary step for the adoption of CW management practices. In this study, Building Information Modeling (BIM) is used to automate CW quantification. In this context, CW generation is estimated as the materials purchased but not incorporated into the actual building structure. Algorithms developed to quantify concrete and drywall waste streams are presented to demonstrate the proposed CW estimation method. The proposed concrete algorithm is validated by comparing estimated waste to actual waste data reported in the waste hauling tickets of a real-world project. Furthermore, CW generation quantities reported in the literature are used to validate estimates of both concrete and drywall waste streams. By leveraging material quantities directly from BIM—as opposed to manual estimations—CW estimation can be streamlined, enabling decision makers to implement more efficient construction waste management practices in the field.

Construction waste generation estimates of institutional building projects: Leveraging waste hauling tickets

The large proportions of waste generated from the construction industry have led to adverse environmental and socio-economic impacts, and as such, there is a need to promote construction waste management (CWM) practices. However, there is limited information regarding construction waste (CW) generated from nonresidential buildings available to support such CWM practices. This study seeks to quantify CW generated from a nonresidential institutional building project using CW data collected from 535 waste hauling tickets. These tickets provide a waste generation summary itemized by various CW streams. The CW data was collected through coordination with the project waste management team. Findings reveal that concrete/masonry is the highest waste stream during the Foundation (46% of CW) and Structural Concrete (88% of CW) stages. During the Masonry Work and Finishing Stage, wood is found to be the primary contributor (54% of CW), followed by concrete/masonry (35.3% of CW). The estimated CW generation rate was approximately 69 kg/m2, with the concrete/masonry and wood waste streams having the highest generation rates of 33.61 kg/m2 and 28.21 kg/m2, respectively, comprising 90% of the total CW across the project. Due to the temporal characteristics of different waste streams, varying CW dumpsters available onsite is recommended based on the construction stage, to mitigate space shortage impacts. Furthermore, this study quantifies the benefits of recycling CW as environmental savings of trees, water, energy and greenhouse gas emissions. Findings of this study would help refine the accuracy of the reported estimates of CW generation for nonresidential construction projects. By shedding light on the corresponding handling practices of the generated waste and project management processes applied on institutional projects, the study can also serve as a guide to better plan for and coordinate the management of CW of these projects. Results may be used to promote and encourage the adoption of CWM practices at the site level to improve the sustainability performance of the construction industry.

Integrated optimization of rebar detailing design and installation planning for waste reduction and productivity improvement

Abstract Cutting rebar stocks to fit to specific requirements of designed structural components on a construction project results in cutting losses, which is the major contributor to the generation of construction waste. Previous research developed mathematical models to analytically minimize rebar cutting losses, but without integrating engineering design, workface plan, detailed estimating, plus environmental factors in optimization. In this research, integer programming technique is applied at the first stage to generate the optimal rebar stock procurement plan and cutting plan for each rebar layout arrangement alternative in a particular structural component. Next, pareto optimization techniques are applied to simultaneously optimize total cost and material waste, resulting in the optimal trade-off solution. A reinforcing concrete slab-on-grade case from a classic textbook of detailed estimating is adapted as a test-bed to show that the proposed methodology is capable of producing trade-off solutions in terms of reducing wastage and lowering total cost, leading to identification of the optimal slab rebar layout arrangement plan and generation of associated rebar stock procurement plan, cutting plan and crew installation plan ready for field implementation. “What if” scenario analyses are also provided to further validate the proposed methodology and gain insight in the relationships between input parameters and optimum solutions.

Alternative construction and demolition (C&D) waste characterization method proposal

ABSTRACT Construction and demolition waste generally represents the majority of solid waste generated in Brazilian cities, and characterization of this waste stream is still incipient. Therefore, to support managers in the process in the diagnostic phase, this study consisted in a proposal qualitative characterization method in field, that use of construction and demolition (C&D) waste generation indicators. For this, a survey which have been divided in two stages: quantitative characterization based on a three-indicator-analysis of C&D waste generation and qualitative characterization consists of an image analysis procedure on C&D waste samples. The qualitative characterization method has proved to be efficient for samples with high-volume parts. However, this method is limited to represent characterizations that contain residues which might cover the other C&D waste types, for example, plastic sheeting, cardboard and packaging. This method of image analysis is suitable for use in early diagnostics, which require fast results about C&D waste composition.

Model for estimating construction waste generation in masonry building

The civil construction sector is an important generator of solid waste. Estimating the quantities of construction waste is crucial in the waste management process. In Brazil, although legislation has required that builders promote waste management since 2002, there are no specific generation models. This work describes a predictive waste generation model implemented with good results in Curitiba, Paraná, Brazil. Through the analysis of 48 buildings and their characteristics, including human and management aspects, a model is proposed to estimate the total volume of waste that is expected on a building site. The analysis considered the following parameters: work execution time, total constructed area, type of masonry, team training and monitoring. The model application revealed that the model is preferred to single or direct relations, such as those that the literature usually recommends. The model presented good results for projects with a total constructed area larger than 4000 m2. Finally, the average error associated with the prediction was 29·8%, which is considered acceptable due to the complexity of the phenomena and the lack of better models.