Construction Waste Materials Research Articles

Investigation of construction waste material using multi criteria decision making method: a case study in Bhutan

Construction waste encompasses all of the leftover or unwanted materials, substances, and by-products that arise from constructing, renovating, or demolishing buildings, infrastructure, or other construction projects. Currently, there is a lack of systematic data on the most common types of construction waste in Bhutan. This research seeks to fill this critical knowledge gap by conducting a comprehensive analysis to identify the predominant types of construction waste in the Bhutanese and quantify it using multi-criteria decision analysis (MCDA). The images of wastes were collected from multifarious construction site from all the dzongkhags (district). Subsequently, questionnaire was designed and distributed to engineers for pair wise comparison. Using a fuzzy analytic hierarchy process, a MCDA technique was calculated to weight the scores for the factors like frequency in occurrence, environmental impacts, and recyclability. This comprehensive analysis resulted in a ranked list of waste according to their total performance scores, with wood identified as the most prevalent type of construction waste in Bhutan.

A Review paper on Durability Studies on Construction and Demolition Waste Material

The global rise in construction and demolition (C&D) waste generation presents significant challenges and opportunities for sustainable construction practices. This study examines the durability performance of concrete made by replacing 30% of natural coarse aggregates with recycled coarse aggregates derived from C&D waste. The research aims to evaluate the feasibility of using recycled materials in structural applications by conducting a series of durability tests, including assessments of resistance to freeze-thaw cycles, sulfate attack, chloride ion penetration, and carbonation. Concrete specimens incorporating 30% recycled coarse aggregates were prepared and tested, and their performance was compared to that of conventional concrete. The results indicate that while there is a noticeable impact on certain mechanical and durability properties, the modified concrete exhibited acceptable performance under specific conditions. Strategies for enhancing the durability of recycled aggregate concrete, such as incorporating supplementary cementitious materials, were also investigated. The findings suggest that partial replacement of coarse aggregates with recycled materials can be a viable solution for sustainable construction, provided that appropriate mix design adjustments are made. This research contributes to understanding the long-term behavior of recycled aggregate concrete and provides a basis for developing guidelines for its use in various construction applications.

Application of Foundry Wastes in Eco-Efficient Construction Materials: A Review

Foundries generate millions of tons of waste annually, posing a challenge to companies that generate it and to the environment due to landfill disposal. Meanwhile, the construction sector contributes heavily to global resource consumption. Adopting a circular economy approach by integrating foundry wastes into construction materials offers two main benefits: reducing landfill accumulation and preserving natural reserves of raw materials while also supporting the UN’s Sustainable Development Goals. This paper presents a review of recent studies on the use of foundry wastes in construction materials and provides an overview of the foundry industry, including its background, waste management, and statistics. Furthermore, a bibliometric analysis highlights the evolution of research in this area, showing a 182% increase in publications over the last 10 years. Key findings include that waste foundry sand is the most widely utilized foundry waste in construction materials, while ceramic mold shells and paraffin waxes remain underexplored. Concrete is the primary material incorporating foundry waste. The incorporation of foundry waste into construction materials improves durability and mechanical strength when used in appropriate proportions. The replacement content can reach up to 100%. These results underscore the feasibility of foundry waste as a sustainable alternative in construction, building circularity, and reducing environmental impact.

Combine the use of rice husk ash and quarry waste for sustainable masonry blocks: mechanical characteristics, durability and eco-benefits

The construction industry faces a growing demand for eco-friendly practices. This study explores the viability of incorporating quarry waste and rice husk ash (RHA) as partial replacements for cement and river sand in masonry block production. The research investigates the combined effect of these waste materials on the critical characteristics of cement blocks, including physical properties, mechanical behaviour, and resistance to environmental degradation. A cost-benefit analysis also considers economic, environmental, and societal factors. Replacing river sand with quarry waste in the mortar mix resulted in higher density and improved impact resistance. Also, it exhibited lower water absorption and early-age strength than the river sand. Partial cement replacement with RHA yielded positive results at lower incorporation levels. Up to 20% RHA content enhanced compressive and flexural strength while reducing embodied energy and CO₂ emissions. However, higher RHA replacements negatively affected these properties. The optimal balance between cost-effectiveness, environmental benefits, and structural performance was achieved with a combination of 20% RHA and complete quarry waste replacement. This approach offers a sustainable and potentially cost-saving alternative for conventional masonry block production. This research demonstrates the potential of utilizing waste materials in construction while promoting eco-friendly practices and responsible waste management in the industry.

Strategies for Minimizing Material Waste with the Application of Lean Construction in Building Construction Projects

Waste of construction materials is one of the problems often experienced by several construction service actors in Bali, especially in Gianyar, the utilization of materials is not efficient so that the project experiences cost overruns. The purpose of this study is to identify the dominant indicators causing building construction material waste and formulate strategies to minimize material waste by applying lean construction principles to building construction projects. The research sample was 15 small-scale contracting companies in Gianyar with 2 to 3 respondents in each company, namely directors, site managers and implementers. Data collection using questionnaires. The data processing technique used is factor analysis and focus group discussion. The test results show that there are 10 indicators of the causes of material waste that often occur, namely, the design does not adjust the size of the available materials, lack of knowledge about construction implementation techniques, drawings with volume calculations are not well integrated, construction materials cannot be stored for a long time, excessive mixture of wet materials, distant material storage locations, incorrect use of conventional formwork, lack of periodic checks related to work results, installed material specifications are not appropriate, lack of attention to material specifications on site. The results of the focus group discussion found that the strategies to reduce material waste based on the application of lean construction principles are training for workers involved, scheduling good material procurement, using standard components available on the market by taking into account modules that can be applied, increasing communication with various parties in exchanging information through discussion forums, checking work results and material specifications regularly.

Research on the Reusability of Bentonite Waste Materials for Residual Chlorine Removal.

Recyclable construction waste can be used as a low-cost material to reduce stormwater pollution caused by various pollutants. In recent years, studies have reported increased water contamination from chlorine and chlorine compounds and its negative impact on aquatic ecosystems. When assessing the need for waste recycling, circularity, and stormwater reuse, it is worth evaluating the capacities of construction waste materials to reduce stormwater pollution from residual chlorine. Laboratory experiments using bentonite waste material (bentonite clay) and sodium hypochlorite solutions were carried out to analyze the potential of bentonite clay to retain residual chlorine in stormwater and evaluate its capacity to be applied as filtration media in green infrastructure. In the first stage, the particle size distribution and texture of bentonite clay were assessed using laboratory sieve analysis and microscopy. The results of the experiments indicated that the optimal grain size to retain pollutants was 0.8-2.0 mm. The microstructure analysis showed the capacity of bentonite to retain residual chlorine. The results of the static and dynamic experiments (leaching and filtration tests) show that the bentonite clay retained up to 44% of the residual chlorine. The obtained results indicate that bentonite clay might be suitable for application as filtration media in green infrastructure to reduce stormwater contamination.

Recycling and optimum utilization of CRT glass as building materials: An application of low CO2 based circular economy for sustainable construction

The construction industry is the major contributor of CO2 emission around the globe. The rapid advances in the electronics industry have transformed the disposal of cathode ray tube glass waste (CRT-WG) into a prominent environmental concern. Recycling of CRT glasses as building materials can help in the production of sustainable construction. Numerous previous studies have documented that CRT-WG can be utilized either as a component of fine aggregate or binder material as it provides a cleaner solution and reduce carbon emission. Under this cleaner production and low CO2 emission perspective, this paper provides a thorough review of the previous studies on the utilization of CRT glass as a partially and fully substitute of sand and cementitious material in mortar production and propose an application of CO2 based circular economy model for reduce carbon emissions. This paper summarized the fresh, mechanical and durability properties of mortar incorporating treated and un-treated CRT-WG with different mineral additives and w/b ratios. Furthermore, this research explores the optimal proportions of CRT glass that can be use as replacements for sand and cement powder to make eco-friendly and sustainable low carbon mortar suitable for both structural and non-structural applications. More particularly, this review emphasizes the benefits, the need for additional research, and the drawbacks of CRT-WG use in construction building. Overall, this study proposes that incorporating CRT glass into building materials through a low CO2 based circular economy offers significant potential advantages. This study will help in optimization of CRT glass in concrete mix design in combination with waste materials for sustainable construction.

Study on the mechanical property and durability of alkali-activated seawater and sea sand recycled aggregate concrete

This study investigates the potential of Alkali-Activated Seawater Sea Sand Recycled Aggregate Concrete (ASSRAC) as a novel sustainable construction material. By utilizing recycled aggregates from construction and demolition waste, seawater, sea sand, and alkali-activated materials such as fly ash and blast furnace slag, this innovative concrete aims to mitigate carbon emissions from cement production and optimize resource usage. The impact of recycled aggregate replacement rate, water-to-binder ratio, and sand type on the compressive strength of ASSRAC was examined through analysis of variance. Cylindrical axial compression and prism flexural tests were conducted to evaluate the long-term performance of ASSRAC under seawater immersion. The results indicate a decrease in compressive strength with higher recycled aggregate replacement rates and water-to-binder ratios, with recycled aggregates being the primary weak link. Additionally, increasing the water-to-binder ratio hampers hydration by diluting alkali activators, weakening polycondensation reactions. Under seawater immersion, ongoing reactions foster denser C-(A)-S-H structures, enhancing compressive strength and elastic modulus over time. Moreover, higher recycled aggregate replacement rates result in improved ductility, attributed to reactions between the old mortar on recycled aggregate surfaces and slag/fly ash at interfaces. For specimens immersed for 0 and 90 days, most theoretical models accurately predict results, except for the CEB-FIP model, which only accurately reflects the stress-strain curve at 180 days. The seawater-sea sand group's flexural strength initially exceeds that of the freshwater-river sand group due to accelerated early hydration, but this advantage diminishes over time due to high salt content.

Performance Study of Stabilized Recycled Aggregate Base Material with Two-Gray Components.

This article studies the practical road performance of recycled materials from construction waste, relying on the paving test section of the supporting project for the Qingdao Cross-Sea Bridge. The research focuses on the construction technology and road performance of using recycled construction waste materials in urban road sub-base construction. Through indoor tests such as sieving and unconfined compressive strength tests, relevant technical indicators were obtained and analyzed. Additionally, periodic core sampling, compaction tests, and rebound deflection tests were conducted on-site according to relevant standards to thoroughly investigate the specific effects of using construction waste in practice and to analyze and evaluate the actual feasibility of the materials for road use. The results indicate that the particle gradation of the construction mix in the test section aligns well with the target gradation, and the dosage of the mixing agent meets the design requirements. The 7-day unconfined compressive strength already satisfied the technical requirements for heavy and extremely heavy traffic on highways as specified in the "Technical Specifications for Construction of Highway Pavement Subbase" (JTG/T F20-2015), with the 14-day strength generally reaching 7 MPa. Core sampling revealed good aggregate gradation, smooth and straight profiles, and the thickness and strength of all parts meet the specifications. The compaction levels met the testing requirements, the surface deflection values showed a decreasing trend, and the deformation resistance was good, consistent with the general development patterns of semi-rigid sub-bases.

Sustainable management of construction and demolition waste in Bangladesh to promote resource recycling

ABSTRACT This study conducted during the fiscal year of 2022–2023 endeavors to offer waste generation rates (WGR) for different Construction and Demolition Waste (CDW) materials and analyze the financial and environmental benefits of CDW recycling at a national level. Findings from the study reveal that CDW in Bangladesh mainly consists of concrete (56%), brick (15%), mortar (9%), metal (6%), and ceramics (6%). Additionally, the collective CDW produced in six major cities studied totals 3.71 million tons (MT). The WGR of CDW is assessed through regression analysis. The mean WGR for Construction and Demolition activities in the fiscal year 2022–2023 are notably recorded at 64.68 kg/m2 and 1626.97 kg/m2, correspondingly for the 12 city corporations. The study highlights the potential for entrepreneurial initiatives in recycling materials like concrete, brick, mortar, metal, ceramics, and timber, leading to reduced CO2 emissions and energy consumption. The estimated economic value of recycling concrete, brick, and metals in major cities is approximately 104.5 million USD and 0.45 MT of CO2 reduction from recycling brick and metals from major cities.

Balancing Sustainability and Strength: Analyzing the Effects of Textile, Tannery, and Water Treatment Sludge on Brick Performance

This study investigates the feasibility of incorporating various industrial waste materials, specifically textile sludge, tannery sludge, and water treatment plant sludge, in brick production as a sustainable construction practice. The research analyses the impact of varying sludge proportions on the compressive strength of fired clay bricks. Results indicate an inverse relationship between increasing sludge content and compressive strength across all types. Bricks incorporating higher proportions of textile sludge exhibited a linear decrease in compressive strength, ranging from 0.1 MPa to a low of 0.005 MPa. Similarly, increasing the ratio of tannery sludge to fly ash Class C and Ground Granulated Blast-furnace Slag within the brick mixture consistently corresponded with reduced compressive strength, with a 5:70:25 mix yielding 0.8 MPa and a 40:30:30 proportion resulting in 0.17 MPa. Water treatment plant sludge exhibited a similar trend. A mix proportion of 5:70:25 (sludge: fly ash class C: GGBS) yielded a compressive strength of 1.87 MPa while increasing the sludge proportion to 40:50:10 resulted in a lower compressive strength of 1.20 MPa. These findings underscore the importance of a balanced approach when incorporating industrial sledges in brick production. While beneficial from a sustainability perspective, the observed reduction in compressive strength, particularly compared to conventional clay bricks exceeding 2.5 MPa, necessitates careful consideration. Future research should focus on optimizing mix designs, incorporating performance-enhancing additives, or identifying applications where lower compressive strengths are acceptable to fully realize the potential of these waste materials in sustainable construction.

Identification of Causes of Construction Waste Materials Generation: A Case Study of Tribhuvan International Airport

Identification of Causes of Construction Waste Materials Generation: A Case Study of Tribhuvan International Airport

MECHANICAL AND PERFORMANCE CHARACTERISTICS OF SEMI-RIGID MIX DESIGN WITH RECYCLED MATERIALS AND STANDARDIZATION OF RUT DEPTH MEASUREMENTS

Pavement industry requires substantial modifications in terms of materials. Stakeholders are in need to opt the solutions of semi-rigid design mix with recycled materials. Necessary evaluations in terms of experimental measures are initially required to represent characteristics properties. Moreover, the behavior to be assessed is rut depth measurements through the implications of wheel tracker apparatus and in accordance with prescribed standards. The mix with specified curing days is being differentiated through subsequent directions focusing choice of recycled materials. The paper presents a model to excel distinguished properties inclusive of the analysis for maintaining air voids, induction of grouting material and stability. The output-oriented data is justified within the enumerations of rut depths for grouted samples. It is analyzed for 25%, 30% and 35% air voids in conditioned to fresh and recycled aggregates. The deliberations are meant with 91 and 13 sample combinations of aggregates and hot mix asphalt respectively followed by the significant tests on bitumen and grouting material. It is observed that critical samples are passed in the configurations of rut depths when processed with reclaimed and construction waste materials at 35% voids. The research data entails its affectivity due to the uniqueness in superior model of current scenario.

Towards sustainable construction: Strength and microstructural assessment of Dillenia suffruticosa and Acacia auriculiformis leaf ash as novel supplementary cementitious materials

Researchers are exploring local, recycled, and waste materials for construction to address environmental concerns. Concrete heavily depends on cement, contributing to energy consumption and greenhouse gas emissions. Substituting cement with alternatives like recycled materials can cut energy use and minimize the environmental impact on concrete production. This research represents the first investigation into using Dillenia Suffruticosa (DS) and Acacia Auriculiformis (AA) leaf ash as sustainable alternatives to cement in producing eco-friendly mortar, an area that other researchers have not previously explored. The study aims to investigate using DS and AA leaf ash as sustainable alternatives to cement in mortar production. In this study, the incorporation of DS and AA leaf ash as a partial replacement for cement was systematically varied in increments of 5 %, ranging from 5 % to 40 % of the total mortar volume. The ash was systematically incorporated into the mortar in increments of 5 %, ranging from 5 % to 40 % of the total mortar volume. The study further conducted a comprehensive investigation into the physical properties of the mortar, including consistency, bulk density, dry density, water absorption, and flow characteristics, alongside an analysis of its compressive strength. Microstructural behaviour was assessed using scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy and thermogravimetric analysis to provide a comprehensive analysis. Results indicate that the enhancement in compressive strength of DS ash specimens, relative to AA ash, ranged from 1.32 % to 24.49 % at 7 days, 5.81 %–16.86 % at 14 days, and 1.87 %–11.91 % at 28 days. Furthermore, the highest enhancement in compressive strength is observed with a composition containing 10 % DS ash and 5 % AA ash content, underscoring the superior performance of DS ash compared to AA ash. The mineralogical characteristics of DS and AA leaf ashes illustrate their effectiveness as supplementary cementitious materials in sustainable construction. The significant advantages of using DS and AA leaf ash as a cement substitute are environmental sustainability, innovative materials use, and contribution to sustainable construction.

Geopolymer-based insulated wall incorporating construction and demolition waste: Experimental assessment of thermo-physical behavior

The benefit of the application of geopolymers in the building sector is nowadays undisputed. In addition to good structural characteristics, these are characterized by interesting thermophysical properties, obtained through a production process, that reduces CO2 emissions and could incorporate recycled material, thus responding to environmental sustainability. However, it is noted the lack of studies regarding the in-field thermal performance. Thus, the aim of the present study is to investigate the thermal performance, under real conditions, of an innovative geopolymer-based insulated wall. It incorporates over 70% of net weight of Construction and Demolition Waste materials. The wall is conceived within the European project called “Green INSTRUCT” aimed to realize modular prefabricated building elements, for retrofitting and new construction of buildings. Two wall prototypes are analysed, which differ for the type of lightweight aggregate of geopolymer matrix, 3% by weight: expanded polystyrene or extruded polystyrene. The study refers to almost one year of continuous monitoring within a full-scale test room located in southern Italy. The method developed consists of 5 different phases and it involves also a normative-insulated reference wall. The results show higher insulation level of the proposed wall package, with a reduction of the heat flux of about 66% and more stable indoor thermal conditions, compared to the reference wall. Also the inertial properties are satisfactory, showing an experimental decrement factor equal to 0.05 and a time-shift of decrement factor higher than 6 h. All told, the experimental results can provide valuable insights into the real impact of innovative technology on energy efficiency and indoor thermal comfort.

FGD-Gypsum Waste to Capture CO2 and to Recycle in Building Materials: Optimal Reaction Yield and Preliminary Mechanical Properties.

The use of waste to capture CO2 has been on the rise, to reduce costs and to improve the environmental footprint. Here, a flue gas desulfurization (FGD) gypsum waste is proposed, which allows us to obtain a CaCO3-based solid, which should be recycled. The CO2 capture stage has primarily been carried out via the direct carbonation method or at high temperature. However, a high energy penalty and/or long reaction times make it unattractive from an industrial perspective. To avoid this, herein an indirect method is proposed, based on first capturing the CO2 with NaOH and later using an aqueous carbonation stage. This allows us to capture CO2 at a near-ambient temperature, improving reaction times and avoiding the energy penalty. The parameters studied were Ca2+/CO32- ratio, L/S ratio and temperature. Each of them has been optimized, with 1.25, 100 mL/g and 25 °C being the optimal values, respectively, reaching an efficiency of 72.52%. Furthermore, the utilization of the produced CaCO3 as a building material has been analyzed. The density, superficial hardness and the compressive strength of a material composed of 10 wt% of CaCO3 and 90 wt% of commercial gypsum, with a water/solid ratio of 0.5, is measured. When the waste is added, the density and the mechanical properties decreased, although the compressive strength and superficial hardness are higher than the requirements for gypsum panels. Thus, this work is promising for the carbonation of FGD-gypsum, which involves its chemical transformation into calcium carbonate through reacting it with the CO2 of flue gasses and recycling the generated wastes in construction materials.

Application of Energy-Saving Materials in Architectural Design

The conventional process of building construction is associated with issues such as the waste of construction materials and environmental pollution. Sustainable development highlights the importance of energy conservation and eco-friendly practices. It is essential to use energy-efficient and green materials in building designs to ensure the healthy growth of construction companies. This article discusses the advantages and principles of incorporating energy-saving materials in architectural design. It examines the strategies and critical control points for using energy-saving materials in architectural design, offering guidance for the sustainable development of the construction industry.

Pseudo strain-hardening alkali-activated composites with up to 100 % rubber aggregate: Static mechanical properties analysis and constitutive model development

Strain-hardening alkali-activated materials (SHAAM) provide a sustainable alternative to conventional strain-hardening cementitious composites (SHCC), offering significant environmental and economic benefits. This study examines the effects of various rubber powder (RP) volume replacement ratios (0 %, 25 %, 50 %, 75 %, and 100 %) on the properties of Rubber Powder Modified Strain-Hardening Alkali-Activated Composite Material (R-SHAAM), assessing workability, uniaxial compressive behavior, and uniaxial tensile behavior. The findings reveal that R-SHAAM with 100 % RP aggregate significantly enhances durability, achieving a 50.7 % reduction in crack width. Optimal axial tensile performance is observed at a 25 % replacement ratio, where R-SHAAM shows an 8.1 % increase in tensile strength and a 4.1 % increase in ultimate tensile strain. The robust multi-dimensional performance of R-SHAAM across different RP replacement ratios suggests its potential for diverse applications including pavement, marine structures, and explosive engineering, thereby offering valuable insights into sustainable material design and the effective recycling of waste materials in construction.

Rheological, mechanical, and microscopic properties of polypropylene fiber reinforced-geopolymer concrete for additive manufacturing

This study focuses on developing fiber-reinforced geopolymer concrete (GPC) for 3D printing, utilizing construction waste materials and polypropylene fibers. The GPC, reinforced with 0.8 %, 1.0 %, and 1.2 % polypropylene fibers by volume, underwent comprehensive testing, including rheological, mechanical, and microstructural analyses for lab-cast and 3D-printed samples. The results indicated that the 0.8 % polypropylene fibers enhanced flexural and tensile strengths by 8.2 % and 71.7 %, respectively, albeit decreasing compressive strength by 26.2 %. Higher polypropylene percentages led to adverse effects on material properties. Microscopic analysis revealed the formation of voids around fibers and features associated with incomplete hydration. The study emphasizes the need for optimizing water content and the use of longer polypropylene fibers. It also highlights the benefits of using GPC in the 3D printing of structural components.

Effect of rubber granules and rubber threads on mechanical properties of cement-bound base course

The study investigates the application of waste rubber in cement-stabilized base course (CBC), aiming to address internal stresses, reflective cracks, and waste disposal issues. Mixtures of gravel and sand stabilized with varying cement and rubber content were examined, including reference mixtures and those with granulated rubber or rubber threads, a total of 17 mixtures. Mechanical properties, durability, and environmental impact were evaluated through standard tests such as Proctor elements, compressive and tensile strengths, freezethaw resistance, shrinkage, and scanning electron microscope analysis. Non-standard, non-contact methods like ultrasonic pulse velocity and 3D digital image correlation were employed. Results indicate the feasibility of using waste rubber in CBC, with the optimal mixture containing 5 % cement and 20 % rubber as a replacement for sand showing satisfactory compressive strength (3.01 MPa) for application as a base layer, reduced stiffness, improved frost resistance (9.76 %), improved tensile to compressive strength ratio (52.99 %), and increased resistance to reflective cracking comparing to reference mixture. Moreover, it exhibited minimal shrinkage compared to other mixtures. The study underscores the importance of assessing environmental acceptability in waste materials for road construction, emphasizing the need for further research. Furthermore, the possibility of employing non-contact testing methods has been demonstrated.