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Purpose: The purpose of this study is to explore the multifaceted challenge of managing construction and demolition waste within the context of the Jordan construction industry. Design/methodology/approach: Using data sourced through desk research, interviews and questionnaires, this study examines the principal causes of increased volumes of construction and demolition waste, as well as the obstacles to both developing and implementing better waste management strategies. Findings: This study identifies multiple causes of issues related to waste management and barriers to developing and implementing solutions and concludes by recommending a holistic approach to this multifaceted problem. A lack of adequate construction waste management infrastructure, regarding both physical facilities and regulations, was highlighted as the key challenge. Social implications: The accumulation of waste that results from construction and demolition activity, and activities characterized by unsustainable utilization of raw materials and inefficiency are a global issue. The challenge of effectively managing construction waste is importantly tied to factors including the availability of the necessary infrastructure; economic conditions; and the scarcity of skilled laborers, among others. Originality/value: This study focuses on the Jordan construction industry, which is so far not very well researched. By building upon previous studies, this study supports further research to illuminate the causes of waste and the barriers to better management, an issue that is not only a pillar of progress at the country level but also key for a sustainable development in general. [ABSTRACT FROM AUTHOR]

As urbanization and construction activities in China continue to accelerate, the management of construction waste has become crucial. This study comprehensively investigated the current status and challenges in construction waste management in China. Through the application of building area estimation methodology combined with the Grey Prediction GM (1,1) model, we analyzed historical waste generation patterns from 2000 to 2022 and projected future trends for the next 10 years. The results revealed significant regional disparities in waste generation, with the East China region contributing over 50% of the national total, while maintaining continuous growth. National construction waste generation is projected to reach 3.084 billion tons in 2032, highlighting escalating management challenges. This study identified several critical issues in China's current management system, including incomplete statistical data, weak implementation of source reduction measures, underdeveloped classification systems, and a notably low resource utilization rate (below 10% as of 2022). Drawing on successful international practices and domestic pilot experiences, we proposed a comprehensive management framework emphasizing full-process supervision, enhanced data collection systems, improved classification management, advanced resource utilization technologies, and strengthened policy mechanisms. These proposals will foster the development of sustainable construction waste management in China's transition, in parallel with the realization of circular economy principles within the construction sector. [ABSTRACT FROM AUTHOR]

This study evaluates the gradation changes occurring during the sample preparation process using two methods: impact compaction and vibratory compaction, and analyses the shear strength and deformation of samples produced by these two methods. Based on this analysis, we determined the most suitable method for laboratory testing. Utilizing the selected method and through data analysis and experimental observations, we further explore the mechanical properties and particle breakage characteristics of construction waste under varying gradations and brick contents when used as roadbed fill. Research findings indicate that the particle size distribution impact of vibratory compaction on samples is less than that of impact compaction. The stress–strain curves from the former demonstrate brittle characteristics more in line with the properties of construction waste. Under varying gradations, the peak strength is positively correlated with the content of coarse particles. At the same gradation, the brick content tends to decrease the maximum shear strength. Additionally, the primary breakage modes of construction waste particles are fragmentation, fracture, and abrasion, with the resultant particle shapes predominantly being flaky. When calculated based on the initial gradation, the relative breakage rate (Br) shows that particle breakage is positively correlated with the coarse particle and brick contents. When Br is computed using postsampling gradation, particle breakage is inversely related to the maximum dry density of the sample. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Waste management is a key step for addressing both the environmental impact and the growing demand for resources in the construction industry. To answer these challenges, various technologies are available, carrying different environmental impacts and sociotechnical implications. For concrete waste, recycling is the most common solution. Two main recycling roads were identified, leading to products that have low or high value and implying different technical developments and environmental impacts. This study first proposed to characterize recycling technologies by their technical degree, reflecting the complexity needed to process waste. It secondly compared their environmental impacts using LCA methodology to assess which technical complexity led to minor environmental consequences and under what conditions. The results revealed that the technologies with a low technical degree tended to have a lower environmental impact than the ones with a higher technical degree when only the generated impacts were considered. The reverse was observed when considering the aggregated impacts due to the environmental benefits provided by the potentially avoided products. [ABSTRACT FROM AUTHOR]

The construction industry in Kuwait is experiencing a transformative shift with the adoption of Building Information Modeling (BIM) technologies, particularly BIM 6D for sustainability analysis and 7D for facility management. This study investigates the integration of these dimensions to address sustainability challenges in Kuwait's construction sector, aligning practices with the United Nations' Sustainable Development Goals (SDGs). Through qualitative interviews with 15 stakeholders—including architects, engineers, and contractors—and analysis of industry reports, policies, and case studies, the research identifies both opportunities for and barriers to BIM adoption. While BIM offers significant potential for lifecycle analysis, waste reduction, and energy efficiency, its adoption remains limited, with only 27% of construction waste recycled. Challenges include high initial costs, a shortage of skilled personnel, and resistance to change. The study highlights actionable strategies, including enhanced regulatory frameworks, university curriculum integration, and professional training programs led by the Kuwait Society of Engineers, to address these barriers. It also emphasizes the critical role of collaboration among government bodies, industry leaders, and institutions like the Kuwait Institute for Scientific Research. Drawing from successful international BIM projects, the findings offer a practical framework for improving sustainability in arid regions, positioning Kuwait's experience as a model for other Middle Eastern and North African countries. This research underscores the transformative role of BIM technologies in advancing global sustainable construction practices and achieving a more efficient and eco-friendly future. [ABSTRACT FROM AUTHOR]

This research investigates the potential of utilizing types of construction waste as partial cement replacements within concrete formulations. Notably, granodiorite and ceramic powders were introduced at varying substitution ratios. The impact of these waste materials on the compressive strength and radiation shielding effectiveness of traditional concrete was evaluated under both ambient and elevated temperature conditions. Additionally, several microstructural tests like X-ray diffraction (XRD), Thermogravimetric analysis (TGA), and Energy dispersive X-ray (EDX) were conducted to assess the influence of using the optimal replacement ratios of the investigated waste powders on the studied properties of concrete. Results revealed a substantial improvement in the investigated properties of the concrete. Remarkably, a 7% substitution with waste granodiorite powder (WGDP) yielded the optimal mix for compressive strength, exhibiting increases of 24.7%, 26.1%, 22%, and 28% at room temperature, 400 °C, 600 °C, and 800 °C, respectively. Likewise, a 7% replacement with waste ceramic powder (WCP) exhibited quantifiable improvements in compressive strength, with approximately 23.1%, 23.5%, 25.6%, and 32.6% at room temperature, 400 °C, 600 °C, and 800 °C, respectively. For microstructure analysis, XRD analysis confirmed enhanced pozzolanic activity with reduced portlandite and increased calcium silicate hydrate (CSH) formation for the optimal WGDP and WCP mixes compared to the control mix. TGA analysis revealed higher CSH decomposition in modified mixes, indicating greater pozzolanic reaction. Furthermore, density and EDX analyses showed denser microstructures in waste powders-incorporated mixes due to finer particle packing and secondary hydration effect. The radiation shielding investigation show that the optimum WCP mix (C7) enhances the attenuation capability of concrete. The optimum WGP mix (GD7) also contributes positively to attenuation, though to a lesser extent than C7. Ordinary concrete (CO) exhibits the lowest LAC, indicating its baseline performance in linear attenuation. Thus, the studied CM-concrete samples provide the best protection against fast neutrons which pave the way for the utilization of industrial waste, especially ceramic and granodiorite waste, in enhancing the properties of concrete towards radiation shielding against gamma rays and neutrons. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Engineering Management / Gongcheng Guanli Xuebao is the property of Journal of Engineering Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Gorgan, a city with a population of about 400,000, experiences a high rate of urban construction and currently produces 1,600 tons of construction waste daily. This waste is managed using two sites: Jorjan 28 for waste accumulation and the Tuskan Road site for landfill. An environmental assessment of the Tuskan Road construction waste landfill site using the checklist method indicates that 84.2% of the parameters related to the landfill site can adversely impact the environment. Studies reveal that the cumulative environmental values, particularly from the physical and biological environmental parameters assessed using the matrix method at the Tuskan Road landfill site, are negative. The fragile ecosystems of northern Iranian cities, limitations on using river sand, mountain quarries, and gravelly agricultural lands, make recycling construction waste essential. Organizing recycling not only reduces negative environmental impacts but also results in significant economic savings by producing recycled sand and gravel. [ABSTRACT FROM AUTHOR]

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.Article highlights: Assessment and quantification of construction waste is very essential to suit the ecosystem of Bhutanese construction industry to develop strategic plan and management. The research findings serve as paramount importance to policy makers and infrastructure developer for needful action to prevent environment pollution. The findings indicate that wood is the most commonly generated construction waste material in Bhutan, followed by bamboo and bricks. [ABSTRACT FROM AUTHOR]

As one of the main components of urban waste, the appropriate disposal of construction waste is crucial for the sustainable development of cities. The recognition and classification of construction waste are crucial components of construction waste management and lay the foundation for high-value applications. This paper utilized unmanned aerial vehicle (UAV) aerial images and the YOLO model to recognize construction waste on-site. A dataset of indoor scattered, indoor dense, and demolition site conditions was established. The impact patterns of epoch number, initial learning rate, and batch-size on the model were discussed, and the optimal parameter values were determined. The influence of training dataset composition was analyzed, indicating that appropriately adding indoor dense condition images helped improve the convergence speed and recognition accuracy. In the model performance validation, the comparison with manually sorting results revealed a high accuracy in recognizing the five types of construction waste. The recall of all five types was around 0.8. The validation results showed that the model can efficiently and accurately recognize and classify construction waste in demolition site images. The proposed method can aid in the rapid assessment and dynamic monitoring of construction waste, thereby enhancing the efficiency of waste management and recycling. [ABSTRACT FROM AUTHOR]

Abstract Effective construction waste (CW) management, mainly concrete, brick, and steel, is a critical challenge due to its significant environmental and economic impacts. This study addresses this challenge by proposing multiple linear regression models to predict waste generation in residential buildings within the Egyptian construction industry, considering the influence of factors such as building design and site management features. Using data from 25 case studies, the models demonstrated high predictive accuracy, with adjusted R² values of 0.877, 0.893, and 0.889 for concrete, bricks, and steel waste, respectively. These R2 values indicate that the models explain approximately 88–89% of the variance in waste generation in residential buildings, highlighting their effectiveness in enhancing resource planning and waste management strategies. The findings suggest that incorporating variables such as total area, design consistency, and site organization significantly improves the accuracy of waste predictions. Although the models show acceptable performance, future research should aim to expand the dataset, incorporate additional variables, and test the models across different types of construction projects to validate further and refine these predictive tools. The models offer valuable insights for enhancing construction practices, minimizing waste, and supporting sustainable development in Egypt’s construction industry. With accurate forecasts of waste generation, the models help project managers and stakeholders to plan CW more effectively, mitigating unnecessary material consumption and reducing environmental impacts. These findings help to adopt sustainable construction practices, such as improved recycling processes and decreased dependence on landfills, to support Egypt’s Vision 2030.

The mathematical model, which could be represented as a fuzzy inference tree for project man-agement aimed at waste usage in wall manufacturing, is proposed in the article. The factors classification that affect production's environmental and economic efficiency is presented. The proposed ecological and economic efficiency criterion and influence factors are linguistic variables consisting of fuzzy terms on the corresponding universal sets. The proposed hierarchical system of mathematical models allows the intelligent choice of proper building material, depending on the influence of environmental parameters, socio-economic parameters, and engineering and technological parameters of a building object, based on fuzzy logical expressions “IF-THEN”. The proposed model could be used as a support system model in the decision-making process at the early feasibility stage. Estimating pros and cons based on the results of a virtual experiment in terms of proposed criterion value for specific construction waste allows proper planning of construction waste usage in the construction sector. The proposed model can be used as a design and engineering tool in the decision-making process for forecasting the ecological and economic efficiency of the use of waste in the manufacture of walls.

Abstract 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.

Abstract In harsh or corrosive environments, waterproofing is essential for ground-contact structures. Protecting underground structures against groundwater contamination and moisture by waterproofing the base material, usually solid concrete, is beneficial. Long-term insulation system performance depends on component integrity and base material interaction. This study uses a hydraulically modified binder and finely ground construction waste fillers. Optimizing sealant and restoration is the goal. Additionally, this study will explore the characteristics and establish a systematic approach for determining the appropriate waterproofing system composition. The study measures the physical force required to remove the insulating layer in order to assess the adhesive strength of the sealant coating. This paper explains the theoretical conditions that improve the adhesion of the base- sealant sealing layer. A conceptual framework explains the relationship between sealant material adhesive strength, modified binder composition, and base surface moisture content. Empirical testing has proven this model works. A comprehensive study examined how base surface roughness and cracks affect sealant coating performance. We know the ideal strength factors. This study uses global optimization to examine optimized parameters' roles. This study analyzed experimental data statistically and analytically. According to computational analysis and experimental validation, the sealant material has an adhesive strength of 3.8 MPa and a sealant layer strength of 36–37 MPa. This product requires 3.9% acrylic resin, 80 kg/m3 finely broken concrete debris, and 0.38–0.39% plasticizer. For these components, a base surface with 9.7% to 9.8% moisture is ideal.

In harsh or corrosive environments, waterproofing is essential for ground-contact structures. Protecting underground structures against groundwater contamination and moisture by waterproofing the base material, usually solid concrete, is beneficial. Long-term insulation system performance depends on component integrity and base material interaction. This study uses a hydraulically modified binder and finely ground construction waste fillers. Optimizing sealant and restoration is the goal. Additionally, this study will explore the characteristics and establish a systematic approach for determining the appropriate waterproofing system composition. The study measures the physical force required to remove the insulating layer in order to assess the adhesive strength of the sealant coating. This paper explains the theoretical conditions that improve the adhesion of the base- sealant sealing layer. A conceptual framework explains the relationship between sealant material adhesive strength, modified binder composition, and base surface moisture content. Empirical testing has proven this model works. A comprehensive study examined how base surface roughness and cracks affect sealant coating performance. We know the ideal strength factors. This study uses global optimization to examine optimized parameters' roles. This study analyzed experimental data statistically and analytically. According to computational analysis and experimental validation, the sealant material has an adhesive strength of 3.8 MPa and a sealant layer strength of 36–37 MPa. This product requires 3.9% acrylic resin, 80 kg/m3 finely broken concrete debris, and 0.38–0.39% plasticizer. For these components, a base surface with 9.7% to 9.8% moisture is ideal. [ABSTRACT FROM AUTHOR]

Construction and demolition waste management (CDWM) is a grand challenge on a global scale. Traditional CDWM has heavily relied on anthropological approaches, which may prevent stakeholders from acquiring a comprehensive understanding of a macro standpoint for developing effective strategies. The emergence of geospatial technologies offers a more objective and precise approach for CDWM to enhance resource management and support environmental and socio‐economic sustainability. However, a holistic review of how these geospatial technologies have been applied to CDWM is still lacking. To fully harness the potential of geospatial technologies for CDWM, this study aims to examine how different categories of geospatial technologies serve different application scenarios in CDWM through a systematic literature review. Through delving into 73 papers spanning 2004 to 2024, the results find this research discipline has been a hotspot since 2017. Existing CDWM literature has predominantly utilized geographic information systems (GIS) technology, followed by remote sensing technology and a hybrid technology strategy. Geospatial technologies have been extensively integrated with other non‐geospatial technologies. Existing literature is mainly distributed across four application scenarios: identification and classification, site selection, quantification, and decision support. Finally, three research gaps have been also pinpointed, directing future studies to devote specific efforts to improving data accuracy, combining geospatial technologies with traditional methods as well as expanding application scenarios from a life cycle perspective. This paper offers academics and practitioners a clear roadmap on how to utilize geospatial technologies for propelling the discipline of CDWM toward high efficiency and precision. [ABSTRACT FROM AUTHOR]

Water pollution intensifies water scarcity and poses a significant threat to ecosystems and human health. Construction waste generated by rapid urbanization also imposes a considerable burden on the environment. Fortunately, a large portion of this waste can be efficiently converted into recycled aggregates and reused in various fields including environmental remediation. In this study, three types of eco-recycled concretes (ERC) (Control-ERC, Biochar-ERC-1, and Biochar-ERC-2) were formulated by integrating shell-derived biochar with recycled aggregates. The porosity and water permeability of these concretes were characterized, and their efficacy evaluated in treating polluted water with six primary heavy metals (HMs), i.e., cadmium (Cd), chromium (Cr), arsenic (As), manganese (Mn), lead (Pb), and copper (Cu). Biochar addition significantly enhanced the continuous porosity and water permeability of the concrete, and substantially enhanced its adsorption capacity of HMs. Specifically, Biochar-ERCs removed over 90% of As, Cd, and Mn, and achieved a removal rate exceeding 60% for other HMs, surpassing the performance of Control-ERC. This study not only lays a solid foundation for the wide application of Biochar-ERCs in the field of environmental protection and remediation, but also provides strong technical support and practical examples for advancing the circular economy model of converting waste into resources while addressing the challenge of global water scarcity. [ABSTRACT FROM AUTHOR]

Introduction: In New Zealand, the construction sector is responsible for a large proportion of waste sent to landfill. The plastic profile of construction waste is varied and complex in comparison to other waste types (e.g. timber, concrete, metals, plasterboard). Therefore, the diversion of plastics from landfills is less straightforward, and there are less obvious benefits to recycling this low-density, low-value waste stream. Plastic waste generated by construction activities has not been well-characterised, which has affected opportunities for waste reduction, reuse and recycling. To fill this knowledge gap, this study characterised the plastic waste generated from a residential construction site. This was used to identify opportunities to address the full waste hierarchy through reduction, reuse and recycling and ultimately enable more sustainable plastic waste management. Methods: Plastic waste generated from a construction site in Auckland, New Zealand (construction of eight terraced houses) was separated during the project into several categories (pipes, soft plastics, other plastics and hazardous waste). This was followed by in-depth auditing which further sorted waste types by main composition, followed by analysis for polymer type using fourier-transform infrared spectroscopy (FTIR). The research was phased to determine the plastic waste generated across each of the main construction stages. Once the main polymer types had been identified, local waste providers were contacted to establish opportunities for reuse or recycling. Results: The total mass of plastics generated from all construction stages was 725 kg, 66.4% (by wt.) of which was recycled. Soft plastics, predominantly low-density polyethylene, were the most common plastic type; this was followed by pipes and expanded polystyrene. Plastic packaging, primarily soft plastics and polystyrene, accounted for 60% of total plastics and were mostly generated in the final stages of construction (i.e. fittings and fit-out). This characterisation of construction plastic waste can be used to demonstrate the feasibility of sustainable plastic waste management in Auckland and to identify construction plastic waste sources on an international scale. More studies on a variety of construction types (e.g. detached residential, apartment blocks, commercial) are required to address the full breadth of plastic materials used and to drive a more circular economy for this potential resource. [ABSTRACT FROM AUTHOR]

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Copyright of Umm Al-Qura University Journal of Engineering & Architecture (Springer Nature) is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The effective and safe treatment of red mud has become a pressing global issue in recent years. The purpose of this study is to prepare different systems of low-carbon cementitious materials by combining various solid wastes (slag powder, red brick of construction waste) with different systems of low-carbon cementitious materials and to observe the effects of different cementitious compositions on the construction performance, mechanical properties, freeze–thaw resistance, and heavy metal leaching properties by designing different systems of low-carbon cementitious materials, as well as to analyze the microscopic morphology, mineral composition, and strength-forming mechanisms of the different systems of low-carbon cementitious materials through the use of X-ray fluorescence (XRF), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) techniques. The findings reveal that a ternary cementitious system containing 16% red brick powder exhibits the most favorable overall performance. Compared to a binary system, this mixture improves fluidity by 4.5%, increases compressive strength by 18.27%, reduces drying shrinkage by 39.56%, and lowers the mass loss rate during dry–wet cycling by 11.07%. Furthermore, the leaching levels of heavy metals such as Cr, As, Pb, Ni, and Cu in the red mud-based cementitious materials, combined with multiple solid wastes, are within the safe limits for non-hazardous environmental release, as specified by Chinese regulations, under both freeze–thaw and non-freeze–thaw conditions. This study demonstrates for the first time the potential of combining red mud with construction waste brick dust and provides a scientific basis and theoretical guidance for the synergistic utilization of alkaline solid waste, calcium solid waste, and silica–aluminum solid waste. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Engineering Management / Gongcheng Guanli Xuebao is the property of Journal of Engineering Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The waste management sector is crucial for protecting the environment, conserving resources, and promoting sustainable development by ensuring efficient disposal, recycling, and minimizing the harmful impact of waste. This study aims to understand the performance levels (compressive strength), environmental impact, and overall sustainability of three concrete mixes, two of which use recycled materials. The mixes are defined as a conventional mix, mix one, which replaces dune sand for recycled rubber in the mix design, and mix two, which utilizes recycled aggregate as a replacement for fine aggregates. SEM-EDS is used to assess the elemental composition and surface morphology of the materials. The potential leaching of pollutants such as polycyclic aromatic hydrocarbons (PAHs), non-targeted organic compounds, and heavy metals was obtained using GC/MS and ICP-OES. The results showed low concentrations of PAHs in all mixes and a low calculated Potential Ecological Risk Index (PERI), where the conventional mix and mix two had the lowest risk (55 and 33, respectively) compared to mix one, which displayed a higher risk of 125. The results of the heavy metals assessment yielded that mix one was the most contaminated, with 1535 mg/kg of nickel and 1200 mg/kg of zinc, followed by the conventional mix, with 1385 mg/kg of nickel and 135.5 mg/kg of chromium, and finally, mix two was the least contaminated with 378.5 mg/kg of nickel and 142.5 mg/kg of zinc. Overall, the sustainability potential showed that mix two, with the recycled aggregates, was the most sustainable, with a Building Material Sustainability Potential (BMSP) value of 9.25. The study advocates for a shift toward sustainable concrete practices to mitigate environmental impacts while maintaining structural integrity. [ABSTRACT FROM AUTHOR]

Wood construction waste circularity presents enormous potential to significantly de-crease total greenhouse gas (GHG) emissions in the European Union (EU). Latvia could become a frontrunner due to its historic relationship with forestry, wood construction practises and unused potential of the innovative application of wood. This research examines what the potential of "circular wood" in Latvia is, how ready the Latvian wood house construction sector is to engage in a circular economy and wood waste circularity and whether the legal framework is ready to support wood waste management in the country. This study presents a combined approach for systematic wood construction product circularity assessment that includes a review of existing EU and Latvian frameworks for construction and demolition waste (CDW) management and wood construction, a general analysis of wood waste recycling systems and technologies, a quantitative data analysis of construction waste management in Latvia and qualitative data analysis of the Latvian wood house construction sector, and interviews with a focus group of Latvian wood industry representatives. The Latvian scope has allowed us to clarify the pattern methodology and impact points to be replicated, tested and measured further on a broader scale, in other countries, or throughout the whole EU. The main findings reveal a potential life cycle assessment (LCA) verifying the circularity of wood and limitations of wood construction waste circularity in Latvia in terms of wood house construction industry readiness and a legal framework as well as overall social prejudices for circular construction. Findings indicate an overall awareness and level of willingness to participate and engage in the circular construction models among Latvians; however, proactiveness and support (legal and financial) is expected from the government and municipalities. The recommendations point towards improvements in wood waste data management, the wood construction sector and the overall impact on sustainable development goals. [ABSTRACT FROM AUTHOR]

The current framework for managing construction waste, guided by European Union regulations, calls for an integrated waste management system. However, the reuse of old plaster waste, particularly from deteriorated facades, remains underexplored. This study investigates the potential of repurposing old plaster waste as a substitute for aggregates and cement in mortars, with the aim of promoting environmental sustainability and resource efficiency. Three mortar mixes were analyzed: a control mix, a mix with 45% waste replacing aggregates, and a mix with 10% waste replacing cement. Results show that replacing 45% of aggregates with plaster waste led to a 30% reduction in flexural strength, while the 10% cement replacement increased flexural strength by 6%. Compressive strength dropped by 27% and 38% for cement and aggregate replacements, respectively. Despite these reductions, the waste replacement remained within acceptable limits for structural integrity. Further microscopic analysis revealed that the incomplete integration of portlandite particles from the waste contributed to non-uniform bonding and crystal formation, weakening the mortar's structure. This research demonstrates the feasibility of reusing old plaster waste, offering a novel approach to reducing construction waste and promoting a circular economy. It contributes to filling the knowledge gap on the reuse of plaster mortars while aligning with sustainable construction goals. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The effect of dosage of recycled aggregate from construction waste on the mechanical strength of cement stabilized macadam (CSM) was investigated, the optimal dosage and proportion of recycled aggregate were proposed based on the principle of the highest strength or the maximum dosage. The growth law of mechanical strength of cement stabilized macadam recycled aggregate ( CSMRA) was investigated under the optimal dosage, a prediction model of mechanical strength of CSMRA was proposed, and the reliability of prediction was verified. The results show that the compressive strength of CSMRA increases and then decreases with the increase of recycled fine aggregate dosage, decreases with the increase of recycled coarse aggregate dosage, and the maximum dosage of recycled aggregate is 70% (mass fraction). The correlation coefficient of established mechanical strength growth equation and prediction model is more than 0. 98, and the error between predicted value and measured value is no more than 14. 0%. This indicates that the model can accurately predict the mechanical strength of CSMRA at other ages after determining cement dosage, aggregate type, mineral proportion and 7 d strength. [ABSTRACT FROM AUTHOR]

Extreme rainfall significantly threatens the safety of the landfill cover system, especially under humid climates. This study aims to provide design recommendations for a sustainable landfill cover system consisting of a low-permeability soil layer underlying a two-layer capillary barrier for humid climates. First, the numerical back-analysis was conducted for verification against a series of flume model tests. Then, a parametric study was performed to investigate the effects of inclination angle, particle size and layer thickness on the lateral diversion length (DL) of the three-layer cover system under the 100-year return period rainfall of humid climates. The results show that the water lateral DL of the cover system can be greatly enhanced by increasing the inclination angle from 3° to 18°. Moreover, the bottom layer of the cover system with a coarser d10 was more susceptible to the impact of the heavy rainfall, while this can be alleviated by increasing the thickness of the bottom layer. A dimensionless number, defined as the ratio of thickness and d10 of the bottom layer, is proposed for designing lateral diversion of the three-layer cover system under humid climates. To preserve the maximum DL, it is suggested that the proposed dimensionless number should be larger than 95 and 110 for the design of rainfall events with 50-year and 100-year return periods for humid climates, respectively.

Abstract Background Due to growing global concerns regarding the management of construction waste, this study investigates the feasibility of creating engineered geopolymer composites by replacing traditional industrial by-products (slag) with construction waste, specifically recycled brick waste powder. Results Polyvinyl alcohol fibers were incorporated into the engineered geopolymer composite mixtures. The substitution of slag with recycled brick waste powder was carried out at varying percentages: 0, 20, 40, 60, 80, and 100%, resulting in six different engineered geopolymer composite mixtures. The study evaluated the flexural strength, sorptivity, water absorption, and abrasion resistance of the engineered geopolymer composites, and also, microstructural characterization was conducted using scanning electron microscopy. The findings demonstrated that incorporating recycled brick waste powder into the engineered geopolymer composite mixes resulted in a decrease in flexural strength by 35.59% and a notable increase in midspan deflection by 339% when slag was replaced. Concurrently, there was a significant rise in water absorption and sorptivity by approximately 304 and 214%, respectively, when slag was entirely substituted with recycled brick waste powder. Conversely, abrasion resistance decreased, with the inclusion of recycled brick waste powder resulting in an 84% increase in volume change. The scanning electron microscopy (SEM) analysis showed active geopolymerization of recycled brick waste powder within the engineered geopolymer composite mixtures. Conclusions The results of this investigation demonstrate that it is feasible to produce engineered geopolymer composites using recycled brick waste powder instead of slag. The greater ductility and increased midspan deflection point to areas that require further optimization, even in spite of the observed decreases in flexural strength and abrasion resistance. The SEM examination reveals an active geopolymerization, highlighting the potential of recycled brick waste powder to produce environmentally friendly and sustainable construction materials. These results offer a good starting point for further studies that try to maximize the durability and performance of these composites.