Search Results (1,307)

The construction industry in Australia generates a significant amount of construction and demolition (C&D) waste, necessitating better waste management (WM) practices. This research addresses this issue by investigating CE strategies aimed at minimising C&D waste in Australian construction projects (CPs). Utilising a qualitative approach, the study is based on 20 interviews and four case studies of commercial CPs, analysed through NVivo content analysis. The findings emphasise the need to integrate CE strategies at every CP stage. In the pre-design phase, setting sustainable objectives and engaging stakeholders early is crucial for aligning goals to reduce C&D waste. The tendering process benefits from incorporating WM into contracts, demonstrating early commitment to sustainability. The design phase, through Building Information Modelling and designing for disassembly, offers substantial waste-reduction opportunities. Modular and prefabricated components during the construction phase enhance material reuse and recycling. Operational strategies like regular maintenance and retrofitting extend material lifespan, while selective demolition and digital cataloguing at the end-of-life phase enable efficient material recovery. This highlights the essential roles of policy, technology, and stakeholder collaboration in advancing CE practices, providing practical insights for construction professionals and policymakers to implement CE-related strategies in CPs. The research concludes that adopting CE strategies can lead to significant reductions in C&D waste and improved sustainability in the construction sector. Full article

A snapshot multi-wavelength birefringence imaging measurement method was proposed in this study. The RGB-LEDs at wavelengths 463 nm, 533 nm, and 629 nm were illuminated with circularly polarized light after passing through a circular polarizer. The transmitted light through the birefringent sample was captured by a color polarization camera. A single imaging process captured light intensity in four polarization directions (0°, 45°, 90°, and 135°) for each of the three RGB spectral wavelength channels, and subsequently measured the first three elements of Stokes vectors (S₀, S₁, and S₂) after the sample. The birefringence retardance and fast-axis azimuthal angle were determined simultaneously. An experimental setup was constructed, and polarization response matrices were calibrated for each spectral wavelength channel to ensure the accurate detection of Stokes vectors. A polymer true zero-order quarter-wave plate was employed to validate measurement accuracy and repeatability. Additionally, stress-induced birefringence in a PMMA arch-shaped workpiece was measured both before and after the application of force. Experimental results revealed that the repeatability of birefringence retardance and fast-axis azimuthal angle was better than 0.67 nm and 0.08°, respectively. This approach enables multispectral wavelength, high-speed, high-precision, and high-repeatability birefringence imaging measurements through a single imaging session. Full article

Tea disease detection is crucial for improving the agricultural circular economy. Deep learning-based methods have been widely applied to this task, and the main idea of these methods is to extract multiscale coarse features of diseases using the backbone network and fuse these features through the neck for accurate disease detection. This paper proposes a novel tea disease detection method that enhances feature expression of the backbone network and the feature fusion capability of the neck: (1) constructing an inverted residual self-attention module as a backbone plugin to capture the long-distance dependencies of disease spots on the leaves; and (2) developing a channel–spatial attention module with residual connection in the neck network to enhance the contextual semantic information of fused features in disease images and eliminate complex background noise. For the second step, the proposed channel–spatial attention module uses Residual Channel Attention (RCA) to enhance inter-channel interactions, facilitating discrimination between disease spots and normal leaf regions, and employs spatial attention (SA) to enhance essential areas of tea diseases. Experimental results demonstrate that the proposed method achieved accuracy and mAP scores of 92.9% and 94.6%, respectively. In particular, this method demonstrated improvements of 6.4% in accuracy and 6.2% in mAP compared to the SSD model. Full article

The self-excited oscillation system, owing to its capability of harvesting environmental energy, exhibits immense potential in diverse fields, such as micromachines, biomedicine, communications, and construction, with its adaptability, efficiency, and sustainability being highly regarded. Despite the current interest in track sliders in self-vibrating systems, LCE fiber-propelled track sliders face significant limitations in two-dime nsional movement, especially self-rotation, necessitating the development of more flexible and mobile designs. In this paper, we design a spatial slider system which ensures the self-rotation of the slider propelled by a light-fueled LCE fiber on a rigid circular track. A nonlinear dynamic model is introduced to analyze the system’s dynamic behaviors. The numerical simulations reveal a smooth transition from the static to self-rotating states, supported by ambient illumination. Quantitative analysis shows that increased light intensity, the contraction coefficient, and the elastic coefficient enhance the self-rotating frequency, while more damping decreases it. The track radius exhibits a non-monotonic effect. The initial tangential velocity has no impact. The reliable self-rotating performance under steady light suggests potential applications in periodic motion-demanding fields, especially in the construction industry where energy dissipation and utilization are of utmost urgency. Furthermore, this spatial slider system possesses the ability to rotate and self-vibrate, and it is capable of being adapted to other non-circular curved tracks, thereby highlighting its flexibility and multi-use capabilities. Full article

In recent decades, plastic waste management has become one of the main environmental challenges for today’s society. The excessive consumption of so-called single-use plastics causes continuous damage to ecosystems, and it is necessary to find alternatives to recycle these products. In this work, a mechanical and hygrothermal characterisation of novel plaster composites incorporating LDPE waste in their interior was carried out. Thus, prefabricated plasterboards have been designed with a partial replacement of the original raw material with recycled LDPE in percentages of 5–10–15% by volume. The results show how these new composites exceeded the 0.18 kN minimum breaking load in panels in all cases, while decreases in density and thermal conductivity of up to 15% and 21%, respectively, were obtained. In addition, an increase of 3.8%in thermal resistance was obtained by incorporating these new gypsum boards in lightweight façade walls through simulations. In this way, a new pathway was explored for the recovery of these wastes and their subsequent application in the construction sector. Full article

Solid waste disposal and management have become a global problem, which is particularly tricky in China with its large population and rapid urbanization. This study focused on the disposal status of multi-source solid waste as well as the park management of some typical cities of China. Firstly, the main technical methods for solid waste disposal were summarized as follows: landfill, incineration, anaerobic digestion and aerobic compost. Secondly, the network analysis method was applied to seek an optimized method for solid waste disposal and management. Thirdly, typical demonstration parks for solid waste disposal and management were analyzed to study their respective operating modes and strategies for synergistic development in terms of resources, environment and economy and to explore the sustainable development potential of the Guangdong–Hong Kong–Macao operating mode. The results showed that the collaborative disposal and recycling of solid waste are important for cities (especially megacities) to achieve resource conservation and environmental protection. The NIMBY effect and environmental pollution risks caused by decentralized construction could be reduced through the construction of circular industrial parks. Advanced technologies and the national policy for solid waste disposal and recycling in industrial parks of small–medium cities, large–medium cities and megacities were systematically analyzed so as to explore a self-operating management mode of industrial parks. Finally, reasonable suggestions, such as sharing, saving and cycling and propaganda education, as well as green and low-carbon solutions were put forward for solid waste disposal and management in typical industrial parks, effectively resolving the contradiction between economic development and environmental protection so as to help urban sustainable development. Full article

The wrapped method is the most widely used method for constructing distributions for circular data. In this paper, we provide a review of all known wrapped distributions, including 45 distributions for continuous circular data and 10 distributions for discrete circular data. For each wrapped distribution, we state its nth trigonometric moment, mean direction, mean resultant length, skewness, and kurtosis. We also discuss data applications and limitations of each wrapped distribution. This review could be a useful reference and encourage the development of more wrapped distributions. We also mention an R package available for fitting all of the reviewed distributions and illustrate its applications. Full article

(1) Background: Romanian earthquakes caused severe damage over time to a significant number of constructions, and that is why efforts are being made to make structural systems safer. (2) Methods: For structural systems with protection against seismic actions or vibrational actions that have linear viscous dissipation devices, the requirement to assess the equivalent modal damping rate for the entire functional assembly related to the other dynamic parameters arises. (3) Results: This article presents the analytical development of formulas for the compound damping and circular frequency when anti-seismic devices have different dynamic characteristics and their application in order to solve some real engineering cases of bridges and viaducts in Romania with distinct viscoelastic supports. In support of this idea, some experimental tests on a beam system resting on two different anti-seismic elastic supports highlighted the fact that the compound damping of the system can be calculated with the relations established in this paper, provided that the displacements in the horizontal direction of excitation are in the linear domain. Also, we determined the seismic response considering the Vrancea 1977 accelerogram for critical damping ratios of 5% and 18.5%, and then we obtained the variation in the factor of transmissibility depending on the frequency, in order to highlight the optimized value of the equivalent amortization/damping. (4) Conclusions: In the specific context of Romanian seismicity, seismic isolation through the use of isolators with different characteristics represents an optimal technical solution, and it is also optimal from an economic point of view, with an appropriate level of dynamic isolation obtained. Full article

In view of the climate crisis, green technologies should be used to ensure sustainable structures in the construction industry. Road construction could also contribute to the creation of a circular economy, as it is partly responsible for several current environmental phenomena, such as greenhouse gas (GHG) emissions and depletion of natural aggregates and landfills. The use of Reclaimed Asphalt Pavement (RAP) is considered one of these recycling solutions, as it can be reused in road construction projects. Implementing it in practice is already a topic that should be included in the technical guidelines for road construction and maintenance. Therefore, this study is a critical overview of the worldwide experiences with the installation of RAP in road pavements published by different road authorities worldwide, aiming to prove the inconsistency in using these materials in pavement courses. The results of this review are analyzed to identify possible knowledge gaps regarding RAP content. It was shown that the use of RAP is different on all five continents. The main findings were that the RAP content in asphalt layers is still at a low level of about 30% and that the use of RAP materials in unbound layers in road pavement construction is not yet fully accepted. It is expected that the results of this study will help to improve further research on the performance of RAP and motivate more countries to develop appropriate guidelines for the use of RAP materials in road pavement construction. Full article

In response to the pressing need for effective implementation of the Circular Economy (CE), this research introduces a comprehensive theoretical framework for CE roadmapping. This study addresses the prevalent issue of fragmented and inconsistent CE strategies that often hinder the successful translation of long-term goals into achievable KPIs. Through a carefully designed methodology, this framework incorporates strategic management, systems thinking, sustainability science, and other disciplines, providing a structured approach to navigating the complexities of long-term planning for CE. The foundation for this framework is laid through an extensive review of the literature, which identifies theoretical gaps and guides its development. Practical insights are gained through an examination of various CE roadmaps, including sectoral, municipal, national, and regional strategies, thereby enhancing this framework’s applicability and robustness. This research highlights substantial variations in current CE roadmapping methods, emphasizing the need for a standardized approach. While acknowledging limitations due to the diverse contexts of the case studies, this study offers significant implications for policymakers, business leaders, and sustainability practitioners by presenting a versatile tool for strategic CE planning. Its interdisciplinary construction mirrors the multifaceted nature of CE, rendering it exceptionally adaptable across various disciplines and levels, reflecting the diverse reality of CE applications. Full article

Biomimicry creates designs inspired by nature and uses ecological benchmarks to assess their sustainability. It is believed that biomimicry can help society produce and consume in more sustainable ways, as well as address some of the key challenges facing the world today. However, research into the applications of and possible barriers to using biomimicry for creating more sustainable Architectural, Engineering and Construction (AEC) projects is still limited. This paper addresses this gap by undertaking and analysing twelve semi-structured interviews with leading global experts and practitioners in the field of biomimicry as applied to the built environment industry. The study identifies substantial potential in the use of biomimicry in AEC projects, including the following: adopting circular approaches; enhancing interactions between human and natural infrastructure; optimising material and energy use; recycling and re-use of materials; reducing time and costs; plus more collaborative and interdisciplinary working. However, a wide range of multifaceted barriers also exist that are currently hindering the exploration and exploitation of this potential, including the following: lack of knowledge; insufficient research and testing at the scale of AEC projects; fragmentation, poor communication and traditional nature of the industry; perception of high risks and costs; as well as outdated and unsuitable legislation and planning processes. Full article

This study reports on the application of an innovative plastering system that reuses organic waste, namely spent coffee grounds (SCG), to improve energy efficiency in historical buildings according to the European Green Deal. The case study was conducted in the village of Polizzi Generosa, selected from 21 small villages located in the extensive UNESCO Geopark of Madonie Park in Sicily. Over time, traditional plasters used in Madonie buildings have shown durability issues due to thermal and hygrometric stresses caused by significant temperature fluctuations in the area. Moreover, much of the considered architectural heritage lacks energy efficiency. Given the global increase in coffee production and the need for more sustainable waste management systems, this investigation proposes an ecological method to reuse SCG in plaster formulation, thereby enhancing the circular economy. To achieve this, many thermoplaster formulations were developed, and the best-performing one, considering both material and aesthetic compatibility with historical buildings, was selected for a real-world application. Additionally, virtual modeling and energy simulations were conducted to test the energy performance of a traditional building in Polizzi Generosa using SCG-based thermoplaster in comparison to traditional lime mortar and commercial alternatives. The real-world application demonstrated the technical feasibility of the process, and the energy simulations showed an improved building masonry energy performance of 0.788 W/m²K and an 11% improvement compared to traditional plaster. Results clearly indicate that SCG can be successfully reused to produce eco-friendly bio composite plasters, providing a more sustainable housing option. This approach offers a durable and cost-effective alternative for housing solutions that meet regulatory requirements for energy efficiency, serving as a smart, highly sustainable, and long-lasting choice for the construction sector. Finally, this result supports the research goal of transforming the 21 municipalities of Madonie into smart and green villages, with the “Smart Coffee-House” exemplifying intelligent rehabilitation processes of existing heritage buildings. Full article

Reuse in new buildings of structural concrete components from demolitions holds the potential for avoiding the use of raw materials to produce new components, including cement for new castings. Reuse rates are high in the circular economy; however, reusing structural components requires documentation of the properties to equate the safety of using reused and new components. Yet, there is no structured or recognized way to perform the documentation. This paper discusses a framework for the documentation requirements for structural concrete, stating the need for documenting the mechanical properties, concrete heterogeneity, and corrosion status of the reinforcement. The possibility is explored for documenting the required properties while the components are in the donor building by use of non-destructive test (NDT) methods. Such use of NDT methods is new. A comprehensive literature survey on the indirect literature, where NDT methods are used to demonstrate similar concrete properties though related to other purposes, is conducted. The overall conclusion is that the use of NDT methods has the potential to document the requested properties before reuse. The next steps towards implementation of NDT for documenting the properties of structural concrete components for reuse involve research in combined NDT methods and the development of AI systems for data interpretation. Full article

Phosphate waste rock (PWR) is gaining attention as a potential alternative aggregate for concrete. Its valorization could reduce the environmental impacts of quarrying natural resources and stockpiling phosphate mining waste. This study comprehensively investigated the properties of fine and coarse aggregates produced from three rock types selected from PWR in Morocco: Flint, Phosflint, and Dolomite. A range of techniques was used to study their characteristics, including microstructural observations up to the microscale and X-ray computed tomography (X-CT), mineralogical and chemical compositions, physical and geotechnical properties such as Los Angeles (LA), micro-Deval (M_DE), flexural strength, real dry density, and total porosity. The results showed that the coarse fractions of Flint, Phosflint, and Dolomite are code A or B of NF P 18-545 and exhibit good shape, density, and water absorption properties. Flint aggregates had the highest wear and fragmentation resistance with the lowest and finest porosity. They contained mainly quartz but also small proportions of Dolomite and fluorapatite. Phosflint aggregates had high resistance, shown by code A in LA and M_DE values, and flexural strength equal to 17.1 MPa. They contained phosphate microfacies with a Ca/P atomic ratio equal to 1.8, cemented by cryptocrystalline silica. Dolomite aggregates’ mineralogical make-up consisted mainly of dolomite with the presence of quartz particles in addition to impurities. They also displayed significant total porosity (10–12%), as confirmed by X-CT. These findings were discussed to develop insights for the use of three types of PWR as alternative aggregates for concrete production. This investigation contributes to unveiling the properties of PWR as concrete aggregates and encourages circularity between the mining and construction sectors. Full article

This article presents the concept of green transformation of the coal mining sector. Pump stations that belong to Spółka Restrukturyzacji Kopalń S.A. (SRK S.A., Bytom, Poland) pump out approximately 100 million m³ of mine water annually. These pump stations protect neighboring mines and lower-lying areas from flooding and protect subsurface aquifers from contamination. The largest cost component of maintaining a pumping station is the expenditure for purchasing electricity. Investment towards renewable energy sources will reduce the environmental footprint of pumping station operation by reducing greenhouse gas emissions. The concept of liquidation of an exemplary mining site in the context of a circular economy by proposing the development/revitalization of a coal mine site is presented. This concept involves the construction of a complex consisting of photovoltaic farms combined with efficient energy storage in the form of green hydrogen produced by water electrolysis. For this purpose, the potential of liquidated mining sites will be utilized, including the use of pumped mine wastewater. This article is conceptual. In order to reach the stated objective, a body of literature and legal regulations was analyzed, and an empirical study was conducted. Various scenarios for the operation of mine pumping stations have been proposed. The options presented provide full or nearly full energy self-sufficiency of the proposed pumping station operation concept. The effect of applying any option for upgrading the pumping station could result in the creation of jobs that are alternatives to mining jobs and a guarantee of efficient asset management. Full article