Search Results (458)

This study assesses the technical performance and environmental impact of traditional and eco-efficient materials used in civil construction in Colombia through a structured synthesis of scientific, technical, and regulatory evidence covering the period 2010–2025. The analysis integrates mechanical performance indicators, environmental footprint metrics, and the national regulatory framework supporting sustainable material adoption. Results show that conventional materials—Portland cement, structural steel, ceramic bricks, and timber—remain essential due to their proven structural reliability but are also responsible for the highest contributions to CO₂ emissions, energy consumption, and resource depletion. In contrast, eco-efficient alternatives, including blended concretes with mineral additions, geopolymers, rammed earth, Guadua angustifolia, and natural biocomposites, achieve carbon emission reductions between 40% and 85% while maintaining comparable mechanical performance for specific applications. Colombian policies—notably Resolutions 1257 of 2021 and 0194 of 2025—promote waste valorization and low-impact materials, yet their implementation remains limited by technical, economic, and knowledge barriers. The findings support a decision-oriented framework for material selection that balances structural efficiency with environmental responsibility. Full article

The aim of this study is to determine the reliability level (the probability of failure-free operation) of a masonry building with load-bearing walls based on the conducted experimental investigations. The objective of the study is to compare the obtained reliability and failure risk values with the corresponding values calculated using the results of the structural certification. In 2017–2018, and subsequently in 2023–2024, a comprehensive structural certification of the multi-apartment residential building stock was carried out for the first time in the city of Almaty. A total of 1609 multi-story masonry buildings with heights of two to four stories were identified. Based on the certification results, quantitative estimates of the prior and posterior probabilities of failure and reliability for masonry buildings were obtained for the first time. The recurrence of earthquakes was taken into account. The novelty of the study lies in the experimental investigation of a three-story masonry building of series 308. The dynamic excitation was generated by an inertial vibration machine installed on the floor slab. As the inertial load increased, the resonant vibration period changed by a factor of three. This indicates that the building underwent significantly nonlinear deformation. The structure sustained substantial damage. Using statistical simulation methods based on the experimental data, the prior probabilities of failure for masonry buildings were calculated. In this case, the seismic action was modeled as a non-stationary random process with the deterministic envelope proposed by F. F. Aptikaev. Probabilistic estimates of the reliability of masonry buildings were obtained from the certification results both with and without taking into account the recurrence of earthquakes. The obtained estimates of reliability and failure probability can be used to develop practical recommendations aimed at reducing risk and expected losses in the event of possible earthquakes. It is recommended that masonry buildings with load-bearing brick walls either be structurally strengthened or be demolished. Full article

The rapid growth of the construction sector has substantially increased the demand for natural resources, resulting in growing pressures on ecosystem services and resource sustainability. This study presents a dynamic emergy-based assessment of construction material consumption in Kerala, India, for the period 2009–2023, focusing on four major construction materials: steel, cement, river sand, and brick clay. Emergy accounting was employed to quantify annual material consumption, emergy per unit cost, ecosystem service deficits, economic losses associated with ecological degradation, and the contribution of recycling and material substitution. Temporal trends were evaluated using the non-parametric Mann–Kendall test and Sen’s slope estimator, while logistic (sigmoid) functions were fitted to characterize resource-use transitions and identify growth, transition, saturation, and overshoot phases. Steel and cement exhibited significant positive consumption trends ($\tau =0.752$ and $0.790$, respectively), whereas river sand and brick clay displayed strong declining trends ($\tau =-0.891$ and $-0.638$, respectively). Logistic modelling revealed that steel and cement remain in growth phases supported by recycling and material substitution, whereas river sand and brick clay exhibit characteristics of transition and ecological overshoot. Carrying-capacity assessments indicate that river sand and brick clay extraction exceeded sustainable ecosystem-support capacities, resulting in persistent ecosystem service deficits. The study demonstrates that recyclability plays a critical role in reducing transformity, delaying resource scarcity, and moderating ecological overshoot. Full article

Despite growing interest in sustainable construction materials, unfired clay bricks still exhibit limited thermal insulation performance. This study investigates the enhancement of perforated raw earth bricks through the integration of a bio-based phase change material (PCM) derived from coconut oil to improve thermal damping and heat storage capacity. A numerical analysis was conducted on several configurations, including a solid reference brick, a hollow brick with air-filled cavities, and bricks incorporating one, two, or three rows of PCM encapsulated in polylactic acid (PLA) tubes. Results show a progressive improvement in thermal performance with increasing PCM content showing that the three-row PCM configuration achieved the best dynamic thermal behavior. Thermal gradient and enthalpy analyses revealed the combined effects of the thermal conductivity of PLA and raw earth and the latent heat storage capacity of the PCM. Replacing 17 PCM tubes with a single container of equivalent volume further improved performance while reducing system complexity and cost, decreasing the decrement factor by nearly 50% compared with the three-row configuration. These findings demonstrate the potential of PCM-enhanced raw earth bricks for passive thermal regulation in sustainable buildings, although experimental validation remains necessary. Full article

The growing demand for sustainable construction materials has spurred the use of recycled aggregates in cementitious composites to reduce the consumption of natural resources and the generation of construction waste. This study investigates the combined effects of recycled glass (RG), recycled brick (RB), and recycled concrete (RC) aggregates used as partial replacements for natural aggregate (NA) on the fresh properties of mortar. A multi-factor experimental design was employed, with RG, RB, and RC replacing NA at levels of 5–25%, 15–45%, and 10–30% of the total aggregate content, respectively. The fresh properties evaluated included the final water-to-cement ratio (w/c), fresh density, and air content. The results indicated that increasing the proportion of recycled aggregates, especially RB and RC, increased water demand and air content, which is likely attributed to their higher porosity and water absorption. Consequently, the final w/c ratio increased, while the fresh density decreased by up to 12%. In contrast, mixtures with higher NA and RG contents exhibited improved compactness and higher fresh density. Furthermore, the Response Surface Methodology (RSM) and sensitivity analysis framework established in this study provide a robust quantitative tool (R² up to 0.95) for optimizing the proportioning of multi-source recycled aggregate mortar. The findings confirm the feasibility of using multi-source recycled aggregates to develop optimized and sustainable mortar mixtures with predictable fresh-state performance. Full article

Greenhouse cultivation in winter faces significant challenges in maintaining suitable air temperature and humidity conditions for crop growth during nighttime. This study proposes an innovative thermal management system that integrates a solar air collector circulation system with clay bricks to regulate the microclimate of plastic greenhouses. Comparative experiments were conducted in Suzhou, China (subtropical monsoon climate), using two identical greenhouses (2.6 m × 1.5 m × 2.0 m) over nine consecutive days in winter. Three experimental scenarios were designed and implemented, and the results demonstrated that the clay brick system improved the greenhouse temperature and humidity regulation performance. Under the relatively optimal schedule (9:00–16:00 external circulation, 16:00–9:00 internal circulation), the average nighttime indoor air temperature was 13.68 °C during the three experimental days. The cumulative suitable temperature duration (10–35 °C) reached 4050 min over the three test days, which was 30.6% higher than that of the ordinary greenhouse, and the suitable relative humidity duration (40–80%) was 1140 min, an increase of 40.7% during the three experimental days. This study innovatively combines low-cost clay bricks with solar air collectors for passive temperature and humidity control in greenhouses and determines the relatively optimal operation schedule for application in winter. Featuring low cost, simple operation and high sustainability, the system provides a novel energy-saving technical solution for microclimate regulation in agricultural greenhouses in winter. Full article

The growing volume of industrial waste and the need for sustainable material solutions drive the search for cost-effective fillers and energy-efficient processing methods for polymer composites. This study investigates the valorization of brick dust (BD), a fine ceramic waste, as a reinforcing filler for unsaturated polyester resin (UPR), combined with microwave (MW) treatment applied at different stages of composite fabrication. The brick dust was comprehensively characterized using laser diffraction, SEM, EDX, XRD, and FTIR, revealing an environmentally safe aluminosilicate powder with a mean particle size of 3–6 µm, plate-like morphology, and surface hydroxyl groups favorable for matrix interaction. The optimal filler content was found to be 50 phr, which increased flexural strength by 6.5%, flexural modulus by 134%, tensile strength by 11%, and impact strength by 40% compared to neat UPR. Among the MW strategies evaluated, post-curing of the fully polymerized composite for 120 s proved most effective, yielding further improvements in flexural strength (110 MPa, +34.1%), flexural modulus (8250 MPa, +49.7%), impact strength (13.8 kJ/m², +119%), and Shore D hardness (88). MW post-curing also increased the gel fraction from 95.0% to 97.8%, raised the thermal stability index (THRI) from 150.6 to 165.8, and reduced equilibrium water absorption from 0.62% to 0.47% with a reversibility index of 87.5%. Fracture surface analysis confirmed a transition from interfacial debonding to cohesive matrix failure, with ultra-thin polymeric veils replicating the scaly filler structure. These results demonstrate that microwave post-curing synergistically enhances the mechanical, thermal, and moisture-resistant properties of brick dust-filled polyester composites. Full article

Permeable concrete bricks incorporating waste tire rubber particles were prepared to improve sustainability and optimize the balance between mechanical performance and hydraulic behavior. Orthogonal experiments and response surface methodology were used to investigate the effects of aggregate-to-binder ratio (A/B), water-to-binder ratio (W/B), rubber content, and rubber particle size on compressive strength and permeability coefficient. Results showed that rubber content dominated compressive strength, while A/B ratio had the greatest influence on permeability. Compressive strength decreased continuously with increasing rubber content and A/B ratio, whereas permeability increased with A/B ratio and showed non-monotonic responses to rubber content and particle size. Response surface optimization identified an optimum mixture: A/B = 3.006, W/B = 0.45, rubber content = 0.103, and rubber particle size = 0.525 mm, yielding a compressive strength of 18.97 MPa and a permeability coefficient of 1.82 mm/s. Validation tests showed relative errors of 1.32% for compressive strength and 3.85% for the permeability coefficient, respectively. SEM and CT analyses revealed that the performance of the permeable concrete bricks was governed by the balance among skeleton integrity, interfacial bonding, and pore connectivity. These findings support the valorization of waste tire rubber in sustainable permeable paving materials. Full article

At the archeological site of Pompeii, the deterioration of exposed structures is frequently associated with the combined action of microbial colonization and soluble salts, both recognized as major agents of decay affecting ancient surfaces. Although biocides are commonly applied during cleaning procedures to reduce microbial biomass, their incorporation into restoration-oriented formulations for the protection of porous stone substrates requires careful assessment of efficacy, microbiological risks, and sustainability. This study evaluated the performance of 2,4,5,6-tetrachloroisophthalonitrile (chlorothalonil) and iodopropynyl butylcarbamate (IPBC) as candidate active ingredients for conservation applications in activated new mortars. Yellow tuff, gray tuff, and brick samples collected from different sectors of Pompeii were investigated through culture-based analyses, ATP quantification, and metabolic profiling. Biocidal treatments were subsequently tested under laboratory conditions. The investigated substrates exhibited variable microbial counts and metabolic activity, generally reflecting different degrees of deterioration. Chlorothalonil showed negligible inhibitory effects, whereas IPBC reduced fungal growth in a dose-dependent manner. However, the highest IPBC concentration induced a red chromatic alteration associated with the selection of a bacterial strain preliminarily identified as Micrococcus roseus. Phenotype microarray analyses revealed broad chemical tolerance. Overall, biocidal treatments may alter microbial communities, favor tolerant microorganisms, and produce undesirable aesthetic effects. Finally, the study also assessed the environmental impact associated with laboratory and field activities, highlighting potential mitigation strategies to support more sustainable conservation research practices. Full article

This study investigates the valorization of construction and demolition (C&D) waste streams and an industrial by-product for sustainable concrete production. Recycled concrete aggregates (RCA) and recycled brick aggregates (RBA), derived from C&D wastes, together with pelletized recycled fly ash aggregates (FAA) produced from thermal power plant fly ash, were used as total replacements for natural coarse aggregates. Six concrete mixtures were prepared at a constant water-to-cement ratio of 0.50 using untreated and slag slurry–treated aggregates. A slag slurry-based two-stage mixing approach (TSMA), incorporating ground granulated blast furnace slag (GGBFS), was applied as a practical and potentially scalable treatment method to enhance aggregate quality and interfacial bonding. The results show that complete replacement of natural aggregates reduced fresh concrete unit weight by up to 17%, while meeting the minimum compressive strength requirements for structural applications. Slag slurry treatment led to statistically significant improvements in mechanical properties, reduced variability, and enhanced overall reliability. In addition, widely used code-based prediction models (TS500, ACI, Eurocode-2, NZS 3101-1:2006, and CSA A23.3-04), originally developed for conventional concrete, were evaluated for their applicability in estimating key mechanical properties of recycled and by-product aggregate concretes, and alternative regression-based models were developed to improve prediction accuracy. Overall, the findings demonstrate the potential for effective utilization of C&D wastes and industrial by-products in structural concrete, contributing to resource efficiency and reduced reliance on natural aggregates. Full article

Fire protection remains one of the key challenges in the field of architectural heritage conservation, particularly for heritage buildings dominated by timber structures, which face greater difficulties in fire prevention and risk assessment. To systematically evaluate the fire safety performance of high-rise timber heritage buildings, this study takes the Shengjin Pagoda, a typical brick–timber pavilion-style ancient tower in Jiangxi Province, China, as the research object. A three-dimensional performance-based fire assessment framework was developed using Fire Dynamics Simulator (FDS) and PyroSim. Based on field survey data and historical documentation, the geometric characteristics, material properties, and vertical circulation system of the pagoda were reconstructed. Three representative fire scenarios, including bottom-floor ignition, simultaneous multi-level ignition, and wind-driven top-floor ignition, were established to investigate smoke propagation, thermal insulation degradation, and the thermal response of critical timber components under different fire conditions. The results show that brick walls provide effective thermal insulation during the early stages of fire, with efficiency exceeding 90%, but this decreases to approximately 55% in upper regions due to chimney-effect-driven smoke accumulation. Under wind-driven top-floor ignition, exposed dougong components can reach temperatures of 782 °C, resulting in a progressive “top-down and outside-in” failure mechanism. The study reveals the dominant smoke-driven heat transfer pathways and the failure sequence of critical load-bearing elements. Based on these findings, a performance-based fire protection strategy incorporating vertical virtual smoke control zoning and fire-resistance enhancement of key structural components is proposed to support the sustainable conservation of historic high-rise timber structures. Full article

Concrete bricks have been used in construction for over a century, often used for foundations and retaining walls. Its production contributes significantly to carbon emissions and the depletion of natural resources. Thus, this study aims to develop an outdoor brick using crushed bivalve shell (Vivipara angularis), locally known as “Ige”, as an aggregate to reduce the need for natural aggregates, which are a finite resource, and molasses as an admixture to improve the brick’s workability and strength. A series of experiments was conducted to test the bricks’ fire resistance, water absorption, and compression, aiming to determine the feasibility of making bricks from crushed bivalve shells, shredded plastic bottles, cement, sand, water, and molasses. The project used an experimental and developmental research approach. The study was conducted at the Caraga State University, Cabadbaran Campus. Results showed that (a.) Sample 2, which contains 400 g of cement, 800 g of sand, and 1200 g of bivalve freshwater shell with the ratio of 1:2:3, has good fire resistance characteristics (b.) Sample 5, which contains more plastic bottles rather than freshwater shells, performed well in water absorption and (c.) Sample 2, a mixture of 400 g of cement, 800 g of sand, and 1200 g of bivalve freshwater shell with a ratio of 1:2:3, exhibits good comprehensive strength. The study revealed that using bivalve freshwater shells can improve the durability of concrete bricks and, when combined with plastic bottles, reduce water absorption; however, it can also compromise brick durability. Full article

The European Union produces approximately 8 million tons (dry matter) of sewage sludge annually. Conventional management approaches, such as landfilling and incineration, pose significant environmental concerns, including greenhouse gas emissions and pollutant dispersion. This study evaluates the environmental sustainability of an innovative sludge recovery pathway, Hydrothermal Dewatering (HTD), developed and validated within the LIFE FREEDOM project. A Life Cycle Assessment (LCA) was conducted on a pilot plant treating 1000 tons of sewage sludge. The quantitative results reveal that the HTD process generates a total climate change impact of 8.95 × 10⁴ kg CO₂ eq per functional unit (1000 t). The heating and reaction phase represents the main environmental hotspot, accounting for 92.9% of the overall single-score impact. Crucially, comparative analyses indicate that the HTD process exhibits statistically comparable aggregated impacts to incineration and landfilling, while demonstrating distinct environmental advantages in specific midpoint categories. Furthermore, the assessment of the solid residue (HTD-cake) as a 10 wt% substitute for natural clay in brick manufacturing confirmed the absence of environmental burden shifting. Overall, the findings quantitatively validate HTD as a viable and competitive alternative to traditional end-of-life options. Full article

Mining and industrial activities generate large volumes of waste, up to 99% of the extracted material, forming a major global residue source. In this context, the valorization of mining sludge for sustainable construction materials gains relevance. This study examines the fabrication of ceramic bricks incorporating mining sludge from the Panasqueira mine, evaluating sludge incorporation levels and sintering temperatures to optimize resource use and reduce environmental impacts. Bricks were produced by blending residual clays from Víznar (Granada, Spain) with Panasqueira sludge at substitution rates of 10, 25 and 50%, and fired at 800, 950 and 1100 °C. Granulometry was determined for the Víznar clay and mining sludge, while bulk density was measured for the fired bricks. The raw materials were analyzed by XRF and XRD, whereas the ceramic samples were characterized by water absorption, porosimetry, ultrasound pulse velocity, compressive strength testing, ESEM, leaching and colorimetry, to assess their chemical, physical and mechanical behaviour. Both clays and sludge are rich in SiO₂ and Al₂O₃, suitable for ceramic processing, while fluxing oxides promote vitrification and densification. Incorporating 25 and 50% sludge reduces porosity, increases ultrasonic velocity and improves mechanical strength, achieving optimal performance at 1100 °C. Moreover, firing immobilizes toxic metals and allows controlled colour development, confirming their technical performance and suggesting their potential suitability from an environmental perspective. Their microstructure and stability depend on sludge content and firing temperature, essential factors for sustainable construction and architectural rehabilitation. Full article

Polycarbonate is a thermoplastic material well known for its high impact resistance and thermal stability, making it a strong candidate for non-structural aerospace applications. Within the framework of the LIDER project for the techno brick BUS, the behavior of polycarbonate has been experimentally assessed under critical conditions, aiming to validate its potential use in a future tail bumper design for helicopters. The experimental campaign included high strain rate impact tests, ageing tests to evaluate water absorption effects, and high-temperature exposure to assess thermal performance. The results of these tests form the core of this study, demonstrating the material’s capabilities and limitations under operationally relevant conditions. These findings aim to support the development of lightweight and robust non-structural components in aerospace systems. Full article