Search Results (339)

This study underscores the importance of sustainable practices by exploring the utilization of recycled plastic within the global construction industry. Plastic recycling has emerged as a crucial strategy that aligns with environmental, social, and economic sustainability indicators. Currently, substantial volumes of plastic waste are either deposited in landfills or incinerated, neglecting the potential to harness its embodied energy and the energy consumed for producing virgin materials. A key advantage of plastic lies in its promising mechanical properties. Concrete mix design is fundamental to a wide range of construction applications, including brick walls, reinforced concrete slabs, and concrete pavements. Despite the adoption of recycled plastic in construction materials in various countries, its widespread implementation remains limited. This is primarily due to the scarcity of experimental research in this area and the absence of a robust waste management system. This research specifically investigates the reuse of two common types of plastic waste: polyethylene terephthalate (PET) and high-density polyethylene (HDPE) to mitigate plastic waste accumulation in landfills and enhance the performance of construction materials. The study investigates the use of recycled HDPE and PET as a replacement for coarse aggregates in concrete pavement mixtures. While recycled PET is more prevalent in concrete applications, recycled HDPE has demonstrated exceptional efficiency and durability. The recycling method used in this research is the mechanical recycling method due to its superior effectiveness in comparison with other methodologies. This research assesses the performance of recycled PET and HDPE in concrete pavement, aiming to diminish non-renewable energy consumption by 15–20%, curtail the carbon footprint by 15–30%, and decrease plastic waste in landfills by 20–30% compared to conventional concrete. Full article

There is an increasing demand to replace traditional construction techniques with more sustainable systems that can reduce environmental impacts. Emissions are typically assessed only in carbon dioxide and embodied energy terms, yet these metrics alone cannot fully capture the overall impact generated. This study provides a comparative Life Cycle Assessment (LCA) of three steel warehouse projects with varying cladding systems: steel walls (SW), steel-clay brick walls (SClaW), and steel-concrete block walls (SConW). Life Cycle Assessment (LCA) methodology was used to assess the environmental impact of materials used during the whole life cycle. The study used the software program SimaPro (System for Integrated Environmental Assessment of Products) version 9.6.0.1, with data extracted from the international Ecoinvent database. ReCiPe Midpoint approach were adopted to assess potential impacts. The results indicate that the SW project under end-of-life Scenario 2—waste recycling—exhibited the lowest impacts across most categories, followed by the SConW and SClaW projects. The findings emphasize the environmental benefits of utilizing steel cladding systems over brick or concrete masonry and considering recycling as the end of life of the materials. Additionally, the study provides insights into the significance of material choices in minimizing environmental impact on human health, resource availability, and ecosystems. Full article

The use of recycled burnt clay brick sand (RBS) and recycled concrete sand (RCS) in historical lime-based repair mortars can reduce the environmental impact caused by construction and demolition waste disposal. This study examined the use of fine recycled concrete and recycled brick aggregates for the production of historical repair mortars using hydraulic lime binder and the influence of the resulting mortars on the performance of historical buildings in reduced scale walls (stacks). Natural-river-sand mortar (NSM) was used as control. Results showed that the recycled-burnt-brick-sand mortar (RBSM) performed better in terms of strength compared to the recycled-concrete sand (RCSM) and the NSM mortars. At the age of 7 and 28 days, the flexural strength of the RBSM and the RCSM was 131% and 44%, respectively, and 300% and 68% above that of the control mortar. The 45-day flexural strength of the NSM and RCSM was similar whilst the RBSM mortar’s strength was 177% higher. The compressive strength followed similar trend. On the other hand, the strength and modulus of elasticity of the stacks were found to be largely influenced by the strength of the brick units. Full article

This article explores the possibility of using metallurgical waste slags formed during the smelting of cast iron and steel as cementless binders that harden due to forced carbonization and the subsequent hydration processes of some minerals that form the basis of these slags. This study presents the results of multi-objective optimization using statistical methods of mathematical experimental design, with the purpose of obtaining a carbonized material with good mechanical and physical properties. As a result of the research, carbonized stone with compressive strength up to 116.5 MPa was obtained. Water absorption by weight is within the range of 6.0–17.0%, and quantitative CO₂ binding was 6–11.9%, depending on the type of slag. A pilot batch of wall product samples (hollow bricks and paving elements of various territories) was manufactured under production conditions. During the tests, we found that the compressive strengths of products based on BOF and EAF slags were 96.3 and 81.1 MPa, respectively, and that of bricks based on BS slag was 37.1 MPa. A comprehensive analysis of the performance properties of products from the pilot batch showed that these samples meet the requirements of national standards. Full article

Fiber-reinforced polymers (FRPs) are effective for strengthening masonry walls. Debonding at the polymer–masonry interface is a major concern, requiring further investigation into interface behavior. This study utilizes detailed micro-modeling finite element (FE) analysis to predict failure mechanisms and analyze the behavior of brick masonry walls strengthened with externally bonded carbon fiber-reinforced polymer (CFRP) under in-plane loading. The research investigates three CFRP strengthening configurations (X, I, and H). The FE model incorporates the nonlinear behavior of brick masonry components using the Concrete Damage Plasticity (CDP) model and uses a cohesive interface approach to model unit–mortar interfaces and the bond joints between masonry and CFRPs. The results demonstrate that diagonal CFRP reinforcement enhances the ductility and capacity of masonry wall systems. The FE model accurately captures the crack propagation, fracture mechanisms, and shear strength of both unreinforced and reinforced walls. The study confirms that the model can reliably predict the structural behavior of these composite systems. Furthermore, the study compares predicted shear strengths with established design equations, highlighting the ACI 440.7R-10 and CNR-DT 200/2013 models as providing the most accurate predictions when compared to experimental results. Full article

This study investigated the mechanical properties of a cementitious material used to prepare irregular-shaped brick masonry structures (PG-ISBs) from industrial solid wastes, including phosphogypsum, calcium powder, cementitious agents, and construction brick debris. The hydration products, microstructure, and elemental composition of the system were analyzed using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Based on the experimental stress–strain relationship curves, a constitutive model for the cementitious material was established. The results show that the compressive strength of the PG-ISB cementitious material meets the requirements for filling retaining walls. SEM observations reveal a significant number of micro-pores within the PG-ISB cementitious material, which are important factors affecting its strength. An empirical constitutive model for the uniaxial compression of the specimen was established based on the experimental stress–strain full curves, and the fitting curves showed good agreement with the experimental data. Full article

This paper presents research concerning simulating the thermal firebrand effect due to its accumulation in exterior construction wall elements by developing a 3D finite element model (FEM) via ABAQUS (2022) software to analyze the exterior walls commonly applied to the exterior of dwellings in southern Europe and South America. A non-linear thermal transient analysis is undertaken, in which the results are directly compared with a previous experimental campaign, in which firebrands are deposited on localized surfaces of construction wall specimens, and the temperature is measured in the several layers of the construction elements. The walls are composite elements, made of different layer combinations of masonry brick and wood, varying the type of thermal insulation in the internal core from cork to classical rigid rockwool and polystyrene foam (XPS). It can be summarized from the results that the FEM effectively simulates the thermal response of brick, normal wood (NW), and cross-laminated timber (CLT) walls when insulated with materials like cork or rockwool coated with mortar against firebrand accumulation. However, the lack of accounting for uncontrolled combustion leads to inconsistent results. Additionally, for walls using XPS as the insulation material, the model requires further refinement to accurately simulate the melting phenomenon and its thermal impact. Full article

After Germany’s planned withdrawal from coal-fired power generation by 2030, the by-product known as FGD gypsum will no longer be available. As an alternative, loam can be utilized as a building material for non-load-bearing interior walls. Recycling loam is advantageous as it is readily available in large quantities. However, its unique properties, such as moisture retention and drying shrinkage, are crucial for its usability. Loam samples are modified with various additives and molded into prisms to investigate and optimize these aspects. These prisms are tested for drying shrinkage and strength behavior. The most effective mixtures undergo further evaluation of their long-term behavior when subjected to changes in moisture—the addition of 20 wt.-% brick dust results in a reduction of the drying shrinkage by 25%. In long-term tests, swelling deformation has been reduced by 35%. This article demonstrates the effectiveness of additives in minimizing moisture-inducted deformations while maintaining the same compressive strength. Additionally, it compares various measuring methods for recording length changes in loam blocks. Full article

Self-regulated learning (SRL) is often defined as goal-directed behavior of learners that they display on a regular basis. Models of SRL present general stages of SRL through which learners go without making a difference between different fields of learning. However, there is also research showing that there is not one set of self-regulated actions which assist learners in regulating their behavior in every context. Instead, there are types of self-regulated actions which fit into different contexts for different learners and for different tasks as well as different domains. To shed light on this matter, this study investigated whether self-regulation is a general concept or a domain-specific characteristic. The data of the study were collected from high achieving students studying at the top-ranking science high schools of Türkiye which accept students through a competitive centralized exam. The data were collected via interviews (n = 15) whose participants were selected among the ones receiving the highest score from Self-regulatory Strategies Scale (SRSS). The results of the study showed that self-regulated learning can be depicted as a general characteristic as well as a domain-specific one, as it is a complex process that subsumes both general and domain attributes. The results of this study can be utilized to design impactful SRL interventions, as it provides a comprehensive report of the general and domain-specific phases of SRL. Full article

The accurate thermal performance assessment of building components is critical for improving energy efficiency in buildings, mainly as space climatization accounts for a large percentage of energy consumption. The literature review points out multiple parameters that influence the measurement of the U-value using the HFM method. However, most of these studies are focused on in situ tests and little information exists on the variability of the results of the hot box method to assess thermal resistance. According to EN 1934, a baffle must be positioned between the surface of the specimen and the fans of the climatic chamber to maintain acceptable air temperature gradients and uniform air temperature distribution to minimize the convective effects. However, no clear information about its position is given. This study investigates the variability in the measurement of the thermal resistance of double leaf brick wall specimen using the hot box method, focusing on the effect of the layout configuration. An experimental campaign was carried out and three configurations were considered: no baffle, a baffle positioned 1.15 m from the wall, and a baffle positioned 0.05 m from the specimen. The experimental results demonstrate that baffle positioning significantly influences measurement variability. The best-performing configuration (P1) resulted in the lowest variability and the closest agreement with theoretical values, with an average R-value deviation of approximately 25%. These findings are relevant for optimizing testing protocols and improving the reliability of thermal resistance assessments. Furthermore, the results have implications for energy efficiency policies and building retrofitting strategies, aligning with global sustainability goals to reduce building energy demand and carbon emissions. Full article

This study examines the reduction in energy consumption in residential and commercial buildings by utilizing eco-efficient ceramic bricks, converted into building blocks for the construction industry, in light of their significant energy usage and the challenges associated with solid waste management. A ceramic brick composed of zeolite and sugarcane bagasse ash (ZS brick) was selected and simulated as a building block. Such building blocks were used in building design models, and annual building energy simulation was performed by applying different approaches and modes. The results in four different climatic regions in Iran proved that the use of ZS bricks in building envelopes without a thermal insulation layer could lead to a reduction in building energy consumption from 5 to 12.5% compared with conventional fired clay bricks. Also, the use of ZS brick in the layering of the building walls with a thermal insulation layer, compared with conventional fired clay bricks, resulted in an energy consumption reduction from 2.3 to 7.5%. Full article

Composite phase-change materials (PCMs) exhibit significant potential for enhancing the thermal performance of building walls. However, previous studies have generally lacked detailed investigations of the performance of PCM-integrated walls under cold climate conditions. Therefore, in order to evaluate the thermal performance and wall adaptability of hollow bricks with composite PCMs in cold climates, a brick model was created by filling the hollow bricks with PCMs. Then a comparative test was conducted between the PCM-filled bricks and the conventional non-PCM-filled hollow bricks. The comparative experimental method and the thermal performance index evaluation method resulted in the following: (1) Compared with conventional hollow bricks, PCM-filled bricks showed an increase of approximately 0.99 °C in inner surface temperature and 3.85 °C in midsection temperature. This demonstrates that PCM-filled bricks can retard the rate of temperature drop, significantly enhancing the insulation performance of walls. This improvement contributes to enhance indoor thermal comfort and reduce energy consumption. (2) The temperature difference between the interior and exterior surfaces of the non-PCM-filled hollow bricks is 23.54 °C, which is 5.62 °C higher than that of the PCM-filled bricks. This indicates that bricks filled with PCMs possess superior heat storage capacity, effectively reducing indoor heat loss, which aligns with the principles of green building design. (3) Compared with the conventional non-PCM-filled hollow bricks, the heat flow on the inner surface of the PCM-filled bricks is significantly lower, with the average heat flow reduced by 8.57 W/m². This suggests the ability of bricks filled with PCMs to moderate heat flux fluctuations through a “peak-shaving and valley-filling” effect, contributing to reduced energy consumption and enhanced occupant thermal comfort. Full article

In this study, unreinforced masonry (URM) walls constructed from concrete blocks and clay bricks were strengthened using horizontally and vertically oriented glass fiber-reinforced polymer (GFRP) grid strips bonded with sprayed polyurea. The walls were subjected to diagonal compression loading until failure. The results demonstrated a significant improvement in both the shear capacity and pseudo-ductility of the strengthened URM walls compared to their unstrengthened counterparts. The primary conclusions drawn from this research are as follows: (1) the maximum strain in the vertical GFRP strips increased with the higher axial stiffness of the strips; (2) the discrete vertical strips contributed substantially to enhancing the shear capacity and pseudo-ductility of the URM walls; (3) increasing the axial stiffness of the vertical strips can alter the failure mode of the walls, shifting it from joint failure to tension or compression failure of the blocks or bricks; (4) a reduction factor is necessary to account for the potential asymmetrical performance of double-sided strengthening schemes applied to URM walls. The experimental program was reported in a previous publication and additional information is presented in this paper. Full article

This paper examines the potential for shielding against electromagnetic (EM) radiation in traditional buildings. The primary objective is to evaluate how effectively these buildings can reduce the intensity of the electric field from external sources, while also identifying the factors that influence this reduction, such as geometry, structure, and the characteristics of EM waves. Measurements were conducted on the transmission parameter S₂₁, which indicates how EM waves propagate through the walls of residential buildings constructed using traditional methods. The buildings analyzed were made from wood, rammed earth, raw bricks blended with straw (known in Croatian as ćerpič), and baked bricks, which served as the reference material. During the measurements, conditions such as the thickness, humidity, and temperature of both the walls and the surrounding environment were carefully controlled. The buildings represented traditional construction styles typical of Croatia and most of Central and Eastern Europe. The results indicate that structures made from rammed earth and raw bricks with added straw significantly decrease the transmission of EM wave energy compared to those made from wood and baked bricks. It is important to note that the walls of wood buildings were considerably thinner than those made from the other materials tested. Additionally, both the moisture content and thickness of the walls contributed significantly to reducing transmission parameters. These findings support the use of these traditional materials for constructing environmentally friendly buildings, while also suggesting the need for further architectural design and testing. Since this research does not cover all types of traditionally constructed buildings—such as stone houses, wicker structures, and dugouts—future studies will aim to expand this investigation to include a broader variety of traditional building styles. Full article

The construction sector has a high environmental impact, especially due to C&D waste. At the same time, the increase in the temperature of the Earth’s surface due to pollution requires interventions on the built environment, aimed at improving the performance of the envelope in hot climates. In the literature, there are studies on components to increase thermal efficiency, but they are limited by long or expensive production processes or high environmental impact. This research considers Italy as a reference area. The aim of this research is to design, prototype, and verify a sustainable component to be included in the stratigraphy of light mass vertical closures to increase their heat capacity that allows for the reuse of C&D waste and the optimization of site operations both in the selective demolition phase and in the redevelopment phase of the building. The method follows the following phases: analysis of the type of waste from C&D, analysis of international best practices, analysis of the possibilities of intervention on vertical closures according to the pre-existing structure and choice of cases of greatest scientific interest, design of the sustainable big bag by reusing inert materials from selective demolition and recycled polypropylene fabrics, prototyping and verification by laboratory tests, and software analysis to verify the thermal advantage. The use of the sustainable big bag allows for construction advantages, facilitating site operations both in the construction and waste disposal phases, energy advantages by improving the heat capacity of the envelope, and increases in the sustainability of the intervention through the reuse of waste materials. Full article