Search Results (35)

Massive construction systems have always characterized traditional architecture and are currently the most prevalent, straightforward, and cost-effective in many Mediterranean countries. However, in recent years, the construction industry has gradually shifted towards using lightweight, dry construction techniques. This study aims to assess the effects on energy consumption, comfort levels, and environmental sustainability resulting from the adoption of five high-performance construction systems in a multi-family residential building: (i) reinforced concrete structure with low-transmittance thermal block infill; (ii) reinforced concrete structure with light-clay bricks and outer thermal insulation; (iii) steel frame; (iv) cross-laminated timber (CLT); (v) timber-steel hybrid structure. To achieve this goal, a multidisciplinary approach was employed, including the analysis of thermal parameters, the evaluation of indoor comfort through the adaptive model and Fanger’s PMV, and the quantification of environmental and economic impacts through life cycle assessment and life cycle cost applied in a long-term analysis (ranging from 30 to 100 years). The results highlight that heavyweight construction systems are the most effective in terms of comfort, cost, and long-term environmental impact (100 years), while lightweight construction systems generally have higher construction costs, provide lower short-term environmental impacts (30 years), and offer intermediate comfort depending on the thermal mass. Full article

The textile industry, renowned for its comfort-providing role, is undergoing a significant transformation to address its environmental impact. The escalating environmental impact of the textile industry, characterised by substantial contributions to global carbon emissions, wastewater, and the burgeoning issue of textile waste, demands urgent attention. This study aims at identifying the feasibility of the future use of textile scraps in the construction and architecture industry by analysing the effect of different binders. In this study, synthetic knitted post-consumer-waste fabrics were taken from a waste market for use as a reinforcement, and different binders were used as the matrix. In the experiment phase, the waste fabrics were mixed with synthetic binders and hydraulic binders to form brick samples. The mechanical and thermal properties of these samples were tested and compared with those of clay bricks. In terms of mechanical properties, unsaturated polyester resin (UPR) samples showed the highest mechanical strength, while acrylic glue (GL) samples had the lowest mechanical strength. White cement (WC) samples showed moderate mechanical properties. Through several tests, it was observed that UPR samples showed the highest values of tensile, bending, and compressive strengths, i.e., 0.111 MPa, 0.134 MPa, and 3.114 MPa, respectively. For WC, the tensile, bending, and compressive strengths were 0.064 MPa, 0.106 MPa, and 2.670 MPa, respectively. For GL, the least favourable mechanical behaviour was observed, i.e., 0.0162 MPa, 0.0492 MPa, and 1.542 MPa, respectively. In terms of thermal conductivity, WC samples showed exceptional resistance to heat transfer. They showed a minimum temperature rise of 54.3 °C after 15 min, as compared to 57.3 °C for GL-based samples and 58.1 °C for UPR. When it comes to polymeric binders, UPR showed better thermal insulation properties, whereas GL allowed for faster heat transfer for up to 10 min of heating. This study explores a circular textile system by assessing the potential of using textile waste as a building material, contributing to greener interior design. This study demonstrated the usefulness of adding short, recycled PET fibres as a reinforcement in UPR composites. The use of the PET fibre avoids the need to use a surface treatment to improve interfacial adhesion to the UPR matrix because of the chemical affinity between the two polyesters, i.e., the PET fibre and the unsaturated polyester resin. This can find application in the construction field, such as in the reinforcement of wooden structural elements, infill walls, and partition walls, or in furniture or for decorative purposes. Full article

Masonry structures are susceptible to damage and collapse due to seismic actions, a problem in many urban areas. To address this issue, researchers are studying the use of fibre-reinforced mortars as overlay strengthening systems. This study assessed the use of synthetic polyacrylonitrile (PAN) fibres as reinforcement of natural hydraulic lime mortar, focusing on their influence on fresh behaviour and mechanical properties. Natural hydraulic lime (NHL) was chosen for its compatibility with typical older ceramic and natural stone structural masonry and contemporary ceramic brick infill masonry substrates, as well as for the sustainability benefits. The study also assessed the contribution of the PAN fibres to toughness enhancement in the developed formulations. The fresh behaviour of fibre-reinforced mortar (FRM) was found to be adequate for applications with fibre volume fractions below 0.50%. The compressive and flexural strengths were affected differently by the increase in fibre volume fraction, with compressive strength decreasing and flexural strength increasing. The maximum compressive strength of 13.3 MPa was obtained for 0.25% of fibres, while for flexural strength a maximum of 6.70 MPa was achieved with 1.00% of fibres. The compressive and flexural toughness, related to the post-cracking responses, increased with the fibre fraction, and even for fractions as low as 0.25%, an important increment of the capacity to dissipate energy was achieved. Full article

The direct modeling of masonry infill walls on many buildings, based on damage recorded by various past earthquakes, has become increasingly necessary in order to identify the seismic behavior of these elements, which constitute an important part of reinforced concrete buildings. In this paper, several 3D models were analyzed by the nonlinear static (pushover) method, when ignoring, and when considering, masonry infill walls. The finite element software SAP analyzed the proposed models. These models represent low and mid-rise reinforced concrete buildings infilled with double-leaf hollow bricks. The properties of materials used in Algeria, either in the frame elements or the infill elements, were used. The results obtained were compared according to two parameters, the natural time period of the building and the pushover curve, by varying the values of the dead load and the concrete compressive strength. The results were discussed according to the suggested parameters. The results showed that indirect modeling of such walls, either by taking assumptions embedded in the seismic behavior factor or by means of the macro-modal, can lead to a poor appreciation of the seismic behavior of such buildings. Consequently, direct modeling of walls by the infill of the real void showed acceptable results to some extent. This contributes greatly towards understanding the seismic behavior of this type of building. Full article

Restoring historic buildings is a challenging task in an environment where any insensitive or unprofessional intervention can cause irreparable damage. Among the most important demands currently placed on the construction industry are the protection of structural details, materials and technologies, and the extension of the life of these historic buildings. In this context, we should mention the protection of the high number of tenement buildings in European cities from the second half of the 19th and early 20th centuries, whose structural quality is relatively high and where many other building details and elements have been preserved. The brick dwellings of the period, which are between 85 and 170 years old, do not fully comply with many of the requirements and provisions of the current regulations and standards. The serious shortcomings of brick tenement buildings include, among other things, the inadequate thermal resistance of the envelope and infill structures and the high energy consumption of the operation of these buildings. This paper focuses on analysing this situation and defining the requirements for renovation, while preserving the architectural and historical values of urban buildings; achieving acceptable compliance with the requirements and provisions of the currently applicable regulations and standards; and demonstrating cost-effectiveness. Full article

Three-dimensional printing technologies are transforming various sectors with promising technological abilities and economic outcomes. For instance, 3D-printed concrete (3DPC) is revolutionizing the construction sector with a promise to cut projects’ costs and time. Therefore, 3DPC has been subjected to extensive research and development to optimize the mechanical and thermal performance of concrete walls produced by 3D printing. In this paper, we conduct a comparative investigation of the thermal performance of various infill structures of 3DPC walls. The targeted outcome is to produce an infill structure with optimized thermal performance to reduce building energy consumption without incurring additional material costs. Accordingly, a computational model is developed to simulate the thermal behavior of various infill structures that can be used for 3DPC walls. The concrete composition and the concrete-to-void fraction are maintained constant to focus on the impact of the infill structure (geometric variations). The thermal performance and energy-saving potential of the 3DPC walls are compared with conventional construction materials, including clay and concrete bricks. The results show that changing the infill structure of the 3DPC walls influences the walls’ thermal conductivity and, thereby, the building’s thermal performance. The thermal conductivity of the examined infill structures is found to vary between 0.122 to 0.17 W/m.K, while if these structures are successful in replacing conventional building materials, the minimum annual saving in energy cost will be about $1/m². Therefore, selecting an infill structure can be essential for reducing building energy consumption. Full article

A series of structural tests were conducted to examine the seismic performance of masonry infills strengthened with particular materials on infilled reinforced concrete (RC) frame structures. Six 1:4 scaled-down RC frame specimens had been prepared, including one brick-infilled frame without strengthening and five brick infills strengthened with innovative strengthening materials. The materials were steel wire mesh, chicken hexagonal wire mesh, plastic wire mesh, fiber-reinforced polymer (FRP), and plastic stretch film. The strengthening was diagonally applied on both surfaces of the masonry infill. The steel wire mesh, chicken hexagonal wire mesh, and plastic wire mesh were sewn using steel wire, while the FRP sheet was glued using epoxy resin and the plastic stretch film was glued using synthetic rubber adhesive. The specimens were tested following the FEMA 461 standard testing protocol, which involved applying lateral static cyclic loading to the specimens. The displacement transducer apparatus measured the deformations of the specimens, and crack propagation was observed during experimental works. The experimental results showed that most specimens exhibited an increase in their lateral strength, secant stiffness, deformation capacity, and energy dissipation. Among all prepared specimens, the specimen using plastic stretch film showed the best and most promising results, i.e., long deformation and steady lateral strength after yielding. This result suggests that using plastic stretch for strengthening can increase ductility performance. It is expected to withstand earthquake shaking, has low application costs, and is feasible for application even by unskilled local laborers. Full article

When buildings are exposed to earthquake sequence, damage aggravation is expected to occur. Although several studies report seismic vulnerability of reinforced concrete (RC) buildings under the mainshock–aftershock sequence, indicating damage aggravation due to aftershock, none, to the best of our knowledge, quantifies seismic vulnerability of buildings under foreshock–mainshock–aftershock sequences. Since foreshock–mainshock–aftershock sequences are also expected in many active seismic regions, we aim to quantify the level of vulnerability under seismic sequences considering the seismically highly active Himalayan region as the case study location. Fragility functions are derived considering foreshock, foreshock–mainshock sequence, and foreshock–mainshock–aftershock sequence for a low-rise special moment-resisting frame (SMRF) building that represents a typical low-rise owner-built construction system in Nepal, one of the most active seismic regions in the world. The results highlight that the foreshock significantly increases seismic vulnerability of the structures with respect to the often-considered case of a mainshock–aftershock sequence. Full article

The bundled lipped channel–concrete (BLC-C) composite wall structure is a new structure with several advantages such as a high bearing capacity and good seismic performance. However, interface cracks between a BLC-C composite wall and the infill wall (non-structural wall) are a severe problem and need to be urgently resolved. Interface cracks affect not only the esthetics, but also the normal use of a building. The presence of interface cracks changes the perceptions of the owners of a structure, forcing them to question its safety and even take legal action against its developer. Therefore, in this study we aimed to investigate the initial cracking of the interface between a BLC-C composite wall and an infill wall. Unidirectional horizontal loading tests were conducted on two infill wall specimens constrained by BLC-C composite walls on both sides. The finite element analysis software ANSYS was used to simulate the loading process of the tests. The test results were compared to verify the accuracy of the finite element model. A finite element analysis was conducted to determine the effect of the horizontal displacement of the specimens when the interface initially cracked under different parameters such as the widths of the BLC-C composite wall, infill wall, and opening as well as the strength grade of the bricks and maximum normal contact stress. The results showed that a decrease in the width of the BLC-C composite wall or a rise in the width of the infill wall delayed the appearance of interface cracks. A large opening also delayed the occurrence of interface cracks. An enhancement in the strength grade of the bricks led to an earlier appearance of interface cracks. Interface cracks occurred later with an increase in the maximum normal contact stress between the BLC-C composite wall and the infill wall. Full article

Brick masonry veneer walls connected to infill walls inserted in a reinforced concrete (RC) frame are a common constructive system in Portugal. The stability of the veneer wall is ensured by ties that make the connection with the masonry infill walls. These ties enable the transferring of out-of-plane loads to the main structure due to wind, and particularly due to earthquakes. However, the characterization of the seismic behavior of these tie connections is an insufficiently explored topic. The present paper shows a numerical investigation that aims to simulate experimental results of tension and compression tests performed on masonry prisms connected by means of steel ties. The main objective of the present research is to obtain a better understanding of the complex structural behavior of this specific construction system to then develop simplified numerical tools to be used in engineering practice for the seismic design and retrofitting of brick masonry veneer walls. The numerical results match well the experimental ones, and the validated approach can be used in the future to carry out parametric analyses to evaluate the influence of material and geometric properties of the tie and masonry, as well as the type of action and construction details. Full article

The results of an experimental study of four infilled frames with brick masonry walls subject to reversal cyclic lateral load are presented. The variables studied were the height to length aspect ratio of the wall and the use of joint reinforcement. The investigation was motivated by the fact that the Mexican code establishes the same specifications about the use of joint reinforcement for infill walls as for confined walls, because there is not enough experimental evidence on joint reinforced infill walls. To investigate the possible interaction of the study variables in the seismic performance of the walls, two pairs of specimens, scaled 1:2, with different aspect ratios (H/L = 0.75, 0.41) were tested. The specimens in each pair were identical except that one of them included steel bars into the bed-joints as reinforcement leading to amount $p_h{f}_{yh}=0.6 \mathrm{MPa}$. The infill walls with H/L = 0.41 were included from a previous study. The behavior of the specimens was defined in terms of lateral strength, ductility, displacement capacity, deformation of the joint reinforcement and crack pattern. The results indicate that joint reinforcement increases the strength of the system; however, the increase was more pronounced in longer walls. Ductility was reduced with horizontal reinforcement and this behavior was more important for longer walls. As occurred in confined walls, the joint reinforcement generates a more distributed cracking and reduces the width of the cracks. The experiments are described and this and other results are discussed in detail. Full article

Most of the reinforced concrete buildings in Nepal are low-rise construction, as this type of construction is the most dominant structural form adopted to construct residential buildings in urban and semi-urban neighborhoods throughout the country. The low-rise residential constructions generally follow the guidelines recommended by the Nepal Building Code, especially the mandatory rules of thumb. Although low-rise buildings have brick infills and are randomly constructed, infill walls and soil–structure interaction effects are generally neglected in the design and assessment of such structures. To this end, bare frame models that are used to represent such structures are questionable, especially when seismic vulnerability analysis is concerned. To fulfil this gap, we performed seismic vulnerability analysis of low-rise residential RC buildings considering infill walls and soil–structure interaction effects. Considering four analysis cases, we outline comparative seismic vulnerability for various analysis cases in terms of fragility functions. The sum of observations highlights that the effects of infills, and soil–structure interaction are damage state sensitive for low-rise RC buildings. Meanwhile, the design considerations will be significantly affected since some performance parameters are more sensitive than the overall fragility. We also observed that the analytical fragility models fundamentally overestimate the actual seismic fragility in the case of low-rise RC buildings. Full article

Hollow concrete masonry blocks made of low strength self-compacting concrete with recycled crushed brick and ground polystyrene as an aggregate (RBC-EP blocks), and their expected structural role as masonry infill in steel frames, has been confirmed in previous research studies, thus the extensive investigation of thermal properties is presented in this paper to fully approve their potential application in practice. The Heat Flow and Temperature Based Method was used to conduct in-situ measurements of the wall thermal transmittance (U-value). The experimental U-values of the wall without insulation varied from 1.363 to 1.782 W/m²·K, and the theoretical value was calculated to be 2.01 W/m²·K. Thermal conductivity of the material used for making RBC-EP blocks was measured in a laboratory by using a heat flow meter instrument. To better understand the thermal performance characteristics of a wall constructed from RBC-EP blocks, a comparison with standard materials currently used and found on the market was performed. Walls constructed from RBC-EP blocks show an improvement of building technology and environmentally based enhancement of concrete blocks, since they use recycled materials. They can replace standard lightweight concrete blocks due to their desired mechanical properties, as well as the better thermal performance properties compared to commonly used materials for building walls. Full article

Construction projects are often challenged by tight budgets and limited time and resources. Contractors are, therefore, looking for ways to become competitive by improving efficiency and using cost-effective materials. Using three-dimensional (3D) printing for shaping materials to produce cost-effective construction elements is becoming a feasible option to make contractors more competitive locally and globally. The process capabilities for 3D printers and related devices have been tightened in recent years with the booming of 3D printing industries and applications. Contractors are attempting to improve production skills to satisfy firm specifications and standards, while attempting to have costs within competitive ranges. The aim of this research is to investigate and test the production process capability (Cp) of 3D printers using fused deposition modeling (FDM) to manufacture 3D printed parts made from plastic waste for use in the construction of buildings with different infill structures and internal designs to reduce cost. This was accomplished by calculating the actual requirement capabilities of the 3D printers under consideration. The production capabilities and requirements of FDM printers are first examined to develop instructions and assumptions to assist in deciphering the characteristics of the 3D printers that will be used. Possible applications in construction are then presented. As an essential outcome of this study, it was noticed that the 3D printed parts made from plastic waste using FDM printers are less expensive than using traditional lightweight non-load bearing concrete hollow masonry blocks, hourdi slab hollow bocks, and concrete face bricks. Full article

The study analyzes the anisotropy effect for ceramic masonry based on experimental tests of samples made of 25 × 12 × 6.5 cm³ solid brick elements with compressive strength f_b = 44.1 MPa and cement mortar with compressive strength f_m = 10.9 MPa. The samples were loaded in a single plane with a joint angle that varied from the horizontal plane. The load was applied in a vertical direction. The samples were loaded at angles of 90°, 67.5°, 45°, 22.5°, and 0° toward the bed joints. The most unfavourable cases were determined. It was observed that the anisotropy of the masonry significantly influences the load-bearing capacity of the walls depending on the angle of the compressive stresses trajectory. Approximation curves and equations for compressive strength, Young’s modulus, and Poisson’s coefficient were proposed. It was observed that Young’s modulus and Poisson’s ratio will also change depending on the trajectory of compressive stresses as a function of the joint angle. Experimental tests allowed to determine the failure mechanism in prepared specimens. The study allowed to estimate the masonry strength with the load acting at different angles toward the bed joints. Full article