Construction Materials

In this study, we present a novel methodology for reducing uncertainties in detecting high-permeability regions in bricks by integrating brick imagery, color theory, unsupervised learning, and petrophysical concepts. Leveraging smartphone technology, our methodology identifies and analyzes moisture regions in red bricks, demonstrating its potential as a cost-effective tool for moisture characterization. This approach complements specialized moisture detection devices, highlighting the versatility of existing technology. Applied within the context of traditional red brick manufacturing in San Agustín Yatareni, Oaxaca, México, our results show that this methodology effectively identifies moisture-related anomalies, with water absorption values verified according to the NMX-C-404-ONNCCE-2012 and NMX-C-037-ONNCCE-2013 Mexican standards. We observed a significant inverse correlation between luminosity and moisture content, and a direct correlation between hue and moisture content. These findings suggest a reliable, non-invasive indicator of moisture levels, potentially improving the longevity of construction materials. The broader applicability of this approach in construction material analysis, particularly for bricks incorporating organic fibers, underscores its value as a tool for quality control. Furthermore, the integration of smartphone technology and interdisciplinary techniques contributes to advancing sustainable construction practices and improving material durability. Full article

Rigid road pavements and industrial floors are not only subjected to moving traffic loads, but can also be exposed to environmental influences such as acid attack. The strength and corrosion resistance of fiber-reinforced concrete with steel fibers (15–25 kg/m³) and polypropylene fibers (2–3 kg/m³) in an acidic environment were compared. The influence of the amount and type of dispersed reinforcement on water absorption and the volume of permeable voids, which in turn characterizes the durability of fiber-reinforced concrete under the action of acids, was determined. The change in the compressive strength of the studied fiber-reinforced concrete after 12 months of exposure in an acidic environment was studied. At low dosages of fibers (15 kg/m³ for steel and 2 kg/m³ for polypropylene fibers), dispersed reinforcement has little effect on the corrosion resistance of concrete. In turn, the decrease in the compressive strength of concrete without fibers after 12 months of aging in acid medium led to a reduction in the design class of the concrete from C25/30 to C20/25. At a higher consumption of dispersed reinforcement (25–30 kg/m³ of steel fiber and 2.5–3.0 kg/m³ of polypropylene fiber), fiber-reinforced concrete had a higher corrosion resistance while maintaining the design compressive strength class C25/30. Structural changes in fiber-reinforced concrete after aging in an acidic environment were determined by X-ray diffraction analysis and compared with samples aged in water. It has been experimentally confirmed that the efficiency of polypropylene fibers in an acidic environment is not lower than that of steel fibers. However, the use of polypropylene fibers is economically advantageous. Full article

Alkali-activated materials are promising alternatives to cement. This study investigated the effects of the silica content, particle size, and replacement ratio of rice husk ash (RHA) on the compressive strength and the optimization of these parameters. Seventeen mixtures with different materials were tested to evaluate their compressive strengths. Three levels of particle size, silica content, and RHA replacement ratio were used. The effects of RHA characteristics on the compressive strength were investigated based on Archimedes porosity, pH, ignition loss, and X-ray diffraction. The experimental results reveal that the replacement ratio of RHA was p-values < 0.002, which affected the compressive strength compared with the particle size (p-values < 0.450) and silica content of the RHA (p-values < 0.017). It was confirmed that the optimum values of particle size, silica content, and replacement ratio of RHA were 50 µm, 90%, and 15 wt.%, respectively. After re-testing, the compressive strength of mortar made with the optimum values was 49.8 MPa. This increase in compressive strength was also found to be closely related to the porosity, pH, and ignition loss of the paste. It was confirmed that the replacement ratio of RHA increased with decreasing porosity and pH and increasing ignition loss, which was related to the formation of calcite and C-S-H. Full article

Thermal insulation is a reliable strategy for achieving optimal thermal comfort in built environments and is among the most effective energy-saving measures. Currently, environmentally friendly insulation materials produced from plant and animal fibers constitute a significant component of the building industry, largely due to their minimal embodied energy and concerns about certain synthetic insulation materials’ potential adverse health effects. The main objective of the present study is to encourage and facilitate the utilization of environmentally friendly thermal insulation materials derived from biological sources, including vegetal and animal fibers, to improve thermal comfort and consequently reduce energy consumption in buildings. The study attempts to simulate the indoor air temperature profiles of a single building constructed using locally sourced materials and insulated in a series of stages with the aforementioned insulation materials. Firstly, insulation is applied exclusively to the roof. Secondly, the insulation is applied to the remaining wall surfaces. Alternatively, the insulation is applied to both the roof and the wall surfaces simultaneously. The objective is to ascertain the optimal combination of bio- and geo-insulating materials to achieve thermal comfort in buildings constructed with local materials in tropical climates. The Gauss-Seidel iterative method was employed to solve the energy equations that had been written on the walls and roof of the building. The equations were then discretized using the nodal method. To ascertain the thermal comfort of the simulated buildings, a comparison was made of the indoor air temperatures. The results of the simulations demonstrated that the utilization of wood fiber, reed panels, and straw bales as insulation materials led to a notable enhancement in comfort levels across all five building types, with an average increase of 17.5%. Among these materials, wood fiber emerged as the most effective insulation option, reducing temperatures by up to 19%. Its integration into the sheet metal-clad Banco building would be particularly advantageous. The findings demonstrate that the simultaneous insulation of walls and roofs with natural fiber thermal insulation materials markedly reduces indoor air and wall temperatures in buildings by up to 19% in comparison to uninsulated walls and roofs. Full article

Rapid repair materials (RRMs) have been used in concrete overlay systems to rehabilitate infrastructure for many years. The bond performance between RRMs and a concrete substrate is crucial for maintaining the desired performance and can deteriorate due to freeze–thaw action. In the case of partial depth repairs (PDRs), the mechanical and durability properties at the interface between the substrate and repair materials have not been thoroughly studied resulting in frequent failures. There is limited research on the freeze–thaw durability of RRM overlay–substrate interface, and no standardized test methods exist for evaluating the performance under freeze–thaw cycling. The proposed experimental procedure combines freeze–thaw cycling of an overlay–substrate specimen with pull-off testing of the overlay. Three RRM overlay systems were used consisting of calcium sulfoaluminate cement and ordinary Portland cement (PC), and a ternary blend of PC, calcium aluminate cement, and calcium sulfate cement. A correlation between tensile bond strength and fundamental transverse frequency in composite specimens was observed, and the results demonstrated that RRMs can maintain robust adhesion following 300 cycles of freeze–thaw exposure. Furthermore, the employed testing methodology elicited bond-only failures, underscoring the necessity for continued investigation into optimal conditioning intervals and substrate integrity to enhance the durability of repair systems. Full article

A new scheme for forming partially regular microreliefs by rotational rolling is proposed. A new transcendental curve-shaped, partially regular microrelief (of a trochoid type) is discussed; the shape and geometric parameters of its grooves are substantiated. Grooves discussed below proved to be technologically advanced, providing for a high performance of all types of equipment. Once combined, they act together to provide for the best in-service properties of planar, partially regular microreliefs formed by rotation, which are unparalleled among those of their kind. Analytical dependences are presented that describe the groove’s shape. A relationship is established between the main technological parameters, that is, feed rate and rotation frequency of the deforming element that produces microrelief grooves of different shapes and sizes. Possible location variants for microrelief grooves are given and classified. Technological layouts and movement cyclograms are substantiated for the tool that forms regular microrelief grooves by means of rotation. A comparative analysis of the profile lengths of the grooves of rotational and sinusoidal microreliefs modeled in the MathCAD environment was conducted. Full article

The inadequate resistance of traditional asphalt binders to aging, temperature fluctuations, and fatigue cracking underlines the necessity for innovative modifications to boost pavement durability. This study aims to state the inadequate exploration of the direct application of composite nanomaterials in asphalt binders by assessing their direct effects on physiochemical and durability properties without the inclusion of additional additives. The composite nanomaterials, combined with different amounts of Nano-Silica, Nano-Alumina, and Nano-Copper oxide, were incorporated into the binder at 2%, 4%, and 6% by weight. A series of conventional and rheological tests were conducted, including penetration, temperature susceptibility, Dynamic Shear Rheometer (DSR), Rolling Thin Film Oven Test (RTFOT), and Bending Beam Rheometer (BBR). The results demonstrated that the addition of 2% nanomaterials improved penetration by 34% and 41% for unaged and aged samples, respectively, while a 4% addition reduced temperature susceptibility by 64% for aged binders in a mix containing equal amounts of combined nanomaterials. DSR analysis indicated enhanced stiffness and viscoelastic properties, with increased complex shear modulus (G*) and reduced phase angle (δ). Aging resistance was enhanced as established by RTFOT, and acceptable low-temperature performance was attained per BBR results. These results found composite nanomaterials as a capable key for advancing asphalt binder performance. Full article

This study presents the results of using innovative and sustainable recycled fibers in different asphalt mixtures. Laboratory design and performance evaluation were focused on the cracking and rutting resistance of asphalt mixtures reinforced with recycled fibers. Two mixtures were designed for this research: 1. A dense-graded hot-mix asphalt (HMA) mixture containing 15% reclaimed asphalt pavement (RAP) and a PG 64-22 asphalt binder. 2. A cold-recycled mixture (CRM) incorporating silica fume and Portland cement as a mineral filler and CSS-1H asphalt emulsion. The recycled fibers used in this study included PET, LDPE, and carbon and rubber fibers. A balanced mix design (BMD) approach based on cracking and rutting performance parameters was used to design the control mixtures. The IDEAL-CT (ASTM D8225) was conducted to assess the cracking resistance, and the IDEAL-RT (ASTM D8360) was applied for rutting resistance. For the HMA mixture, results showed that the addition of PET, carbon, and rubber fibers enhanced cracking resistance and influenced the rutting resistance; ANOVA analyses revealed statistically significant differences in both CT index and RT index between the control mixture and the fiber-reinforced mixtures. In the case of the cold-recycled mixtures, the addition of LDPE, PET, and rubber improved cracking resistance; however, a decrease in rutting resistance was also observed among the evaluated CRM samples. Full article

To investigate the reinforcement–soil interfacial effects in fiber-reinforced soil, this study developed a novel horizontal pullout tester and conducted pullout tests on coarse polypropylene fibers in plain soil, cemented soil, and fine fiber-reinforced cemented soil. Three soil types were analyzed: low liquid limit clay, high liquid limit clay, and clay sand. The pullout tester proved to be both scientifically robust and efficient. Depending on the soil properties, coarse polypropylene fibers were pulled out intact or fractured. The pullout curves displayed distinct multi-peak patterns, with wavelengths closely linked to the fiber’s intrinsic characteristics. The pullout curve wavelength for plain soil matched the fiber’s intrinsic wavelength, while it was slightly greater in cemented soils. The peak pullout force increased with extended curing periods, higher cement content, more excellent compaction, and the addition of fine polypropylene fibers. Among these factors, compaction had the most significant impact on enhancing the soil–fiber interfacial effect. Friction, cohesion, and fiber interweaving created interlocking effects, inhibiting fiber sliding. Cement hydration processes further deformed the fiber, increasing its friction coefficient and sliding resistance. Hydration products also fill soil voids, improving soil compactness, enlarging the fiber–soil contact area, and enhancing frictional and occlusal forces at the interface. Full article

Ultra-high-performance concrete (UHPC) is a recently emerged material with exceptional durability and ductility. While widely used in bridge retrofitting, particularly to replace expansion joints and deck overlays, UHPC has seen limited use in jacketing piers for the improvement of lateral load resistance. It presents superior mechanical properties and deformation resilience, enabled by the distributed fibers and the dense microstructure, providing corrosion resistance and a maintenance-free service life. The significant tensile strength and ductility establish UHPC as an attractive resilient jacketing system for structural members. The experimental literature documents the effectiveness of this solution in enhancing the strength and ductility of the retrofitted member, whereas premature modes of failure (i.e., lap splices and shear failure in lightly reinforced piers) are moderated. A comprehensive database of tests on UHPC-jacketed piers under lateral loads was compiled for the development of practical guidelines. Various UHPC jacket configurations were evaluated, and detailed procedures were developed for their implementation in bridge pier retrofitting. These procedures include constitutive models for UHPC, confined concrete, and the strengthening of lap splices, flexure, and shear resistance. The results are supported by the database, providing a solid foundation for the broader application of UHPC in improving the lateral load resistance of bridge piers. Full article

The availability of petroleum asphalt, derived from non-renewable natural sources, is steadily declining in tandem with dwindling petroleum reserves. To mitigate the reliance on petroleum, alternative renewable natural sources are being explored for use as both modifiers and replacements for petroleum asphalt, particularly as binders in asphalt mixtures. The development of bio-asphalt represents a significant innovation aimed at reducing or even eliminating the dependence on petroleum as a source of asphalt. This paper examines the chemical, rheological, and mechanical properties of Gopal (Gondorukem Asphalt), a bio-asphalt derived from Gondorukem (gum rosin) and CPO (Crude Palm Oil). Two types of Gopal, Gopal-GEM130 and Gopal-GEG90, were analyzed using FTIR (Fourier Transform Infra-Red) and EDX (Energy Dispersive X-ray) tests, with Pen 60 petroleum asphalt serving as a control for comparison. The results indicate that the chemical groups of Gopal-GEG90 and Gopal-GEM130 share 86% similarity with those of Pen 60 petroleum asphalt. Compared to Pen 60, Gopal-GEM130 is less toxic and less alkaline, while Gopal-GEG90 is also less toxic but more alkaline. Rheologically, Gopal-GEG90 and Gopal-GEM130 fall within the same classification as Pen 60, based on the Pen 60 classification grade of asphalt. Gopal-GEG90 exhibits slightly better stripping resistance and lower aging resistance than Pen 60, whereas Gopal-GEM130 demonstrates significantly better stripping resistance but lower aging resistance. Performance-wise, both Gopal variants belong to the same performance grade (PG64S) as Pen 60 petroleum asphalt. However, Gopal-GEG90 has slightly better rutting resistance compared to Pen 60 but lower than Gopal-GEM130, and it ages faster with lower fatigue resistance. Conversely, Gopal-GEM130 has superior rutting resistance but lower fatigue resistance and ages faster than Pen 60 petroleum asphalt. Full article

Flooding hazards due to climate change are increasingly becoming a frequent global occurrence. The aim of this study is to provide a comprehensive review of the various structural mitigation and adaptation strategies available to engineers and designers at various stages of road construction and rehabilitation to increase the resilience of roads to flooding damage. The criteria for categorising the various strategies available were the time of intervention with respect to the occurrence of the hazard. Thus, all studied strategies were separated into pre-construction design changes, post-construction mitigation and adaptation options like Sustainable Urban Drainage Systems (SuDS). The main findings were that changing the specifications of commonly used materials can provide increased flood resilience, and a preliminary design for flooding can reduce post-flooding rehabilitation. The study can be used as a guide for the different options available to deliver a design that takes flooding into consideration. Full article

Concrete use is enhanced daily due to infrastructure development, but it has adverse impacts on the environment. Modern lifestyles have led to the increased use of plastic, and, for households, polyethylene terephthalate (PET) plastics are used. However, PET is non-biodegradable and causes adverse impacts on the environment and marine health. So, there is a need to minimize the amount of plastic waste by finding an alternative use for the waste. Our study focuses on creating sustainable concrete by utilizing PET-based plastic waste as a partial substitution for aggregates, aiming to use this concrete for various low-load-bearing construction applications. From our phase analysis study, no adverse effects were found on cement phase formation. We also found that up to 10 wt.% PET incorporation leads to acceptable compressive strength reduction as per ASTM guidelines. To enhance adhesion, the PET was roughened, and, from FESEM, we found effective adhesion of PET waste into the cement matrix. We believe that this sustainable concrete will not only contribute to waste reduction but also promote eco-friendly construction material development. Full article

This article explores the impact of strengthening reinforced concrete beams under different load levels, focusing on the use of polyphenylene benzobisoxazole (P.B.O.) fibers in a stabilized inorganic matrix to enhance the shear capacity. This research examines the interaction between modern composite materials and existing reinforced concrete structures, highlighting the practical challenges when the full unloading of structures is impossible. The experiments demonstrate that strengthening significantly increases the shear strength, with a maximum enhancement of 25%. However, the effect decreases as the load applied during strengthening increases, dropping to 16% at 70% of the ultimate load. This research also highlights the importance of refining current calculation methods due to the complex stress–strain state of beams and the unpredictable nature of shear failures. It concludes that composite materials, especially fiber-reinforced cementitious matrix (FRCM) systems, provide a practical solution for enhancing structural performance while maintaining the integrity and safety of concrete elements. This article emphasizes that the strengthening efficiency should be adjusted based on the applied load, suggesting a 5% reduction in effectiveness for every 10% increase in the initial load level. The findings support the empirical hypothesis that the shear strength improvement diminishes linearly with higher load levels during strengthening. Full article

The results of shaking table tests from previous studies on a one-story, two-bay reinforced concrete frame—exhibiting both shear and axial failures—were compared with nonlinear dynamic analyses using simplified models intended to evaluate the collapse potential of older reinforced concrete structures. To replicate the nonlinear behavior of columns, whether shear-critical or primarily flexure-dominant, a one-component beam model was applied. This model features a linear elastic element connected in series to a rigid plastic, linearly hardening spring at each end, representing a concentrated plasticity component. To account for strength degradation through path-dependent plasticity, a negative slope model as degradation was implemented, linking points at both shear and axial failure. The shear failure points were determined through pushover analysis of shear-critical columns using Phaethon software. Although the simplified model provided a reasonable approximation of the overall frame response and lateral strength degradation, especially in terms of drift, its reduced computational demands led to some discrepancies between the calculated and measured shear forces and drifts during certain segments of the time-history response. Full article

This review paper explores the integration of phase change materials (PCMs) in building insulation systems to enhance energy efficiency and thermal comfort. Through an extensive analysis of existing literature, the thermal performance of PCM-enhanced building envelopes is evaluated under diverse environmental conditions. This review highlights that PCMs effectively moderate indoor temperatures by absorbing and releasing heat during phase transitions, maintaining a stable indoor climate. This paper also delves into the detailed concepts of PCMs, including their classification and various applications within building insulation. It is noted that different types of PCMs have unique thermal properties and potential uses, which can be tailored to specific building requirements and climatic conditions. Furthermore, cost–benefit and environmental assessments presented in the reviewed studies suggest that incorporating PCMs into building materials offers significant potential for reducing energy consumption and mitigating environmental impacts. These assessments indicate that PCMs can lead to substantial energy savings by decreasing the reliance on heating and cooling systems, thereby lowering overall energy costs and carbon emissions. However, despite the promising outlook, this review identifies a need for further research to optimize PCM formulations and integration methods. This optimization is essential for overcoming current challenges and facilitating the widespread adoption of PCMs in the construction industry. Addressing issues such as long-term durability, compatibility with existing building materials, and cost-effectiveness will be crucial for maximizing the benefits of PCMs in enhancing energy efficiency and sustainability in buildings. Overall, this review underscores the transformative potential of PCMs in building insulation practices. By providing a comprehensive overview of PCM classifications, applications, and their impacts on energy efficiency and environmental sustainability, this paper lays the groundwork for future advancements and research directions in the field of PCM-enhanced building technologies. Full article

This paper introduces a novel approach to pavement material crack detection, classification, and segmentation using advanced deep learning techniques, including multi-scale feature aggregation and transformer-based attention mechanisms. The proposed methodology significantly enhances the model’s ability to handle varying crack sizes, shapes, and complex pavement textures. Trained on a dataset of 10,000 images, the model achieved substantial performance improvements across all tasks after integrating transformer-based attention. Detection precision increased from 88.7% to 94.3%, and IoU improved from 78.8% to 93.2%. In classification, precision rose from 88.3% to 94.8%, and recall improved from 86.8% to 94.2%. For segmentation, the Dice Coefficient increased from 80.3% to 94.7%, and IoU for segmentation advanced from 74.2% to 92.3%. These results underscore the model’s robustness and accuracy in identifying pavement cracks in challenging real-world scenarios. This framework not only advances automated pavement maintenance but also provides a foundation for future research focused on optimizing real-time processing and extending the model’s applicability to more diverse pavement conditions. Full article

To address SDG12 (ensure sustainable consumption and production patterns), and to provide technical evidence for alternative concrete constituents to traditional natural river sand, stone fine aggregate (SFA), brick fine aggregate (BFA), ladle-refined furnace slag aggregate (LFS), recycled brick fine aggregate (RBFA), and washed waste fine aggregate (WWF), ready-mix concrete plants were investigated. Concrete and mortar specimens were made with different variables, such as replacement volume of natural sand with different alternative fine aggregates, water-to-cement ratio (W/C), and sand-to-aggregate volume ratio (s/a). The concrete and mortar specimens were tested for workability, compressive strength, tensile strength, and Young’s modulus (for concrete) at 7, 28, and 90 days. The experimental results show that the compressive strength of concrete increases when natural sand is replaced with BFA, SFA, and LFS. The optimum replacement amounts are 30%, 30%, and 20% for BFA, SFA, and LFS, respectively. For RBFA, the compressive strength of concrete is increased even at 100% replacement of natural sand by RBFA. For WWF, the compressive strength of concrete increases up to a replacement of 20%. Utilizing these alternative fine aggregates can be utilized to ensure a circular economy in construction industries and reduce the consumption of around 30% of natural river sand. Full article

Concrete is one of the most commonly used materials in civil engineering construction, and it continues to have increased production. This puts pressure on the consumption of its constituent materials, including Portland cement and aggregates. There are environmental consequences related to the increased emission of CO₂ that are associated with the production process of Portland cement. This has led to the development and use of alternative cementitious materials, mainly in the form of condensed silica fume, pulverised fuel ash, and ground granulated blast furnace slag. All of these are by-products of the silicon, electrical power generation, and iron production industries, respectively. In recent years, attention has turned to the possible use of sustainable bio-waste materials that might contribute to the replacement of Portland cement in concrete. This research investigates the effects of using rice husk ash as cement replacement material on the 1 to 28-day concrete properties, including the compressive strength, workability, and durability of concrete. The findings indicate that including rice husk ash in concrete can improve its strength at 3–28 days for percentage replacements of 5% to 20% (ranging from 2.4% to 18.7% increase) and improvements from 1 day for 20% replacement (with 11.1% increase). Any percentage replacement with rice husk ash also reduced the air permeability by 21.4% and therefore improved the durability, while there was a small reduction in the workability with increased replacement. Full article