Search Results (615)

Fiber-reinforced resin composites (FRRCs) are widely used in several fields such as construction, automotive, aerospace, and power. Basalt fiber (BF) has been increasingly used to replace artificial fibers such as glass fiber and carbon fiber in the production of BF-reinforced resin matrix composites (BFRRCs). This preference stems from its superior properties, including high temperature resistance, chemical stability, ease of manufacturing, cost-effectiveness, non-toxicity, and its natural, environmentally friendly characteristics. However, the chemical inertness of BF endows it with poor compatibility, adhesion, and dispersion in a resin matrix, leading to poor adhesion and a weak BF–resin interface. The interfacial bonding strength between BF and resin is an important parameter that determines the service performance of BFRRC. Therefore, the interfacial bonding strength between them can be improved through fiber modification, resin–matrix modification, mixed enhancers, etc., which consequently upgrade the mechanical properties, thermodynamic properties, and durability of BFRRC. In this review, first, the production process and properties of BFs are presented. Second, the mechanical properties, thermodynamic properties, and durability of BFRRC are introduced. Third, the modification effect of the non-destructive surface-modification technology of BF on BFRRC is presented herein. Finally, based on the current research status, the future research direction of BFRRC is proposed, including the development of high-performance composite materials, green manufacturing processes, and intelligent applications. Full article

The growing demand for high-performance and cost-effective composite materials necessitates advanced computational approaches for optimizing their composition and properties. This study aimed at the application of machine learning for the prediction and optimization of the functional properties of composites based on a thermoplastic matrix with various fillers (two types of fibrous, four types of dispersed, and two types of nano-dispersed fillers). The experimental methods involved material production through powder metallurgy, further microstructural analysis, and mechanical and tribological testing. The microstructural analysis revealed distinct structural modifications and interfacial interactions influencing their functional properties. The key findings indicate that optimal filler selection can significantly enhance wear resistance while maintaining adequate mechanical strength. Carbon fibers at 20 wt. % significantly improved wear resistance (by 17–25 times) while reducing tensile strength and elongation. Basalt fibers at 10 wt. % provided an effective balance between reinforcement and wear resistance (by 11–16 times). Kaolin at 2 wt. % greatly enhanced wear resistance (by 45–57 times) with moderate strength reduction. Coke at 20 wt. % maximized wear resistance (by 9−15 times) while maintaining acceptable mechanical properties. Graphite at 10 wt. % ensured a balance between strength and wear, as higher concentrations drastically decreased mechanical properties. Sodium chloride at 5 wt. % offered moderate wear resistance improvement (by 3–4 times) with minimal impact on strength. Titanium dioxide at 3 wt. % enhanced wear resistance (by 11–12.5 times) while slightly reducing tensile strength. Ultra-dispersed PTFE at 1 wt. % optimized both strength and wear properties. The work analyzed in detail the effect of PTFE content and filler content on composite properties based on machine learning-driven prediction. Regression models demonstrated high R-squared values (0.74 for density, 0.67 for tensile strength, 0.80 for relative elongation, and 0.79 for wear intensity), explaining up to 80% of the variability in composite properties. Despite its efficiency, the limitations include potential multicollinearity, a lack of consideration of external factors, and the need for further validation under real-world conditions. Thus, the machine learning approach reduces the need for extensive experimental testing, minimizing material waste and production costs, contributing to SDG 9. This study highlights the potential use of machine learning in polymer composite design, offering a data-driven framework for the rational choice of fillers, thereby contributing to sustainable industrial practices. Full article

This study investigates the mechanical properties and microstructure of basalt fiber (BF) and nanoalumina (NA)-modified ultra-high-performance concrete with recycled aggregates (UHPC-RA) under high-temperature conditions. The effects of different replacement rates of recycled aggregates (RAs), BF content, and NA content on the compressive strength, splitting tensile strength, and elastic modulus were evaluated at ambient temperatures and after exposure to 200 °C, 400 °C, 600 °C, and 800 °C. The results show that mechanical properties decrease with temperature rise, but specimens containing BF exhibited improved crack resistance and better high-temperature integrity. The incorporation of NA enhanced the thermal stability and heat resistance of the concrete. Digital image correlation (DIC) was used to monitor real-time surface deformation, and scanning electron microscopy (SEM) analysis revealed improved microstructure with reduced porosity and cracks. This study demonstrates that the combination of BF and NA significantly enhances the high-temperature performance of UHPC-RA, which holds promising potential for applications in environments subjected to elevated temperatures. Full article

In the transition towards a circular economy, redesigning construction materials for enhanced sustainability becomes crucial. To contribute to this goal, this paper investigates the integration of carbonated aggregates (CAs) and basalt fibre-reinforced polymers (BFRPs) in concrete infrastructures as an alternative to natural sand (NS) and steel reinforcement. CA is manufactured using accelerated carbonation that utilizes CO₂ to turn industrial byproducts into mineralised products. The structural performance of CA and BFRP-reinforced concrete simply supported slab was investigated through conducting a series of experimental tests to assess the key structural parameters, including bond strength, bearing capacity, failure behavior, and cracking bbehaviour. Carbon footprint analysis (CFA) was conducted to understand the environmental impact of incorporating BFRP and CA. The results indicate that CA exhibits a higher water absorption rate compared to NS. As the CA ratio increased, the ultrasonic pulse velocity (UPV), compressive, tensile, and flexural strength decreased, and the absorption capacity of concrete increased. Furthermore, incorporating 25% CA in concrete has no significant effect on the bond strength of BFRP. However, the load capacity decreased with an increasing CA replacement ratio. Finally, integrating BFRP and 50% of CA into concrete slabs reduced the slab’s CFA by 9.7% when compared with steel-reinforced concrete (RC) slabs. Full article

This study explores the combined effects of nanosilica (NS) and basalt fibers (BF) on the mechanical and microstructural properties of superabsorbent polymer (SAP)-modified concrete. NS (0–1.5% replaced by cement weight) and BF (0–1.2% by volume fraction) were incorporated to optimize compressive, flexural, and split-tensile strengths using response surface methodology. Digital Image Correlation (DIC) was employed to analyze failure mechanisms. Results show that while SAP alone reduced strength, the addition of NS and BF mitigated this loss through synergistic microstructure enhancement and crack-bridging reinforcement. The optimal mix (0.9% NS and 1.2% BF) increased compressive, flexural, and split-tensile strengths by 15.3%, 10.0%, and 14.0%, respectively. SEM analysis revealed that NS filled SAP-induced pores, while BF limited crack propagation, contributing to improved mechanical strength of SAP-modified concrete. This hybrid approach offers a promising solution for durable and sustainable concrete pavements. Full article

The high seismic vulnerability of unreinforced masonry buildings urgently calls for researchers to develop sustainable reinforcing methods and materials. This paper presents an innovative lime-based mortar reinforced with randomly oriented basalt fibers for the reinforcement of masonry heritage. The main aim of this study is to understand the effect of the content and the length of basalt fibers on the mortar’s mechanical behavior. As a cementitious material made mostly out of lime, the mortar is chemically compatible with the historical substrate and therefore suitable in cases of restoration works on architectural heritage. Moreover, the chopped basalt fibers are randomly oriented, and this characteristic makes the overall layer effective in all directions, as the state of stress induced by seismic action is directionally undetermined. The newly proposed reinforcement system is characterized by a twofold aspect related to sustainability: 30% of the aggregates composing the mortar mix design is a recycled result of the ruins of the 2009 L’Aquila earthquake, and the chopped fibers are made out of basalt, widely known for its environmentally supportable peculiarity. The study consists of testing samples characterized by two fiber lengths and six fiber contents, along with one set of plain mortar samples. Specimens measuring 160 mm × 40 mm × 40 mm are first tested in a three-point bending (TPB) configuration, aiming to determine the flexural strength and the post-peak capacity through the calculation of the fracture energy. Then, the two broken pieces resulting from the TPB tests, each measuring 80 mm × 40 mm × 40 mm, are tested in splitting and compression, respectively, aiming to compute the tensile and compressive strengths. Finally, to provide a trend for the mortar’s mechanical properties, a regression analysis is performed by fitting the experimental data with simple linear, polynomial, and exponential regression models. Results show that: (i) both fiber content and fiber length are responsible for a linear increase of the flexural strength and the fracture energy; (ii) for both short- and long-fiber mortar samples, the tensile strength and the compressive strength parabolically increase with the fiber content; (iii) the increase in fiber content and fiber length always generates a reduction in the conglomerate workability. The fiber content (FC) optimization with respect to the mechanical properties leads to a basalt FC equal to 1.2% for long-fiber samples and an FC equal to 1.9% for short-fiber ones. Full article

This study involved the exposure of epoxy-coated basalt-plastic rebars, with diameters of 6 and 8 mm, to the open climate conditions of Yakutsk and Tiksi, located in the Arctic region of Russia. The exposure duration was 54 months. Basalt-plastic rebars were tested both untreated and after contamination with a set of neutral microorganisms resilient to cold climates, including spore-forming bacteria from the genus Bacillus, and mold fungi from the genera Aspergillus. Results showed that after 12, 24, and 54 months of exposure, the tensile strength and modulus of elasticity of untreated rebars increased by 5–14% due to the post-curing of the epoxy matrix. However, in biologically contaminated rebars, these indicators decreased on average by 11%. Bacterial cells and fungal mycelium, which penetrated surface irregularities of the rebars under open climate conditions, contributed to microcrack development, reducing the mechanical properties of the basalt-plastic rebars and causing additional moisture diffusion in the radial direction of the bars. Full article

This study investigates the influence of basalt fiber on the rheological, mechanical, and microstructural properties of sustainable self-compacting concrete (SCC) incorporating fly ash and microsilica as supplementary cementitious materials (SCMs). Various SCC mixes were prepared, incorporating five different volume fractions of basalt fiber (0.05%, 0.1%, 0.5%, 1%, and 1.5%), along with a control mix. The rheological properties of fresh SCC were evaluated using slump flow and V-funnel flow tests. Subsequently, the mechanical properties, including compressive strength, splitting tensile strength, and flexural strength, were measured after 28 days of curing. Additionally, microstructural analysis was conducted using scanning electron microscopy (SEM) on fractured specimen surfaces. The results indicated that the inclusion of basalt fiber adversely affected the flowability of fresh SCC mixes, with increased fiber volume. However, the hardened concrete exhibited significant improvements in mechanical properties with the addition of basalt fibers. The optimal performance was observed in the SCC70-85/0.10 mix specimens, which demonstrated a 69.90% improvement in flexural strength and a 23.47% increase in splitting tensile strength compared with the control specimen. SEM analysis further revealed enhanced microstructural density in the concrete matrix containing basalt fiber. A two-factor analysis of variance (ANOVA) with repetitions was conducted to evaluate the effects of varying basalt fiber concentrations on the compressive, flexural, and tensile strengths of SCC mixes. The ANOVA results indicated significant effects for both SCC grade and basalt fiber concentration, demonstrating that each factor independently affected the compressive, tensile, and flexural strengths of SCC. These findings suggest that the incorporation of basalt fibers holds promise for extending building lifespans and enhancing concrete quality, representing a valuable advancement in structural engineering applications. Full article

Traditional materials such as steel and concrete often face limitations in terms of corrosion resistance and long-term performance. Over the past few decades, the search for alternative reinforcement solutions has grown, driven by the need for more sustainable, lightweight, and corrosion-resistant materials. Basalt fibers, with their superior mechanical properties and resistance to environmental degradation, have emerged as a promising candidate. This study investigated the tensile mechanical properties and constitutive behavior of basalt fiber-reinforced polymer (BFRP)–steel–BFRP composite plates. A total of 12 specimens were fabricated, varying in BFRP layer thickness, and subjected to uniaxial tensile testing. The results reveal that bonding BFRP layers significantly enhances the strengthening stiffness and strength of the steel plates, while maintaining ductility and fracture stability. The stress–strain analysis indicates a bilinear behavior, with the BFRP layers contributing to a higher slope during the strengthening stage and stable fracture strain across specimens. Additionally, a three-segment constitutive model was proposed and validated, demonstrating high accuracy in predicting tensile behavior. The findings highlight the potential of BFRP–steel–BFRP composite plates as efficient reinforcement solutions, offering a balance of strength, flexibility, and cost-effectiveness. This study provides data and modeling insights to guide the design and optimization of composite materials for structural applications. Full article

Fiber-reinforced concrete (FRC) has become increasingly important in recent decades due to its superior mechanical properties, especially flexural strength and toughness, compared to normal concrete. FRC has also received significant attention because of its superior fire resistance performance compared to non-fiber concrete. In recent years, studies on the mechanical performance, fire design, and post-fire repair of thermally damaged fibrous and non-fibrous concrete have gained importance. In particular, there are very few studies in the literature on the mechanical performance and flexural behavior of steel and basalt hybrid fiber concretes after high temperature and water re-curing. This study aims to determine the mechanical properties and toughness of concrete containing steel fiber (SF) and basalt fiber (BF) after ambient and high temperature (400 °C, 600 °C, and 800 °C). Additionally, this study aimed to examine the changes in fire-damaged FRCs as a result of water re-curing. In this context, high temperature and water re-curing were carried out on non-fibrous concrete (control) and four different fiber compositions: in the first mixture, only steel fibers were used, and in the other two mixtures, basalt fibers were substituted at 25% and 50% rates instead of steel fibers. Furthermore, in the fifth mixture, basalt fibers were replaced by polypropylene fibers (PPFs) to make a comparison with the steel and basalt hybrid fiber-reinforced mixture. This study examined the effects of different fiber compositions on the ultrasonic pulse velocity (UPV) and compressive and flexural strength of the specimens at ambient temperature and after exposure to elevated temperatures and water re-curing. Additionally, the load–deflection curves and toughness of the mixtures were determined. The study results showed that different fiber compositions varied in their healing effect at different stages. The hybrid use of SF and BF can improve the flexural strength before elevated temperature and particularly after 600 °C. However, it caused a decrease in the recovery rates, especially after re-curing with water in terms of toughness. Water re-curing provided remarkable improvement in terms of mechanical and toughness properties. This improvement was more evident in steel–polypropylene fiber-reinforced concretes. Full article

The use of basalt fibers, which are employed in various fields, such as construction, automotive, chemical, and petrochemical industries, the sports industry, and energy engineering, is also increasingly common in soil reinforcement studies, another application area of geotechnical engineering, alongside their use in concrete. With this growing application, scientific studies on soil reinforcement with basalt fiber have also gained momentum. This study establishes the effects of basalt fiber on the liquid limit, plastic limit, and strength properties of soils, and the relationships among the liquid limit, plastic limit, and unconfined compressive strength of the soil. For this purpose, 12 mm basalt fiber was used as a reinforcement material in kaolin clay at ratios of 1.0%, 1.5%, 2.0%, 2.5%, and 3.0%. The prepared samples were subjected to liquid limit, plastic limit, and unconfined compressive strength tests. As a result of the experimental studies, the fiber ratio that provided the best improvement in the soil properties was determined, and the relationships among the liquid limit, plastic limit, and unconfined compressive strength were established. The experimental results were then used as input data for an artificial intelligence model. The used neural network (NN) was trained to obtain basalt fiber-to-kaolin ratios based on the liquid limit, plastic limit, and unconfined compressive strength. This model enabled the prediction of the fiber ratio that provides the maximum improvement in the liquid limit, plastic limit, and compressive strength without the need for experiments. The NN results were in great agreement with the experimental results, demonstrating that the fiber ratio providing the maximum improvement in the soil properties can be identified using the NN model without requiring experimental studies. Moreover, the performance and reliability of the NN model were evaluated using 5-fold cross-validation and compared with other AI methods. The ANN model demonstrated superior predictive accuracy, achieving the highest correlation coefficient (R = 0.82), outperforming the other models in terms of both accuracy and reliability. Full article

The growing production of glass fibers is a major challenge due to the later problem of their sustainable recycling. This article reports the potential use of post-production waste glass fibers and basalt powder as additives in resin compounds designed for repairing concrete elements. The aim of this research was to develop a repair compound based on epoxy resin with the addition of waste materials, offering a competitive alternative to currently available repair compounds on the market by utilizing lower-cost materials and addressing pro-environmental aspects through waste reuse. The prepared research samples were characterized by varying proportions of basalt powder (0–20%), ground HP 12 fibers (40/60%), and HP 6 fibers (10/20%). A series of tests, including tensile strength tests, were conducted as part of this study to determine the effect of the applied additives on the ultimate tensile force and maximum deformations. Abrasion resistance tests were also carried out to evaluate the impact of basalt powder as a filler on enhancing the abrasion resistance of the designed repair compound. Additionally, SEM and EDS analyses were used to evaluate the uniformity and distribution of the additives within the sample. This study examined samples containing varying percentages of basalt powder and fibers, both virgin and milled. The most significant reinforcement effect was observed for sample E/20HP/20bp, where its tensile strength decreased by 8%, while its abrasion resistance increased by 44% compared to the reference sample. The obtained results confirm that incorporating waste materials as additives into epoxy resin can significantly enhance the mechanical properties of repair compounds while reducing cost and promoting environmental protection. In addition, the repair compound developed complies with the selected principles within the 6Rs environmental regulations: RECYCLING (reuse of waste glass fibers), RETHINK (reduce environmental impact by avoiding landfill), REDUCE (minimize the use of virgin glass fibers in the production of repair compounds) and REPAIR (increase the efficiency of repairing damaged concrete structures). Furthermore, as the percentage of basalt powder increases, the abrasion resistance of the repair compound improves. The obtained repair compounds may serve as an alternative to currently used compounds for the repair of bridges and factory floors. Full article

In recent years, researchers have focused on the usability of fiber-reinforced polymer (FRP) bars due to their lightweight, corrosion-resistant, and eco-friendly characteristics. Geopolymers, as low-carbon alternatives to traditional binders, aim to reduce CO₂ emissions in concrete production. The bond strength between FRP bars and concrete is critical for the load-bearing capacity and deformation characteristics of reinforced elements. The objectives of this work are to investigate the bond performance of GFRP bars in chopped glass and basalt fiber-added geopolymer concrete using hinged beam tests. Since the hinged beam test accurately represents the behavior of real bending elements, this test method was selected as a main bonding test. Initially, three geopolymer mixtures with Ms modulus values of 1.2, 1.3, and 1.4 were prepared and tested. The mixture with a modulus of 1.2 Ms, achieving a compressive strength of 56.53 MPa, a flexural strength of 3.54 MPa, and a flow diameter of 57 cm, was chosen for beam production due to its optimal workability and strength. After mechanical and workability tests, SEM analysis was performed to evaluate its internal structure. For evaluating the bond performance of GFRP bars, 12 geopolymer beam specimens were prepared, incorporating varying fiber types (chopped glass fiber or basalt fiber) and embedment lengths (5 Ø or 20 Ø). Hinged beam tests revealed that the bond strengths of glass and basalt fiber-added mixtures were up to 49% and 37% higher than that of the control geopolymer concrete, respectively. It was concluded that incorporating fibers positively influenced the bond between geopolymer concrete and GFRP bars, with glass fibers proving more effective than basalt fibers. These findings enhance the understanding of bond mechanisms between GFRP bars and geopolymer concrete, emphasizing their potential for sustainable and durable construction in both industrial and scientific applications. Full article

This paper presents a novel design of prefabricated steel–EPS foam concrete composite wall panels, which can solve issues such as long curing times, decreased impermeability and durability, easy corrosion of steel reinforcement, and difficult construction under the cold climate conditions in Northeast China. A parametric analysis of the composite wallboard was carried out using the finite-element analysis software ABAQUS 6.12. In-depth exploration was conducted on the contributions of parameters such as the density of foam concrete, the strength of cold-formed thin-walled C-section steel, and the cross-sectional height of cold-formed thin-walled C-section steel compared to the overall flexural bearing capacity of the composite wallboard as well as the impacts of these parameters on the failure modes. The mechanical properties of the composite wallboard were verified through four-point bending tests. The bearing capacity of this composite wallboard can reach up to 100.58 kN at most, and its flexural bearing capacity can reach 30.44 kN·m. Meanwhile, its ductility coefficient of 2.9 is also within the optimal range. The research results confirm the superior mechanical properties of the designed composite wallboard, providing beneficial references for the research on similar composite material structures. Full article

The incorporation of desert sand-mineral admixture improves the abrasion resistance of concrete. To prolong the service life of assembled concrete channels and mitigate the depletion of river sand resources, the effects of fly ash (FA), silica fume (SF), desert sand (DS), and basalt fiber (BF) on the mechanical properties and the abrasion resistance of concrete were examined, alongside an analysis of their microstructures to elucidate the underlying mechanisms of influence. The results indicated that the abrasion resistance strength of concrete mixed with 10% FA and 0.05% BF alone increased by 80.19% and 81.59%, respectively, compared with ordinary concrete (OC). When SF was added to the concrete at a dosage of 10%, it improved the mechanical properties and the abrasion resistance of the concrete. Furthermore, adding SF resulted in a 12.50% increase in compressive strength and a 12.27% increase in abrasion resistance strength compared to OC. The addition of DS did not significantly enhance the concrete’s abrasion resistance. The combination of ingredients for desert sand concrete (DSC) that provides excellent abrasion resistance was determined using an orthogonal experiment. The optimal mixture consisted of 10% FA content, 10% SF content, 40% DS content, and 0.05% BF content, which increased the abrasion resistance strength by 112.95% compared to OC. Through microscopic analysis, it is found that the width of the interfacial transition zone (ITZ) is an important factor in determining the abrasion resistance of concrete, and a narrower ITZ enhances the concrete’s abrasion resistance. The study’s findings could function as a theoretical reference for the engineering design of DSC. Full article