Search Results (175)

Basalt-fiber-reinforced polymer (BFRP) composites, utilizing a natural high-performance inorganic fiber, exhibit excellent weathering resistance, including tolerance to high and low temperatures, salt fog, and acid/alkali corrosion. They also possess superior mechanical properties such as high strength and modulus, making them widely applicable in aerospace and shipbuilding. This study experimentally investigated the mechanical properties of BFRP plates under various strain rates (10⁻⁴ s⁻¹ to 10³ s⁻¹) and directions using an electronic universal testing machine and a split Hopkinson pressure bar (SHPB).The results demonstrate significant strain rate dependency and pronounced anisotropy. Based on experimental data, relationships linking the strength of BFRP composites in different directions to strain rate were established. These relationships effectively predict mechanical properties within the tested strain rate range, providing reliable data for numerical simulations and valuable support for structural design and engineering applications. The developed strain rate relationships were successfully validated through finite element simulations of low-velocity impact. Full article

The construction industry is exploring alternatives to traditional steel reinforcement in concrete due to steel’s corrosion vulnerability. Glass Fiber Reinforced Polymer (GFRP) and Basalt Fiber Reinforced Polymer (BFRP), known for their high tensile strength and corrosion resistance, are viable options. This study evaluates the flexural performance of concrete beams reinforced with GFRP, BFRP, and hybrid systems combining these materials with steel, following ACI 440.1R-15 guidelines. Twelve beams were assessed under three-point bending to compare their flexural strength, ductility, and failure modes against steel reinforcement. The results indicate that GFRP and BFRP beams achieve 8% and 12% higher ultimate load capacities but 38% and 58% lower deflections at failure than steel, respectively. Hybrid reinforcements enhance both load capacity and deflection performance (7% to 17% higher load with 11% to 58% lower deflection). However, GFRP and BFRP beams show reduced energy absorption, suggesting that hybrid systems could better support critical applications like seismic and impact-prone structures by improving ductility and load handling. In addition, BFRP beams predominantly failed due to debonding and concrete crushing, while GFRP beams failed due to bar rupture, reflecting key differences in their flexural failure mechanisms. Full article

The use of short cylinders of recycled aggregate concrete (RAC) reinforced with basalt fiber-reinforced polymer (BFRP) circumferential strips and polyvinyl chloride (PVC) tubes has been proven effective in previous studies. However, BFRP circumferential strips are cumbersome to install and do not ensure the integrity of the BFRP strips. Therefore, this study investigates axial compression experiments on RAC short cylinders reinforced with BFRP spiral strips and PVC tubes. A combination of experimental studies, finite element simulations, and theoretical analyses revealed that the winding angle and spacing of BFRP strips significantly affect the load-bearing capacity and ductility of the restrained specimens. Additionally, an improved strength model was developed based on an existing model. When evaluated using both computational and experimental results, the equations generated in this study showed an average error of less than 10%. The findings indicate that the composite structure provides effective reinforcement and offers valuable reference information for practical applications. Full article

This study focuses on the influence of prolonged ultraviolet (UV) irradiation on the mechanical properties and surface microstructure of glass fiber-reinforced plastics (GFRPs) and basalt fiber-reinforced plastics (BFRPs), which are widely used in construction and transport infrastructure. The relevance of the research lies in the need to improve the reliability of composite materials under extended exposure to harsh climatic conditions. Experimental tests were conducted in a laboratory UV chamber over 2000 h, simulating accelerated weathering. Mechanical properties were evaluated using three-point bending, while surface conditions were assessed via profilometry and microscopy. It was shown that GFRPs exhibit a significant reduction in flexural strength—down to 59–64% of their original value—accompanied by increased surface roughness and microdefect depth. The degradation mechanism of GFRPs is attributed to the photochemical breakdown of the polymer matrix, involving free radical generation, bond scission, and oxidative processes. To verify these mechanisms, FTIR spectroscopy was employed, which enabled the identification of structural changes in the polymer phase and the detection of mass loss associated with matrix decomposition. In contrast, BFRP retained up to 95% of their initial strength, demonstrating high resistance to UV-induced aging. This is attributed to the shielding effect of basalt fibers and their ability to retain moisture in microcavities, which slows the progress of photo-destructive processes. Comparison with results from natural exposure tests under extreme climatic conditions (Yakutsk) confirmed the reliability of the accelerated aging model used in the laboratory. Full article

Leveraging the sensitivity of long-period fiber grating (LPFG) to changes in the environmental refractive index, an LPFG-based seawater concentration monitoring sensor is proposed. Considering the highly saltine and alkali characteristics of the sensor’s operating environment, the proposed sensor is packaged by basalt fiber-reinforced polymer (BFRP), and the sensor’s sensitivities were studied by sodium chloride and calcium chloride solution concentration experiments and one real-time sodium chloride solution concentration monitoring experiment. The test results show the wavelength of LPFG, a 3 dB bandwidth and a peak loss of LPFG’s spectrogram change with changes in the concentration of sodium chloride or calcium chloride solutions, but only the wavelength has a good linear relationship with the change in solution concentration, and the sensing coefficient is −0.160 nm/% in the sodium chloride solution and −0.225 nm/% in the calcium chloride solution. The real-time monitoring test further verified the sensor’s sensing performance, with an absolute measurement error of less than 1.8%. The BFRP packaged sensor has good corrosion resistance and a simple structure, and it has a certain application value in the monitoring of salinity in the marine environment and coastal soil. Full article

Plain concrete specimens and FRP(Fiber Reinforced Polymer)-reinforced concrete specimens were fabricated to investigate concrete’s mechanical and surface degradation behaviors reinforced with carbon, basalt, glass, and aramid fiber-reinforced polymer under coupled sulfuric acid and freeze–thaw cycles. The compressive strength of fully wrapped FRP cylindrical specimens and the flexural load capacity of prismatic specimens with FRP reinforced to the pre-cracked surface, along with the dynamic elastic modulus and mass loss, were evaluated before and after acid–freeze cycles. The degradation mechanism of the specimens was elucidated through analysis of surface morphological changes captured in photographs, scanning electron microscopy (SEM) observations, and energy-dispersive spectroscopy (EDS) data. The experimental results revealed that after 50 cycles of coupled acid–freeze erosion, the plain cylindrical concrete specimens showed a mass gain of 0.01 kg. In contrast, after 100 cycles, a significant mass loss of 0.082 kg was recorded. The FRP-reinforced specimens initially demonstrated mass loss trends comparable to those of the plain concrete specimens. However, in the later stages, the FRP confinement effectively mitigated the surface spalling of the concrete, leading to a reversal in mass loss and subsequent mass gain. Notably, the GFRP(Glassfiber Reinforced Polymer)-reinforced specimens exhibited the most significant mass gain of 1.653%. During the initial 50 cycles of acid–freeze erosion, the prismatic and cylindrical specimens demonstrated comparable degradation patterns. However, in the subsequent stages, FRP reduced the exposed surface area-to-volume ratio of the specimens in contact with the acid solution, resulting in a marked improvement in their structural integrity. After 100 cycles of acid–freeze erosion, the compressive strength loss rate and flexural load capacity loss rate followed the ascending order: CFRP-reinforced < BFRP(Basalt Fiber Reinforced Polymer)-reinforced < AFRP(Aramid Fiber Reinforced Polymer)-reinforced < GFRP-reinforced < plain specimens. Conversely, the ductility ranking from highest to lowest was AFRP/GFRP > control group > BFRP/CFRP. A probabilistic analysis model was established to complement the experimental findings, encompassing the quantification of hazard levels and reliability indices. Full article

With the advancement of urbanization, recycled aggregate concrete derived from construction waste has received increasing research attention. This study primarily focuses on a novel method to enhance the mechanical properties of recycled aggregate concrete derived from brick–concrete waste by mixing short-cut BFRP fibers. A series of experimental tests, including an axial compression test, a splitting tensile test, and a bending test, were conducted on specimens of RBCAC (recycled brick–concrete aggregate concrete) with different brick–concrete ratios and BFRP fiber contents. The effects of the brick–concrete ratio and BFRP content on various mechanical properties were systematically investigated. The results indicate that the brick–concrete ratio significantly affects the mechanical properties of RBCAC. The compressive strength decreased by approximately 2.0–4.7% as the brick-to-aggregate ratio increased from 0.25 to 4, with the peak strength (34.3 MPa) occurring at a ratio of 0.67. In addition, a strong linear relationship was observed between the compressive strength and other mechanical properties of BFRP-RBCAC. Based on the experimental data, the existing constitutive model for recycled concrete was modified by introducing a brick–concrete ratio correction factor and a fiber reinforcement factor. The proposed compression constitutive model is suitable for recycled brick–concrete aggregate concrete incorporating hybrid BFRP fibers. Full article

This study investigates the effect of fiber weight fraction on the tribomechanical behavior of basalt fiber-reinforced polymer (BFRP) composites under dry sliding conditions. Composite specimens with 50%, 65%, and 70% basalt fiber contents were manufactured and tested through tensile, flexural, and pin-on-disc tribological evaluations. Key tribological parameters, including the coefficient of friction (COF), specific wear rate (K), and contact temperature, were measured under various applied loads and sliding speeds. Statistical analysis was performed using a generalized linear model (GLM) to identify significant factors and their interactions. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) analyses indicated that abrasive wear, matrix cracking, and fiber–matrix interfacial failure were the dominant wear mechanisms. The experimental results revealed that the fiber weight fraction had the most significant influence on COF (42.78%), while the sliding speed had the predominant effect on the specific wear rate (77.69%) and contact temperature (32.79%). These findings highlight the potential of BFRP composites for applications requiring enhanced wear resistance and mechanical stability under varying loading conditions. Full article

The increasing demand for sustainable and resilient construction solutions calls for the integration of innovative, non-conventional materials in structural retrofitting. This study investigates the use of basalt fiber-based engineered geopolymer composites (BFEGC) as a retrofitting material for fire-damaged reinforced concrete (RC) short columns. A total of 14 columns (150 mm × 150 mm × 650 mm) were cast. Two columns were used as control specimens. The remaining 12 columns were exposed to various fire conditions: 300 °C for 30 min, 600 °C for 20 min, and 900 °C for 15 min, followed by gradual (GC) or rapid cooling (RC). Among the columns, six were left unwrapped (GC-NW, RC-NW), while six others were retrofitted with BFEGC (GC-W, RC-W) and subjected to axial loading until failure. The results showed that BFEGC wrapping improved the mechanical performance of fire-damaged columns, especially at 600 °C. The 600RC-W columns exhibited 1.85 times higher ultimate load, 1.56 times greater displacement ductility, and 2.99 times higher energy ductility compared to unwrapped columns. The strength index and confinement coefficient of the 600RC-W columns increased by 2.31 times and 40.2%, respectively. Microstructural analysis confirmed the formation of salient hydration products under elevated temperatures. BFEGC shows significant reduction in carbon emissions and embodied energy, compared to conventional cement-based binders for fiber-reinforced polymer systems. Full article

Based on the formula for the sizing agent for basalt fiber, this paper presents a comprehensive study of the effects of lubricants on the properties of sizing agents, basalt fiber, and epoxy resin composite materials. Through testing and analysis of physical and chemical parameters, a new sizing agent with excellent performance was developed. The results demonstrated that the components and proportions of the lubricant significantly affected the physical and chemical parameters of the emulsion, as well as the mechanical properties of the basalt fibers and their epoxy resin composite materials. The lubricant with the combination ratio of 0.70% saturated fatty acid polyoxyethylene ester and 0.30% unsaturated fatty acid polyoxyethylene ester and imidazoline lubricant-I produced basalt fiber with the best mechanical properties. The single fiber tensile strength and yarn breaking strength increased by 18.42% and 12.5%. Furthermore, the lubricant with the combination ratio of 0.70% saturated fatty acid polyoxyethylene ester and 0.30% unsaturated fatty acid polyoxyethylene ester and imidazoline lubricant-III resulted in the best mechanical properties for Epoxy–BFRP composite materials. The tensile strength of the Epoxy–BFRP composite material increased by 13.2%, the tensile modulus increased by 45.2%, and the flexural strength increased by 12.0%. Full article

This paper investigates the effects of the basalt-fiber-reinforced polymer (BFRP) and polyethylene (PE) hybrid fiber ratio on the mechanical properties and durability of engineered cementitious composites (ECC). First, four different PE-BFRP hybrid fiber ECC mixtures were systematically prepared by controlling the fiber volume ratio of PE and BFRP fibers. The workability and mechanical properties of the hybrid fiber ECC (HFECC) were then evaluated using flowability tests and multi-scale mechanical tests, including compressive strength, flexural strength, bending toughness, and tensile performance. After that, the durability of HFECC with different fiber ratios was comprehensively assessed through freeze–thaw cycle tests and rapid ion migration tests. Finally, the interface morphology of fibers within the matrix was observed using scanning electron microscopy (SEM). The results show that an appropriate hybrid of PE and BFRP fibers can synergistically enhance the crack resistance and toughness of ECC, improving its failure mode. The best performance in terms of flowability and mechanical properties was observed for the HFECC mixture with 1.30% PE fiber volume and 0.30% BFRP fiber volume. With the increase in BFRP fiber content, the freeze–thaw resistance and chloride ion erosion resistance of HFECC were gradually enhanced. This study provides experimental and theoretical support for the design and engineering application of high-performance hybrid fiber ECC materials. Full article

This study addresses the need for thermomechanically robust materials for high-temperature environments by investigating fabric-reinforced composites produced through polymer infiltration and thermal pressing using phenol-formaldehyde (PF) and epoxy (ER) resins. Experimental validation was required due to the lack of comparative data across different textile reinforcements under identical conditions. Seven technical fabrics—carbon, aramid, basalt, silica, fiberglass, asbestos, and a carbon/aramid hybrid—were used as reinforcements. Mechanical testing revealed that carbon- and hybrid fiber composites exhibited the highest tensile (up to 465 MPa) and compressive strengths (up to 301 MPa), particularly when combined with ER. Conversely, the use of PF generally resulted in a 30–50% reduction in mechanical strength. However, PF-based composites demonstrated superior thermal resistance, with the silica/PF combination showing the lowest back-face temperature (401 °C), up to 37% lower than other pairings. Thermal conductivity ranged from 0.041 to 0.51 W/m·K, with PF-based systems offering 6–12% lower values on average compared to ER-based analogs. Morphological analysis confirmed better interfacial bonding in ER composites, while PF systems showed higher structural integrity under thermal loading. Overall, the results emphasize the trade-offs between mechanical strength and thermal protection depending on the fabric–resin combination. Among all variants, the silica fabric with PF demonstrated the most balanced performance, making it a promising candidate for thermomechanical applications. Full article

Filled joints are widely found in natural rock masses and are one of the main factors causing rock mass engineering instability. The use of bolts can effectively control the shear slip of filled joints, research on bolts filled joints in the filling degree, and other key parameters of the influence of the law, to ensure the stability of the engineering rock body is of great significance. This paper presents shear experiments on bolted filled joints of Basalt Fiber-Reinforced Polymer (BFRP) materials with different joint roughness and filling degrees, while acoustic emission technology monitors the shear failure process of the specimens. The results show that the peak shear strength decreases with the increase in filling degree, and the peak shear strength decreases by 23.9% when the filling degree changes from 0 to 2.0 at 4 MPa and J2 conditions, while the normal stress, the Joint Roughness Coefficient (JRC) and the peak shear strength both show a positive correlation. The normal deformation of bolted filled joints exhibits three distinct evolutionary patterns depending on the filling degree, while both JRC and normal stress significantly influence the magnitude of shear dilatancy-shrinkage deformation. The shear resistance of BFRP bolts is mainly reflected in the post-peak plastic stage, and some of the fibers break during its shear deformation to form controlled yielding, with vertical and horizontal deformation controlled within 15.5~22.3 mm and 4.7~6.9 mm, respectively. The Acoustic Emission (AE) results show that the AE events are mainly in the post-peak plasticity stage, and the proportion is about the sum of the proportion of the other two phases, and this proportion increases with the increase in the filling degree. Full article

This study investigates the effects of post-curing temperatures on the tensile properties of hybrid basalt-jute-glass-carbon fiber-reinforced polymers (FRPs). Composite specimens were post-cured at 60 °C and 100 °C for 60 min, and their tensile behavior was assessed using a servo-hydraulic testing machine. Numerical simulations using the Abaqus software V6.14 were also conducted to compare experimental and computational results. The findings indicate that post-curing heat treatment enhances ductility due to increased polymer cross-linking, but excessive heat treatment at 100 °C negatively impacts elongation at fracture. The results revealed that specimens post-cured at 60 °C exhibited the optimal balance between strength and ductility, with increased elongation and moderate tensile strength. However, at 100 °C, while tensile strength improved in some cases, a significant decrease in elasticity and an increased risk of brittleness were observed, suggesting that extreme heat treatment may degrade polymer integrity. Natural fiber composites, particularly jute-based samples, outperformed synthetic composites in terms of elongation and overall mechanical stability. The numerical simulations provided further insights but showed discrepancies with experimental results, mainly due to fiber property variations and fabric waviness, underscoring the challenges of accurately modeling woven composites. The study highlights the importance of controlled post-curing temperatures in optimizing the mechanical performance of FRP composites, with 60 °C identified as the most effective condition for achieving a favorable balance between tensile strength, flexibility, and material durability. These findings offer valuable insights for material scientists and engineers working on the development of high-performance composite materials for structural and industrial applications. Full article

This study investigates the mechanical performance of basalt fiber-reinforced polymer (BFRP) laminates as a suitable alternative to conventional glass fiber-reinforced composites for marine applications. The laminates were produced by varying the main process parameters: the fiber type was either glass or basalt; the resin material was either polyester or vinylester; the fiber orientation in selected layers was set to either 0°/90°, or to ±45° by rotating the woven fabrics during lay-up, and finally the manufacturing technique was either hand lay-up or vacuum infusion. Three-point flexural tests with different spans were conducted to evaluate the flexural behavior and fracture mechanisms. The best-performing configuration, based on glass fibers and vacuum infusion, achieved a maximum flexural strength of about 500 MPa, while basalt-based laminates reached values of up to 400 MPa. Basalt laminates exhibited the highest flexural modulus, with values exceeding 24 GPa. An increase in span length from 120 mm to 220 mm resulted in a reduction in flexural strength of approximately 6–18% depending on the laminate configuration, highlighting the influence of loading conditions on mechanical behavior. The effect of the manufacturing processes was also evaluated using an analysis of variance. This showed that fiber type, manufacturing method, and span significantly influenced the mechanical performance. Full article