Synergistic experimental and ANN-based prediction of mechanical properties of basalt fiber reinforced high-strength concrete

MECHANICAL PERFORMANCE OF HYBRID FIBER-REINFORCED CONCRETE: THE SYNERGISTIC EFFECT OF RAMIE AND MICRO SYNTHETIC FIBERS

Conventional concrete has limitations in tensile strength and crack control. Fiber-reinforced concrete improves these properties, but single fiber types can hinder performance. While steel fibers are common, synthetic and natural fibers are gaining traction due to their cost-effectiveness, performance, and eco-friendliness. This research explores hybrid fiber concrete using micro synthetic (polyamide, 12 mm, 0.06% fiber volume fractions) and natural ramie (19 mm, 0.25%, 0.50%, 0.75% by cement weight) fibers to enhance mechanical performance. Five mix designs (V1-V5) were evaluated for compressive strength, splitting tensile strength, and modulus of elasticity at 28 days. Results showed that plain concrete (V1) had the highest compressive strength of 32.44 MPa but suffered brittle failure. V2 (micro synthetic fibers only) showed the lowest strength, indicating limited effectiveness. The addition of hybrid fibers (V3-V5) significantly increased the splitting tensile strength of concrete by 0.99-15.84% and modulus of elasticity by 101.73-198.05% higher than plain concrete. Hybrid fibers also transformed the failure mode from brittle to ductile. The V4 mixture represents the most effective combination of strength, stiffness, and crack resistance. This research highlights the synergistic potential of hybrid fiber reinforcement for improving concrete's tensile capacity, stiffness, and post-cracking behavior, offering valuable insights for durable concrete applications.  

Experimental investigation of the mechanical and durability performance of hybrid basalt fiber-reinforced concrete using gaussian process regression-based prediction

Experimental evaluation and multi-objective optimization of hybrid steel–shape memory alloy fiber reinforced concrete for enhanced mechanical and microstructural performance

This study presents a comprehensive experimental investigation and multi-objective optimization of Hybrid Steel–Shape Memory Alloy Fiber Reinforced Concrete (HS–SMA FRC) designed to enhance mechanical performance and material efficiency. M40-grade concrete mixes incorporating steel fibers, NiTi-based SMA fibers, and hybrid combinations at volume fractions of 0.5% and 0.75% were evaluated. Mechanical properties, including compressive strength, split tensile strength, flexural strength, bond strength, and modulus of elasticity, were assessed at 7 and 28 days. The results indicate that hybrid fiber systems outperform mono-fiber and control mixes, with the 0.75% HS–SMA FRC mix achieving the highest compressive strength (64.25 MPa), split tensile strength (10.80 MPa), and flexural strength (12.5 MPa), attributed to synergistic crack-bridging and stress redistribution mechanisms. Microstructural observations using SEM and EDS suggest improved fiber–matrix bonding and a denser interfacial transition zone, supporting the observed mechanical enhancements. A hybrid optimization framework combining Response Surface Methodology (RSM) and NSGA-III was implemented to identify optimal trade-offs among performance parameters, with model-predicted results indicating efficient material configurations. However, the findings are limited to material-level behavior under monotonic loading conditions, and the optimization results are not experimentally validated. The study provides a robust foundation for developing high-performance hybrid fiber reinforced concrete with potential applicability in advanced structural systems.

Performance Assessment of Hybrid Polypropylene Fiber-Reinforced Concrete for Rigid Pavement Structures

This study was conducted to investigate the effects of fiber reinforcement on the mechanical strength and energy absorption capacity of concrete under varying watert/cement(w/c) ratios and aggregate gradations, using commercially available sikafiber and polimono fibers. Using the Taguchi method, four levels of w/c ratio, fiber content and gradation were optimized. When only sikafiber was used, compressive strength increased by 4% and flexural strength by 9.2%. With polimono fiber, increases of 3.3% and 7.3% were observed, respectively. The combined use of both fibers resulted in a 7.5% increase in compressive strength and a 43% increase in flexural strength. Increasing fiber content improved the energy absorption capacity by 173.957%. Fiber addition reduced the brittleness of concrete and enhanced its ductility, thereby improving structural performance. These findings indicate that fiber-reinforced concretes are an effective option for structural applications requiring enhanced strength and durability.

Study on Mechanical Properties and Crack Evolution of Basalt Fiber-Reinforced Desert Sand High-Strength Concrete Based on DIC

This study investigates the strength development, crack evolution and toughening mechanism of basalt fiber-reinforced desert sand high-strength concrete. An L9(33) orthogonal design was first used to optimize the reference mixture, after which basalt fibers with volume fractions of 0, 0.3%, 0.4% and 0.5% were incorporated. Mechanical testing, digital image correlation, SEM, XRD, TG and FTIR were combined to clarify the relationship among fiber dosage, crack propagation and microstructural reinforcement mechanisms. The optimized matrix mixture was obtained with a water-to-binder ratio of 0.32, a desert sand replacement ratio of 40% and a fly ash content of 20%. The incorporation of basalt fiber had little influence on the 28 d compressive strength, whereas the splitting tensile strength was markedly improved. The highest splitting tensile strength was observed in the 0.4% fiber group, reaching 5.46 MPa, which was 12.81% higher than that of the reference mixture. DIC results showed that basalt fiber reduced strain localization and limited crack opening. The 0.5% group had the lowest COD, while the 0.4% group showed a better balance among tensile strength, strain redistribution and crack-opening control. SEM observations showed fiber bridging and fiber–matrix interaction near the fracture region. Meanwhile, XRD, TG-DTG and FTIR showed no obvious changes in the main phases or functional groups, indicating that the improvement was mainly related to the physical crack-control effect of basalt fibers rather than chemical modification of the matrix. Overall, 0.4% basalt fiber was identified as the preferred dosage for the present system.

Mechanical and Environmental Performance-based Evaluation of Areca Nut Fiber-reinforced Concrete

The present study investigates the effect of incorporating areca nut fiber as a partial replacement (0.1%-0.5%) of coarse aggregates on the mechanical and environmental performance of concrete. Concrete mixtures incorporating varying proportions of areca nut fiber were prepared and evaluated through compressive strength, split tensile strength, and water absorption tests to examine their mechanical response and moisture transport characteristics. Regression-based curve fitting was further employed to model the relationship between fiber content and strength parameters. In addition, a series of performance indices, namely Compressive Strength Efficiency, Tensile Strength Efficiency, Ductility Index, Relative Water Absorption Index, and Water Absorption Severity Index, were formulated to facilitate integrated performance assessment. A multi-objective performance score was subsequently established to combine strength and durability considerations for identifying the most favorable mixture composition. Concrete performance exhibited a distinct nonlinear dependence on fiber content. Compressive strength reached the greatest improvement, approximately 21% above the control mixture at 0.4% fiber addition, whereas the maximum split tensile strength was observed at 0.2% fiber content owing to improved crack-arresting and stress-transfer mechanisms. In contrast, water absorption increased steadily with increasing fiber dosage, highlighting a trade-off between mechanical enhancement and durability performance. The developed regression models successfully captured the observed trends, while the proposed performance indices provided additional insight into strength utilization, durability implications, and overall material effectiveness. Areca fiber incorporation produced only marginal changes in embodied CO 2 emissions; however, a notable improvement in eco-efficiency was achieved within the optimum fiber content range. The experimental evidence suggests that areca fiber can serve as a viable and environmentally conscious reinforcement material when used in controlled quantities. The benefits associated with strength enhancement and improved crack resistance are most pronounced within a limited dosage range, beyond which the adverse effects of increased permeability become significant. Consequently, performance optimization requires balancing mechanical gains against potential durability concerns. The study confirms that areca fiber-reinforced concrete can achieve enhanced mechanical performance and improved eco-efficiency without substantially increasing environmental burden. However, the increase in water absorption at higher fiber dosages highlights the need to identify an optimum fiber content that balances strength, durability, and long-term performance.