Fresh and Hardened Properties of Concrete Reinforced with Basalt Macro-Fibers

This study examines the fresh and hardened properties of normal- and high-strength concrete (NSC and HSC) reinforced with basalt macro-fibers (BMF) at a volume fraction (nu(f)) of 0.5-1.5%. Workability tests were conducted on the fresh concrete to evaluate the slump, compacting factor, and vebe time. Mechanical tests were performed on the hardened concrete to examine the compressive strength, tensile properties, and flexural performance. Different durability characteristic tests were carried out to evaluate the water/chloride penetrability, bulk resistivity, and abrasion resistance of the hardened concrete. The addition of BMF reduced the concrete workability of both NSC and HSC at almost the same rate. A maximum slump reduction of 78%, on average, was recorded at nu(f) of 1.5%. The compressive strength of the NSC slightly increased by 1-5% due to the addition BMF, whereas that of the HSC with BMF was, on average, 6% lower than that of their plain counterparts. The NSC with BMF exhibited significant improvements of 10-52% in the splitting tensile strength, 18-56% in the flexural strength, and 17-27% in the abrasion resistance. The enhancement caused by the addition of BMF was less pronounced for the HSC, where maximum respective improvements of 22, 25, and 4% were recorded. The NSC and HSC with BMF exhibited a similar reduction in the water absorption (max. of 12%), chloride penetrability (max. of 19%), and a comparable improvement in the bulk resistivity (max. of 21%), relative to those of their plain counterparts. The flexural test results along with an inverse analysis were employed to develop new tensile softening laws of concrete with different BMF volume fractions.

Automated summary

This study investigates the effects of adding basalt macro-fibers on the fresh and hardened properties of normal and high-strength concrete. The results show that the addition of basalt macro-fibers reduces the workability of the concrete but improves its compressive strength and tensile properties. Additionally, the inclusion of basalt macro-fibers enhances the abrasion resistance and durability of the concrete.