Flexural response of basalt textile reinforced concrete with pre-tension and short fibers under low-velocity impact loads

The flexural properties of basalt textile reinforced concrete (BTRC) specimens with pre-tension, short carbon, steel, and AR-glass fibers were investigated through three-point bending in a utilizing drop-weight impact setup. The flexural impact parameters, such as flexural strength, flexural modulus, ultimate strain, maximum strain, and energy absorption capacity, were determined under different impact velocities. The flexural strength and toughness of the BTRC specimens without pre-tension significantly increased when the impact velocity (1.0-3.0 m/s) and layers of basalt textiles were increased. By contrast, the flexural modulus initially increased and subsequently decreased with increasing impact velocity, whereas the loading rate exerted a marginal influence on the ultimate strain and the maximum strain. When the basalt textile had four reinforcement layers, the BTRC reinforced with 0.5 vol% of short carbon fiber or short steel fiber exhibited varied different flexural responses under different impact velocities (1.0-4.0 m/s); in particular, the BTRC reinforced with short steel fibers had a higher maximum strain. In addition, pre-tensioned BTRC with different short fibers were tested under an impact velocity of 1.0 m/s. The flexural strength decreased as the short carbon fiber and glass fiber contents increased. The highest flexural strength was observed in the pretensioned specimen with 0.5 vol% of short glass fiber and three layers of basalt textile. The addition of short fibers in cement matrix, the number of textile layer used as reinforcement, the pretension on textile, and the impact velocities used in the tests can significantly affect the flexural impact behavior of BTRC specimens. The Weibull parameters were analyzed to quantify the degree of variability in the flexural strength.