Flexural Performance of Basalt Textile-Reinforced Concrete with Pretension and Short Fibers

Abstract

The flexural behavior of basalt textile-reinforced concrete (BTRC) with and without pretension and with one of two types of short fibers was investigated using an instrumental four-point bending test under quasi-static loading. BTRC samples consisted of five layers of basalt textile, with and without pretension, and the cement matrix contained short carbon or steel fibers in various volume fractions (0%, 0.5%, 1.0%, and 1.5%). Critical flexural performance, including first-crack stress, flexural strength, energy absorbed, flexural strain at peak stress, number of cracks, and crack spacing, were analyzed. Test results revealed that the addition of short fibers in the BTRC samples enhanced their flexural capacity. The addition of short fibers (1.0 vol%) without pretensioning resulted in good crack patterns and flexural mechanical properties. The reinforcing effect of BTRC with pretensioning was more apparent than that of BTRC without pretensioning. The maximum flexural strength of all samples reached approximately 23.6 MPa, which was approximately triple that of the first-crack stress of the pretension samples. The addition of short steel fibers (1.0 vol%) in flexural samples without pretension showed the highest flexural strength. The maximum flexural strain and crack patterns obtained by experiments and digital image correlation revealed satisfactory agreement. Weibull analysis was conducted to quantify the variability in BTRC flexural strength with different short fiber types and volume fractions. Textile pretensioning, type and type and volume fraction of short fibers were shown to significantly affect the flexural behavior of BTRC.