The following conclusions are formed:
1. The addition of basalt fiber can effectively increase the compressive strength, splitting the tensile and flexural strength (especially splitting tensile and flexural strength) of the concrete; values of 9.9%, 37.5% and 44.2% are attained;
2. After mixing concrete with basalt fiber, the initial crack impact cycle number of the concrete improves by 60% ~ 170%, the impact energy improves by 90% ~ 260%, and the ductility index increases by a minimum of two times, compared with ordinary concrete. Thus, we can deduce that adding basalt fibers to ordinary concrete can significantly improve the impact resistance and toughness of concrete, which affects its strengthening and toughening; and
3. The fiber content has a significant impact on the mechanical behavior of concrete. According to the experimental results of this paper, the optimal basalt fiber content of C30 concrete ranges from 1.5 ~ 2 kg/m³. If the basalt fiber content exceeds this range, a declining trend is observed for the concrete strength and impact properties.
Hai Cao, School of Civil Engineering and Architecture, Huangshan University, China.