Post-cracking behavior of cementitious composite incorporating nano-silica and basalt fiber pellets

Recently, fiber reinforced polymers (FRPs) have been increasingly used to reinforce concrete structures in harsh environments, due to their non-corrodible nature. Developing a nonferrous reinforcement system (corrosion-free system) for concrete using FRP bars along with discrete fibers is a promising option for exposed concrete structures in cold regions or marine environments. Incorporating highly efficient non-metallic fibers into any cementitious composite is capable of reducing bleeding, controlling shrinkage cracking, and improving toughness and impact resistance. Therefore, in this study, a new type of basalt fiber pellets with high tensile strength was investigated. This paper reports on the flexural performance of the basalt fiber-reinforced cementitious composite (BFRCC) compared to steel fiber-reinforced cementitious composite (SFRCC). The cementitious composite incorporated general use cement, slag and nano-silica. The key mechanical property determined was the post-cracking behavior in terms of residual strength, and toughness. Standard prisms (100 × 100 × 350 mm) were cast using basalt fiber pellets and steel fibers with three different dosages and tested after 28 days following the general guidelines of ASTM C1609 (Standard Test Method for Flexural Performance of Fiber-Reinforced Concrete). Analysis of results showed a high level of effectiveness of the basalt fibers to enhance the post-cracking behavior of specimens, as they behaved comparably or superiorly (first cracking, load-deflection relationship, and toughness) to counterpart specimens comprising steel fibers.