Mechanical behaviors of cementations matrix composites reinforced with basalt weft-knitted spacer fabric under low-velocity impact

The attention of this paper is focused on the impact resistance behavior and reinforcing mechanism of cement-based composites reinforced with weft-knitted spacer fabrics (FKRCs). Composites were manufactured with basalt spacer fabrics and calcium sulfoaluminate cement, both of which are eco-friendly materials. Three kinds of FKRCs with varying needle span distances of the spacer fabrics were compared with plain concrete and concrete reinforced with basalt fibers via a static-bursting test and low-velocity impact test. In addition, the failure morphologies of damaged specimens were analyzed. The experimental results revealed that the basalt spacer fabric was able to obviously enhance the impact resistance and energy absorption capacity of the concrete, while the reinforcing effect of basalt fibers was relatively restricted. In addition, spacer fabrics played a crucial role in retarding the crack generation and propagation in the cement matrix by the textile bridging effect. Furthermore, FKRCs were more sensitive to dynamic impact load, exhibiting a higher maximum peak load but lower maximum displacement. With the increase of span distances, the impact resistance of the specimens was enhanced with higher maximum impact load and energy absorption, and the brittleness of plain concrete was improved. In addition, the spacer yarn structure exhibited considerable effects on the impact behavior of the composites rather than basalt spacer fabrics. Therefore, the FKRC is suitable for structural components that require higher impact resistance in engineering applications.