Experimental study on fire resistance of 200-300 mpa high strength concrete with synthetic fiber and steel fiber

This paper investigated the effects of synthetic and steel fibers on the fire-induced spalling behavior of 200 - 300MPa high strength concrete. The following conclusions were derived. 1. The combined use of 0.2%.vol synthetic fiber and 0.25 - 0.5%.vol steel fiber can significantly reduce spalling. 2. The smaller the synthetic fiber diameter and the longer the length, the higher the spalling resistance. 3. The steel fibers with a smaller diameter showed higher spalling resistance due to a larger fiber number per unit volume. 4. The higher the concrete compressive strength and the higher the moisture content, the more easily spalling occurs.