Residual strength of hybrid-fiber-reinforced high-strength concrete after exposure to high temperatures

Residual strengths of high-strength concrete (HSC) and hybrid-fiber-reinforced high-strength concrete (HFRHSC) after exposure to high temperatures were investigated in the paper. The results showed that normal HSC is prone to spalling after exposure to high temperatures, and its first spalling occurs when the temperature approaches 400 degreesC. For HSC reinforced by high melting point fibers, the first spalling occurs when the temperature reaches to approximately 800 degreesC, while there is no spalling during exposing to high temperatures for HSC reinforced by polypropylene (PP) fiber with a low melting point. Mixing high melting point fiber (i.e., carbon or steel fiber) with low melting point fiber (i.e., PP fiber) HSC greatly improves the properties of HSC after exposure to high temperatures. (C) 2004 Elsevier Ltd. All rights reserved.