Residual strength and pore structure of high-strength concrete and normal strength concrete after exposure to high temperatures

摘要

Based on normal strength concrete(NSC)and high-strength concrete(HSC),with compressive strengths of 39,76,and94 Mpa respectively, demage to concrete under high temperatureswas identified. After exposure to temperatures up to 1200℃,compressive strength and tensile splitting strength weredetermined. The pore structure in HSC and in NSC was clsoinvestigated. Results show that HSC lost its mechanical strengthwere determined. The pore structure in HSC. The range between400 and 800℃was critical to the strength loss. Hightemperatures have a coarsening effect on the microstructure ofboth HSC and NSC. On the whole HSC and NSC suffereddemage to almost the same degree, although HSC appeared tosuffer a greater worsening of the permeability-related durability.1999 Elsevier Science Ltd. All rights reserved.