EXPERIMENT OF MECHANICAL PERFORMANCE OF FIBER CERAMSITE CONCRETE AFTER ELEVATED TEMPERATURE

It was carried out that loading tests of polyacrylonitrile fiber ( PANF) ceramsite concrete and polyvinyl alcohol fiber ( PVAF) ceramsite concrete at 20，200 400，600 and 800 ℃ to study the change laws of the compressive ＆ tensile strengths and elastic modulus of the ceramsite concrete with temperatures，which were also compared to the ceramsite concrete without fibers． The test results show that the cubic compressive strength of fiber ceramsite concrete is not significantly improved． However the splitting tensile strength after elevated temperature is improved effectively． PANF can improve the brittle fracture performance of ceramsite concrete at the peak loading． The residual prism compressive strength of PANF ceramsite concrete is also obviously increased when the temperature ranges from 20 ℃ to 600 ℃，and the elastic modulus of the PANF decreases more slowly when the temperature ranges from 20 ℃ to 400 ℃．