Abstract: C60 high performance concrete with 0% and 0.2% polypropylene fiber were subjected to high temperature test of simulated fire.The uniaxial compressive strength of concrete were carried out before and after exposed to high temperature.Infrared thermography technique was used to study the infrared thermal image of concrete after high temperature.The relationship among the average temperature rise of infrared thermal image, the fire temperature and the ratio of uniaxial compressive strength was established.The CT scan test was conducted on the high-strength concrete specimens at room temperature and 300 ℃,400 ℃,500 ℃ respectively.The effect of fiber on crack generation and expansion in concrete was analyzed.

Key words: high performance concrete;polypropylene fiber;high temperature;infrared thermal image;CT scan