The influence of the elevated temperature and fire duration on material characteristics of concrete was studied in this paper.The damage along the vertical direction was examined by testing the splitting tensile strength layer by layer.Results show that the concrete mechanical properties

including compressive strength

tensile strength and elastic modulus

decrease sharply as temperature rises.Compressive strength and tensile strength decrease as fire duration increases.The results also show that the residual strengths for different fire durations are of great difference even treated with the same elevated temperature.The curves of strength along the depth show nonlinear presentation with short durations

while show linear presentation with long durations.Multiple transverse splitting method based on the core drilling method

and modified ultrasonic testing method which assumes that the damage model was hyperbolic and the propagation path of the head wave was parabola were presented for concrete testing.