关键词: 高温下;温度场;混凝土强度;粘结性能;本构模型

Abstract: To investigate the influence of temperature on the bonding performance between steel bar and concrete, thirty standard cube specimences , eight specimens for temperature field test and fifteen central pull-out test specimens were cast .After exposed to 20 ℃, 100 ℃, 200 ℃, 400 ℃, 600 ℃, the compression strength and tensile splitting strength of the standard cube specimens , temperature field test of pull-out specimen and pull-out test between rebar and concrete were tested immediately .The influence of high temperature on concrete compressive strength and tensile splitting strength are studied systematically .According to the temperature field test results , a simplified test method for the pull-out test between reinforcing bar and concrete under high temperature is proposed .The degradation law of bond behavior between rebar and concrete under elevated temperature is investigated . A bond-slip constitutive model with considering the influence of temperature on bond strength , slip and failure states is proposed based on Harajli Model .The experimental results show that the strength of concrete and the bond strength between steel bar and concrete under high temperature decline with increasing temperature generally , with a steep reduction at 100 ℃.The variation trend of bond strength under high temperature is similar to the tensile strength of concrete .A bond-slip constitutive model between steel bar and concrete under high temperature is proposed .

Key words: high temperature;temperature field;concrete strength;bond property;constitutive model