高温后混凝土抗剪性能试验研究

Experimental Study on the Shear Properties of Concrete after Exposure to High Temperature

通过对不同温度、不同恒温时间下四点受力等高变宽梁的剪切试验,研究高温后混凝土近似纯剪状态下的抗剪性能。试验结果表明:不同温度下剪切破坏的形态基本一致,形成与梁轴线的夹角约为45。(受拉主应力面)的裂缝断裂。随着温度增加,剪切强度线性下降。在400℃以下时极限剪应变基本保持不变,当温度大于400℃时,随着温度增加,极限剪应变急剧增大,最高受热温度对其也有一定影响。初始割线模量和峰值割线模量随着温度的增加成线性降低。通过试验还获得了高温后混凝土的剪应力一剪应变关系曲线.

Based on shearing tests of concrete specimens under different temperatures and thermostatic times,the shear properties of concrete after exposure to high temperature were studied in this paper.The results show that the shear failure modes were similar,and the specimens were all damaged with cracks the axis angle of 45 °.With the increase of the temperature,the shear strength linearly decreases.When the temperature is below 400 ℃,the maximum shear strain remains unchanged under different temperature conditions.However,as the temperature goes beyond 400 ℃,the maximum shear strain increases dramatically with the temperature and it is influenced by the temperature elevation.With the increase of temperature,the initial and peak shear modulus decreases linearly.Concrete stress-strain relationships under temperature elevation were obtained through the experiments.