高温后轻质多孔混凝土力学性能试验

Experimental Study on Mechanical Properties of Lightweight Aerated Concrete After High Temperature

摘要:

通过高温后轻质加气混凝土的力学性能试验，测得了抗压强度、弹性模量和峰值应变与温度的关系.试验表明：高温后轻质加气混凝土的抗压强度在100 ℃时略微提高，到300 ℃时逐渐下降，超过300 ℃时，强度变化不明显;在100 ℃以内，弹性模量基本保持不变，超过100 ℃后，弹性模量不断减小，与温度成线性关系;随着温度的升高，峰值应变逐渐增大，呈直线上升趋势.最后分析了不同温度下的应力应变曲线，提出了高温后轻质加气混凝土的本构模型.

Abstract:

In this paper, through the axial compression test of lightweight aerated concrete after high temperature, the relationships between temperature and mechanical properties, such as compressive strength, elastic modulus and peak strain, are obtained. The results show that the compressive strength of lightweight aerated concrete increases slightly at 100 ℃, and decreases gradually at 300 ℃. When the temperature exceeds 300 ℃, the strength change indistinctively. At 100 ℃, the elastic modulus remained basically unchanged; across 100 ℃, the elastic modulus decreases continuously, and comes into being linear relationship with temperature. With the increase of temperature, the peak strain gradually increases in a linear upward trend. Finally, by analyzing the stressstrain curves at different temperatures, a constitutive model of lightweight aerated concrete after high temperature is proposed.