高温后机制砂混凝土的本构关系试验研究

Experimental study on constitutive relation of concrete with manufactured-sand after high temperatures

对常温及高温(100、200、300℃)后机制砂混凝土的力学性能进行了试验研究。结果表明,机制砂混凝土的应力应变关系呈现非线性表征,且非线性程度受温度影响明显。基于Jones-Nelson-Morgan模型并引入温度系数,将机制砂混凝土的力学性能表达为与应变能相关的函数,建立了机制砂混凝土单轴压本构模型。模型的预测结果与试验测得的应力应变曲线吻合较好,表明建立的本构模型可以有效的描述高温后机制砂混凝土的力学性能。

Mechanical properties of the concrete with manufactured-sand were investigated experimentally at room temperature and high temperatures （ 100,200,300 ℃ ）.The result shows that stress-strain relationship of the concrete with manufactured-sand appears non- linear characteristics, and the degree of nonlinearity is significantly affected by temperature.A uniaxial compressive constitutive model of concrete with manufactured-sand was developed based on the incorporation of temperature coefficient into Jones-Nelson-Morgan model, in which the mechanical property of the concrete with manufactured-sand was expressed as a function of strain energy.Predictions of the model were agreed well with the stress-strain curves measured experimentally, which shows that the constitutive model can describe effec- tively the mechanical properties of concrete with manufactured-sand after high temperatures.