塑性混凝土三轴受压本构关系试验研究

Experimental Research on the Constitutive Relation of Plastic Concrete under Triaxial Compression

试验研究了掺黏土和膨润土龄期(540 d)的塑性混凝土三轴受压本构关系。根据定侧压三轴试验拟合不同围压下的塑性混凝土应力-应变曲线,对比发现(σ1=0.4 MPa,σ2=0.6 MPa)、(σ1=0.4 MPa,σ2=0.8 MPa)中高侧向围压下的应力-应变曲线基本一致,中高侧向围压下的应力-应变曲线上升段斜率及峰值压力比(σ1=0.2 MPa,σ2=0.4 MPa)低侧向围压的应力-应变曲线上升段斜率和峰值压力大,此外还提出了塑性混凝土定侧压情况下的峰值割线模量计算公式及三轴受压本构关系模型,为塑性混凝土三轴受压条件下数值仿真分析提供了依据,进一步推动塑性混凝土的工程应用。

The triaxial compression constitutive relation of plastic concrete with clay and bentonite age(540 d)is studied.The stress-strain curves of plastic concrete under different confining pressures are fitted according to the fixed lateral pressure triaxial test.The results show that under medium and high lateral confining pressures(σ1=0.4 MPa,σ2=0.6 MPa),(σ1=0.4 MPa,σ2=0.8 MPa)lateral confining pressure stress-strain curves are basically the same.Medium and high pressure stress-strain curve segment rising slope and the peak pressure are larger than in(σ1=0.2 MPa,σ2=0.4 MPa)the low pressure side stress-strain curve rising slope and the peak pressure.In addition,the calculation formula of peak secant modulus and the constitutive model of triaxial compression under the condition of plastic concrete lateral pressure are proposed,which provides numerical simulation analysis for plastic concrete under triaxial compression conditions.On this basis,the engineering application of plastic concrete is further promoted.