玄武岩机制砂混凝土应力-应变关系研究OA

Taking the machine-made sand produced by the waste basalt of a tunnel in Yunnan as the aggregate,standard prismatic and cube specimens were prepared for uniaxial compression test,and their stress,deformation and failure characteristics were analyzed.The whole process curves of compressive strength and stress-strain under uniaxial compression are obtained,and the stress-strain relationship and modulus calculation method are established combined with Guo Zhenhai model.The accuracy of the stress-strain relationship is verified by numerical simulation.The result shows that due to the obvious edges and corners of machine-made sand,the fracture surface or cracks appear at the junction of aggregate and cement mortar.During failure,the edges on both sides of the concrete specimen are displaced greatly and spalling occurs,that is,X-shaped failure.Compared with conventional river sand concrete,basalt machine-made sand concrete has more cracks in compression failure.With the increase of strength of basalt machine-made sand concrete,its brittleness increases gradually.The cube compressive strength test of basalt machine-made sand concrete and the conversion coefficient of axial compressive strength are recommended to be 0.76.The stress-strain relationship calculation method of basalt machine-made sand concrete based on Guo Zhenhai model can better reflect its stress and deformation characteristics,and the fitting values are close to the numerical simulation results,the error is small,and the calculated results are relatively resonable.