Experimental Study On The Behavior Of Uniaxial Loaded Concrete Under High Compression Rates

Generally, concrete is a elastic-plastic material. When the strain rate is low, the concrete is not sensitive to the strain rate. With the strain rates increasing, the sensitivity of concrete is increasing. Therefore, the exploration of the behavior of uniaxial loaded concrete under high compression rates on the constitutive relation is very important for practical engineering.The dynamic axially compression experiments of concrete are carried. According to those results, the model of uniaxial loaded concrete under high compression rates have been built.Through systematic and comprehensive experimental study and theoretical analysis, the effects of strain rates are considered, and stress–strain constitutive relation of C20 ~ C35 concrete under uniaxial compression is established. The work have provides a theoretical basis for analysis of concrete structures. Rule of the different loading rates on the different strength of concrete compressive strength, modulus of elasticity in compression, Poisson ratio, critical strain and stress–strain curves under different strain rates are studed through a large number of tests, uniaxial compression stress-strain curve equations under different strain rates are given. The collecting device is the U.S. Iotech's high-speed portable test system. It is used to measure high-speed of dynamic vibration response signals. The main work and some conclusions are as follows:1 ) The premise of measuring stress–strain curve for concrete is analyzed theoretically. The device has been revised to raise its rigidity. The device has higher rigidity and greater load range.2)In order to make stress–strain curve more precise, the factors which affect the result of mesuring are analyzed theoretically.Through a large number of tests, loading rates have no effect on stress–strain curves, Poisson ratio, critical strain and modulus of elasticity. Loading rates only have an effect on compressive strength.