STUDY ON DYNAMIC BEHAVIOUR OF CONCRETE BY CYCLE LOADING AND UNLOADING CONDITIONS

The dynamic cyclic loading and unloading tests under five different loading rates are implemented with large multi-function static and dynamic force triaxial apparatus. The statistical analysis of the change rules about basic physical and mechanics parameters is carried out. The results show that the peak stress and the elastic modulus increase with the increase of loading rates, and that the peak strain has a large discreteness with the change of loading rates. On this basis, the stiffness degradation rule of concrete under different loading rates is further studied. Finally, a dynamic damage constitutive model based on Weibull statistical theory in a sectional form is selected for fitting the experimental data. It is verified that this model can simulate the constitutive properties of concrete material well.