Compressive behavior and constitutive model for roller compacted concrete under impact loading: Considering vertical stratification

This paper presents fundamental investigation on the dynamic compressive behavior and constitutive model of roller compacted concrete (RCC) at intermediate strain rates. Dynamic uniaxial compression tests of RCC specimens were performed by split Hopkinson pressure bar (SHPB). Then, the dynamic compressive properties of RCC material under intermediate strain rate are investigated in terms of failure pattern, stress-strain curve, dynamic increase factors (DIF) of compressive strength, Young's modulus and critical strain at peak stress. The polynomial fitting method (in terms of lgε̇) was well adapted to describe the empirical strain rate effect. The vertical stratification of RCC caused by different mix proportion and compacted layer structure has influence on its dynamic mechanical behavior. Due to the statistically discreteness of RCC material, the distributions of dynamic mechanical properties were analyzed with statistics theory. A new statistical constitutive model was proposed with statistical analysis, in which the two main parameters were related to strain rate and conventional mechanical properties. Finally, the developed constitutive model is verified and demonstrated to be high applicability to RCC material and improves the estimations of the dynamic mechanical properties of RCC.