Compressive behavior of stirrup-confined concrete under dynamic loading

- The new design of the pure stirrup confined specimen without concrete cover.
- The coupling between the strain rate effect and the stirrup confinement effect.
- The newly developed stochastic damage model with considerations of the strain rate effect and the stirrup confinement effect.

Systematic experiments were designed and performed to investigate the compressive behavior of cuboid stirrup confined concrete under dynamic loading. A total of 123 prismatic concrete specimens with four stirrup volume ratios were tested under three levels of strain rates with the help of an electro-hydraulic servo-controlled concrete testing system. Photos of the failed specimens and the complete stress-strain curves were obtained under the strain control loading scheme. The mean values and the standard deviations of stress-strain curves were also obtained and analyzed. The results show that the strength of concrete are enhanced by the stirrups as well as strain rates. The enhancement of stirrup confinement and the enhancement of strain rate are comparable to each other. The stochastic damage model is adopted to describe the nonlinear performance and the randomness of concrete. Based on the experimental data, the model is verified and the parameters are identified. This study provides a foundation for the dynamic analysis of concrete structure.