Investigation of the curing time on the mechanical behavior of normal concrete under triaxial compression

- Effect of curing time on the triaxial mechanical behavior of concrete was studied.
- Failure strength, plastic deformation is highly dependent on the confining pressure.
- Present curing time dependent model can describe the main behavior of the concrete.

Due to its hydration process and applications under complex loadings, concrete is a live material and might be subjected to triaxial loadings in short time after pouring. The aim of this study is to investigate the main mechanical behavior of normal concrete at different curing time under different confining stress state. A series of triaxial compression tests of a concrete are conducted firstly. Four curing times of 3, 7, 14 and 28 days, as well as four confining pressures of 0, 5, 10 and 20 MPa, are considered at a C30 concrete type. The interesting observation is that the failure strength and plastic deformation of concrete is not only related to curing time, but also highly dependent on the confining pressure. With the increasing of confinement, curing time dependence on deformation and failure strength is increasing and decreasing respectively. Based on experimental investigations, a curing time dependent constitutive model is proposed. In this model, the effect of curing time is introduced to elastic characteristic, failure function and plastic hardening law. Finally, calibration of the proposed model shows good agreement with the test results.