Finite element analysis of steady-state uniaxial basic creep of high-performance concrete

This study aims to propose a new approach to predict the long-term thermal compressive and tensile uniaxial basic creep behavior of high-performance concrete sample at different temperature levels (20 degrees C, 50 degrees C, 80 degrees C), by using nonlinear finite element analysis. The new approach is based on the coupling between Burger's rheological model, two-phase composite material models and maturity concept. Burger's rheological model is employed to predict the compressive single axial BC strain. Furthermore, the maturity approach is employed to evaluate the mechanical properties of concrete. However, the thermal properties of concrete (thermal conductivity and specific heat capacity) are estimated by seven models available in literature based on two-phase composite material models. The obtained results show that the thermal shrinkage plays an important role in the estimation of the BC. In addition, increasing the temperature amplifies the rate and the magnitude of the BC and thermal stress generated by thermal shrinkage. The numerical results show that the BC is more relevant in tension than in compression when compressive and tensile creep in isothermal conditions and stress/strength ratio (30%) are equivalent.

Automated summary

This study proposes a new approach to predict the long-term thermal compressive and tensile uniaxial basic creep behavior of high-performance concrete at different temperature levels. The results show that thermal shrinkage plays an important role in the estimation of basic creep, and increasing the temperature amplifies the rate and magnitude of basic creep and thermal stress.