In view of the fact that the creep degree of concrete commonly used in mass concrete engineering is actually a visco-elastic model which considers concrete age under load,and it is inconsistent with the reality because the thermal stress calculated by visco-elastic model is bigger under big temperature load,the elastic creep formula was promoted to elasto-plastic creep formula.It was proposed that the plastic creep should be considered through linking a Bingham series whose strengthen parameter and viscosity factor increase as the concrete age increases on the basis of elastic creep model.An elastio-plastic creep formula with implicit and explicit arithmetics was deduced.and relative programs were developed based on this formula.The analysis of engineering examples showed that the elastio-plastic creep formula is feasible, and the values calculated by it are more reasonable than that of elastic creep one.
