EARLY-AGE CREEP EFFECTS OF CEMENT CONCRETE PAVEMENT

Based on a creep model for microprestress-solidification theory, considering the influence of material, structure and environmental parameters, a three-dimensional simulation program for early-age mechanical behavior of pavement was established, and the creep effects mechanism of three-dimensional pavement structure were analyzed. The results show that creep is a relaxation effect on early-age pavement, which significantly reduces the early-age curling and stress. The influence magnitude of creep on early-age behavior of pavement is similar to that of temperature gradient and that of edge constraint. Creep effect is also significantly affected by edge constraint, temperature gradient, humidity gradient and overall temperature conditions, and has spatial position non-uniform distribution characteristics. Under the effect of creep, the maximum relaxation position of stress is close to the middle of the restricted edge. The creep relaxation effect has significant time-dependent characteristics. It is most significant in the first 7 days and tends to be stable after 60 days. Creep relaxation effect increases significantly with temperature gradient and overall temperature increasing. Theoretical comparison shows that, ignoring the influence of temperature will underestimate the creep effect under high temperature and overestimate the creep effect under low temperature. It is recommended to use creep effect design to reduce early-age curling and stress in pavement engineering.