CURLING BEHAVIOR MECHANISM OF CEMENT CONCRETE PAVEMENT AT EARLY AGE

In order to understand the behavior and formation mechanism of cement concrete pavement curling at its early age, vibrating wire sensors with a large range were designed to monitor the vertical displacement of slabs, and the whole vertical deformation in the first 14 days of slabs under summer conditions was continuously monitored. The behavior and formation mechanism of early-age curling were numerically analyzed by the special early-age character simulation program. The results show that: the evolution behavior of the early-age curling has three stages, namely, flat slab to corner curling, corner curling to intermediate curling with slab uplift at 1/4 positions, and corner curling to intermediate curling to curling at the middle of a slab. There are several curling modes and asymmetric phenomena in the early age of slab deformation. Early-age curling is significantly correlated with an environmental field, with concrete modulus, with creep and with structural restraint. Creep has a significant dissipation effect on the early-age behavior of a slab. In the combination case of insufficient constraint and insufficient driving of temperature deformation, the solidification shape of 1/4 diagonal slab uplift and will be produced, resulting in local unevenness and the void in corresponding position of a slab. It is suggested that the action characteristics of early-age built-in deformation and basis parameters should be distinguished, and the effect of built-in deformation can be equivalently reflected by support states.