There is no temperature stress and temperature curling according to the present cement concrete pavement design, when the temperature gradient of cement concrete pavement in service is zero, and it does not consider the effect of Built-in curling caused in early-age setting process of cement concrete to cement concrete pavement in service. In fact, there is Built-in curling in cement concrete slab when it is after the completion of the cement concrete slab is poured, and the curling is mainly upward. It is in the setting process, when cement concrete is on the final set, the cement concrete is at the critical moment when is just able to bear load, and it exists temperature gradient but no strain in the pavement slab, the temperature gradient is known as "Built-in construction temperature gradient" in AASHTO2002 design guidance, and it is the important part of the Built-in curling. In this paper, cement concrete beam specimens were poured in outdoor and temperature sensor and strain sensor were buried in the cement concrete specimens to detect early-age internal temperature field and strain field, and then the study of Built-in curling and Built-in construction temperature gradient were carried out.
