Effect Of Curing Methods On Properties Of High Performance Concrete

High performance concrete(HPC) has been gradually used widely at present. However, many engineers have observed that curing methods in the field affect the properties of HPC significantly. HPC has been found to be even more sensitive to curing conditions than ordinary concrete, particularly at early ages. But so far, the amount of information on the effects of various curing methods on its properties is limited. Therefore, it is necessary to understand the behavior of HPC under various curing conditions.In this paper, the effect of seven different curing methods on the properties of HPC, such as the compressive strength, the shrinkage, the resistance of carbonation and the resistance of chloride, was investigated. The curing methods included air-dry curing, curing agent, plastic film, standard curing and wet straw-matting curing with different curing time.The main conclusions are summarized as follows:1.HPC subjected to wet straw-matting curing have the highest compressive strength, the lowest depth of carbonation and the lowest chloride ion diffusion coefficient.2.The wet straw-matting curing can effectively reduce the shrinkage of HPC at early ages. But it does not always reduce the shrinkage at late ages. However, the shrinkage of HPC can be reduced effectively by the selected curing agent.3.An increase in curing time results in a considerable decrease in the carbonation depth and the chloride ion diffusion coefficient of HPC. The first 3 days of curing period are most effective. 7 days of curing time can ensure the strength development of HPC. However, 14 days of curing time can make a durable concrete.