Abstract
The property of concrete surface which influences the durability of concrete structure will be greatly affected on curing conditions. In this study, the effects of mix proportions, demolding timing and curing methods on concrete surface were investigated. As a result, it was better to delay the demolding timing, when atmospheric curing or membrane curing was carried out. When the atmospheric curing was carried out at the early age, it allowed the concrete strength to reach only 70％ of the strength demolding at the age of 7 days in case the water-cement ratio of 53.5％. However, it was better to be earlier the demolding timing, when the wet curing was carried out. Then, the wet curing was carried out at the early age, it could allow the concrete strength to reach 150％ of the strength demolding at the age of 7 days after in air, in case the water-cement ratio of 45％. Furthermore, the coefficient of air permeability could become small, it was between 2×10－16m2 and 0.1×10－16m2.
