Abstract
Long term curing using Water-Repellent Sheets was applied to seven actual structures and it was confirmed that the substance permeability was improved by a nondestructive test. In addition, the effect of quality improvement was analyzed under blending conditions of concrete such as cement type, unit water volume and water cement ratio. As a result, we confirmed the proportional relationship between water cement ratio of concrete and surface water absorption rate by long term curing and when its water cement ratio is large, its suppressing effect is high. This indicates that the hydration reaction is continued by suppressing dissipation of free water by sheet curing, the concrete surface becomes dense, and the increase in surface water absorption rate can be suppressed.