2022 Volume 76 Issue 1 Pages 386-392
The frost damage resistance of the high-strength concrete using a shrinkage reducing agent was examined based on the amount of air after hardened. Two types of shrinkage reducing agents were used, and the water-cement ratio of concrete was 38％. The amount of air in the fresh concrete was set to 3, 5, and 7％. As a result of the experiment, it was found that all the shrinkage reducing agents showed high frost damage resistance even when the air volume of fresh concrete was 3％. As for surface damage, in principle, the smaller the spacing factor after curing, the higher the frost damage resistance, but the smaller the spacing factor, that is, the greater the deterioration when there is a lot of air in the concrete. It was found that too much air was taken as a weak point in the strength of concrete and caution was required.
