Abstract
Durability of concrete structures depends on the mass transfer resistance of cover concrete. Therefore, the quality of the cover concrete is very important for ensuring the concrete structures' durability. For the reason, in order to ensure the durability of concrete structures, quality control of concrete based on mass transfer resistance of the structural cover concrete should be performed. To accomplish this, this study focused on the air permeability, one indicator of mass transfer resistance. When evaluating the test results, it is necessary to understand characteristics of the surface air permeability test, factors which may influence the measured values. As a result, considering the effect of dimensions of members on air permeability, it was found that the air permeability is less affected if the concrete age is more than 56 days. Therefore, it was found that one technique to solve influence of the age of concrete is to conduct the evaluation with the same water content comparing standard specimen to structural cover concrete under the same curing and conditions. in concrete having the same water-cement ratio it was clear that the surface air permeability was affected by the difference in bleeding properties even in the standard specimens. It is very important to take the bleeding properties into consideration in addition to water-cement ratio of concrete for predicting the surface air permeability as an indicator of durability.
