Effect of Mineral Additives on Internal Relative Humidity and Dry Shrinkage of Light Weight Aggregate Concrete

摘要

Effect of fly ash and slag on internal relative humidity (IRH) and dry shrinkage of light weight aggregate concrete (LWC) are studied in this paper. As indicated in this test, mixed with mineral additives can reduce dry shrinkage of concrete. The more volume of fly ash and slag ash, the lower decrease speed of IRH is, which contribute to the decreases of dry shrinkage rate too. At the same curing-age and dosage, the relative humidity inside the fly ash concrete is higher than the slag one. As consequence, the rate of dry shrinkage of fly ash concrete is lower than slag concrete. Also, there is a significant linear correlation between the lowered values of IRH and dry shrinkage rate.