EFFECTS OF Y TYPE PP FIBERS AND HYDROXYETHYL METHYLCELLULOSE (HEMC) ON DRY-SHRINKAGE OF CEMENT MORTARS

摘要

Dry-shrinkage has evident effect on the durability of cement mortars, so the research on it has great significance. The effects of Y type PP fibers, hydroxyethyl methylcellulose (HEMC), and the two admixtures together on the dry-shrinkage of cement mortars are studied in this paper. The dry-shrinkage is expressed by the length shrinkage of mortars at curing time of 2 d—180 d comparing to the length of mortar at 1d after casting. The experimental results show that HEMC and Y type PP fibers can reduce the dry-shrinkage of cement mortars, and the reduced extent increase with their increased amount (except for Y type PP fibers in volume fraction of 0.3%). Furthermore, the two together can obviously reduce the dry-shrinkage. However, either HEMC or Y type PP fibers or the two together all have limited effects on the dry-shrinkage.