Effect of water binder ratio and fiber content on the drying shrinkage characteristics of hydraulic ECC

Abstract

Hydraulic ECC is a major attempt to apply ECC to hydraulic engineering based on the crack resistance requirements and technical characteristics of hydraulic structures. Hydraulic ECC materials with similar diffusivity are prepared, and the effect of water binder ratio and fiber content on the drying shrinkage characteristics is analyzed. The results shows that the drying shrinkage deformation of hydraulic ECC mainly occurs within 7 d age, and the shrinkage rate tends to be stable at the 28 d age. Besides, when increasing the water binder ratio, the water quantity increases slightly while the amount of cementitious material decreases, in addition, the amount of sand increases, as a result, the drying shrinkage of hydraulic ECC decreases. Moreover, PVA fibers are conducive to hinder water loss and offset the negative pressure of capillary pores, therefore, with the increase of PVA fiber content, the drying shrinkage of hydraulic ECC decreases. Furthermore, the smaller the maximum particle size of sand, the greater the drying shrinkage of hydraulic ECC.

Keywords

hydraulic ECC / drying shrinkage / water-binder ratio / PVA fiber / sand particle size