Research on Hydration of Waterproof-Typed Semi-Hydrated Gypsum
The influences of saline waterproof agent composed of carboxylic acid sodium (RCOONa), Al2(SO4)3, K2SO4 on the hydration of semi-hydrated gypsum were investigated. The results showed: (1) with the concentration of K2SO4 increasing, the ζ potential rose due to the increasing K+ entering the electric double layer of gypsum; (2) with the concentration of Al2(SO4)3 heightening, the ζ potential gradually decreased as a result of the formed AFt phase during the hydration process and the increasing Al3+ entering the electric double layer of gypsum. The ζ potential rose because the RCOO- base groups adhered to the surface of gypsum crystal, which slowed down the growth rate of the gypsum crystal in direction c, and short hexahedron poles were produced.
Shiquan Liu and Min Zuo
J. Q. Li et al., "Research on Hydration of Waterproof-Typed Semi-Hydrated Gypsum", Advanced Materials Research, Vols. 306-307, pp. 909-912, 2011