THE EFFECT OF ORTHOPHOSPHORIC ACID ON THE SETTING AND HARDENING OF GYPSUM BINDER
Authors
- N. Kozhakulov M. Auezov South Kazakhstan Research University, Shymkent, Kazakhstan
-
B. Kopzhasarov
M. Auezov South Kazakhstan Research University, Shymkent, Kazakhstan
-
S. Mominova
M. Auezov South Kazakhstan Research University, Shymkent, Kazakhstan
-
S. Duisenbayeva
Kazakh National University of Water Management and Irrigation, Taraz, Kazakhstan
-
G. Kopzhasarova
M. Auezov South Kazakhstan Research University, Shymkent, Kazakhstan
DOI:
https://doi.org/10.55956/WCIL8851Keywords:
orthophosphoric acid, gypsum, water, solution, hydrate, concentration, binder, setting, hardening, crystalsAbstract
This article discusses the possibilities of the influence of orthophosphoric acid on the setting and hardening of binders of the obtained results under various conditions. The effects of orthophosphoric acid of various concentrations on the basic physical and mechanical properties of gypsum binder have been studied. According to the results of the studies, it was found that the hydration rate of calcium sulfate semihydrate crystallizing in phosphoric acid solution is much lower than the hydration rate of the control semihydrate (hydration in water) and depends on the concentration of acid in the solution. Delayed hydration of the semihydrate in the initial period is characteristic, which indicates the possibility of film formation on the crystal surface. The conducted studies allow us to conclude that the recrystallization of semi-aqueous gypsum during treatment with aqueous solutions of orthophosphoric acid proceeds both through the solution and in the solid phase, with the solution simultaneously dissolving the semihydrate and forming dihydrate crystals.
