The influence of water-repellent admix-tures on the water resistance of hardened gypsum-cement-puzzolan paste based on low-grade gypsum

摘要

The widespread use of gypsum-cement-puzzolan binder (GCPB) is a result of its low cost, environmental friendliness and the high performance properties of the products based on it. GCPB is also used during the production of partition panels, floors, three-dimensional utility blocks, finishing materials and other products [1, 2]. It is noted that widespread use of products based on gypsum, which includes GCPB, is limited because of their low water resistance. P.P. Budnikov and V.N. Yung consider that the main reason for the low water resistance is the high solubility of gypsum (2.05 g/1 at 20 ℃). P.A. Rebinder and other scientists find the reason for the loss in strength to be the wedging action of water films on the internal surfaces of mi-crocracks, causing detachment of separate microelements of the crystalline structure. The current studies are therefore oriented towards improving the water resistance and increasing the scope of use of products based on gypsum.