Water-Resistant and Frost-Resistant Mortar Based on Composite Gypsum Binder

Innovative composite materials based on a mixture of cement and gypsum are currently gaining popularity due to the advantages of both components. This paper proposes using fine-grained concrete based on a composite gypsum binder (CGB) for the manufacture of facade tiles instead of the traditionally used portland cement with a filler made of crushed quartzite sandstone screenings. Research has shown that as a result of the complex effect of the optimal granulometric composition of the filler made of crushed quartzite sandstone screenings and CGB particles as well as a complex chemical additive including a polycarboxylate superplasticizer and a hydrophobic redispersible polymer powder on the properties of fine-grained concrete, a dense packing of mineral skeleton grains is achieved. This together made it possible to obtain fine-grained concrete on CGB Class C22.5 with a softening coefficient Ks=0.9 and frost resistance grade F150, and recommending it for the production of facade tiles.