Comparative studies of moisture protection properties of the lightweight hydrophobic plasters on lightweight fillers in relation to aerated concrete

Introduction. One of the most important properties of facade plasters is their ability to resist the effects of atmospheric moisture or hydrophobicity. Water penetrates into the facade plaster layer by adsorption. In this case, the passage of moisture through the plaster solution is caused by capillary action (water absorption, moisture permeability). Hydrophobization is a sharp decrease in the ability of materials to be wetted with water and aqueous mortars while maintaining vapor permeability. In this paper, a comparative study of the moisture-proof properties of lightweight mineral hydrophobic plaster based on foam ceramic granules "SPADAR", plaster mixtures with other similar lightweight fillers, in relation to aerated concrete. The values of capillary water absorption of plaster compositions, as well as water absorption by weight and the depth of water penetration into the body of aerated concrete samples uncoated and coated on all sides with the studied plaster compositions were compared. Aim. To investigate the moisture-proof properties of a plaster composition with foam ceramic granules "SPADAR" and similar plaster compositions (on foam ceramic granules "KERWOOD" (another manufacturer), granular foam glass and perlite sand) in relation to aerated concrete. Materials and methods. To conduct the study, previously developed lightweight hydrophobic plaster compositions for facade work with a dry density of no more than 600 kg/m3 and aerated concrete samples with a density of 600 kg/m3 were used. Water absorption by weight values of a control sample of aerated concrete, as well as aerated concrete samples coated on all sides with the studied hydrophobic plaster solutions were compared. The depth of water penetration into the body of these samples was also compared. Results. Water absorption by weight of control samples of aerated concrete and plastered with lightweight plaster mortars and the depth of water penetration into the aerated concrete layer after 1.5 hours were established. The advantages of the plaster composition using foam ceramic granules "SPADAR" are revealed. Conclusions. Based on the data obtained, the composition of a light hydrophobic plaster mortar was developed using foam ceramic granules "SPADAR" and further studies of these plaster compositions on vapor permeability and frost resistance are planned.