DESTRUCTION OF POLYMERCEMENT PLASTER COATING DURING OPERATION OF WALL STRUCTURE

Abstract

The disadvantage of limesand, limecement and cementlime plaster mortars is the intensive formation of cracks during hardening and operation, which leads to rapid destruction of the plaster coating, its detachment from the masonry, which causes increased humidity and loss of heat through it, as well as reducing the service life of the wall structure.The main reason for this is choosing the components of the mixture and their quantity without taking into account the processes occurring during curing of the coating and its "work" as part of the wall structure during operation.To solve the problem, the wall structure should be considered as a system that includes a plaster coating associated with the masonry through the contact area. The composition of the soluble mixture must be prescribed taking into account the processes occurring during its hardening and operation of the wall structure, the stresses that occur in it. It is necessary to choose the components of the mixture and their quantity, so as to ensure the reduction of stresses in the plaster coating and its contact zone with the masonry, to values, less than destructive. This will increase the service life of the coating and wall construction.Since the properties of polymercement plaster mortar are determined by its composition and structure, to achieve these goals, the possibility of managing them by purposeful selection of components of the soluble mixture was analyzed. For this purpose, redispersible polymer powders (RPP), polymer fiber, cellulose esters, and a fine filler with a low modulus of elasticity were used.Studies have shown that their use has changed the nature of the destruction, reduced the number of cracks formed during the hardening of the plaster mortar, slowed down their development and increased the service life of plaster mortar and the wall structure.