Behavior of natural additives in earthen coatings Study with Casein, molasses and banana gel

Abstract

Within earthen architecture, the coatings have the function of protecting the support wall from atmospheric agents that can affect it, degrading it. As components of the mixture, soil, stabilizers, additives, binders and water are used. The article presents the results of an investigation that aims to characterize the behavior of coatings on land, in tropical climates, with the addition of three organic additives: casein, molasses and banana gel, for use as a coating in restoration works. and in new constructions. As a methodology, field and laboratory tests were carried out on the mixtures. The field tests correspond to tests carried out or on site, which do not require specialized equipment. In the laboratory, their characteristics were evaluated without additives, and then with the additives in three determined proportions, seeking to identify their behavior against environmental factors. to which mortars are exposed. According to the results of the compression, shrinkage and water absorption tests, it is evident that mortars with molasses additive are recommended for new buildings, exposed to a medium level of rain. However, the mortar is not recommended for restoration works, since a greater loss of color on the surface was evidenced. Regarding linear shrinkage, the results for the banana and casein gel additives suggest that they will have little appearance of fissures or cracks.