Estudo da aderência do revestimento de argamassa executado com chapisco lançado e rolado sobre substrato de bloco cerâmico e de concreto

Abstract

With the increasing of competition in the civil construction field, it becomes necessary to improve the techniques employed in the construction systems, such as the walls coating with inorganic mortars. Roughcasting is part of the external mortar coating system and were created new methodologies regarding the execution of this layer in order to achieve higher levels of production and quality. One of them is known as rolled roughcast, which has physical characteristics similar to the traditional practice and its execution is carried out with the assistance of a texture roller. In this paper was compared the difference between the two execution methods of roughcast regarding to the adhesion resistance of the mortar coating, both on ceramic block and concrete block walls. The analysis was carried out according to the outcomes provided by the pull off adhesion test in accordance to ABNT NBR 13528/2010, which was conducted with two walls prototypes, one made of ceramic blocks and the other one with concrete blocks, both executed with one side of traditional roughcast and the other one with rolled roughcast. The results suggest that the adhesion of the coating conducted with the rolled roughcast had higher resistance of pull off than the one carried out with traditional roughcast for both substrates, presenting an increase up to 40,33% in the average adhesion strength value. In addition, it was verified that usually the adhesion of the mortar coating is higher to the walls made with concrete blocks because the porosity surface. Therefore, even with the large variability of the pull off resistance outcomes between the four tested systems, all of them can be used in the construction, because they achieved the minimum resistance prescribed in the standards.