Análise da resistência de aderência em revestimento de argamassa aplicado em paredes de concreto moldadas no local

Abstract

The objective of this research is to analyze the adherence of mortar coating applied to elements obtained through the concrete walls construction system. Six concrete substrates were molded using aluminum formworks and the coating was made with industrialized mortar. The variables analyzed were the age of the substrate (11 and 117 days) and the surface treatment (without roughcast, rolled roughcast and conventional roughcast 1:3). The characterizations of fine aggregate (granulometric distribution, specific mass and unit mass), cement (fineness index and specific mass), roughcasts (specific mass, consistency index, tensile strength in flexion and compression), mortar (consistency index, fresh mass density, water retention, capillary absorption, hardened mass density, tensile strength in flexion and compression), concrete (slump, capillary absorption, total absorption and resistance to compression), substrate (absorption by the pipe method) and coating (tensile bond strength). It was observed that the adherence of the mortar coating on the walls without superficial treatment and on the walls with conventional roughcast was insufficient, being zero the result of most of the testimonies in the tensile adherence strength test. On the other hand, on the walls where rolled roughcast was used, there was an improvement in the adhesion of the coating. From these walls, a greater resistance to traction adhesion was also identified in the walls with curing of 11 days, when compared to the walls with curing of 117 days executed with the same coating system. In addition, it was found that there was an increase in tensile adherence strength in the coating on substrate with greater total and surface absorption and in substrate with less resistance to compression. [resumo fornecido pelo autor]