Análise da potencialidade do uso de resíduo de borracha de pneu, em argamassa de revestimento externo, na cidade de Pelotas/RS.

Abstract

A constant concern of society is the impacts caused by man to the environment, and for this reason researchers have been studying ways to advance techniques of (re)use of alternative materials as a way to mitigate the impacts caused by the disposal of them. Among the waste generated, one that has been growing in great quantity is that of the tire. One way of using waste is by incorporating it into mortars, replacing a non-renewable component with waste, as this material is widely used in construction and is present in many façade. When the mortar does not have adequate properties, pathological manifestations appear in this coating, impairing its performance in its functions. This research had the objective of evaluating the potentiality, from physical and mechanical properties, of the use of tire rubber residue as partial substitute of the small aggregate, in mortars for external coating. Also, the objective was to evaluate if the use of this residue interferes in the appearance of pathological manifestations, when they are used in the city of Pelotas/RS. The experiments are based on two distinct traits, one of cement mortar, the other of cement and lime. The replacement of sand by rubber residue occurred in proportions of 0%, 2,5%, 5%, 10% and 15%. The properties evaluated in the first step were axial compressive strength, diametral compression tensile strength, capillary absorption, immersion absorption and void index. For the second stage of the research the tensile strength in the flexion was analyzed and, through masonry prototypes, an evaluation was made of the appearance of pathological manifestations, the absorption by the pipe method and the tensile bond strength. The results of the first stage showed that mortars with residual, when compared to the reference, obtained a decrease in the mechanical performance of all the families and an improvement in the absorptions and voids index of some families. In the monitoring of the appearance of pathological manifestations in the prototypes with mortar coating, carried out in the second stage of the research, it was verified that the use of the rubber residue in the mortar did not influence in the appearance or minimization of such problems. It was also found that mortars with residual presented worse performance at flexural traction when compared to reference mortars. The absorption by the pipe method was shown to be statistically the same in most mortars. The tensile bond strength of a mortar did not reach the limit required by the Brazilian standard. However, the other mortars were found to be inside the required one, being able to be used both as internal coating and as external coating.