Desenvolvimento de argamassas para revestimento de alvenaria com adição de borracha reciclada de pneu.

Abstract

The external coating of the masonry is an element of high importance for buildings, exerting outstanding function related to sealing, finishing, thermal and acoustic insulation and mechanical resistance, among others. However, a closer look is required regarding the thermal insulation role that the wall covering can exert. The objective of this research was to evaluate the influence of the coating of alternative mortars containing recycled rubber tires on the thermal performance of masonry, and also carried out studies on the physical-mechanical characterization of these alternative composites. Initially, the reference mortar was made in the 1:5 trace (cement: sand), and later the natural aggregate was partially replaced by recycled rubber in the percentages of 5, 10, 15, 20, 25%, making possible the study of six traces of mortars. The tests were carried out for physical characterization in the fresh and hardened state (consistency index, mass density and water absorption by capillarity) and for mechanical characterization (resistance to axial compression, diametral compression traction and flexural tensile strength). Experiments were carried out for thermal characterization of the mortar (inertia and thermal conductivity). The results showed that the inclusion of recycled tire rubber causes a reduction in mass density in the fresh and hardened state, as well as the absorption of water by capillarity. It was also observed a strong reduction of the mechanical strength of the alternative mortars containing tire rubber. As for the thermal characterization analysis, it was found an inversely proportional relation between the coefficient of thermal conductivity and the amount of tire rubber in the mortar. Through this research, it was possible to conclude that the tire rubber helps the mortars to function as a good thermal insulation, which contributes to an increase in the thermal comfort of the occupants of the buildings. Observed that the greater the amount of tire rubber, the better the thermal performance of the composites. The results make it possible to conclude that mortars, containing tire rubber, make a valuable contribution to the masonry coating, making it possible to use it in rural construction.