Blocos EVA de vedação: compatibilização entre aspectos físicos, mecânicos e térmicos

Abstract

Ethylene Vinyl Acetate (EVA) is a thermoset and non-biodegradable polymer widely used in the footwear industry, wherein about 20% of this material becomes waste during the production of soles and midsole. Several researches aiming at recycling of these EVA waste have pointed out possibilities of elaborations of lightweight concrete composites with varied applications in buildings. In this context, the purpose of the present study is to evaluate the compatibility between physical, mechanical and thermal aspects of masonry of EVA blocks, highlighting the adhesion between the coating mortar and the components. This work investigates the need for a layer of roughcasts in the coating system applied to cementitious components (EVAi Blocks), which has a high EVA content (80%) and therefore has a rather rough surface. The study was structured in three experimental stages: adequate choice of EVA residue/aggregate; characterization/compatibility of the physical and mechanical properties of EVAi Blocks and laying/coating mortars; and evaluation of the mechanical and thermal performance of masonry with and without roughcast in the execution of the coating. Based on the results, it can be concluded that: the process of beneficiation of the EVA residues/aggregates to produce the EVAi Blocks favored the compatibility between the largest unit mass of the EVA aggregate (278.60 kg/m³) and the values of water absorption (12%) and compressive strength (1.45 MPa) of the blocks within the requirements proposed in the literature; the walls with EVAi Blocks presented satisfactory adhesion between the coating mortar and the substrate only in the system with roughcast; and the thermal evaluations (heat flow and thermal shock) performed on the walls did not cause damage to the adhesion of the coating mortar to the substrate or to the compressive strength of the walls (1.51 MPa). Thus, it was demonstrated the compatibility between the physical, thermal and mechanical aspects of the system of sealing with EVAi Blocks and confirmed the necessity to apply the roughcast layer in the execution of the coating in the evaluated case.