Produção de concretos com resíduos de poliuretano triturado em substituição ao agregado miúdo

Abstract

The reuse of potential materials that would otherwise be sent to landfills or stored in incorrect locations, contributing to the pollution of water courses and influencing the sewage system of cities and the most varied damages to the environment and the population, is a reality each more current. Among these materials, the polyurethane polymer (PU) stands out in its many variations, where its reintroduction into the production chain brings socio-environmental advantages. This article presents a comparative analysis between a mix of conventional concrete and concretes with partial replacements of fine aggregate by crushed expanded polyurethane waste, from refrigerator scrap, in 5% and 10% contents, replaced in relation to the volume of the sand, this procedure was also performed for a mix with the addition of silica fume. Two pilot traces were developed, one with silica (CS) and one without silica (SS). The properties of the concrete produced were evaluated through the slump test of the cone trunk (NBR 16889: 2020), analysis of compressive strength (NBR 5739: 2018), tensile strength by diametrical compression (NBR 7222:2011), mass specific and water absorption (NBR 9778:2005). The results obtained from this study demonstrate that the increase in the amount of PU foam in concrete reduced significantly the specific mass and reduced the mechanical strength of the part. It is noteworthy that the use of silica fume can be a differential in the production of concrete with recycled aggregates such as expanded PU foam, so that the resistances are maintained.