Use of waste collected from wind turbine blade production as an eco-friendly ingredient in mortars for civil construction

Abstract

Most countries worldwide are making efforts to diversify their energy supplies, employing alternative sources of energy that can minimize environmental impacts. Wind power is especially attractive in countries with abundances of territory and wind, such as Brazil. One of the main components of wind generators is the turbine blade, which is essentially composed of a metal structure enveloped in glass fiber and epoxy resin, together with wood and adhesive. The aim of this work was to incorporate a solid waste composed of a mixture of glass fiber embedded in epoxy resin, which was produced during the manufacture of wind turbine blades, into mortar based on Portland cement (cement:aggregate ratio of 1:3). The waste replaced part of the aggregate (sand), consequently reducing the use of a natural resource (sand), and providing a suitable route for the disposal and use of the wind blade waste. The solid waste was collected and converted to a powder with granulometry similar to that of sand, employing a turning process. The powder was characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), granulometry, contact angle measurements, and determination of the inorganic content, enabling evaluation of the behavior of the waste in the cementitious matrix. After the characterizations, test specimens of mortar (40 × 40 × 160 mm) were produced with 0 (waste-free), 7.5, 15, 22.5, 30, and 37.5% of the aggregate (sand) replaced by the powdered waste. The prepared specimens (in the hardened state) were used in assays of mechanical resistance (compression and flexion), voids index, and specific mass, as prescribed in Brazilian standards (NBR), envisaging the use of the materials in civil construction. The results showed that the cementitious composites produced with replacement of up to 15% of the sand complied with relevant technological criteria, such as compression resistance (8 MPa). The mortars containing the waste also presented lower specific mass, offering advantages for civil construction applications. The results demonstrated the viability of incorporating this waste into cementitious matrices.