Valorization of recycled FRP materials from wind turbine blades in concrete

Abstract

This article examines the viability of valorizing waste glass fiber-reinforced polymer (GFRP) materials extracted from wind-turbine blades (WWTB) — (WWTB-GFRP) — into concrete. A comprehensive material characterization was carried out and the influence of WWTB-GFRP as powder, aggregate, or fiber on concrete performance was investigated. Cement replacement rates of 10–30% were attempted. Coarse aggregate replacement levels of 33–100% were considered, while fiber addition rates of 1–1.75 vol.% were investigated. Resulting concretes were characterized for their compressive strength and flexural capacity. Resulting concretes were characterized in terms of compressive strength and flexural capacity. Results show that the form at of WWTB-GFRP (as a powder, aggregate, or fiber) significantly impacts the properties of resulting concretes. Thus, while WWTB-GFRP powder leads to substantial increase in the setting time (owing to the wooden content and its associated soluble sugars) as well as to a significant drop in compressive and flexural strengths, it should be noted that mixtures with 10% cement replacement by WWTB-GFRP powder (after removal of wooden content) demonstrated comparable compressive strength as that of the reference mixture (without WWTB-GFRP) at 90 days. When WWTB-GFRP is incorporated in concrete as a fiber reinforcement, an enhancement in flexural capacity of up to 15% was achieved without noticeable drop in compressive strength. Therefore, it is feasible to valorize WWTB-GFRP in concrete to obtain mixtures with comparable long-term compressive strength while achieving higher flexural capacity and contributing to promoting the sustainable development.