Deformability and energy absorption of concrete made with selectively crushed wind-turbine blade

Abstract

The crushing of the glass fiber-reinforced polymer (GFRP) previously separated from the other wind-turbine-blade materials produces a waste with minimum contents of deformable particles of balsa wood and polymers, being mainly composed of GFRP-composite fibers. This residue is named selectively crushed wind-turbine blade (SCWTB). This research evaluates the impact of adding up to 6.0% by volume of SCWTB on the deformability, load-bearing capacity and energy absorption of concrete subjected to compression, bending, and indirect-tensile stresses. SCWTB increased the failure strain of concrete in the direction parallel to a compression load, although it led the failure and fracture strains to match. However, the strain increase from failure to fracture was 2000–3000 µε in the transverse direction to loading, so concrete with SCWTB was load-bearing after failure. GFRP-composite fibers’ stitching effect was more noticeable under bending stresses. Thus, 1.5% vol. and 6.0% vol. SCWTB resulted in almost the same bending failure stress in concrete, around 6.1–6.2 MPa, and contents from 3.0 and 6.0% vol. SCWTB provided load-bearing capacity in simple and notched-specimen bending, respectively. In addition, the low content of deformable particles in SCWTB increased the deflection increment from failure to fracture in bending, although the presence of such particles augmented energy absorption. No SCWTB content provided load-bearing capacity under indirect-tensile stresses, although it did increase pre-failure deformability. In general, the energy absorbed by concrete increased by up to 43% when adding SCWTB, the use of up to 6.0% of this waste being recommended to increase the ductility of concrete.