Sustainable cement-based mortar with shredded material recycled from end-of-life wind turbine blades.

The growing demand for sustainable construction materials has driven interest in reusing industrial waste. This study explores the feasibility of incorporating shredded composite (SC) recycled from end-of-life (EoL) wind turbine blades (WTBs) into a cement-based mortar. Two SC fractions were tested: 0-2 mm as a partial cement replacement (10%, 15%, 20% by volume) and 0-32 mm as a partial aggregate replacement (20%, 30%, 40% by volume). Mechanical testing, digital image correlation (DIC), and microstructural analysis were used to assess performance. The 0-32 mm SC fraction significantly enhanced mortar properties when used as aggregate replacement, reducing porosity by up to 23.22%, increasing flexural strength by 36.51%, and improving the toughness index by 248.11%. In contrast, the 0-2 mm SC fraction, used as a cement substitute, led to a 27.55% increase in porosity, a 6.60% reduction in density, a 44.64% decrease in toughness, and a 45.12% decrease in compressive strength, indicating the need for further optimization of this approach. These findings demonstrate the potential of SC from EoL WTBs as a sustainable additive in cementitious composites, particularly when used as aggregate replacement. The study supports circular economy practices by reducing construction waste and valorising materials from decommissioned renewable infrastructure.