Exploring the behavior of concrete containing selectively crushed wind-turbine blade from a water-transport perspective

Abstract

Glass Fiber-Reinforced Polymer (GFRP) can be separated from the other components of wind-turbine blades by mechanical cutting, and subsequently knife crushed. The resulting Selectively Crushed Wind-Turbine Blade (SCWTB) is mostly composed of GFRP-composite fibers, with small contents of porous particles of balsa wood and polymers. SCWTB can be used as non-corrosive reinforcement in concrete, although it modifies its porosity. This study analyzes the effect of up to 6.0 % vol. SCWTB on the porosity and water transport of concrete. The effective porosity and water-absorption rate from water absorption under capillarity revealed that SCWTB favored water entry within the concrete and increased porosity. However, no noticeable increase in water ingress was found in the short term (water penetration under pressure) and in the long term under full immersion up to 4.5 % SCWTB. The GFRP-composite fibers acted as barriers against water passage, and the skin successfully sealed the concrete. 6.0 % SCWTB notably increased the water ingress due to the incorporation of the porous particles that it contained to the capillary pore network of concrete, acting as water-storage points with adequate continuity with the cementitious matrix. Nevertheless, chloride-penetration depths remained always lower than the standard concrete covers for reinforcement, although its diffusion coefficient did increase. In general, SCWTB additions between 1.5 % and 4.5 % did not statistically affect the water-related behavior of concrete. Finally, concrete containing SCWTB exhibited a better water-transport performance than concrete with raw-crushed wind-turbine blade, a waste obtained through blade crushing in a non-selective way that contains higher proportions of porous particles.