Analysis and simulation with a CFD tool of self-compacting concrete with crushed wind turbine blade

Abstract

The decommissioning of wind turbines in the coming years will cause a problem for society due to the pressure on the ecosystem caused by the landfilling of their blades. However, there is currently no sustainable strategy available to recycle these wind turbine components due to the different materials that they are made of. In this research, a recycling option using mechanical crushing to yield Raw-Crushed Wind-Turbine Blade (RCWTB) is evaluated. The flowability of different Self-Compacting Concrete (SCC) mixes with RCWTB contents up to 6% by volume is studied, both experimentally and numerically through tools based on Computational Fluid Dynamics (CFD), as well as their compressive and splitting tensile strengths. The analysis of the fresh properties through CFD showed an increase of the plastic viscosity and therefore a reduced flow speed of the SCC with higher RCWTB amounts. This phenomenon was due to the fibers of glass fiber-reinforced polymer found in RCWTB, which hindered the dragging of the rest of the SCC components by the cement paste. A worsening of mechanical strength followed the increase of the added content of this residue. The higher water/cement ratio when using this waste resulted in an increase of the porosity of the matrix, which resulted in a worsening of the mechanical behavior. Within this general framework, the mixture with 1.5% vol. RCWTB exhibited an adequate behavior in terms of both the fresh state, determined by numerical simulations, and mechanical performance. This preliminary analysis evidences the adequate use of small amounts of RCWTB in self compacting concrete that would be suitable for different construction elements, including structural ones. © fédération internationale du béton (fib).