Investigating the microstructure of mortar systems reinforced with wind turbine blade waste using X-ray computed tomography

The potential of valorising shredded end of life wind turbine blades (EoL-WTB) as reinforcement for mortar applications has been only scarcely explored. The relevant studies prove that incorporating WTBW within the mortar matrix can improve the composite strength. However, this reinforcing amplitude varies significantly. Unravelling the corresponding microstructure, which is known to play a pivotal role on the behaviour of fibre-reinforced cement-based composites, remains a knowledge gap until today. This paper attempts to fill this gap via utilising X-ray computed tomography (XCT) to investigate the microstructure of this novel composite. In line with the state-of the-art industry-trail practices, various sizes of the embedded WTBW have been incorporated into the relevant cement matrices. The effect of the waste size on the composite microstructure is determined via probing differences in the porosity behaviour (pore size and spatial distribution and shape factor) and the cement hydration. The spatial distribution and orientation of the WTBW, dispersed within the composite volume, is also investigated. Microstructural observations are linked with the corresponding sample strength. The results reveal the crucial effect of the embedded waste’ size on both cement hydration and generated porosity. • Mortar porosity rises with growing size of embedded WTBW. • Incorporation of WTBW within mortar extends the composite setting time. • Adding 0.5 % vol. WTBW in mortar raises its compressive strength (2–4 %).