Reusing end-of-life aircraft composites for structural concrete strengthening: a proof-of-concept study

The increasing use of carbon fibre reinforced polymers (CFRPs) in aircraft introduces significant end-of-life (EOL) challenges, as these high-value and high embedded-energy materials frequently face disposal. This study explores reusing EOL aircraft CFRP components for strengthening reinforced concrete (RC) structures, promoting cross-sectoral circularity. The proposed segmentation strategies for fuselage and wing stiffeners were applied to fragments from a decommissioned Airbus A350 fuselage section. Although the reclaimed laminates exhibit lower stiffness and strength than common commercial unidirectional strips used to strengthen concrete, equivalent structural performance can be achieved by increasing the reinforcement cross-section. Experimental tests on RC beams strengthened with composite fragments from a decommissioned aircraft section showed that reused laminates enhanced the flexural response by delaying crack initiation and steel yielding and by increasing load capacity by 123.7%, with favourable bond performance. Moreover, reusing EOL laminates requires far less energy (roughly 400 times lower) than producing virgin or recycled CFRPs, making it a highly sustainable option. Findings confirm structural reuse as a technically viable and highly sustainable alternative for aerospace CFRP waste, linking aircraft decommissioning with civil infrastructure rehabilitation. Based on this initial validation, a more systematic investigation of the parameters governing bond behaviour and flexural performance is necessary before the results can be generalised.