Axial compressive behaviour of substandard concrete confined with 3D-printed PLA strips

This study explores the potential of polylactic acid (PLA) strips as sustainable reinforcement material for substandard concrete requiring enhanced axial load-bearing capacity. Experimental tests and nonlinear finite element analyses were conducted to evaluate the influence of PLA confinement on the axial compressive behaviour of concrete cylinders. The results demonstrate that PLA strips can increase compressive strength with notable improvements in stiffness and ductility depending on strip configuration and spacing. The numerical simulations showed strong agreement with the experimental data, validating the observed behavioural trends. According to numerical case study, compared with conventional carbon fibre-reinforced polymer (CFRP), PLA exhibited lower mechanical performance but offered clear environmental advantages, with significantly lower embodied energy and global warming potential than commonly used externally bonded reinforcement material. While the present work is a proof-of-concept study limited to axial loading, the findings highlight the promise of PLA as an eco-friendly alternative for low-carbon strengthening applications. In future applications, combining PLA with conventional reinforcement materials may offer an optimized balance between mechanical performance and ecological impact.