Abstract
The construction industry faces a significant challenge as many ageing structures are losing their structural integrity due to poor maintenance, outdated design practices, urban decay, overcrowding, climate change, and building hijackings. Residential and commercial buildings are typically designed with a lifespan of 50 years, and many multi-storey buildings in South African city centres have either exceeded or are nearing this limit. The effects of overcrowding can be catastrophic, what bleeds most is the infrastructure of the city, urban decay becomes the unfortunate consequence. Replacing compromised structural elements can be impractical, while demolishing and rebuilding entire structures may be prohibitively expensive and time-consuming. Strengthening, repairing and rehabilitation of deteriorated concrete structures has increasingly become essential not only for the structure to reach it’s intended service life but most importantly to ensure the safety of those that are occupying these building structures. Retrofitting offers an alternative solution to enhance the structural performance of existing concrete structures.
This research investigates the use of Carbon Fibre Reinforced Polymer (CFRP) plates as a retrofitting technique to improve the load-carrying capacity and flexural properties of reinforced concrete beams. An experimental research approach is employed, with tests conducted in a laboratory, and the results compared to ABAQUS finite element software outputs, and detailed theoretical calculations. A total of eight concrete beams with the same dimensions and mechanical properties, were divided into three sets and tested. The three sets differ by flexural properties due to different cross-sectional areas of steel reinforcement in the concrete beams. The concrete beam properties studied were flexural strength, ductility, stiffness and failure modes. The results demonstrate that CFRP plates significantly enhance the performance of the concrete beams compared to the control beams. It improves the stiffness, ductility and flexural properties of the concrete beams, ultimately increasing the load carrying capacity.