Bridges

In recent years the circumferential wrapping with externally-bonded carbon fibre-reinforced polymer (CFRP) composites has proven to be a promising method for strengthening concrete structures. This is particularly valuable when repairing concrete members such as bridge members that may have been damaged due to heating / fire. The purpose of the experiments described in this paper was to investigate the strength enhancement of CFRP-wrapped reinforced concrete (RC) columns post heating and cooling. The former situation is more relevant to the repair of real structures. Columns were subjected to 30 % of the maximum ambient temperature strength and were heated and cooled before being wrapped. Of twelve 204 mm × 750 mm columns, 2 were left as control samples, 4 were wrapped at ambient temperature and 6 were subjected to heating and subsequent cooling under stress (0.3 f′co). The results of this experimental investigation indicate that CFRP can significantly increase the strength of undamaged columns and the residual strength of post-heated columns. The test results also confirm that this can be achieved through the addition of a single layer of CFRP.