The Behavior of Beams Reinforced with Patches Under Three-Point Bending: An Experimental Investigation
Fatima Benaoum, Foudil Khelil, Abdelghani Baltach, Demet Ülkü Gülpınar Sekban, Ecren Uzun Yaylacı, Ali Benhamena, Mohamed Mouli, Dursun Murat Sekban, Murat Yaylacı
Abstract
This study assesses the flexural performance of concrete beams repaired with externally bonded carbon-fiber-reinforced polymer (CFRP) patches under controlled damage conditions. Prismatic beams (7 × 7 × 28 cm) underwent three-point bending tests in four configurations: uncracked, uncracked-reinforced, cracked-unrepaired, and cracked-repaired. Pre-existing damage was caused by mid-span notches at a = 7, 21, and 35 mm. CFRP patches were placed on the tension face, and the ultimate load and failure mode were recorded. Repairing CFRP beams increased maximum load by up to 240% compared to unrepaired counterparts, and the failure characteristic changed from brittle shear to ductile flexural. Strengthening uncracked beams also yielded significant benefits. These findings show that patch-type CFRP reinforcement effectively recovers and enhances flexural performance across a wide range of crack severity, and they provide quantitative guidelines for determining repair levels depending on original crack depth.