Effects of steel reinforcement corrosion on carbon-fibre-reinforced polymer repaired slabs

This paper presents the test results of reinforced-concrete (RC) slabs strengthened with carbon-fibre-reinforced polymer (CFRP) sheets and exposed to a corrosive environment. Nine slab specimens (1500 x 700 x 100 mm) were constructed and subjected to accelerated corrosion exposure. Test variables included the clear concrete cover (10, 25 and 40 mm), the longitudinal reinforcing bar diameter (8, 10 and 12 mm) and different degrees of corrosion. The corresponding current and concrete corrosion cracks were continually monitored throughout the corrosion process. A decrease in the clear concrete cover increased the corrosion crack width and the cracking time of slab specimens to levels higher than those resulting from an increase in the reinforcing bar diameter. All slab specimens were tested to failure in four-point bending, to investigate the load-carrying capacity and average crack spacing of each corroded slab specimen. In addition, some reinforcing bars were extracted, to determine the loss in the steel mass when varying the clear concrete cover and the reinforcing bar diameter. The study reported in this paper thus establishes the effects of the clear concrete cover and the reinforcing bar diameter on corrosion activity in CFRP-strengthened RC slabs.