Effect of combined pre-cracking and corrosion on the method of repair of concrete beams

This study investigated the combined effect of pre-cracking and corrosion on repair methods of reinforced concrete beams. The experimental program consisted of prismatic pre-cracked reinforced concrete beam specimens, exposed to accelerated corrosion. The corrosion rate varied from 5% to 15% and the pre-cracking was achieved by preloading the beams up to 60% of their ultimate loads. Two different methods were used to repair the specimens. Carbon Fiber Reinforced Polymers plates (CFRP) were used to strengthen the bottom portion of the specimens in the first method, and sheets containing carbon fibers were added to the bottom portion, left and right sides of the specimens, in the second method. The test results revealed that, the harmful effect of combined corrosion and pre-cracking was notable especially at 15% corrosion rate. The two methods of repair used can be considered as convenient. The ultimate strengths of the repaired beams were equivalent or significantly higher than those of the control specimens, although reduced deflection capacities were registered after repair.