REPAIR OF CORRODED RC BEAMS

Abstract

Twelve prototype rectangular RC beams (120 x 150 x 1000 mm) were constructed and evaluated using flexural test to investigate the employment of advanced composites in repairing corroded reinforced concrete (RC) beams. Three concrete mixtures with effective w/c ratio of 0.4 and cement content of 370 kg/m3 were utilized in the study: control ordinary Portland cement concrete, silica fume (SF) and ground granulated blast furnace slag (GGBFS) concrete mixes. The RC beams (reinforced with two steel bars having diameter of 12 mm) were immersed (after 28 days of curing) in 2.5% NaCl solution and exposed to accelerated corrosion process using impressed electrical current. The corroded RC beams were repaired using advanced composite of carbon fiber reinforced polymer (CFRP) sheets. The CFRP sheets measuring 300-mm width by 0.131-mm thickness were used to rehabilitate and restore the mechanical behavior of the corroded and damaged RC beams. The investigation results confirmed that the corrosion of steel reinforcement caused significant deterioration and reduction of flexural capacity. The corroded SF and GGBFS beams showed higher flexural capacity compared to the corroded OPC beams. The repaired SF and GGBFS beams showed higher ductility and performance gain in the flexural capacity compared to the repaired OPC beams.