Structural behaviors of different corroded RC members strengthened by different types of concrete jackets

Abstract

Existing corroded reinforced concrete (RC) structures must be repaired and strengthened to extend their service life. Otherwise, they must be demolished and rebuilt. In general, repair and strengthening are more cost-effective than demolition and reconstruction.  This research assessed the performance of corrosion-damaged reinforced concrete beams and columns strengthened with different types of concrete. The corrosion rate of reinforcing columns and beams was assumed to be 10 % using accelerating electrochemical corrosion method. After steel corrosion, the surface of concrete members is roughened by sandblasting; it was then strengthened with different types of concrete: self-compacting concrete (SCC), fiber-reinforced self-compacting concrete (FRSCC), high-performance concrete (HPC), fiber-reinforced high-performance concrete (FRHPC), and fiber reinforced normal concrete (FRNC). Before and after corrosion, the flexural and compression tests were carried out for the beams and columns, respectively. Experimental findings demonstrated that the bearing and axial compression capacities of beams and columns were reduced considerably. due to the corrosion of reinforcements, and concrete jackets from different types of used concrete could efficiently restore the damage resulting from corroded steel rods. The study concludes that the use different types of concrete are suitable for the external strengthening of corroded RC members. However, for flexure, the strengthen concrete beam that achieved the highest increase in flexural and ductility is the one strengthens by 30 mm FRHPC jacket (8,65 %). For axial compression, strengthen concrete column that achieved the highest increase is that strengths with 30 mm of FRSCC (136,78 %)