Experimental Investigation on the Effect of Corrosion on the Bond Between Reinforcing Steel Bars and Fibre Reinforced Geopolymer Concrete

This paper investigates the effect of corrosion on the bond between reinforcing steel bars and fibre reinforced geopolymer concrete. An accelerated corrosion method was used to corrode the reinforcing steel bars embedded in geopolymer concrete. Three types of steel fibres including straight micro steel fibre, deformed macro steel fibre, and hybrid steel fibre were used in this study. A total of ten geopolymer concrete mixes were used to evaluate the effect of corrosion of steel bar on the bond between steel bar and fibre reinforced geopolymer concrete. The pull-out test specimens were composed of concrete cubes with a side length of 160mm and reinforced with a deformed steel bar of 16 mm diameter located at the centre of the specimens. The test results showed that the addition of steel fibres in geopolymer concrete (fibre reinforced geopolymer concrete) significantly enhanced the bond strength of reinforcing steel bar. The bond strength of reinforcing steel bars embedded in steel fibre reinforced geopolymer concrete specimens reduced due to corrosion of reinforcement. However, the reduction of bond strength in steel fibre reinforced geopolymer concrete specimens was less than the reduction of bond strength in plain geopolymer concrete specimen.