Use of sand coating to improve bonding between GFRP bars and concrete

Abstract

Glass fiber-reinforced polymer bars are currently used to reinforce concrete in an attempt to overcome the corrosion issue encountered with ordinary steel. Different types of surface treatment were applied to the smooth rods in order to enhance bonding with concrete. Experimental results show that using bars coated with coarse sand notably improve the bond strength. The influence of granulometry sand, rebar diameter, length embedded, and concrete strength are analyzed. Rebars coated with finer sand lead to a stronger chemical adhesion with concrete. However, the effect of friction and interlocking forces produced by coarse sand prevails over the chemical adhesion in the pull-out test.