Bonding Properties of Carbon Fibre Reinforced Polymer (Cfrp) Reinforcing Bar in High-Strength Concrete with Mineral Admixtures
The effects of mineral admixtures and reinforcing fibres on the bonding strength of high-strength concrete to carbon fibre reinforced polymer (CFRP) reinforcing bars were evaluated. The mineral admixtures consisted of 5, 10 and 15% silica fume or metakaolin in cement. The reinforcing fibres were composed of steel, structural polyvinyl alcohol, or a polyolefin-based structural synthetic polymer. Interactions between the high-strength concrete and the CFRP reinforcing bar were determined by direct bonding tests. The compressive strength of the concrete composites depended on the content and characteristics of the admixture and reinforcing fibres. Bonding strength tests of the composites showed an increase in bonding strength with the strength of the concrete. The addition of reinforcing fibres inhibited crack formation and significantly improved the bonding behaviour and relative bonding strength. Both the absolute and relative bonding strengths were enhanced by adhesion forces induced by the mineral admixture.