Sulfate Environment Influences on the Interfacial Bond Performance between CFRP and Concrete

The potential of Carbon Fiber Reinforced Polymer (CFRP) in the reinforcement of concrete structures has been shown in many studies and practical applications. Some concrete structures are in harsh environment so its reinforcement mechanical properties decrease due to time and environment effect. There are many region where plenty of saline soil, so much SO(4)(2- )ions could permeate into CFRP and concrete structures and cause corrosion. Na2SO4 solution was adopted to simulate the harsh environment and through single shear test to study the interfacial bond properties between CFRP and concrete, and SEM detection technique was adopted to analyse the deterioration mechanism Three parameters just like concrete surface roughness, concrete compressive strength and specimens corrosion time were studied . As the results indicate: With the increase of the roughness, the interface ultimate load also increases gradually. Bond stress occurred biggest value at 7-day, the interface ultimate load drops greatly at various roughness levels after 30 days at different concrete strength. At 60 days, some crystal structures connecting into bulky crystal and the concrete and the adhesive layer were damaged seriously; lacking of epoxy resin connection, the fiber is weak in integrity, which has great influence on bonding effect of concrete.