An Experimental Study on Corrosion Resistance and Bond Behavior of Reinforced Concrete Structures with Various Fibers

In the present study, a zinc phosphate coating was deposited on steel fiber surface and the morphology and corrosion resistance of the coating were investigated. An accelerated corrosion method was utilized to corrode steel bars embedded in concrete, and the impact of adding fibers on the performance of reinforced concrete structures after the accelerated corrosion test was examined. The results revealed that the coating primarily consisted of hopeite phase, exhibiting a dense and uniform structure. The corrosion resistance of the coated steel fibers was significantly enhanced compared to uncoated fibers. Furthermore, the fiber-reinforced specimens exhibited lower levels of corrosion and improved bond performance in comparison to reinforced plain concrete specimens. The bond strength between the reinforcement and concrete in the fiber-reinforced specimens with zinc phosphate coated steel fibers increased by 28.1% (before corrosion) and 112.9% (after corrosion) compared to plain concrete. The reduced porosity and high impermeability of the concrete matrix containing zinc phosphate coated steel fibers contributed to the delayed migration of chloride ions and protection of the reinforcement against corrosion. These findings suggest that zinc phosphate coated steel fibers have great potential for large-scale production of reinforced concrete structures.