Durability of recycled steel fiber reinforced concrete in chloride environment

For structural elements exposed to chloride environments, an important aspect of Recycled Steel Fiber Reinforced Concrete (RSFRC) durability is the corrosion resistance. In the present work, an experimental program was carried out to evaluate the long-term effects of chloride attack on the post-cracking behavior of RSFRC by performing splitting tensile tests and round panel tests. Two RSFRC mixtures defined based on the packing density optimization were produced with a fiber content of 0.8% and 1% per volume of concrete. The influence of different periods of chloride immersion was investigated, as well as the influence of fiber dispersion at crack surfaces of the specimens. Additionally, a simplified prediction of the long-term chloride penetration depth into uncracked RSFRC under immersion aggressive chloride exposure conditions was estimated. The RSFRC revealed high susceptibility to surface corrosion under the chloride exposure conditions adopted. However, the post-cracking resistance of RSFRC was not significant affected. The addition of RSF had a negligible effect in the diffusion of chloride ions into concrete, and the critical chloride content was higher than that found in conventional reinforced concrete structures.
This research was funded by C.F. research grant PD/BD/113638/2015 provided by Fundação para a Ciência e a Tecnologia (FCT) through the Doctoral Program in Eco Construction and Rehabilitation - EcoCoRe, and J.B. through the project ICoSyTec (POCI-01-0145-FEDER-027990) financed by FCT.