Effects of electric arc furnace dust on susceptibility of steel to corrosion in chloride-contaminated concrete

Small additions of electric arc furnace dust (EAFD) are currently being made to reinforced concrete in Saudi Arabia as a means of exploiting this waste material. To elucidate the possible effects of these additions on the susceptibility of reinforcing steel to corrosion, a series of laboratory tests was conducted on steel bars in mortar specimens containing 0%, 2% and 3.5% of EAFD by weight of cement, exposed to chloride ingress at 20 and 40 °C. Effects of deliberately induced crevices at the steel/mortar interface on corrosion initiation were also investigated. The results showed that the above additions of EAFD caused no increase in the susceptibility of the embedded steel to chloride-induced corrosion and tolerance to chloride was actually enhanced by the presence of EAFD under the conditions investigated.

► Chloride-induced corrosion of steel in concrete is highly temperature-dependent.
► Crevices enhance susceptibility of steel in concrete to chloride-induced corrosion.
► Crevice corrosion in EAFD-free mortars occurred at low critical chloride contents.
► In mortars with small additions of EAFD this occurred at higher chloride contents.