Corrosion resistance of fine-grained rebar in simulated concrete pore solutions by means of electrochemical methods

Uniform and pitting corrosion behaviors of fine-grained rebar and low-carbon rebar in simulated concrete pore(SCP) solutions were investigated by means of corrosion potential,linear polarization resistance(LPR) and cyclic polarization.The influence of two different rebar surface conditions,i.e.,sandblasted and as-received,on the corrosion behavior of the rebar was taken into consideration.The results indicate that fine-grained rebar and low-carbon rebar show almost the same uniform corrosion behavior,and the passivation effects are better for sandblasted rebar than as-received rebar.In the latter period of corrosion,sandblasted rebar shows a higher uniform corrosion resistance than as-received rebar.Cyclic polarization measurements reveal that sandblasted rebar performs better in delaying pitting corrosion due to the relatively homogeneous surface than as-received rebar.Since more impurity-containing grain boundaries in fine-grained rebar facilitate the occurrence of pitting corrosion,the probability of pitting corrosion for as-received fine-grained rebar is slightly higher than that of as-received low-carbon rebar.