2019 Volume 75 Issue 1 Pages 19-33
Some performances of stainless steel in concrete had been estimated, and corrosion occurrence amounts for SUS304, SUS316 and SUS410 had been clarified. Also, it had been clear that a corrosion characteristic is different between a bend part and a straight part for carbon steel. However, there is no examination about corrosion of stainless steel with a bend part such as stirrup. Based on above backgrounds, three-steps experiments were conducted in this paper to clear the performance of stainless steel with a bend part. First, anode polarization curves of SUS304, SUS316 and SUS410 were measured in a saturated calcium hydroxide solution. Next anode polarization curves of stainless steels and carbon steel were measured in mortar using special divided steel bars. According to these tests, it could be confirmed that the anode reaction progress at a bend part was easier than that at a straight part even in stainless steels. Finally, the corrosion current density of stainless steels in concrete beam with main rebar and stirrup was evaluated. As a result, it could be confirmed that the corrosion rate of stainless steel was remarkably low in comparison with carbon steel. However, it was clarified that at even stainless steel, the corrosion rate was high at a bend part in stirrup. In addition, there was a special case in third test whose main rebar was made with carbon steel and stirrup was made with stainless steel. This was set because stainless steel with expensive cost used at only limited part which was most severe position. According to this special case, the corrosion rate of stirrup decreased compared to a case whose main rebar and stirrup were made with carbon steel.
