Some existing post-tensioning prestressed concrete (hereinafter PC) members have PC wires insufficiently grouted in sheath. The exposure test for re-grouted PC wires with five grades in corrosion was carried out for a maximum of about 700days in order to examine the applicability of re-grouting technique to PC wires corroded and insufficiently grouted in sheath. The effect of re-grouting for the corroded PC wire was investigated in comparison of the residual diameters of PC wires with and without re-grouting. As a result, the partial corrosion in the border section between grouted and non-grouted portion was especially reduced by re-grouting for the corroded PC wire. Moreover, the greater restriction of corrosion by re-grouting was indicated in PC wires with the reduction by around 4% in diameter, while the corrosion was restrained even in those with the reduction by above 4%.
