Durability Investigation of Patch-Repaired Reinforced Concrete

Effect of a pre-packaged non-shrinkage cementitious grout on corrosion of patch repaired reinforced concrete was investigated in laboratory and field. For laboratory study, reinforced concrete specimens were monitored for corrosion, under accelerated and freely corroding conditions. Corrosion activity on freely corroding steel bars in reinforced concrete specimens in the laboratory and corrosion of steel bars in the repaired concrete slabs in the field were monitored by measuring corrosion potential of the steel bars against Cu/CuSO4 reference electrode. In accelerated corrosion, the steel bar was imposed +4V anodic potential to accelerate the corrosion of the steel bars in the concrete specimens, and corresponding current was plotted against time to determine the time-to-cracking for the specimens. The results showed that repair materials provided higher protection to steel against corrosion compared to normal concrete. The reinforcing steel within the repaired zone was more cathodic to the rest of steel in the original concrete.