REPAIR OF RC HOLLOW SLAB BRIDGE DAMAGED BY CHLORIDE ATTACK USING SPRAYED MORTAR

Abstract

This paper describes the repair of the bottom side of a RC hollow slab bridge damaged by deicing salt and contaminated chloride. It was clarified that removing of concrete 30mm deeper than rebar position and repair of cross section 55mm over thickness were necessary to the bridge by present conditions and prediction. In this experiments using actual bridge models, it was found to be able to remove concrete by water-jet chipping technology and compact repair mortar by spraying technology under such hard condition. Since it was found that the quality of the mortar was influenced by the execution/environment condition, the importance of designing for repair, controlling the quality of mortar and inspecting initially to repaired bridge under consideration of such influence was noted.