Experimental evaluation of overlays for precast concrete decks used in accelerated bridge construction

In accelerated bridge construction, bridge decks are constructed using precast concrete elements ranging from half-depth or full-depth precast concrete panels to decks constructed on entire bridge superstructures moved with self-propelled modular transporters or slide-in bridges. The ability of different bridge-deck-overlay materials to protect the concrete against intrusion of chloride ions is investigated. Two panel configurations were tested considering accelerated bridge construction methods: application of the overlay before movement of the bridge-deck panels and application of the overlay after movement of the bridge-deck panels. Three types of bridge-deck-overlay materials were investigated: thin bonded polymer, polyester polymer concrete, and methyl methacrylate. Criteria used to evaluate the three types of overlay materials included bond strength between the overlay and precast concrete bridge-deck panels and chloride penetration into the deck panels. Although the overlays had slightly different bond performance, they offered similar protection against chlorides. There was no significant difference between the performance of the overlays applied prior to placement of the precast concrete deck panels and that of overlay systems applied after the placement of the precast concrete deck panels.