Effects of Traffic Induced Vibrations on Bridge Deck Repairs

The effects of traffic induced vibrations on concrete-steel bond strength and concrete compressive strength was studied for full depth repairs of reinforced concrete bridge decks. The specimens had blockouts to represent full depth patch repair areas. Two bar sizes, #5 and #8, two topcovers,3in. and 1-1/2 in., and four slumps, ranging from 1-1/2 in. to 7-1/2 in., were used. The bond tests used modified cantilever specimens. Standard 6 in. x 12 in. cylinders were used for the study of the effect of traffic induced vibrations on compressive strength. Based on the results, traffic induced vibrations are not detrimental to the qua 1 i ty of repair concrete when low slump concrete is used and the reinforcing bars are securely fastened to the structure before the concrete placement. They may be detrimental when medium slump (4 to 5 in.) concrete is used. They are, however, detrimental to the quality of repair concrete when high slump concrete is used. Bond strength of #5 bars is affected more detrimentally than that of #8 bars when subjected to the traffic induced vibrations