Nondestructive Testing and Static/Dynamic Loading Detection of A Diseased Fabricated Hollow Slab Bridge

Combined with a repaired project, an old twin decks bridge by simply supported the fabricated prestressed concrete hollow slabs with 16m span was detected in-site. The two decks were built separately in 1987 and 1997 because of economic reasons and demands of traffic flow. The aim of test was to decide whether the bridge can be further used or should be strengthened to meet the demands according to the current design code. Firstly, the damaged and corroded situations of whole bridge were investigated. Then the nondestructive testing methods were adopted to detect the concrete strength and carbonation depth of slabs and piers. The static loading test was conducted to make sure the service behaviors such as crack and mid-span deflection of the whole bridge. Finally, whole bridge was detected by dynamic loading test. The results show that the bridge has enough flexural stiffness to prevent larger deflection and most of slabs are in good service performance. But attacked by the environmental factor such as acid rain, CO2 and winds erosion etc., part of slabs, all railings and sidewalk flats should be replaced. Based on service conditions, the suggestions are given to recover the strength and durability of the bridge. The conclusions would serve as a reference for similar engineering structures.