Destructive and Non-Destructive Testing of Bridge J857 Phelps County, Missouri : Feasibility Study on Damage Detection of RC Structures using Dynamic Signature Tests

This report presents the results of a research program aimed at investigating the constructability and effectiveness of externally bonded FRP strengthening systems for improving the flexural capacity of bridge decks and piers. The joint effort of two universities, industry, and a state DOT provided the premise for a successful outcome. Bridge J857 was constructed in 1932 and was scheduled for demolition in the fall of 1998 due to highway realignment. Two of the three solid reinforced concrete (RC) decks were strengthened using two FRP systems namely, near-surface mounted carbon FRP (CFRP) rods and surface bonded CFRP sheets. Bridge decks were tested to failure under quasi-static loading cycles. Flexural strengthening of bridge columns was achieved by mounting CFRP rods on two opposite sides of the columns. Columns were also jacketed with carbon and glass FRP laminates. The experimental moment capacities of the decks compared well with theoretical values. Strengthened decks exhibited ductile behavior prior to FRP failure. The columns were tested to failure by applying lateral load cycles. The proposed strengthening technique for the bridge columns is feasible and effective for improving the flexural capacity of RC columns. The capacity of the strengthened column sections could be predicted using classical methods of analysis. Dynamic tests were conducted on the deck strengthened with CFRP sheets. The objective of dynamic tests was to relate the change in fundamental frequency to the induced damage, which could be used as a tool to assess the damage level of RC structural members. An effective damage indicator was identified that requires no baseline for damage level detection