Effectiveness of FRP for Strengthening Concrete Bridges

This paper demonstrates an alternative use of FRP for strengthening concrete bridges in response to the demand towards increasing the flexural capacity to accommodate new truck loads. Several large-scale models of a prestressed concrete bridge were constructed and tested to failure to investigate the effectiveness of different FRP strengthening techniques. These techniques include near surface mounted bars and strips as well as externally bonded sheets and strips. Bond characteristics of near surface mounted FRP bars and strips are investigated by testing independently 17 concrete beams under monotonic static loading. Mathematical models for the interfacial shear stresses and the minimum anchorage length needed for near surface mounted bars and strips are presented. The feasibility of strengthening a prestressed concrete bridge using near surface mounting technique is discussed. The paper presents also an overview of the cost-effectiveness of each of the strengthening techniques considered in this study.