Repair Of Impact-damaged Prestressed Concrete Bridge Girder Using Glass FRP Rebar

Abstract

Overpass girders are risked by the impact of the traffic, over height vehicle, travelling under the structure, creating a hazard for the drivers over and under the bridge.When a bridge girder is damaged the repair solution adopted has to meet the following criteria:- Safety. The repaired structure has to provide a minimum level of service to guarantee the safety of the traffic during the life of the structure. - Repair time. To minimize the risk and the inconvenience for the traffic the repair time has to be minimum.- Economy. The adopted solution has not only to fulfill the previous requirements, but also has to be the most economical.Nowadays a lot of construction projects have to confront this kind of issue. The Lyndon B. Johnson (LBJ) Express construction project had to solve this problem. The LBJ project is located on I-635 and I-35 in North Dallas, Texas. The bridge number 54 of the LBJ project was hit by a truck, causing severe damage on one of its girders. The incident caused loss of concrete and exposed several strands. The solution adopted for the engineers was install fiber glass rebar and fill with repair mortar.This study models the damaged girder before and after the repair to analyze its structural behavior. The data obtained by this model have been compared to the data obtained by the field test. The ABAQUS software has been used to model the girder.The objectives of this study are provide a better understanding of the structural behavior and propose adequate modeling techniques of beams repaired with GFRP rebar. The proposed techniques will help to establish adequate repair procedures and to anticipate the structural behavior of damaged girders prior to the repair process