Acoustic monitoring of a prestressed concrete beam reinforced by adhesively bonded composite

The use of adhesively bonded composite reinforcement is relatively widely used for concrete structures. Yet, some questions remain regarding its use in the case of prestressed concrete structures especially in relation with the influence of existing cracking and the verification of the encountered damage phenomena at real scale. French National Organism CEREMA with the help of French motorway bridge owners association ASFA and French National Research Organism IFSTTAR realized several real size experimental investigations of an old prestressed concrete beam coming from a deconstructed bridge to answer these questions (Project CLERVAL). Both flexure and shear tests up to failure were carried out and several measurement methods were used to understand the role of the composite reinforcement on the behavior of the structure and the damage scenario. Acoustic emission was one of these methods and two different systems were investigated. The proposed communication will first describe the two used acoustic systems and their dedication (localized acoustic emission and overall acoustic survey). A specific development will then be presented aiming at optimizing the obtained acoustic phenomena localization taking into account the anisotropy of the prestressed concrete beam. Finally, main results will then be presented for both flexure and shear tests.