FUNDAMENTAL CHARACTERISTICS OF NEW HIGH MODULUS CFRP MATERIALS FOR STRENGTHENING STEEL BRIDGES AND STRUCTURES

Due to corrosion and the continuous demand to increase traffic loads, there is a great need for an effective, cost-efficient system which can be used for the repair and strengthening of steel highway bridge girders. Recently, research has been conducted to investigate the use of carbon fiber reinforced polymer (CFRP) materials to address this need. This paper describes the details of an experimental program which was conducted to investigate the fundamental behavior of steel-concrete composite bridge girders strengthened with new high modulus CFRP (HM CFRP) materials. The behavior of the beams under overloading conditions and fatigue loading conditions was studied as well as the possible presence of a shear-lag effect between the steel beam and the CFRP strengthening. A series of proposed flexural design guidelines are presented which can be used to establish the allowable live-load increase for a strengthened beam and to design the required HM CFRP strengthening