Seismic damage sensing of bridge structures with TRIP reinforcement steel bars

Intelligent reinforced concrete structures with transformation-induced-plasticity (TRIP) steel rebars that have self-diagnosis function are proposed. TRIP steel is special steel with Fe-Cr based formulation. It undergoes a permanent change in crystal structure in proportion to peak strain. This changes from non-magnetic to magnetic steel. By using the TRIP steel rebars, the seismic damage level of reinforced concrete structures can be easily recognized by measuring the residual magnetic level of the TRIP rebars, that is directly related to the peak strain during a seismic event. This information will be most helpful for repairing the damaged structures. In this paper, the feasibility of the proposed intelligent reinforced concrete structure for seismic damage sensing is experimentally studied. The relation among the damage level, peak strain of rebars, and residual magnetic level of rebars of reinforced concrete beams implemented with TRIP steel bars was experimentally studied. As the result of this study, this intelligent structure can diagnose accumulated strain/damage anticipated during seismic event.