OS4-3-2 Flexural Rigidity Evolvement RC Beams Strengthened with Carbon Fiber Laminate under Cyclic Bending Loads

Abstract

The flexural rigidity evolvement of RC beams strengthened with carbon fiber laminate under cyclic bending loads is investigated in this paper. In the fatigue experiment, 14 reinforced concrete beams strengthened with carbon fiber laminates (CFL) are divided into three groups according to the peak stress applied on the CFL, and tested under bending loads with constant amplitude. The results show that: (1) the flexural rigidity development follows a rapid decrease phase, a uniform decrease phase, and a rapid decrease until failure phase; (2) there is linear relationship between flexural rigidity and normalizing fatigue cycles in the uniform decrease phase. Moreover, if the stress level is not beyond the main reinforcement yield stress, the flexural rigidity evolvement rules are independent on the stress levels.