Nonlinear behavior of RC frames strengthened with steel curb and prop

Using steel curbs and props is an appropriate method for strengthening the moment resisting reinforced concrete frames. In this paper, RC frames which were strengthened using steel prop and curb only, and in combination with beam's revival steel sheets and column jacketing are investigated using numerical modeling. After verifying the models, local and global behavior of these frames, such as displacement, ultimate strength, ductility factor and reduction factor were studied. Analytical results show that ultimate lateral load of strengthened frames using the prop with sectional area of 1.2, 2.0 and 3.5 cm2, has grown up to 2.0, 2.66 and 3.3 times of the ordinary frame, respectively. According to the results, when the prop's area increases, the ductility factor and the reduction factor of frames will decrease. The effect of column jacketing and beam revival sheet are opposite each other, while column jacketing increases the strength of the frame, the beam's revival decreases it, and when column jacketing increases ductility, the beam's revival decreases it.