Advanced Crack Width Analysis of Reinforced Concrete Beams under Repeated Loads

Presented is a method which can predict accurately the crack width in reinforced concrete beams under repeated loading. It is known that the crack widths increase with an increase of the number of load cycles. To evaluate the crack widths realistically, the bond stress-slip relation and the variation of transfer length under repeated loading have been modeled and incorporated in the analysis model for crack width. The present study indicates that the transfer length decreases according to the increase of load cycles, which is due to the increase of residual slip. The calculated crack widths from proposed method agree very well with test data available in the literature, while the existing method shows large deviation from the test data. The proposed method also allows the calculation of the residual crack width after repeated loading. The present study provides a realistic base for the prediction of crack width, which is important for the serviceability of reinforced concrete structures subjected to repeated loads.