Interface Shear Transfer of Diagonally Arranged Reinforcing Bars under Repeated Loading

Shear transfer mechanism on a crack interface of reinforced concrete members is composed mainly of aggregate interlocking and dowel’s action due to reinforcing bars. In this paper, the dowel’s action is focused on, which mechanism is relatively reliable and simple to be understood. In the most of existing works on the dowel’s action, the bar perpendicularly to the interface under one-way monotonic loading tests have been examined. In general, the practical observed interface, however, is diagonal, not perpendicular to longitudinal direction of the bar arranged. It has not been, thus, revealed well that the dowel’s action of the diagonally arranged bars under repeated loading. We, therefore, carried out repeated loading tests of two series of the push-off type specimens with various angles of the bar arrengement as to the interface. First, series of the small scaled specimens test have been conducted. The opening of crack mouth developed from around the bars dominated significantly the obsereved slip on the interfaces, which resulted from an insufficient concrete cover around the bars. Thus, series of the large scaled specimens with a sufficient concrete cover were additionally tested. Their shear transfer mechnism and histerisis loops are discussed besed upon the obtained results.