EFFECTIVENESS OF LOOP ANCHORAGES FOR REINFORCEMENT IN PRECAST CONCRETE MEMBERS

Loop anchorages are an effective means of providing anchorage for tie reinforcement when detailing discontinuity regions in reinforced or prestressed, precast concrete members using strut and tie models. However, the ACI Building Code does not contain guidance on the use of loop anchorages. An experimental study on the effectiveness of loop anchorages when subject to various levels of compression across the plane containing the loop is described in this paper. Based on the data obtained, design proposals are made for 180-degree loops in Nos. 4, 5, and 6 reinforcing bars with the minimum bend diameter allowed by the ACI Code. Numerical design examples illustrate the proposed design method