Casting position effects on bond performance of reinforcement bars

The phenomena associated with the consolidation of fresh concrete (bleeding and plastic settlement) significantly affect the performance of anchorage or laps of reinforcement. However, rules to consider the effect of casting conditions on the design of anchorages and laps are not consistent amongst design recommendations and may lead to notable differences. In this paper, a detailed experimental investigation is presented on the influence of bleeding and plastic settlement on both failures modes, in an effort to clarify how shall consistent design recommendations be formulated. Such investigation is based on a comprehensive experimental programme, comprising more than 130 pull-out tests on specimens with different casting conditions, embedment lengths, loading arrangements and concrete covers. On the basis of the test results, the phenomenological differences between pull-out and spalling failures are clarified, as well as the main influencing phenomena.