Anchorage length of reinforcing bars in tension: an assessment of the Australian Standard AS 3600:2018

Abstract

When designing a reinforced concrete member for strength, ductility and robustness, it is essential that a sufficient length of reinforcement is developed on both sides of a critical section in a zone of tension. The specifications of the existing codes of practice for calculating the development length of reinforcement are statistically based on test data mostly from small-scale pull-out and beam specimens, and their applicability outside the range of the test data is uncertain. This paper describes an experimental research program to assess the effects of different structural parameters on the development length requirements for modern high strength steel reinforcing bars, including the case of lapped splices in large-scale reinforced concrete members in bending. The factors of safety obtained in the tests are assessed according to the Australian Standard (AS3600:2018) provisions for the anchorage length of reinforcing bars in tension and also in terms of attainable average bond stress in different anchorage conditions. The study has revealed that modification(s) to two of the coefficients included in the provisions of AS3600:2018 would provide a more consistent and reliable factor of safety for the anchorage of reinforcement in large-scale concrete members, including at lapped splice locations.