Role of different types of varying hoops reinforcement in RC beam-column joint performance

A seven-storied RC building in zone II is analyzed, and one of the exterior beam-column joints at an intermediate story is designed. Six one-third scaled exterior RC beam-column joint specimens detailed as per IS 456 using a headed bar and varying amount of joint hoops reinforcement are prepared and tested under a cyclic and reverse cyclic loading to study their performance. Among six specimens, three specimens detailed as per IS 456 with an additional type of hoops and the remaining three specimens are using headed bars and type of hoops reinforcement. Various parameters such as maximum shear strength, hysteresis behavior, modes of failure and stiffness degradation are studied. The effectiveness of headed bars with short embedded length terminating in the exterior beam-column joint is assessed. The headed bars are having the benefit of transferring greater uniform distribution of compressive stress to the concrete at the headed end; also, they enable the improvement of a much wider compressive strut in the joint, and alongside confinement of joint which enhances the overall performance of joint. From experimental investigation, it is observed that the headed bars with varying amounts of hoops reinforcement enhance the overall performance of the joint. (C) 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the First International conference on Advanced Lightweight Materials and Structures.