Performance of RC columns with debonded bars subjected to cyclic lateral loading

What is it about?

Concrete columns with light confinement reinforcement subjected to cyclic lateral load exhibit brittle shear failure along with flexural yielding of longitudinal steel reinforcement bars. The present study investigates the debonding effect of longitudinal bars on the performance of columns under lateral loading. Column specimens were tested under quasi static reverse cyclic lateral loading. A comparative study has been carried out on the performance of columns with and without debonding using circular steel tubes of varying lengths. The steel tubes were provided in the potential plastic hinge zone. It is observed that the specimens with debonding, have significant enhancement in deformation capacity, ductility and energy dissipation capacity than the specimens without debonding reinforcement. The congestion of reinforcement at the joints can also be eliminated.

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Why is it important?

The objective of the present study is to evaluate the ductility, energy dissipation capacity, stiffness degradation and work damage Indicator of shear dominated RC columns with and without debonding of bars. The column specimens are subjected to quasi static reverse cyclic lateral loading and its enhancement in seismic performances are studied by providing de-bonding at the critical region. The study also examines the effectiveness of debonding provision to reduce the reinforcement congestion near the joint region. An attempt has also been made to compare the performance of the column specimens prepared as per the Indian Standard code IS 456: 2000 with that of the specimen designed as per IS 1893:2002 having ductile detailing as per IS 13920:1993 and with bond controlled reinforcement.