Simplified Design Equation of Minimum Interior Joint Depth for Special Moment Frames with High-Strength Reinforcement
Abstract To avoid excessive slip of beam longitudinal bars at the joints of an earthquake-resisting moment frame, ACI 318 Building Code set a minimum joint depth of 20 times the diameter of the largest longitudinal beam bars passing through the joint, which is based on prior experimental verificatio...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
SpringerOpen
2018-11-01
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| Series: | International Journal of Concrete Structures and Materials |
| Subjects: | |
| Online Access: | http://link.springer.com/article/10.1186/s40069-018-0303-2 |
| Summary: | Abstract To avoid excessive slip of beam longitudinal bars at the joints of an earthquake-resisting moment frame, ACI 318 Building Code set a minimum joint depth of 20 times the diameter of the largest longitudinal beam bars passing through the joint, which is based on prior experimental verification of beam-column joints with Grade 420 MPa reinforcement. In view of that the 20-bar-diameter criterion cannot be simply extended for concrete frame joints with higher grade reinforcement, this paper summarizes international existing design criteria and proposes a simplified equation for the minimum joint depth. The equation applicability is assessed by evaluating the cyclic testing results of beam-column joints conducted in East Asian and Pacific Countries, where Grade 490, 590, and 690 MPa reinforcement have been used for earthquake-resistant concrete structures. Beam-column joints that satisfy the proposed equation can demonstrate satisfactory hysteresis behavior at an interstory drift of 4%. |
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| ISSN: | 1976-0485 2234-1315 |