For the concrete breakout failure, what happens if there is rebar in the top and bottom of the concrete between the edge and the anchor bolt?
*Posted on behalf of a Hilti customer.
Hi Customer,
well this is a good question. Rebar in the top and bottom of the concrete between the edge and the anchor bolt” could be considered “supplementary reinforcement”. ACI 318 anchoring-to-concrete provisions define supplementary reinforcement as reinforcement that “acts to restrain the potential concrete breakout but is not designed to transfer the design load from the anchors into the structural member.” Reference ACI 318-14 page 40 for a definition of supplementary reinforcement. The use of supplementary reinforcement assumes the reinforcement restrains the potential concrete breakout area, thereby permitting a higher phi-factor to be used. ACI 318 anchoring-to-concrete provisions for concrete breakout in shear also permit use of a higher psi-c,V modification factor if edge reinforcement is considered. Reference ACI 318-14 Section 17.5.2.7 for additional information about psi-c,V. Supplementary reinforcement as a design assumption is left to the Engineer of Record to determine. Please feel free to reach out any time, if you need additional information.
Kind Regards
Morgan