*Posted on behalf of a Hilti customer:
I thought adhesive anchors were limited to a maximum embedment depth of 20 bar diameters.
Dear Customer,
well this is a good question. Post-installed reinforcing bar embedment depths are limited to a maximum value of 20dbar when designing per the anchoring-to-concrete provisions of ACI 318 (ACI 318-08/11 Appendix D or ACI 318-14 Chapter 17). Reference the bond strength design tables in the evaluation report for maximum embedment depth values specific to a particular bar diameter and drilling method.
Adhesive systems that have passed the test program outlined in the Table 3.8 of the ICC-ES acceptance criteria ACCEPTANCE CRITERIA FOR POST-INSTALLED ADHESIVE ANCHORS IN CONCRETE ELEMENTS (AC308) can be used to post-install reinforcing bars designed per the development and splice provisions of ACI 318-11 Chapter 12 and Chapter 21. Test number 9 and test number 10 in Table 3.8 are conducted using an embedment depth of 60dbar. Reference the Manufacturer’s Printed Installation Instructions (MPII) in the evaluation report for maximum embedment depth values specific to a particular bar diameter and drilling method when designing a post-installed reinforcing bar for development/splicing. Don't hesitate to contact us if there is anything else we can do for you.
All the best
Aidan