The hilti software does not seem to allow use of rebar for C2 seismic loads. Is there a way around this? Surely you can use post-installed rebar in regions with high seismicity? Can you increase the load and use C1 in the software? or is post installed rebar simply not allowed?
Hello Lucas,
I have broken down your question into three parts and answered those separately.
Why do some post-installed anchor systems allow design with seismic C2 and other do not?
The seismic C2 classification is a method for testing a post-installed anchor system into concrete.
Without a system testing to seismic C2 conditions there is no reference data, and therefore no values to be used in design. A system for example would be HIT-HY 200 V3 epoxy M12 HAS-U Rod with a specified installation parameters, or additionally in this case HIT-HIT RE 500 V4 epoxy HD500 Rebar
The reason that any systems is showing a capacity for and allowing design with seismic C2 is because that system was tested to the C2 criteria as per EAD… you can learn more about the test criteria here on our webinar recording.
What does seismic C2 testing actually cover?
Post-installed anchor(s) for steel to concrete connections tested under cyclic loads with dynamic cracks intersecting with the anchor locations. It is not intended for use with concrete to concrete (typically rebar) connections.
How can I design post-installed rebar for regions with seismicity?
Post-installed rebar in New Zealand is considered an alternative solution wrt the NZBC as it is not covered by any cited building standard and as such the design engineer has the responsibility to select the best qualification system and design method.
There are however internationally recognized test procedures for post-installed rebar to verify their performance as being equal to cast-in bars for various conditions, including seismic. This is covered by EAD 330087-01-0601. Hilti offers a range of systems which are tested to the aforementioned EAD including coverage for seismic applications.
Therefore, we recommend using a rebar system qualified to EAD 330087-01-0601 and designing with your preferred rebar design method for a straight deformed bar.