*Posted on behalf of a Hilti customer:
I’m a Plumbing Contractor and have been informed by the Engineer on the project that drop-in anchors are not acceptable for hanger rods and seismic bracing. The project is a high-rise apartment building, the structure is post-tensioned concrete and the Engineer will not allow fasteners with an embedment greater than 1”.
Which anchor should I use?
Hi Customer,
thank you for reaching out to us.
depending on the phase of construction several options are available. The Hilti HCI-WF Cast-in Anchor can be attached to the concrete form work prior to pouring the concrete. Unfortunately there are currently no post-installed anchors with shallow embedment depths that comply ACI 318 and IBC requirements. Most Engineers require scanning the concrete to locate the post-tensioned cables prior to drilling the concrete.
The Hilti PS 1000 X-Scan system displays a top view of the scan for easy object mapping plus cross sections in both directions for easy identification of multiple layers in concrete structures. Mechanicall anchor options for cracked concrete and seismic applications include the KWIK Bolt TZ Expansion Anchor (cracked concrete and seismic) and KWIK HUS-EZ I Carbon Steel Screw Anchor. The KWIK Bolt 3 Expansion Anchor is an option for uncracked concrete. I hope I have answered your question. If there is anything else, please let me know.
Best Regards
Jorge
Post-tensioned (PT) slabs are typically flat slabs, band beam and slabs or ribbedslabs. PT slabs offer the thinnest slab type, as concrete is worked to its strengths, mostly being kept in compression. Longer spans can be achieved due to prestress, which can also be used to counteract deflections post tension tendon.