This week’s blog post was written by Ryan Vuletic, Manager of Engineering/R&D for Anchor Systems. Prior to joining Simpson Strong-Tie in 2001, he was a structural engineering consultant on projects such as state highways and bridges, Las Vegas hotels and casinos, Disney entertainment buildings and military facilities. Ryan received his B.S. in civil engineering from the University of California Irvine and MBA from the University of Southern California. He is a registered professional engineer in California.
Over the last decade, special types of cast-in-place inserts such as the Simpson Strong-Tie® Blue Banger Hanger® threaded insert have become very popular for anchoring suspended mechanical, electrical and plumbing equipment, piping and conduit.These types of anchors are quickly fastened to wood formwork, or through corrugated metal deck before concrete is poured.
Up until now, design engineers who wanted to specify these anchors had to address the question of code-compliance since these anchors are not specifically included within ACI 318 Appendix D or the International Building Code (IBC).
This issue has now been resolved through the code report process. On October 1, 2014, Simpson Strong-Tie received the first code report (ICC-ES ESR-3707) for this type of anchor under ICC-ES AC 446. The code report:
- Covers all sizes of the Blue Banger Hanger Wood Form Inserts (BBWF) and Metal Deck Inserts (BBMD)
- Addresses both cracked and uncracked normal-weight concrete and sand-lightweight concrete
- Addresses static, wind and seismic loads
AC 446 (Acceptance Criteria for Headed Cast-In Specialty Inserts in Concrete) is a relatively new approval criteria that was developed by Simpson Strong-Tie and several other anchor manufacturers. It was adopted by ICC Evaluation Service in June 2013. Anchors that are approved under these criteria will utilize ACI 318 Appendix D and are deemed to conform to Sections 1908 and 1909 of the 2012 IBC.
Testing in accordance with AC446 establishes the strength of headed cast-in specialty inserts based on the strength design provisions of ACI 318. Although the shear testing requirements of this criteria are similar to those found in AC 193/ACI 355.2, the tension tests required are performed in a unique manner. The tension tests and the seismic tension tests are conducted in a steel jig.
The tests are conducted in this fashion to validate that the specialty insert has a strength that exceeds the calculated concrete breakout strength when f’c is set at 10,000 psi (maximum compressive strength permitted per ACI 318). The test program determines the following parameters for the specialty insert:
- Nominal tension strength
- Nominal seismic tension strength
- Nominal steel shear strength
- Nominal steel shear strength for seismic loading
- Nominal steel shear strength in the soffit of concrete on metal deck
- Nominal steel shear strength for seismic loading in the soffit of concrete on metal deck
This new qualification procedure and code report will give designers increased confidence that they can now properly design and specify the Simpson Strong-Tie Blue Banger Hanger and comply with the requirements of the 2012 IBC. What are your thoughts? Let us know in the comments below.