Update for anyone interested:
I told the GC that I could not approve the system as specified and that I needed the manufacturer to provide calculations (or any other proof) showing that their anchorage designs met the ACI 318 requirements. Due to the potential cost savings, the GC still wanted...
If anyone is curious, here is the calculation I sent to the manufacturer for them to review and tell me why there was a discrepancy. This uses ACI 318-14 Chapter 17 and the epoxy ESR.https://files.engineering.com/getfile.aspx?folder=f013b3e7-4a72-4b16-af99-25c95eba4809&file=Anchor_calc.pdf
driftLimiter - I did my calculations as uncracked just for comparison purposes with their "allowable load" just because I know they would try to argue with me about the difference. I always consider cracked for my anchorage designs. Even assuming uncracked to match them, it was still about 60%...
driftLimiter - Thanks for the feedback. It's helpful to know when/where others are using ATS systems.
To address your questions about the concrete breakout:
1. Somewhere buried in their documentation I found a conversion factor of 1.62. I have seen this on other resources as well and I think...
dold - Yeah, they don't use a take-up device at all with the cable system. They are relying exclusively on "pre-loading" the cable. The way they explained it is that the cable is over-tensioned (~140%) and as the building shrinks the "pre-load" reduces until it has about 5% sustained tension (to...
driftLimiter - This is a really great point. Our original design does not explicitly address shrinkage considerations. We do have notes on the drawings that say something like "install the top part of the straps first, then nail the bottom once the roof framing is completed". I personally don't...
bones206 - Wow, can't believe I missed that. Thank you for the reference.
Something else I am still hung up on too is how much tension the anchorage will actually experience and how the pre-load/post-tensioning amount is determined. The TER says that the tensioning amount is determined by the...
Brad805 - I agree regarding the standard nature of the actual embedment itself. It is just a steel threaded rod in epoxy. The fact it is attached to a steel cable should have nothing to do with the anchorage design in my opinion.
The contractor said there would be a cost savings of over...
WinelandV - Thank you for the link to the field testing procedure. I am not sure how to address the sustained tension capacity. ACI 318-14 Section 17.2.5 Commentary says in part "R17.2.5 For adhesive anchors subjected to sustained tension loading, an additional calculation for the sustained...
I've attached the cable system TER here:https://files.engineering.com/getfile.aspx?folder=54547173-8379-409a-ad63-40de10753fad&file=DrJ_Report_-_QuickTie_Products_Inc_-_QuickTie_System_(QTS)_-__0910-01_(3).pdf
bones206 - The idea of "cert-washing" or "pay to win" is my fear. I believe the testing agency is certified but I am unfamiliar with how that process works.
hokie66 - I think the system can work conceptually. As phamENG said, the cables only resist the tension from uplift. We are still...
Eng16080 - Yes! My thoughts exactly. I am meeting with the GC tomorrow afternoon to explain why we likely won't be using this system, so hopefully they will understand the reasoning.
Rubber bands and hot glue, eh? You're not gonna believe this, but I "tested" it and it will work for your...
phamENG - Agreed. I sent a detailed hand calc to the manufacturer's engineering team showing the concrete breakout strength using ACI 318 equations AND using their own epoxy values/modifications. The calc showed the ~60% discrepancy in allowable tension. They confirmed they would "review" it and...
Eng16080 - Thanks for the reply. I share the same concerns. Regarding how the system is intended to transfer uplift from intermediate levels, the manufacturer's engineering team told me that it behaves essentially as you described. The tension on the uplift side basically acts like upward...
I used to use Enercalc for this design. Now I don't do it as often so I just do it by hand using the Strength Design (LRFD) slender wall provisions in TMS 402. I believe that if you use that method you don't need an interaction equation. My understanding is that there isn't really an ASD method...
TL;DR:
A shear wall hardware product manufacturer is claiming a steel threaded rod with epoxy anchored to concrete does not need to comply with ACI 318 anchorage provisions. I disagree. If ACI equations are used to check the anchor’s capacity, the product would have a reduced capacity and...
