Hilti Anchors vs. Anchor Bolts
Hilti Anchors vs. Anchor Bolts
(OP)
I know that Hilti makes a wide selection of different anchor systems. It seems that the traditional anchor bolts have been the design choice for all types of construction.
When it comes to residential, would you consider using Hilti anchors for anchoring the column baseplates to the supporting footing pads or are the traditional anchor bolts better for that? How about anchoring the sill plate to the foundation wall?
When it comes to residential, would you consider using Hilti anchors for anchoring the column baseplates to the supporting footing pads or are the traditional anchor bolts better for that? How about anchoring the sill plate to the foundation wall?






RE: Hilti Anchors vs. Anchor Bolts
RE: Hilti Anchors vs. Anchor Bolts
RE: Hilti Anchors vs. Anchor Bolts
RE: Hilti Anchors vs. Anchor Bolts
Mike McCann
MMC Engineering
RE: Hilti Anchors vs. Anchor Bolts
While I do agree these anchors are heavily over used onsite, they are very good option for cyclic/fatigue load conditions like wind, if you have to use a post-installed option. I like cast-in anchors the most.
I do not like to use mechanical anchors in wind applications due to the displacement in the concrete required to get ultimate strength conditions, and since you often have alternating loading conditions (ie tension to compression) mechanical anchors if loading past slip condition will fail very quickly.
When in doubt, just take the next small step.
RE: Hilti Anchors vs. Anchor Bolts
RE: Hilti Anchors vs. Anchor Bolts
Please enlarge on your earlier comment. Why do you wish there were no epoxy or adhesive anchors?
BA
RE: Hilti Anchors vs. Anchor Bolts
RE: Hilti Anchors vs. Anchor Bolts
RE: Hilti Anchors vs. Anchor Bolts
BA
RE: Hilti Anchors vs. Anchor Bolts
RE: Hilti Anchors vs. Anchor Bolts
Advantages
* No need to do tedious setting outs. Just do the casting and then fasten. Cast-in-situ anchor positions might change during concrete operations
* Rapid construction. E.g. No need to keep starter bars from columns for lintels etc.
Disadvantages
* Close edge distance, distance between anchors etc. will reduce load carrying capacities
* Mechanical anchors exert pressure on base material when tightening
* Force-displacement curve is better in cast-in-situ anchors
There will be a bigger list.....
KC
RE: Hilti Anchors vs. Anchor Bolts
RE: Hilti Anchors vs. Anchor Bolts
BA
RE: Hilti Anchors vs. Anchor Bolts
Make them put in the anchor bolts properly. Get really stubborn once or twice and have them tear out a footing and re-place the concrete if the bolts don't align...they'll learn how to do it right eventually.
Use leveling nuts and good grout for the baseplates. Keep in mind...residential contractors don't know diddly about steel erection...be prepared to hold their hands a lot.
RE: Hilti Anchors vs. Anchor Bolts
We may not have the final equipment drawings yet. We may not even know which vendor is going to provide the equipment. Yet we are asked to provide final foundation drawings under the assumption that they can go ahead and pour the foundations as long as they can go back and use the post-installed anchors to correct for any issue.
It's a bit more stressful to have to rely on that sort of thing. (hence the sympathy with ArchEng59). But, it also allows us to absolutely impress clients with our ability to meet a demanding schedule.
Josh
RE: Hilti Anchors vs. Anchor Bolts
RE: Hilti Anchors vs. Anchor Bolts
RE: Hilti Anchors vs. Anchor Bolts
RE: Hilti Anchors vs. Anchor Bolts
But I've had projects where if it wasn't for drilled and epoxied reinforcing dowels, I don't know what I would of done. Say I'm adding a concrete structure to another structure and an expansion joint is not feasible. And contractors, not being completely stupid (lazy is another story), realize if I'm anchoring a concrete wall using epoxy, what's the big deal about a couple of ledgers?
So we have to take the good with the bad.
RE: Hilti Anchors vs. Anchor Bolts
I am coming from the Electrical side of building construction. We do Healthcare, Civic and Educational projects. Our anchorage and seismic bracing details are reviewed by the State and Local Agencies and we utilize a lot of Hilti equipment. They have many pre-approved systems that are used for many types of equipment anchorage. It is almost a given that the Hilti "Kwik-bolt III" will appear on all of our work. These are an afterset anchor but it does not use epoxy. I am sure you are familiar with this or something like it. I was curious as to the discussion regarding post installed bolts did not include these? Are these too expensive for residential construction? Or is there another reason?
My switchgear, generator, transformer, conduit trapeze, and all manner of equipment anchorage specifications and details have called for these for many years. I've got thousands of these things installed. The Office of Statewide Health Planning and Development and The Division of the State Architect's Structural Engineers as well as our in-house Structural Engineers favor these. Perhaps not being structural myself, I've misunderstood the message in this thread. I was just curious and thought I would ask an oponion of the experts.
RE: Hilti Anchors vs. Anchor Bolts
Do you have any performance specs indicating "x" percentage of all post-installed anchors must me qualified. I note that ACI has a publication for qualification of post-installed anchors.
How many of you have or have thought of including pull tests to be done on a certain percentage of post-installed anchors? Maybe that will help contractors to bring their "A" game during installing the anchors. If the thing pulls out well before capacity is reached, its on their pocket to get it right.
RE: Hilti Anchors vs. Anchor Bolts
We have seen spec's for 10% of post-installed anchors being tested. We had one particular out-of-this-world OSHPD inspector have 100% of these anchors tested. Contractor was not amused. Especially as the testing was specified to be "as required by the AHJ".
Regards,
EEJaime
RE: Hilti Anchors vs. Anchor Bolts
I also have a question regarding cast-in anchors, what is the standard tolerance provided in connection? I generally aim for +/-40mm, what does everyone else aim for?
EEJaime,
What you are referring to is a mechanical post installed anchor. These are good for situation where loading is required almost immediately after installation, However as noted by msquared48 these anchors can have problems with cyclic loadings, and to minimise the effect of this they generally have a torque that must be applied to ensure no movement during loading. They are also more expensive generally, and have a lag time on ordering. I generally find these have less problems then chemical anchors due to the fact that a tradesmen not a labour has to install, due to the use of a torque wrench.
When in doubt, just take the next small step.
RE: Hilti Anchors vs. Anchor Bolts
We use these on heavy vibrating equipment such as generators and fire pumps, specifically for the seismic bracing of the equipment with the vibration isolation mounts and seismic restraints. msquared48's post specifically states that these are the types of loads he would not recommend these anchors for. Does this concern apply to both epoxy and mechanical type after-set anchors?
Regards,
EEJaime
RE: Hilti Anchors vs. Anchor Bolts
RE: Hilti Anchors vs. Anchor Bolts
http://ww
consider:
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When in doubt, just take the next small step.
RE: Hilti Anchors vs. Anchor Bolts
Kwik III
http://ww
When in doubt, just take the next small step.
RE: Hilti Anchors vs. Anchor Bolts
First, my apologies to the OP for hijacking this thread. It was an excellent question that brought another important question to mind. rowinengineer and sandman21, you have been extremely helpful and I appreciate it. I am going to revise my specifications and details to incorporate the HSL anchor, it is clearly a superior selection for my applications. I am sure our SE's will approve.
My co-workers often limit their participation in these fora to their own discipline, but it is these forays into semi-related or peripherally related fields that often, as today, prove most useful.
Again thank you and regards,
EEJaime
RE: Hilti Anchors vs. Anchor Bolts
I think the Big Dig Bosten has made me rethink my saftey factor for design, and the amount of tests required.
When in doubt, just take the next small step.
RE: Hilti Anchors vs. Anchor Bolts
Hilti anchors are not cheap, and generally it is cheaper to set traditional bolts than use hilti bolts.
Finally the perception that epoxy is an inferior product due to the big dig is not true. The epoxy used was a temporary epoxy not suited to long term use due to a tendency to creep. Further the material was used in an overhead application which is not the best use for epoxy. (a good application for cast in place bolts) Finally the panel loads were supported by five bolts and the loads were distributed by diagonals that were tightened or lossened by turnbukles to adjust the panels, so the load in the bolts was indeterminate. In the end the epoxy manufacterer who supplied the epoxy to a reseller and sold it under a different label took the hit. However I believe this had more to do with a ability to pay rather than truth or justice.
RE: Hilti Anchors vs. Anchor Bolts
RE: Hilti Anchors vs. Anchor Bolts
In regards to pull tests, our general notes have a section on post installed anchors that specifies pull tests consistent with OSHPD (California Hospitals) requirements. OSHPD has a Code Apllication Notice (CAN) for field testing post installed anchors ( http://w
RE: Hilti Anchors vs. Anchor Bolts
(and as a side note - as a woman, am I allowed to read EEJaime's posts? lol)
RE: Hilti Anchors vs. Anchor Bolts
My apologies. I am used to my home forum, (electrical), where as far I can recall, at least in the past two years, we have not had a female member that is a regular participant. I should know that this is different in other disciplines. Even in the last 30 years of working in this business, I can probably still count on one hand the number of women that I've met whom are electrical engineers. Many Architects, Lighting designers, product representatives, engineers of varied disciplines, Mechanical, but not electrical.
I guess I just fell into an industry that is not to the liking of many women. Thank you for lighthearted response. Apparently you are familiar with us that write without always thinking things all the way through.
Have a pleasant day,
EEJaime
RE: Hilti Anchors vs. Anchor Bolts
when you say mechanical "screw" anchor do you mean like the "hilti Hus" anchor or equivalent? I have to be honest in all my years of practice i have never spec'd this type of anchor, I have always been put off by because they have to drill a hole and clean, but if the hole is oversized at all, the anchor capacity is reduced immensely.
When in doubt, just take the next small step.
RE: Hilti Anchors vs. Anchor Bolts