Need help with concrete anchors
- Thread starter kwm322
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FANTM58
Well-known member
it looks like the anchors shown are missing the sleeve that expands .
double check them with some others if you have extras,
double check them with some others if you have extras,
Advan
Well-known member
If you hit rebar, just keep the gun rotating, but put less-than-usual down pressure on it, just enough to keep the hammering action going. It could be 5-60 seconds, but eventually you'll hear the sound change and see concrete dust coming up the flutes!
As a grunt that has installed thousands of concrete anchors during my career, some of the threads like this drive me nuts. However, if I can offer one more piece of advice, never use an impact gun of any type to tighten a wedge anchor, only use a hand wrench!
As a grunt that has installed thousands of concrete anchors during my career, some of the threads like this drive me nuts. However, if I can offer one more piece of advice, never use an impact gun of any type to tighten a wedge anchor, only use a hand wrench!
wssix99
Well-known member
Sounds like you are hitting the edge/side of a piece of rebar. Either you have the wrong bit or you need to...
^ follow this great advice.
If you hit the edge just right, it can get caught up. You just need to give it a light touch. It's actually a lot easier when you hit the rebar straight on.
Do you know the type of bit you are using?
A lot of great advice given. I am in the loading dock and industrial door business. Needless to say we do a LOT of concrete work and a LOT of anchoring. Just be careful if you have to drill any new holes. As a rule we run holes no closer than four inches at a minimum from other holes, seams, cracks, or defects to avoid cracking/blow outs. For real advice you'd have to ask one of my guys, but everyone covered the main points: rebar cutter, epoxy pros and cons, and hilti anchors
DougWil
Well-known member
Not true.
The design strength of concrete is purely dependent on the water cement ratio in the mix design, excluding fly ash and other additives.
The actual achieved strength is very dependent on proper curing.
That is what we have been talking about, how improper curing and lack of water will lower the concrete strength and durability.
And yes the mix water alone is adequate to insure hydration and proper curing if it is not allowed to evaporate, bleed off and be pulled into a dry base.
But that is exactly what does happen to an exposed slab without a curing agent.
And that is why watering the surface of a curing slab is essential to maintaining hydration deep within the slab, not just at the surface.
Regular concrete is both porous and permeable, water passes both in and out of a slab.
I'm using a masonry bit. My plan to use longer anchors in deeper holes seems to be working so I'm gonna keep going with that. So I don't have to move or drill new holes. I probably won't have time to work on it till next weekend I will update then! Thanks everyone!
acmikee
Well-known member
I have used sikabond adhesive to anchor 5000lb fans use it with 3/4" allthread.
we did 2000lb pull tests without a single failure. you can buy the stuff at home depot, just watch the expiration date.
we did 2000lb pull tests without a single failure. you can buy the stuff at home depot, just watch the expiration date.
wssix99
Well-known member
wssix99
Well-known member
Following advice like this can get people killed. I hope those fans aren't mounted overhead, either...
Adhesives don't necessarily all become truly solid, even if they are "strong." They can still creep and many are not appropriate for tension applications like overhead work or for the bolts on a lift. These manufacturers will have warnings against using the products like this.
Before using any epoxy anchor, one should definitely check with the lift manufacturer and make sure the system/adhesive is compatible and approved.
You said Doug was wrong and then posted useful information, however none of which supports your point.
True, curing concrete is a chemical process, not drying
Yes, insufficient water and the chemical reaction can not happen
I guess this is true, but not in any useful or predictable way? I learned something here.
This is true as well isn't it?
So, what is the objection?
This is why I decided to use longer anchors deeper in the concrete. Going deeper is basically like starting a fresh hole and the lift was designed to use 3/4 anchors. The specs say 3.5 inches is minimum depth and I'm 6 to 6.5 now. So hopefully I dont die haha
DougWil
Well-known member
Typical suitable aggregate used in a commercial mix plant is 10-40K psi, so assuming it is properly graded it isn't a limiting factor for anything most of us would be pouring.
wssix99
Well-known member
My comments were more about epoxy/glue choice. There are products that will work but we can't just pick anything off the shelf and have it be safe.
There's lots of goodness in going deeper with the anchors. Did you get through the rebar?
I should clarify. To do epoxy anchors right I would of had to go down to 5/8s rod, or disassemble the lift, move the post, and drill out the holes in the floor to 7/8s then reassemble. The directions on the tube said the holes needs to be 1/8 inch bigger than the rod you use. That's why I decided to just go deeper. It was the easiest thing to do. I haven't had a chance to work on it I have 3 of the 6 done. I was helping on the farm during the day and working at my regular job at night the past couple weeks so I haven't had time. I should have it done next week sometime.
DougWil
Well-known member
I have noticed on internet forums that guys are quick to claim BS or 'you are wrong' but when proven otherwise......... never respond and just disappear.
Out walking the dog, I have taken note of a single family home being built in an established neighborhood.
They poured the footings a few days ago, removed the forms the next day and haven't been back.
Poured on a dry base, no curing agent, no tarps, no wet burlap or carpet, warm, breezy summer days, not a garden hose in sight.. that concrete looks bone dry and I doubt it has ever been watered since pouring.
Wonder what the compressive strength will be at 28 days with that 2500-3000psi design mix??
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Quick update! I picked up a Bosch rebar cutting bit and put it in a 1/2 inch drill because my rotohammer either rotos and hammers or just hammers. So can't use it in that. It chewed right through the rebar. So I used it to chew through the collars left in my other 2 holes too. I punched through the slab put my longer anchors in and they tightened down no problem. All of them are at least 6 inches deep now. I retorqued the other post while I was at it and got kind of concerned because I was able to tighten 3 of the nuts. However it appeared to be squeezing the baseplate down more flush (flusher) not pulling the anchor out. I suspect this was because I only torqued them once the first time around I didn't recheck after the last one was torqued.
I picked my truck up with it and rocked it pretty good and it seems solid. The posts kind of rock a little with the truck rocking. It's probably normal, I've used twin posts before but never analyzed it this close so I'm probably being overly critical of everything. Before I had all these issues with the anchors I did notice the baseplates appeared to have some movement in them when I rocked the truck but they appear to be solid now.
I don't know much about th physics of these thing but it does appear that the weight of the vehicle should be holding the post down and the cross over bar keeps posts from tipping into each other so as long as the vehicle is racked correctly there shouldn't be too much strain on the anchors so hopefully my problems are solved! Thanks for the help again!
I picked my truck up with it and rocked it pretty good and it seems solid. The posts kind of rock a little with the truck rocking. It's probably normal, I've used twin posts before but never analyzed it this close so I'm probably being overly critical of everything. Before I had all these issues with the anchors I did notice the baseplates appeared to have some movement in them when I rocked the truck but they appear to be solid now.
I don't know much about th physics of these thing but it does appear that the weight of the vehicle should be holding the post down and the cross over bar keeps posts from tipping into each other so as long as the vehicle is racked correctly there shouldn't be too much strain on the anchors so hopefully my problems are solved! Thanks for the help again!
lakeroadster
Well-known member
Sika Bond, at least the type that is at Home Depot, is about half the strength of the Hilti HY-200 that is recommended by Rotary for their two post lifts.
Be careful out there fellas. This is one area where you need to strictly follow the lift manufacturers specification.
Ign
Well-known member
Late now but when I did my install I cut the wedge "wings" off my supplied anchors and cut grooves around the circumference of the anchors with an angle grinder. Then dropped 'em in the epoxy. That was 2009, still alive.....
nadogail
Well-known member
I will be the first to admit that I am not as smart as I sometimes appear, but I have found that my Go To names for anchors are Hilti and Simpson. The others, IMHO, are "knock offs"
Those companies have earned their good reputations by providing excellent products and service.
All that comes at a price, if you are not willing to pay their prices then youu take what you get for your money and hope that what you get will be "good enough".
Those companies have earned their good reputations by providing excellent products and service.
All that comes at a price, if you are not willing to pay their prices then youu take what you get for your money and hope that what you get will be "good enough".
ConCretin
Well-known member
I realize this thread has veered off course from the OPs original questions but having returned to civilization after a few days away from technology I was amazed at some of the mis-information presented here. Others have corrected the record somewhat but let me present a few facts.
The final compressive strength of concrete is determined by the ratio of mix water to cement and alternative cementitious materials such as slag or fly ash. There is more than enough batch water in the concrete to support hydration.
The goal of curing is simply to prevent it's premature loss from evaporation. Curing water applied to the surface is one method of achieving this but the concrete doesn't need the additional waterto reach strength. It's just to keep it from drying out. Chemical curing essentially achieves the same outcome.
It's hard to tell from the pics but it appears there is some de-lamination going on. What appears to be a crack, could just be the edge of the de-laminated section that is coming up. If that's the case, it's not a structural issue.
The final compressive strength of concrete is determined by the ratio of mix water to cement and alternative cementitious materials such as slag or fly ash. There is more than enough batch water in the concrete to support hydration.
The goal of curing is simply to prevent it's premature loss from evaporation. Curing water applied to the surface is one method of achieving this but the concrete doesn't need the additional waterto reach strength. It's just to keep it from drying out. Chemical curing essentially achieves the same outcome.
It's hard to tell from the pics but it appears there is some de-lamination going on. What appears to be a crack, could just be the edge of the de-laminated section that is coming up. If that's the case, it's not a structural issue.
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