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Loved the video, for future concrete pours for testing in tension, consider using fiberglass fibers mixed in. It’ll save a lot more surface area for more testing

Im in the construction trade in Jackson Wy. I have a decent back ground in climbing big walls. I found this video pretty neat and shared it with a bunch of guys at work. Most times when we have to hilti and add all thread/epoxy to concrete we have to have a 3rd party engineer watch us do it. Making sure we have the spec depth, properly cleaned the holes, and correctly mixed/applied the epoxy. The slow motion aspect of being able to see the concrete break is awesome! That’s wild you hit 44 KN with that much dust!

I don't even climb and I can't seem to get enough of these videos, after accidentally finding the channel a few days ago.

Appreciate the video, and the willingness to throw your opinion out there.

And that's why, you shouldn't... Something something dirty holes

I work with precast concrete this is a really good example of what's called a pullout cone

Appreciate all the effort you guys spend. And just to say it again, yes we should clean our holes! I just recently pulled a Petzl glue-in at the top of a pit in a cave nearby. Clearly that hole was NOT cleaned. 2K that doesn't not harden is a no go! Chek the best before date on your stuff! Especially if you're not bolting stuff regularly. Stay safe everyone!

Wow, those results were surprising. I would still feel better if the holes were cleaned properly. But dayum those results were way higher then I thought they’d be.

Thanks for another cool video. And very good point: the dirty holes are your second concern, first is **properly mixed epoxy**

Loving the slow mo Great job👍

Hi Ryan & Boby. I´m a fan fo yours from germany and I´d like to see you guys putting Petzl Batinox Bolts to the test. I´ll gladly cover your expenses for one or two if you agree to aquire an destroy them (or your patio). Let me know ;)

I'm curious about the vertical vs horizontal holes. More dust will end up at the bottom in each case, which might result in different failure modes.

Great stuff as always! Thats amazing they still took 40+kN to pull out!

I hope to some day ship you some of the home made bolts used in Brazil... And they are basically pressure hammered inside the granite and sometimes shimmed in

Hi, I am would imagine that the dust of differents rock will act differently in the whole. There are rocks who are very gravely, that may not connect as in your test.

Thanks for the testing information. I've epoxied hundreds of holes over the years and was taught that a key to strong epoxy bolts (besides a clean hole) is not having voids in the epoxy. The following process works well: be sure to let the mixing tip fill with epoxy before you insert it into the hole, so you know it is ready to come out immediately. Insert the mixing tip all the way into the hole and fill the hole from the far end outward. Try to keep an even pace when filling the hole and removing the tip. Maybe this could be another line of testing: do voids cause major weakness.

Love your channel ! Great content every time.

At work with glue in all thread we drill it, spin the drill to pull dust out with a vacuum and then glue them in. Now I don’t feel bad about using a wire brush. Thanks.

i couldnt find the english name, but there are "verbundanker" (compund anchors), a glass vial with resin, quarz grit, and aanister vial with a powdery hardener. normally used in concrete with a threaded rod ancher. i'd be curious to see, how those compare. they're just 1-2 eurobucks a pop.

I think that the porosity of the rock and the viscosity of the glue would Change how well the glue bonds to the rock. The higher porosity Rock types may grab the glue better mechanically, and thinner glue may saturate into porous and finer grain rock types. And the one that you were twisting possibly mixed the remaining dust in with the glue kind of like a rock filler. I use epoxy for many applications From climbing holds to gluing boats together. I'll be gluin titanium bolts in limestone on the next Caribbean's vacation, Good to know if I don't get every speck of dust it should be.. super good enough.

Surely the fact that your fitting the bolts flat to the floor has an effect as all the duat will fall to the bottom of the hole but if your drilling in to a vartical wall the dust will sit along the whole length of the bolt ? The difference might be tiny but its something to consider maby ?

how many days did the concrete cure before test? and what was the PSI rating of the concrete?

Could you have a go at doing Petzl clour bolts

If the cement pad you poured was mixed by hand it will be less poures because a mixer adds air into the wet cement it helps the cement cure and be stronger as well as creating more tiny divots for the glue to hold on to (work in masonry so cement mortar and stone is my specialty

How do these numbers compare to clean and clean-ish holes for strictly glue in (non-expansion) bolts?

Cannot believe you are not getting more like! At the time i have wath there were 2000 view but only 220 like thats disapointing for a good video like that one

So do you think it would make any difference if you set the bolts horizontally in the concrete, then laid the slab down to do the test? I’m just wondering if the dust will settle differently if you’re drilling and placing them in vertical vs horizontal dirty holes.

Gravity kinda cleans out the topmost portion of the hole, so you get really good adhesion or the top 1.5 inches, that's why you see the concrete fail but only at the top. Effectively, you are only glueing in a 2" bolt regardless of the try length of your bolt. If you pulled a bolt glued in to spec, you should see that cone ish shaped failure starting at the approximately the tip of the bolt.

For about $10/yard you can have added to your mix at the concrete plant anti-crack fibers which add lots of strength to the concrete.

I just wanna put this out there. Even the inside of a semi dirty concrete/drilled rock hole is always going to have better engagement with the rock than the bolt, unless it's a screw in bolt. Why? Surface area, and how the glue expands as it sets, in most of the hole even where, say, 1/3rd of the hole is packed with dirt grindings, the bolt (unless it's a finely threaded screw type) is going to have less surface area for the glue to grip, because it's smooth. Even a slightly damaged bolt is going to grip better because the damaged area creates more surface area than it being smoothed/undamaged. When you drill out concrete/rock it's not going to be really smooth inside the hole. There's more surface area on the concrete for the glue to grip than on the bolt. So, if you fill these holes complete, then insert the bolt, it might compromise the matrix in the glue slightly with the dust getting mixed into the glue, but the glue is NOT just sitting on top of these dust particulates, usually it's going to get mixed in with the matrix of the glue. TBH, I think to get the outcome shown by the other guy. You'd have to drill the hole, not clean it at all, insert the bolt and then try to inject the glue around the bolt. Instead of filling the hole with glue and pressing the bolt in. Understand what I'm saying? The obvious exception would be drilling a half inch diameter hole, and putting a quarter inch diameter non threaded bolt. All in all if you do at least 1/3rd of it logically, I think the bolt is going to hold beyond what would be needed for saftey of "SGE". Not a climber, but a rigger for extremely heavy construction loads, with a formal science and engineering background.

This type of adhesive works by expanding as it cures inside the hole; placing the whole mechanical connection in tension. On your first test with the threaded bolts what we are seeing is the concrete fail before the glue or the bolt. Those huge chunks of material being thrown off demonstrate how much bond there was between the adhesive and the concrete; they were basically the same or similar strength. Keep in mind concrete is porus, more so than most rock. This porosity may allow for a much stronger bond than you might find in a more dense rock like granite.

How long have the concrete hardened?

would have been interessting to see a proper bolt with well cleaning in compare

Awesome stuff guys

The glue wasn't sticking the walls at all, but happened to be taking up space, so that's what actually provided the strength. It's like a climbing nut, just the shape of the glue is wedged against the shape of the concrete. It could happen to solidify in a shape that doesn't provide any wedge action though, which I think would pull right out.

I mean it must matter on rock type as of vains going threw the rock could compromise it. Also drilling next the the edge of the concrete is asking for it to be weak

Were his bolts old or newly installed? I would imagine bolts that had been wiggled a bit from use over the course of a few months or longer, would slide out the hole a lot easier...

Can you do a real life tutorial on installation of all aforementioned bolts? And I mean, in rock, at a crag. Do's and do not's, why or why not's.

With a *super* smooth hole, talc like dust coating the walls, and somehow the epoxy not disturbing the talc, you'd probably get lower pullout. Mix the epoxy with the dust and you just get a sand/epoxy composite.

A lot also depends on the MPA of concrete. On residential house it's around 25 MPA. On highrise I've seen 75 MPA. How strong is your concrete? Just curious? I've always cleaned the holes. Compressed air and a brush. In some situations; the builder has specified a primer on everything from glue in bolts to sikaflex construction adhesive sealant work. Interesting to see real life tests! The Ramset type cures extremely fast and in under 5 minutes you can torque it down. As per specification.

I wonder what exactly is going on. The parts that disengaged and pulled out had a very smooth finish. I suspect that when the hole is getting started it is harder to keep the drill steady and that that creates some mechanical features for the glue to jam in. Once it is going you get a very smooth hole and the dust allows the disengagement.

Would've been interesting to know if anything changes when those bolts were loaded to 10kn to all (or one other side) before. Great content btw!

There is a good chance that granite is stronger in tension than concrete, so maybe you could get this effect in rock? Also were you twisting/spinning the bolts in the holes? This dislodges dust from the sides of the hole and gives works the glue into the substrate, so if you simply insert the bolt and don't touch it then that could lead to a glue pull-out.

Have you tried j-bweld?

I wonder how the kn would be after some years..

Just for perspective, do you know what properly brushed bolts in this concrete fail at?

so what would happen if for some reason there was oil in the hole, maybee a guy tryed to lubricate the drill bit

Hey guys, I was wondering if you had ever tried break testing Samson amsteel blue dyneema fiber cord. The one I am looking at is 1/8 inch and was wondering what it would do with a single strand, a double strand, a three cord braid, and double three cord braid. I am looking at this academically from a stand point of an emergency high-rise rappeling system. It would only have to work once but could be retrieved and used again and could be stored in a small space while still allowing for several hundred feet of decent.

I’d love to see a shear test on bolts without glue

Drilling vertically will knock most of the dust that stays in down to the bottom. Where if you drilled horizontally the dust will sit along the "bottom" of the entire hole and not the back. This might create more of the issue you are trying for.

awesome video man! thank you, by the way what is the end song name?

Where can you get the equipment to put in glue in bolts

Would be really interesting to do an over-torque / under-torque tests (pullout & shear) on five piece bolts. 3/8 vs 1/2. SS vs PS. Configuration Shear Pullout 3/8 SS under 50% 3/8 PS under 50% 3/8 SS over 50% 3/8 PS over 50% 3/8 SS over 100% 3/8 PS over 100% ... Keep going up in torque until just before the install breaks the bolt.

You did a science!!

I'd like to meet this Jim you speak of....

Cool to see concrete fail like that. One "ballpark" number for concrete's tensile strength is 300 psi. 51kn is a bit over 11,000 lbf (or 11 kips in US building structural engineering), which at 300 psi would be 38 sq in, or about a 7 inch diameter circle. Not too far off from the patch that "coned out." So the "textbook" way we conceptualize/design for that type of failure in concrete actually lines up with reality!

Someone please correct me if I'm wrong but I think one of the main reasons that the glue separated from the concrete was due to the concrete failing. Atleast for the first two bolts, from this footage, the concrete breaks first and fails catastrophically, causing the concrete around the bolt to crack and fall away from the glue rather than the glue slipping. The 3rd test seems to behave more like expected if the glue was to slip against the concrete however I think it's still a similar thing happening.

My thoughts are the following. The pictures look quite old and I think it's simply possible the glue used then wasn't as good yet. Then for a second I also imagine rock type would make a huge difference. Since then some of the dust might actually be lubricating

so, threaded bolts beat twisted or wavy bolts. and cleaning your holes is good practice. please do, but you have a good chance at survival if you dont.

Cheers.

I feel like you turned a glue-in bolt into an expansion bolt by letting the glue cure in dust.

2:01 “Super coned out” Is this a good or a bad sign?

Are there tests in threaded rod glued-in, with nut-washer and hanger?

This should just make you rest easier knowing your holes are clean. It should make you feel better about the bolt holes to.

Yes clean hole good hole.

WOW!!!

Oh man I have a dirty mind I love all your words😊

These are all the circumstances that will cause a sloppy install to fail before a sling: #1 …..

All anyone really needs to know about clearing holes for epoxy setting is that it was not done during the Big Dig in Boston and led to the death of a motorist via falling cement roof panel. Clear ya holes. Clean holes.

I think my biggest issue here is that concrete is not solid rock. For one, the failure mode is different. The rock almost certainly isn't going to give out structurally before the bolt pulls out. But more importantly, concrete is constructed of very fine rock particles which makes it far more rough of a surface. I could easily imagine that this makes the glue bond much easier with the edges of the hole, whereas the inside of a hole in rock is likely to be very smooth and much more likely to pull out. Just a theory, but I would greatly appreciate a test with real rock!

More powder just helps bond the bolt to epoxy to the concrete,epoxy acts as a fluid an Mixes all together 44 kn an 55 kn come on that hold ur house

Have you ever tried to pull thunderbolts to see the strength of them?

Do you have any idea how much your drop tower is going to cost? We'll need to do a gofundme or something :)

Freshly poured concrete can’t compare to natural rock, so I’d imagine the tests will be compromised.

Epoxy bolts

Its good to stay away from dirty holes, it's bad for your health

I love dirty holes!

Your test are very hole-y. I mean dirt-y. I mean they need a shower. I mean looking good.

You also tested with a vertical hole so all the dust would go to the bottom of the hole and it’s unlikely it would affect strength but a horizontal hole would cause the dust to sit along the whole length of the hole which could reduce strength

Kind of a pointless test, as climbing bolts are placed in rock and this is sub en959. Also the bolts are placed far too close to each other. Plus you didn't allow for the different types of epoxy glues out there.

Epoxy is a broad term covering a range of adhesives. The epoxy that works best for wood is not the epoxy that works best for metals. I have not specific knowledge about epoxy and various materials, but I believe there is no reason to think that the epoxy that works in concrete will work equally well in granite (or limestone or sandstone or shale or . . . .) Since actually climbing/highlining bolts are placed in naturally occurring rock, your experiments in concrete may have little bearing on what happens out in the wild.

Nobody is on tiktok

You all should see how well flex glue holds in bolts lolol

Is it just me, or did anybody else feel sorry for that ant that crawled up to the bolt at 1:33 just before it blasted out of the concrete?

Looks like maybe the concrete wasn't properly cured?