Failure of concrete anchors explained
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- Опубліковано 25 січ 2022
- This video investigates critical failure modes in concrete anchors. Concrete anchors can fail in a number of ways; during design, engineers have to check all possible failure scenarios and ensure that they will not occur. The design process involves a number of parameters that need to be carefully considered and optimized. The most important of these parameters include: embedment, bolt diameter, edge distance, and prying.
The design considerations in this video are based on the Canadian Standard Association (CSA) A23.3 Design of concrete structures, 2019.
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As a licensed professional engineer I can say you did an amazing job with this video. Also Simpson Strong-Tie also makes a really good software and is my preference for design and product selection.
Thanks for the comment Brad! We're currently working on our next video reviewing various structural shapes-hopefully we can get your seal of approval there too!
May I ask what tye software is called?
El
@@NoCrownNoWhereIsHardlyAKing simpson strong tie anchor designer
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7 whole minutes on concrete anchors. I needed this
This was really interesting to watch as a hard surface concept artist for the game industry. It gave me some insight into how to better communicate believable patterns of both construction and damage.
That's amazing
Doscher-Design, we are always glad when our videos educate or like in this case inspire our viewers. Cheers
Thank you for making video games better.
No one asked, no one cares
@Doscher-Design I feel that, I'm still developing my own texturing workflow and I have a hard time figuring out how to texture damage in a way that looks good
Very concrete explanation.
He would be a great anchor 😝
He nailed it!
Italian restaurant in Canberra, waiting for my wife to have dinner. This popped up on my UA-cam and I watched it without sound immediately sent to my best mate. Builder and my favourite apprentice in Sydney. Great work
I appreciate the information . I was once told by my brother of a failure of structure that the root cause was where the rebar placed in the concrete was not correct . It was at the wrong dept in the concrete . Not shocking news but it was important to note how placement of the rebar effects the load handling of concrete
explanation is simple and concise.
thank you.
wonderful after images and failure animation too.
Thank you for the nice words Infinity, it means a lot to us and encourages us to do more!
I've been a drafter specializing in precast concrete structures for the past few years, and I like the way the info in this video was presented. I'd love to see a video on concrete embeds and prestressing strand. But for now I'm off to watch any other videos you have.
Watching while on your lunch break 👀
Hence the famous movie quote "We're gonna need a bigger bolt". Who knew Jaws was an engineering movie?
haha exactly!
I built some footings/bases for some very large planters and being an auto technician thought I would get some advice first, Which I sought from a guy in our village who designs big civil engineering stuff docks,quays,bridges etc.over a couple of pints in our local pub. Following his tips and adding my own idea by constructing a welded framework of 3/4" rebar to hold the fixings so the load is spread more evenly through the concrete base. Later when he came by I proudly showed him them,he said that they were far too big and his quick estimate reckoned the fixings offered about 40-50 ton of clamping force and that combined they could support one end of a typical pedestrian overpass🤣🤣🤣.They are still there though😁
You got photos or info on your project somewhere? Sounds quite impressive!
@@jesseharris6466 I can't do stuff like that😂,anything practical comes naturally to me but,uploads,downloads and the like are beyond the scope of my social media interest.
Lol those are basically anchor points for a small wired telecom tower, but hey it works!
Call it future proofing. You don't know what else you plan on adding later, but you are ready for it.
I don't see a problem
Being a psychology grad from a family of engineers I thoroughly enjoy your content to relax before bedtime
You have done an amazing job! You have shown the impact engineering can have in solving global problems. Bravo for your hard work and dedication!
Excellent presentation on anchors. In the past, I preferred using post install types. I found it easier to accurately place anchors when working on a flat finished slab. When using J Bolts, we used a template made from plywood with holes for the bolts. We would place template and bolts in concrete together; depth, spacing, final dimensions. in 1 step. We also had dimension points on template and outer forms. This helped getting accurate placement. Once the concrete has hardened, very difficult to fix an error. It was always less expensive doing it right, than having to fix it later.
Why can't more contractors be more like you, everytime I ask for cast in anchors, the anchors end in the wrong location. For post fixed anchors, the rebar always gets in the way later requiring modifications!
@@dimvolyThan you. We found out 'fixing' mistakes later cost lots of money. If we had time to fix, we had time to do it right first time.
Post installed are the way to go. Absolutely zero mistakes. It costs more to correct the mistakes of CIP than using post-installed.
@@sackerz9 Thanks for ocmment. Always cost more to fix mistakes.
very impressive demonstration.
Further more comprehensive videos will be awaited on "Anchors"
Considerations, Specifications for anchor bolts via use of concrete: no to be used when vibrations and exposure to freezing temperatures are present…in time they such type of anchorage will fails. (vibrations will be a pulverizing action between the bolts threads and the holding concrete…freezing temperatures will act as a expansion and contraction of water moisture between the bolt and holding concrete reducing the holding strength bolt-concrete to failure.
Amazing video, Dude. You're killing it
thank you!
I don't do civil or concrete, but my bet as an electrical engineer with a materials background:
Best anchor: welded to the steel reinforcement or glued to whatever other reinforcement. All other anchors subject concrete to tension.
Thanks for the explanation/information I work in the rope access field and this helps a lot to keep remembering all this types of works
Glad it was helpful!
Thanks especially for the math. Math for these subjects is greatly under-appreciated. I over the weekend, I was installing a handrail for my swimming pool - it bolts to the concrete on the edge of the pool and has a massive 48" overhang out over the underwater steps. So the leverage on it is huge and I worried that the four drop-in anchors provided with the kit might be insufficient. I did the math for a 300lb person leaning on the end of the handrail - and looked up the specs on those anchors - and...holy cow...nowhere near enough! So I got some 1/2" undercut anchors and was happily installing them when I found that the holes in the base plate of the handrail were a little too small. So...drill them out - right? Well, it's a 5mm stainless steel plate and I wrecked three drill bits trying to do that! So, score 10/10 for the math, 1/10 for my own materials knowledge!
Nicely done, at least you won’t have to worry about it. Recently had to enlarge the holes in a cast iron hanger to do something similar; certainly easier than stainless. The trick with any metal cutting or drilling is to use cutting & tapping fluid, it cools and slightly lubricates the part & bit you’re using, which makes it much more efficient. Also, speed is not helpful - gear down the drill and start really slow. Once you get started you can sped up a little. You know you’re doing it perfectly when the steel peels up in those little rinds - swarf I believe it’s called - rather than little chips. Same with pressure, less is better, you don’t have to bare down on the drill. Have found these steps work for me so far, they make it faster believe it or not - and with less failures.
Very nice and short, and perfectly illustrated, thank you.
Glad you liked it!
Good video, I use drop ins during concrete core drilling and always wondered what kind of failures could occur but I didn't think of how many there could be.
A very good presentation! Thank you for the clear and concise explanation. Your animations were particularly well done. You are a gifted communicator.
agreed !
Thank you for an informative video that helps explain the data sheets that suppliers post on their websites. I have been trying to investigate the differences between wedge anchors and drop in anchors as to their abilities to suspend loads. Drop in anchors are industry standard in my trade, plumbing, for hangers, while wedge anchors are used mostly for mounting items to floors and walls. I have seen only a few times wedge anchors used to suspend items and wondered why they are not used ,ore often.
Expansion anchors are difficult to install overhead because of the hammering and using a torque wrench. Drop-ins are a slightly easier install, but their load rating is quite low. The superior product is a screw-in anchor like a Simpson Titen HD.
Great explanation. Don't forget cleanliness of the hole. Gotta blow it out....
This the one side of UA-cam that I like I was not aware of this information and I would like to say thank you very much
Our pleasure!
These videos are incredible - keep up the good work!!
Thanks, will do!
A very interesting thing to observe about the anchoring mechanism it is its capacity to (if its properly designed) to act as a fuse, locating the damage due seismic or dynamic loads in the anchors.
Nice video by the way
Props to whoever made the animated illustrations.
Good video. First I've seen, almost worth watching twice... I'll be back for more.
Clear and succinct information! Well done.
Excellent video, once again. Thank you for your effort.
This is a pretty good high level overview. Nice job.
thank you!
I like your approach to defining these issues.
Thanks Van!
It many years of study and work in this topic to develop the knowledge
Love the aesthetic. Beautiful. Licensed civil engineer here.
I didn't learn anything new.
That has me relieved because I studied this shit too 😂
(other than the available software that was nice)
Great presentation!
I'm just a homeowner diy-er and was looking for which anchors i should buy for my aluminum pergola and i ran into this video....my head just exploded.
Now I'll never be too sure in the way i install this pergola 😅
Awesome video though. 2 thumbs up!
Excellent information, presentation, graphics.
thanks!
Excellent video! We highly recommend post installed anchor bolts with chemicals as epoxy grout. Thanks for your video.
Well done, thanks for sharing this!
animations are great and helps to understand easily
thanks for the comment--more videos coming out soon!
We had flexible anchors bedded into the concrete in a cone, as the concrete around it hardened the bolt was waggled so it remained flexible. When the pilar was introduced the anchors would move according to the finished position of the pillar. The pillar was fixed with one nut under it and two above, that allowed the introduction of a grout to fill all the gaps through a pre-drilled hole in the base. These were used as the mounts for a 275kv, S&C mod 2020 switch disconnector.
Neatly explained ! Thank you
Great presentation. Thank you!
I appreciate this information. Thank you.
Thank you for sharing this wonderful video.
Thanks again for practical information.
very detailed. thank you!
this channel is gold
Thank you so much for the encouragement Roy! It means so much to us!
I have no need for this knowledge but I enjoyed learning it.
Excellent presentation
Great video, Thank you!
Glad you liked it!
Thank you for the educational information video.
Our pleasure! Hope you enjoyed it.
Great video, I have noticed recently from using the new tapcon bolt system that there’s not a lot of resistance, in the install process and the diameter of the hole they recommend you to drill has everything in the world to do with that. This manufacture is hesitant to create a tighter fit because of The possibility of the bolt shearing off because probably they don’t use a good quality metal behind their product.
interesting--are you referring to the bolt or screw failing in shear during installation?
Greatly explained, please next explain how adhesive anchorage are tested, and the parameters. +1❤️
I have no need to know this, but now I do. Much obliged!
Thank you. Please make more videos.
I have had to reattach several handrails that had broken the corner off the concrete. I drilled and installed some direct into concrete screws into the remaining good concrete. I also drill into the remaining and use either drop in anchors or wedge type anchors with coupling nuts and all thread to come up thru the replacement pour. So I am anchoring the hand rails deeper and the screws sticking up give the pour something to bite onto better. I dont always have the option to redo it with new stairs or slabs.
The Engineers on Boston's Big Dig learned the hard way about proper anchoring. That's why I don't like using adhesives. At least not on suspended loads. You have to understand creep and make sure you selected not only the proper adhesive, but also educate the contractor who will be using it as well. Dust that isn't cleaned out of drill holes is a big problem with adhesives. Especially when the anchors are installed on a suspended concrete panel weighing over 50 tons. They killed one and injured another in a car that was driving through the tunnel, and it was all due to creep. That kind of thing should not happen. Simple errors can and will lead to disaster, followed by a failure analysis contractor going through your designs with a fine tooth comb.
Sometimes you think you know, but you don't. Great Video.
thanks!
Awesome video
Recently we had a course for exactly this topic. It was done by Fischer, a German company which is very known in germany. At first we though; what could possibly go wrong when you set an anchor. Man were we wrong. It lasted about 3 days with theory and practical work and was really informative. At the end there was even a small test to become certified.
What is also REALLY important is the materials you use outdoors. Stainless Steel is sometimes not enough to prevent rust from entering the material of the anchor.
And if you live near a Coast with salt water you should really invest in even better materials or it could corrode over time.
The material for your anchor should always be better than what you fasten. If you want to fasten something galvanized your anchor should be made from stainless steel
This isn't necessarily true. It is much more beneficial to use "like materials" in fastener and fixture to prevent dissimilar metal corrosion (galvanic corrosion). Additionally, spending more money on a stainless fastener doesn't make sense if the fixture will rust/fail first: Just use the same materials for both.
More concrete videos ..I subscribed and notification Bell's to see if you have more in future
Thanks Gurvir, more videos will come. Meanwhile, you can check out our video on stirrups in concrete beams.
Thanks for the video....Peikko Designer also great to use for designing fasteners and its free.
great work
Thank you! Cheers!
Great video bro👍🙏
Appreciate it
Thank you!
The most failure you get with the ones you screw in directly into the concret. If the temperatur gets low it gets even worse.
Hit ancor sometimes locked lose. They went into the drilled hole. The concrete sometimes has air gaps are non rebar or less cement. So the anchor locked in the hole. But didnt get a grip. He turn till eternity.
The glued ones are the strongest ones. If you clean the hole properly with a pump. Also it takes the most time to set, and fasten the grip. Normal temperatur 20-25 degree is 15 Minutes, 5-10 degree is 3-5 hours. We use them to fix robots and heavy maschines to the ground wall or ceiling.
If you have full material you can use Glaspatronen/capilar anchor. 😂😂😂 plase some in the hole and drill a screw,bolt or thread through. That will mix two chemical components. That will react and create a hold.
very interesting.
Good channel!
Thanks for the visit
Great video, I'm going to make my coworkers watch it.
Wow great info on anchors!
BTW, software is an uncountable noun, as in it can't end in a plural.
Thank you.
Pretty good, can you do one with forklifts hitting posts/ guards/ floor guards? Using different sizes and types of lifts? From typical sitdowns all the way to the bigger turrent style?
Good video- focuses on teaching you HOW to think about the subject, not WHAT to think.
With increasing popularity of the home shop car lift that is retrofit bolt down installation, people really need to do some research. A two leg lift hoisting a 5000 vehicle 5' in the air is going to present a lot of prying force. Coupled with often unknown concrete conditions and it's all coming down
how do you do your animations? I like the coffee color background and the font and would like to make my own notes look like that.
Thank you
I'm going to start installing anchors properly =D
Apparently most of this program didnt provide the stiffener, using built up stiffener to reduce arm length from anchor to flange could significantly reduce plate thickness. I suggest calculate it using plate yielding when it comes to optimized plate thickness
Can the heat/speed from the drill have any effect?
Nice!
Thanks!
What’s your animation software?
What a bunch of nerds! Love it.
hehe no argument there--cheers!
I'm using Peikko Designer. Very good software
one thing to consider is what conditions the structure will be subjected to as external degradation. the most common being are you anywhere near salt water or when annual frost thaw is prevalent.
that's awesome
I'm having difficulty finding out if the anchors I purchased for my car lift are right. I have purchased 14 Hilti HIT-ZR stainless steel anchors bolts size 3/4"x9 3/4" long. My concrete is 8 inches deep with rebar, 4000 psi concrete, and fiber strand added to concrete. Anyway, I want to use them with the Hilti HY-200R adhesive. The Challenger lift company sell ANKR-RITE wedge anchors with the lift. I've read a lot of negative reviews on wedge anchors. I've read chemical anchors are the way to go. How can I figure out if the Hilti Anchors are acceptable for my application?
An important inspection criteria seemingly missed here is anchor hole perpendicularity (skew). If >5degs, expected cone (at failure) becomes significantly less.
The calculated strength is no longer valid.
Thank you for interesting topic!
Do you know what a program used by engineers at 06:20?
That video is from Red Bull Racing's F1 team: ua-cam.com/video/iptAkpqjtMQ/v-deo.html
They use Siemens NX.
03:52 would you mind telling me how that hole in the concrete was made conical and bigger at the bottom?
edit : because that is my problem,the hole cannot be made bigger at te bottom
: in dynamic cases,like solar panels on the roof,the wind is constantly pushing and pulling,grinding down the bottom feathers of the anchor,and it becomes loose; i have repaired them, such that in some cases i could just pull them out with pliers; any solution for that?
*(wow, i was just thinking now that i could pour 2 part epoxy down the hole prior to insertion of the anchor,maybe ?! or is there maybe a better adhesive? in other words,a combination of both bonding and expansion?)*
jackhammering concrete with jackhammer, you space your holes so to take advantage of the spall that occurs when you punch a hole through it, just like a bullet, it pushed out a cone on the bottom end, catch that cone and its easier to break as you go, go beyond the cone of spall, then your going through the entire slab again and again. the difference between working hard and making progress and just plain working hard.
How do they account for quality control in the metal and concrete? Are there some statistical analysis(fudge factor) built into the engineering calculations for less than average quality metal or concrete? Also, has non-destructive testing of metal and concrete changed with new technologies? My dad was an engineer and they had x-ray contractors come in at night to X-ray the welds on pressure vessels. Neat stuff to think about.
Quality control for steel is based on the varying testing agencies used in steel testing and qualifications. Like ISO9000. Testing of concrete is done on sight with a core sample and is standard for code approval. Also, the testing standard for concrete anchors is a 4x factor of safety, meaning manufacturers test their anchors to failure and then divide that number by 4. So, a test failing at 10,000 pounds would have a printed load rating of 2500lbs. Hope that helped.
2:28 This might be a silly question.
But for the fastener to bend to the left like that the little broken bit of concrete on the left appears to be compressed, i.e. occupy a smaller volume then before.
Can concrete do that? And if it does, what sort of forces are we looking at?
Concrete can break in both tension and compression. Usually, it is significantly weaker in tension, so much more likely to break under tensile loads, and the tensile regions of concrete are where you aim to install the reinforcing steel. A typical rule of thumb I've heard is that it is about 10 times weaker in tension than its nominal strength in compression.
Back in my boilermaker days doing Field construction I got excellent results from hilti Anker products. Dispite the plant guys hitting the beam Anker's with the forks on they're fork trucks
I used skyciv for designing baseplates and connection plates
5:42 I don't understand how prying force is amplified by a factor of 16? where you get that from?
I always see handrail anchors breaking out the edges of concrete...
Could this be a freeze thaw issue as well in colder climates?
If you used an epoxy anchor system would this prevent water and ice from freeze thaw integration?
It might... but often the concrete is too narrow to receive the load without failure. A very common weak point of designs
Here we also have FIXPERIENCE by Fischer.
ha! Do you use a lot of Fischer products?
I'll drink every time i hear "Nut" and "load"
6:14 does that spacing eliminate prying?