Avoid Some Common Concrete Failures!
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- Опубликовано: 22 апр 2022
- This video introduces the topic of avoiding concrete failures due to incorrect use of reinforcing steel. I also introduce my new channel, "Ray Does Cool Stuff" where I'll post fun things that I do when I'm not building things. This was inspired by multiple requests to post scuba videos. I have thought of posting some other things on the channel that might be of interest but don't want to get off of the topic of this channel which is sharing things that I've learned in my career of building and studying building science. The new channel gives me a way to keep this channel focused on that while allowing a place for more fun stuff so I hope you will check that out and subscribe. / @raydoescoolstuff1135
RayDoesCoolStuff channel link: ruclips.net/channel/UCjM7OlhpIyw_mcivB1N0zSA
Great video! Good reminder of the importance to ensure adequate concrete coverage over reinforcing steel.
To me concrete is almost magical stuff. Over here (the Netherlands) the groundwater level is very high so in certain areas water seeps in basements through cracks in the walls and floors. They do use concrete to build the basement and they even drive concrete piles in the ground to support the foundation of buildings.
The old city of Amsterdam is even built using wooden piles and as long as they stay under water (no air !) they are still in good condition. Due to lowering water levels, the top of these wooden piles are rising above the water level which make them rot.
I am not sure if they still use wood but I read that the use of pine has been prohibited since 1970. Pine is affected by certain bacteria and these poles all have to be replaced in time. They now use steel pipes that are being filled with concrete instead of wood.
Haha i mostly watched your videos because of the DIY battery thing and such. but this was as as much entertaining. always wondered about these rust and concrete. thank you and please do more !
Ray once again the educator for a lot of DIY people and builders, the ingress of water from poorly finished and sealed structure is a beast to control. I totally agree that Stainless pegs as a welding point are the best for railings etc.
Thanks Jeremy, I hope you enjoy the scuba videos. The eagle Ray and the mating turtles are my favorites and happened on the same dive, just 15 minutes apart if I recall correctly.
Thanks Ray, I will enjoy watching your underwater adventures.
Interesting tour of the construction there. Looks to be very similar to how they do things down here in the Philippines. I've never seen or even heard of stainless rebar but it sounds like a good thing for concrete. Thanks for sharing your knowledge Ray.
great advice about stainless steel in concrete
Excellent video Ray, it's all about common sense and H2O. Amazing what you can learn if you walk around and look at things. With concrete its all about the details- proper planning, placement of rebar, good mix design for the application, quality control at time of pour, etc. Stick to basics, no need for exotic components. Looking forward to more videos.
Thanks Greg. You are a great engineer sir, one of the best. Let’s go diving sometime.
That's a lot details to get right. Just recently on youtube channels that I watch, I saw a stem wall poured in freezing weather with the consistency of pea soup. The channel hasn't revealed yet what they are going to do. Most knowledgeable commenters say it should be torn down. Another channel didn't bend his rebar enough at the connection between his lite-deck roof and ICF walls. Rebar bends exposed to air. This problem admittedly DIY'r inexperience. Of course let's not forget what can happen if all the details are not correct and maintained...98 dead with the Surside condominium collapse. FGRP rebar is not exotic and has been around since 1982. It is used a lot in aplications with lots of dynamic loads and exposure to moisture...bridges, seawalls, parking garages, swimming pools. Also, I understand the cost of steel has skyrocketed, so alternatives like FGRP and helix steel might actually be more cost effective.
@@markstipulkoski1389 I think plastics and resins have gone up even more than steel. The surf side collapse happened to a building that has similar damage to many buildings in this country. It isn’t a one-off. In fact an engineer friend recently shared pictures of a building he saw that had some very similar issues.
Once again, fascinating, educational and very interesting. Thanks for sharing your experience with us. Keep up the good work.
Looking forward to the new channel.
Greetings from Dublin, Ireland.
Thanks for sharing! 👍
Thank you for sharing your experience.
Especially when you talk about different materials and how they interact
I love your channel and will subscribe all of it
Good advice. I always wondered about them putting already rusting rebar and mats in concrete.
I don't believe that to be a problem within reason. What you want to avoid is further contact with oxygen which is found in water in all its forms. Fun fact along the lines of this topic is how a cutting torch works. The acetylene heats up the steel and and then the oxygen is added and it oxidizes(rusts) the steel at a very rapid rate. You can't use an oxygen/acetylene cutting torch to cut stainless steel. I find this kind of stuff fascinating.
This explains exactly a common problem i see in my country, If 2 inches should be maintained between the rebar and the formwork, does this apply for concrete columns as well? (2 inches to separate the inside rebar of a columns to the casting formwork) Here we use concrete block for walls and put a column at each room corner and if it's a long span at every 4meter or so
Yes 2” and a bare minimum of 1.5” although I would fight for a full 2”, especially in a coastal climate.
Are you familiar with Roman concrete? Metakaolin is manufactured in Georgia, and I think it’s use along with fiberglass or epoxy coated reinforcement would make a much more durable system
What do you think of Helix Micro Rebar? These twisted carbon steel fibers are electroplated with zinc to prevent corrosion. Very important since they would be distributed evenly throughout the concrete mix and thus also be near the surface. Hopefully the zinc plating was engineered to withstand the abrasion during the mixing process. I've also seen fiberglass rebar. Though not as strong as steel, they don't rust. I don't know if FG rebar would be approptiate for all applications and I don't know if there are prefab fiberglass bends and stirrups. So some steel may be necessary. But maybe that could be stainless. Obviously, not the most cost effective, but looking for what would be best for a multi-generational home.
I think we already have the technology to create concrete that will endure hundreds of years. We simply need to use a low water to cement ratio with the appropriate admixtures for the conditions and adequate consolidation. We combine that with adequate reinforcement which we protect with adequate coverage. Use vapor barriers below and protect the concrete from chemicals and salt and you will have arrested the mechanisms of degradation, especially if it is protected from solar heat cycles by putting a building on top of it. When fiberglass rebar was pitched to me I rejected it because it doesn’t help solve the issue in the areas that are most prone to issues and seemed more of a gimmick. It never caught on though it was specified sometimes after a successful “lunch and learn” sales pitch. I have used stainless rebar when pouring concrete that had to be fire resistant. That concrete also can’t contain silica sand or aggregates. Carbon steel and silica sand expand at a much higher rate than the cement used in this specialty type of concrete when exposed to heat. I’ll leave it there for now.
I can tell you not to use zinc plated copper busbars. It only took 3 months near an evaporative cooler to figure that out.
Check out the answer by Greg Xikes for a good answer to your thoughts about rebar alternatives. Thanks for the discussion.
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congreet beautiful material but you have to know how and what to do with it
How about fiberglass rebar ?👍
It is expensive and difficult to work with. Think about the stirrups and corner bars. The solution is proper coverage by a well designed concrete mix.
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14:11
"Concrete tends to crack away from circular pipe penetration"
what is going t to happen to our electrical conduit pipe buried inside decking? hope there is no potential danger?
Any piping that penetrates concrete can induce a crack. Reinforcing steel limits the size and growth of cracks. Piping that reduces the thickness of concrete can create a stress crack along the line of the pipe. It isn’t the biggest issue but it can be an issue.
Is there such a thing as hot dipped galvanized rebar?
I’ve never heard of it but the cheapest solution is to solve the issue with means and methods and not products. Also, rebar is bent, formed and otherwise manhandled and abused in ways that galvanizing would not withstand.
Hey Ray, next time you are around some concrete bags, read the ingredients of the concrete bag. you'll probably get a laugh out of that.
What would I find amusing?
@@RayBuildsCoolStuff I read on a bag of concrete the ingredients. listed "concrete "
Couldn't you use water resistant concrete? There's stuff you can add to your concrete to make it water resistant no?
Yes but you are probably thinking about liquid water. Most concrete resists liquid water but water moving by vapor diffusion is a different matter. The water that caused the damage to the ceiling in this video was in vapor form. For more information on this search for vapor diffusion in materials and adsorption with a “d”.
Ja fem cm beton omkring jernarmering,evt. varmgalvaniseret armering.
Easy for you to say if you are loic suberville! 🇬🇧 vs 🇫🇷