In this time when many feel there is no driver driving the bus..it is most comforting to know there are competent experts in the Engineering field.

@jenniferwhitewolf3784

3 жыл бұрын

There is a driver, but he was placed there by fraudulent methods and is suffering dementia. His handlers believe their feelings and political rhetoric above science and engineering.. a formula for absolute failure and destruction.

@144Donn

3 жыл бұрын

@@jenniferwhitewolf3784 I was referring not only to political, but to health wellness and medical, financial, local gov't, you name it the train is off the track!

@davidschwartz5127

3 жыл бұрын

@@jenniferwhitewolf3784 Right on Jen!

@ironmagma

3 жыл бұрын

@@jenniferwhitewolf3784 same story last President. It doesn’t matter which you vote for, all you get is crap.

@builtonabudget6767

3 жыл бұрын

@@ironmagma thanks people to trust God not those in office the will all fail you at some point and that's no fake news FACTS

As an old structural Concrete Contractor, I've wondered how come the rebar did not start rusting right away since we had to pour or pump it in a liquid state. Now I know, Thanks

@jwenting

3 жыл бұрын

and makes me even more worried seeing the amount of rusting rebar on construction site after construction site...

@tuberroot1112

3 жыл бұрын

@@jwenting A little light rust is good because it gives some roughness and adhesion but thick brown rust with a thickness you can brush off is bad. There should not be loose material. That is just one of a hundred defects in construction reality, like less rebar than spec, insufficient lapping, not properly tied, insufficient coverage ( too near surface ) etc. etc.

@willbee6785

3 жыл бұрын

@@tuberroot1112 Exactly.

@ApriliaRacer14

3 жыл бұрын

@@tuberroot1112 Bingo!

@vitaliypro8441

2 жыл бұрын

@@tuberroot1112 concrete does not adhere to rebar ever. Watch the video one more time and note when he says “mechanical bonding” it doesn’t mean “glued” together.

Josh... YOU Sir are THE authority on the Champlain Tower tragedy. That "Other Guy" couldn't explain his way out of a wet paper bag! Thank You for the expertise you share with us!

Years ago, my aunt and uncle were going to retire next to the ocean in Northern California. They rented a house near the beach before purchasing land. After seeing the damage that sea air does, they decided to move inland a bit.

More people need to realize that cutting corners is NOT the way to go.

@windsofmarchjourneyperrytr2823

3 жыл бұрын

The guy who's construction company it was has been dead since 2014. So...he just cashed his check and moved on, I guess.

@TyphoonVstrom

3 жыл бұрын

Unless you have spalling, then cutting corners is a good idea, as in the video.

@jasonhaynes2952

3 жыл бұрын

How about Spalling corners?

@richodude2679

3 жыл бұрын

Sure , what if your spalling is in your corners ? Then you would need to cut those corners out ?

@joelritz5372

2 жыл бұрын

Cutting corners = corruption in modern times ,it's always the cause of all causes of failures .

Don't know when I'll ever get to use the education you're providing but I hope to earn an honorary degree in engineering by continued viewing. Thanks Professor Josh, I find your content fascinating!

@scottkelley1558

3 жыл бұрын

This is only a small piece of engineering. You are not getting any of the mathematical modeling. Engineering is about applying mathemetics, physics and chemistry and making a simple model to explain what is happening. We test the model to see how well it explains what is happening and then work to improve it and reduce error. Because we know we have errors, we assign a safety factor to ensure there is enough strength.

@forevergeralyn

3 жыл бұрын

@@scottkelley1558 I think the intention of my comment may have been lost in translation. It was an attempt to deliver a sincere compliment in a humorous manner. Clearly I failed. I understand that the field of engineering requires many years of study spanning a deep dive into subjects I failed miserably in, especially math. That being said, as a lay person I'm grateful to this channel for a better understanding, albeit simplistic, of why the building I'm living in manages to keep itself upright.

@dp26385

2 жыл бұрын

@@scottkelley1558 , Do engineers monitor builders at building sites so that they don’t take shortcuts to save $$$ ?

@apieceofbread9022

2 жыл бұрын

🤣🤣🤣🤣 an honorary degree? 🤣🤣🤣🤣🤣🤣🤣🤣

@donaldlee6760

2 жыл бұрын

@@dp26385 I was wondering the exact same thing.

When you see someone talking so fluently about such specialized stuff without any „err‘s“ „hmm‘s“ or other flaws, you easily can see, that this person is a person of outstanding ability and knows, what he is talking about. Found this channel via the Champlain disaster - great vid Josh, as always, thanks and best regards from Germany.

I live about 2 km from the Andaman Sea in Phuket Thailand. I now have an appreciation for the cracks I see in the buildings here.

I really hope you're a teacher, in you field. Our young people really need competent educators.

@BuildingIntegrity

3 жыл бұрын

Thanks that means a lot!

@dbspecials1200

3 жыл бұрын

Many people mention that. maybe he still feels he's more helpful being out working in the field. with each decade priorities and desires change. I know he would be a natural for instructor. I also know first hand about going out every day and solving problems. don't be surprised if he and his firm are still doing this 40 years from now.

@frankmiller95

3 жыл бұрын

He is, right here.

@lacrewpandora4164

3 жыл бұрын

@@BuildingIntegrity Along those lines, I was curious if you've ever considered packaging continuing education units/professional development hour lessons that people can buy. Honestly most of what's out there is trash, and your style and presentation are very good, in my opinion.

@owl1873

2 жыл бұрын

Amen!

My husband wanted to know why I was subscribed to an engineering video-- he just wouldn't understand! lol :) :) I've learned so much!

@BuildingIntegrity

3 жыл бұрын

Glad you're learning!

@ianchandley

3 жыл бұрын

Good for you! More women in STEM!!!

@pia9343

3 жыл бұрын

Mine does too!! I am utterly fascinated with this subject and the teacher is outstanding.

@janerubeo8318

3 жыл бұрын

@@ianchandley Yes!! I've just retired from teaching 5th grade science for 20 years! ( Not anywhere on the same level, but those kiddos have got to start somewhere lol)

@annecolumbo8713

3 жыл бұрын

All my aptitude tests in high school said I would be really good in engineering. I thought that sounded really boring. ( although I was the only female in the mechanic drawing class ) Now I can't get enough of watching these videos. What have I missed 😳. A little too late as now I'm 75! 😥

Amazing that I seriously watch each episode and am learning. All because of the Florida structure collapse. Now I see better as to why my two contractor buddies take their jobs seriously.

@joelritz5372

2 жыл бұрын

No kidding , the Florida collapse sure awakened me to learn all about concrete structures . I live in Central America and concrete is all over structures . The instructor in this video should talk about what has happened in Cuba over time ( buildings just topple unexpectedly ), and now we know why .

@supernova8962

2 жыл бұрын

This isnt what really happened... It was not salt water or oxygen ... It was much more than that...They arent tell you the whole story... Unless you can figured this out... You have to observe why it happen or how it happened...No one has mention anything about Chlorine or Shock water ... WHY ??? Coney Island Buildings has ever failed ? We have Frost and Rust also .... Explain that ... and we are talking over 75 years with no issue.

@ZEPRATGERNODT

2 жыл бұрын

@@supernova8962 I guess you missed the part about the original contractor and his shenanigans huh? There is a whole other issue related to this and is damn near criminal.

Excellent teaching for ordinary people. Keep it coming

In London there’s a condition known as ‘Regent’s Street disease’ due to the fact the first reinforced concrete used in construction was to the lintels of the buildings constructed around 1910 down Regent’s Street (it was mostly rebuilt at this time). Within a few short years they had to be replaced (including cracked stone cladding) due to the corrosion.

Excellent presentation especially for lay-people. I’m a CE by academia, and this was easy for anyone to follow. Unless they don’t understand why steel rebar is in R/C to begin with. But you’ve explained that to novices well enough in other videos.

This engineer seems to explain the issues pertaining to the recent structural failure on everyone’s mind much more straightforward than the other channels -& without a lot of hullabaloo + pets thrown in for no good reason. Thank you.

@tissuepaper9962

2 жыл бұрын

Real engineers are allergic to bullshit. This channel really exemplifies that.

I learned a lot about chloride ion penetration into steel reinforced concrete structures during my first internship. I left the military to pursue civil engineering after being a draftsmen from an early age (although through my time in the service I was IT). That internship was rough. My PM, within my first week at this giant bridge project, handed me a post-it note with something along the lines of, “research coatings to knock down the chloride ion permeability of concrete.” It was basically gibberish but he stuck it on my forehead and I went on my way. His intentions were to provide me real-world experience in researching field applicable problems in civil engineering, the kind of stuff which isn’t taught in school-the kind of situations which formal engineering education doesn’t begin prepare you for-where you need to think fast and solve a problem in the field QUICKLY. I’m about to finish my degree soon, at one of the best civil programs in your state, although as a UCF grad I’m sure you’d disagree (haha). While I certainly didn’t enjoy being in the field 6 days a week, working 12-14 hours a day, it has been the foundation for my engineering knowledge. Your videos have been awesome too, Josh. Thanks man, keep up the good work. I hope we meet some day since the CivE field in FL is so close-knit. I won’t disclose my personals here on KZread, but hey, if you read this comment and we do in fact cross paths (hopefully not you investigating one of my projects!) I’ll let you know. Keep on keepin’ on brotha.

@windsofmarchjourneyperrytr2823

3 жыл бұрын

Yeah, I agree. That's the main issue with college. They never teach you stuff you actually WANT and NEED to know. Or it's the exact opposite of the real world.

I’m just going to go live in a tent. Thank you, Sir for always explaining everything so clearly.

@frankmiller95

3 жыл бұрын

Hollow logs work well, too. Just get one from a really big tree.

@sparkytoday8455

3 жыл бұрын

@ jerome, so much for that, I guess, haha!

@Sashazur

3 жыл бұрын

Sure, you’ll love living in your nice safe tent, until a bear comes along. Then you’ll miss having those reinforced concrete walls around you!

@ant6516

3 жыл бұрын

My tent didnt survive from last windy season. Those tent just flies away like paper! Any suggestion for tent alternative?

@-._.-KRiS-._.-

2 жыл бұрын

@Sergei Torockov You really shouldn't be using insects and snakes as foreplay.

ngl this stuff is fascinating and the pH explanation was easy to understand. thanks for the quality videos! much respect to the hardworking engineers and contractors out there!

@BuildingIntegrity

3 жыл бұрын

Thanks for watching!

@KirkHermary

3 жыл бұрын

I also learned lots from this as well as your other videos. You do a great job explaining things and use handy visuals. Keep up the great work!

@lilacscentedfushias1852

3 жыл бұрын

I’ve learned a lot from a select few channels like this. They’d make great teachers or lecturers. I can’t even build Lego, but the way it’s explained I understand it, but I don’t feel like I’m being patronised. I was talking to a friend about this & he asked where I got the information from 😀 I tried ‘I’m just a genius’ it didn’t work. So I showed him this channel and a couple others 😀

@larrybe2900

3 жыл бұрын

@@lilacscentedfushias1852 Sure you are a genius, you just don't know it yet. ;)

@jonmould2946

3 жыл бұрын

Let’s build buildings out of thin strips of iron that rusts and make the building fail. People that design these buildings have high IQ?

You know I’m not an engineer, contractor or have any building experience at all, but I find your videos fascinating. I found you by your Champlain videos but I’m here to stay just to keep learning. 😊

@BuildingIntegrity

3 жыл бұрын

Glad to have you!

@katiekane5247

3 жыл бұрын

Same here

@debrazawacki923

2 жыл бұрын

LOVE learning this about concrete and how it gets damaged with time. I’m loving all this info

Wow, the rebar in the opening clip was totally disintegrated. That was eye opening! How many buildings worldwide are in danger of collapse?

@ianchandley

3 жыл бұрын

I don’t think we wanna know...... 🤦🏼‍♂️

@johnhaller5851

3 жыл бұрын

@@anna-lisagirling7424 I stayed in a condo hotel on Waikiki Beach. The lanais on a number of units were undergoing the first repair described in this video.

@anna-lisagirling7424

3 жыл бұрын

@@johnhaller5851 How long ago was that? Crazy amount of high rises in that neighborhood, eh? In the 70's when I was first there, there were still single family houses scattered beneath just a few high rises but they were disappearing fast! I'm glad i saw it all before it statred to look like Hong Kong. But that whole area was entirely swamp land and the Alaw Wai canal was dredge out to drain that swamp to allow for development. The "land" is coral. After our tutorial here with Building Integrity, my heart beat faster thinking of the entire Waikiki Beach tourist district and the possible nightmares awaiting.

@johnhaller5851

3 жыл бұрын

@@anna-lisagirling7424 I think where we stayed was 2500 Kalakaua, Foster Tower. Most of the lanais are now enclosed, they were all open when we were there. I'm guessing a bit more than 10 years ago, my son was still in college. It was sort of an air-bnb place, where there was an office which rented out the condos when the owners weren't there.

@anna-lisagirling7424

3 жыл бұрын

@@johnhaller5851 Wow. Just close the lanais. Imagine such a thing. That speaks volumes, doesn't it? I wonder if the Champlain Towers collapse set off a bit of a panic in Hawaii re: their old re-enforced concrete high-rised building inventory? Maybe I'll do some snooping in my "spare" time. . . Thanks for this!

Richard Feynman was known as "the great explainer". Not only was he a knowledgeable person, but had a special talent for sharing that expertise with us laypersons - and making it interesting. Josh, I'd put you in that camp of great explainers. Top notch work on these videos, you have a real talent for sharing your knowledge in an understandable and interesting way. "Dumbing down" without being condescending or pretending to be the holder of all knowledge. In particular with the Surfside series, I particularly like how you distinguish between definite facts, probability, possibility, and indications. All without sensationalism too. I have a couple of engineers in the family. I'm not sure if they just lack that ability to translate into non-engineer info as well, or they think that I'm smarter than I really am. But you sir, absolutely nail it. Thank you.

@katdistefano8551

3 жыл бұрын

Now if Josh takes up playing bongos . . .

@markwallace1727

3 жыл бұрын

@@katdistefano8551, yes. Love it. From now on I fully expect Josh to personally play any intro or background music on bongos. I'll be one happy chappy. I'm guessing being in construction engineering, he already knows how to break into houses and knows how to spot weak points in security devices. Possibly not as good at gleaning information to guess safe combos though (or cracking them), unless he also has a practical joker side to him.

Your explanations are so good I could watch this for hours.

How I have become so interested in concrete is due solely to your fascinating and educational videos on the subject. You really are an amazing teacher. Can you explain how is it that there is Roman concrete that has been under water for >2000 years that is still structurally sound?

@markvasiloff2217

3 жыл бұрын

I found this on the Internet regarding Roman concrete: Roman concrete was based on a hydraulic-setting cement. It is durable due to its incorporation of pozzolanic ash, which prevents cracks from spreading. When seawater gets into its cracks, it causes a chemical reaction that actually strengthens the concrete. Minerals called Al-tobermorite and phillipsite form as the material leaches mineral-rich fluid that then solidifies, reinforcing the concrete and making the structures even stronger.

@bill.angelus

3 жыл бұрын

@@markvasiloff2217 any idea where these minerals are located in abundance? Looks to be a smart move to mine and export to contractors bent on creating strong structures. A niche to be considered.

@markvasiloff2217

3 жыл бұрын

@@bill.angelus It comes from volcanic ash and was (or is) found in areas of Italy. I don’t know how abundant it is.

@Roger_Gadd

3 жыл бұрын

I've understood for many years that at least some Roman concrete was accidental. Bricks were mixed with aluminium rich ore. The bodies of dead slaves were thrown into the mix, and the resulting reaction of bone calcium with aluminium ore created a cement. I was told this by a university lecturer. I don't have a reference to cite.

@KH-sd8kr

3 жыл бұрын

@@markvasiloff2217 so interesting. TY. I wonder how much of the chemistry they understood or if it was just a lucky use of locally available materials?

This is brilliant thank you, it all makes sense now.

@BuildingIntegrity

3 жыл бұрын

Thank you so much!

So let me get this straight, when a guy in shorts and a polo shirt can rip apart your concrete building with his bare hands, that's a bad thing, right?

@BuildingIntegrity

3 жыл бұрын

Bingo!

@birdlady2725

3 жыл бұрын

🤣🤣😪

@1everydaycooldude

3 жыл бұрын

Thanks for the laugh!

@samuelburnley1846

3 жыл бұрын

That’s almost exactly what he said as we were filming that segment! I think he said, when you can pull chunks of your building off with your bare hands, you know it’s pretty bad. It was moments after the clip in this video.

@gordonrichardson2972

3 жыл бұрын

It's bad when those bits of concrete fall under gravity onto parked cars and pedestrians.

As always you did a great job of explaining and illustrating the problem. Josh the illustrator !!! EVERY Visual learner should love you !!! THANKS !!!

@jmlewis435

3 жыл бұрын

💯

@BuildingIntegrity

3 жыл бұрын

Thanks!

I've spent most of my career evaluating public works contractors' financial condition and experience to guarantee their performance of their jobs and payment of their bills. I have learned and understood more in the last couple weeks since finding these videos than in decades previously. Josh Porter is a wonderful instructor, able to make these concepts easy to grasp and entertaining as well.

You make the engineering and science more interesting than the way I learned in university. Thanks so much for your videos.

Building Tegrity Farms is quickly becoming my new favorite channel

I imagine that once there is cracks and such, that even more water, oxygen, etc. can penetrate creating positive feedback leading to rapid deterioration.

@bbgun061

3 жыл бұрын

You're correct! He's mentioned that in some of his other videos...

My father in law and almost every one of my friends are all engineers. I’m learning so much from your presentations. I’ve never trusted beach front condos. Everyone wants to be on a high floor. Not me. I want to be on the ground floor. Why? The pool and beach are right outside and you don’t have to worry about a deck rail failing causes your loved one to fall to their death. Now, because of you, I will only rent a beach front condo that is less than a decade old.

I'm seeing major cracks all over the place now, mostly older retail store fronts. One was so bad the other day I called an employee out to show him. Not sure if he took me seriously.

@langdons2848

3 жыл бұрын

Another applicant for the "Not my job award". Here's hoping the building doesn't collapse on him one day.

@kingdomfor1

3 жыл бұрын

Employees are not paid enough to care , if he reported to his manager he would have been told, to go back to his job , if you are really concerned you should call for the manager directly.

@Sashazur

3 жыл бұрын

Hah! This reminds me last week I went into my usual Thai place to get takeout and the place stank of leaking gas. I told the lady at the register (who speaks English fine) and she just said “Gas?” with a bland smile on her face, same as if I’d commented on the weather. There was only her and the cook in there. I just grabbed my food and left. I guess I would have heard by now if it had exploded…

@kingdomfor1

3 жыл бұрын

@Sergei Torockov yes I'm sure they do .

@user-sm3xq5ob5d

3 жыл бұрын

If you only care now what do you expect from an employee (not his building or enterprise) who has no education (would he work there in the first place) nor the knowledge that you have now. Better call the local government and make a complaint.

Great explanation, well done! Having lived in a coastal environments most of my life I have seen concrete and repairs continually fail over time. Also happens with brickwork where the mortar and certain kinds of brick seem to go through a similar process of degradation.

Really interesting! We look at concrete every day and never know the science that goes into it!

Thanks very much for this tutorial. I am a formulation chemist,designing impermeable acid/caustic/chemical resistant coatings for concrete structures. Novalac epoxies are typically used to coat concrete in large chemical plants. Problems arise because there are only two types of concrete...concrete that has cracked or concrete that will crack. Epoxies are unfortunately nearly as crack prone as the concrete,so when concrete cracks,the epoxy coating that`s supposed to protect the concrete cracks as well. This new coating,soon to be released,will solve those issues. Understanding the deterioration functionality of concrete is extremely important to the design of industrial coatings. I need to say in touch with your channel. Best regards.

I now understand that sealing my concrete is more about preserving the concrete rather than esthetics. You don't know what you didn't know. Till you know what you didn't. Thanks for this valuable information.

Every time I go by a large garage I am looking for spalling. I think I might need help. ..... And thanks for another insightful video.

@windsofmarchjourneyperrytr2823

3 жыл бұрын

Join the paranoid about parking garages club, lol. I have nightmares about someone WALKING in there around the corner or at the top of the slope where you can't POSSIBLY see them, and are DEFINITELY NOT expecting them! I could see someone walking around there on purpose to get hit and sue. Plus, I refuse to pay for parking, so there's that. Especially in like a hospital. They have nerve even asking for more $$. Lol

@erictam7014

3 жыл бұрын

A trained eye is a terrible thing.

Thank you Josh. This was very educational and informative. I will look at concrete buildings differently.

This guy is the best educator

I always thought, if you HAVE to buy a condo, buy one that used to be a heavy duty factory. It'll be tremendously overbuilt for residential (tho you'll have odd design things, like a short top floor or MAJOR beams sticking out of the ceiling), but you'll ALSO probably get a free sprinkler system, too. As they were made in the late 1800s in their modern form. Assuming it works. It makes sense that it would or they'd have pulled it all out. Also, it would probably be near perfect in fires, assuming doors and new walls were as solid that way. Open spaces being not good for that at all. You'd have sold brick or stone walls, most likely. Miss the old days in that, MAN, those building were made to last HUNDREDS of years!

Our three story condo in SWFL was built in the mid 1970’s and was retrofitted with an electric cathodic protection system about 20 years ago. That was a costly upgrade but the system greatly minimizes spalling.

@BuildingIntegrity

3 жыл бұрын

Don't ever forget to have the regular maintenance done on that system. I saw a condo in FL with cathodic protection and they didn't change the anodes one year and almost all the balconies spalled completely apart within a year.

@langdons2848

3 жыл бұрын

@@BuildingIntegrity does that indicate that the system was holding off the effects of serious water/salt intrusion? Or can a system like that exacerbated the problem when it stops working? I ask because one year seems (to uneducated me) like quite a short period for significant spalling to appear.

@johnhaller5851

3 жыл бұрын

@@langdons2848 The anode sacrifices itself as a material which corrodes more readily than steel. It's like a galvanized nail, once the zinc corrodes, the steel will go quickly.

@langdons2848

3 жыл бұрын

@@johnhaller5851 I understand what you are saying John, but it still seems very fast unless there was already a *very* acidic environment waiting to attack the steel. I was wondering if there were any other effects that could come from a failed cathodic protection system.

@gordonrichardson2972

3 жыл бұрын

@@langdons2848 Cathodic protection cannot prevent the intrusion of corrosive elements, it just delays the process and hides the severity of the underlying problem. Most likely the waterproofing failed years previously.

When new concrete buildings are erected, are the exterior walls usually waterproofed? And what is the best waterproofing for concrete?

@fatihbaskin2000

Жыл бұрын

There was a construction next to my house few years ago and in that buildings foundation, they used some sort of tar-paper like material.

They don't teach anything about concrete when studying Mechanical Engineering, but I've learned more about it in a few of your videos than I'd ever thought I wanted to know about it.

Thank you for your informative video. I retired in coastal Mexico. I have been living in a rented house that has a history of roof issues. Like most Mexican construction, it is made of reinforced concrete. The owner of the house is a wonderful lady doctor who lives in a city an hour away. She tried to sell the house until I rented it 6 years ago. She wants me to buy the house, but the foundation is cracked and the roof still leaks. Actually, part of it just blew off during Hurricane Nora recently. The lower floor becomes a shallow lake during tropical storms. Thanks to your video, I now understand the deep gouges in the first floor walls at ankle level. The superficial repairs and paint of the past haven't worked. Now I understand why. I wish you were local, and could help la doctora.

Very interesting, excellent explanation, WOW, maintenance is very a serious and necessary business.

@BuildingIntegrity

3 жыл бұрын

Yes it is!

Thank you Josh from SW Va. Protect the concrete and you will protect the steel.

@BuildingIntegrity

3 жыл бұрын

Thanks for watching!

I worked on alcatraz island for 24 years, with the sea air on the island I have seen rebar 1/8 in diameter in the concrete went doing my repairs! Thanks

I got a new concrete driveway about 5 years ago - don't remember how many thousands it cost because a city grant loaned me the money interest free, and the loan is now half forgiven, having lived here 5 years - that was the deal. The concrete used was very high quality, according to the company putting it down, and I believe it, given the nice finish. Anyway, just last week I finished pressure washing and putting down a light coat of Thompson's water seal - the 2nd time I've done this. Watching your video makes me feel good about putting in the work.

Thank you for this video! It’s so informative! I’m reminded of Roman Harbour concrete that’s been getting stronger over the centuries in the ocean instead of breaking apart. I went and looked up the article I read a while back on it and it makes me wonder if something like that might be better for coastal structures than standard concrete… my understanding from the article was that the special minerals in it react with seawater make the concrete’s pH higher, which sounds like a good thing for preventing the rebar from rusting! The article is from 2017 in Nature and it sounds like at the time companies were still playing around with recipes to find one that can work with modern manufacturing.

I live in Chicago and the arches in many of the viaducts for the red line trains are massively spalled from top to bottom. It never looked safe, and thanks to you I know what to call it! Your subject matter, which I never gave a thought to before the Surfside condo collapse, is totally enthralling! (Enspalling?!) Thanks for all you do and your peaceful demeanor while teaching us.

@windsofmarchjourneyperrytr2823

3 жыл бұрын

Me too! But it's a non-issue since the virus. I'm not on the tuberculosis express any more. I do know an arch is the most solid design, if I recall right...I wonder if those are something that covers something else, because those train lines are well over 100 years old (no rebar then)

As a person who has spent plenty of time at and near marine environments over my 62 years, my hunch is that most of these concrete buildings on ocean coasts are going to experience this type of internal cancer. The marine environment is very harsh. But people don’t care. Just go ahead and and let development happen wherever, however. I have never been able to see how patching this kind of damage can possibly stop the inevitable. At best, it might only delay it a bit. At worst, seems like repairs will just cover up the rotten steel bar. Good luck

My thirst for knowledge brought me to your channel but it is the clear straightforward explainations and relaxed conversational pacing that keeps me coming back. Bravo

Maintenance is key. The condo or building also needs someone with a good eye. Once the condo shows blatant problems it's probably already too late for minor repairs. The expense of major repairs may also be at fault. Once the condo board has to come up with 15 million dollars, the repairs might not happen.

@sandramorris7774

3 жыл бұрын

This is handy also to know about any building. Just about every building has a concrete base.

@1556cm

3 жыл бұрын

No one gives you a maintenance manual with a building like you get with your car. And buildings conceal issues much better/longer than your car before you know there's any problem. This information is invaluable to substitute for that missing owner's manual to help HOAs get and stay on top of maintenance so there is never another Champlain Towers-type tragedy.

@1556cm

2 жыл бұрын

@Sergei Torockov not idiots, just people who have no training in that field

@-._.-KRiS-._.-

2 жыл бұрын

@@1556cm That's why it's so stupid that people are bidding tens of thousands of dollars (in some cases, hundreds of thousands of dollars) over the asking price for houses _in addition to_ waiving all inspections in this insanely hot housing market. They are basically signing themselves up for a financial deathtrap if there is anything wrong with the property by foregoing inspections.

@coasteyscoasteys4150

2 жыл бұрын

@@-._.-KRiS-._.- Never buy without an inspection Asking for trouble

A few years ago, can't remember exactly how many, I watched the video on a comparison between waterproof concrete made by the Romans and waterproof concrete made nowadays. I have often wondered why waterproof concrete isn't a standard when it comes to building buildings that are going to be subjected to water. Also, I'm wondering if you can provide an opinion as to why buildings being constructed use rebar that has a layer of surface rust on it. I've seen this in so many construction sites that I have observed. The rebar sits there for days and gets a layer of rust on it, some of which gets knocked off when they start actually building the rebar portion prior to the pour of concrete. Then it sits there for days waiting for the concrete to be poured and gets a renewed layer of rust on the rebar. Then the concrete gets poured and that layer of rust gets sealed into the concrete. Is there a reason why this is done? And is this surface rust as dangerous as the rust you referred to in this video?

@bradsanders407

2 жыл бұрын

The only alternative would be to epoxy all the rebar prior to sending it to the job. The cost of that would be astronomical. As he was saying rust needs water. The best defense is a good offense. Keep the concrete dry through coating any exposed areas and staying on top of caulking joints. These new buildings are such pieces of crap and will need extensive maintenance early and often. Next time you're in a building that's about five years old look around the windows and I guarantee you will find some that are already leaking and that's all it takes.

@rainscratch

2 жыл бұрын

Very good question. There are many variables, including if the concrete is not properly mixed, poorly compacted, of low quality ingredients, (including using water that has a higher than acceptable saline component). The concrete needs to bond to the rebar obviously the main purpose of the rebar. If the rebar is already rusting when concrete added should theoretically be detrimental to the process. Ultimately depends how much moisture exposure the concrete then gets in its lifetime. In most exterior applications - a lot.

The videos of this channel should be required viewing for all property owners, property management boards and councils, building contractors, real estate agents. I'm sure insurance companies will use 'lack of maintenance' as an excuse for limiting or avoiding many building failures or issues.

I've watched quite a few of your videos, and they've simply convinced me that I don't want to live in a concrete/rebar building. It looks like they're destined to fail. I've mostly lived in brick or stone-built houses, some 100 - 200 years old, there might be (usually were) timber faults that needed fixing, but not the stone work. Even the house I lived in, built on the cheap by miners, primarily using mine-waste - built 1905, it lacked modern facilities, but was structurally sound.

Wowwwww. When you pulled that off like that I immediately thought about the massive internal damage to south

I can't stop watching! I literally do not want to buy any structure remotely near saltwater without you Josh! I'm learning so much!

Total layman here, but SO appreciate your clear and concise explanations. If nothing else, hundreds or thousands of us will now have at least a modicum of knowledge as we enter into, and spend time in, the concrete buildings around us. Who knows, maybe one day that knowledge will save lives!

Very good just glad you explain about how Rebar rust causes Concrete to crack I didn't know it expanded any so much

Brilliant! So helpful! Thank you so much!

Thank you for your easy to understand explanation. Good graphics and photos.

Clear, consise and professional!

Could you please do a video on “preventive and maintenance measures”. Great videos!!!

Thank you for this series. You are doing a wonderful job teaching us

I know very little about building construction but have been around boats a lot. The key thing boat owners learn is how exceptionally corrosive an ocean environment is. You see that on docks and marinas, as well as boats, with even a ten year old dock looking in need of replacement. Whenever I see apartment buildings directly exposed to ocean weather I have always thought: Do those owners appreciate just how accelerated the deterioration is, simply by being that close to the ocean?

You are very thorough in all your explanations and make things so clear. You’re a pleasure to listen to.

So in the images where the soundings were done, even though we see the oxidation going on in the rebar, it does still appear they are getting to this particular example before that bar deteriorated any more. the first rebar you showed on that house was just crumbling apart. time really is the most valuable thing we have.

@BuildingIntegrity

3 жыл бұрын

Correct. The second property rusted rebar was salvageable. The first property at the beginning of the video had completely disintegrated rebar.

I'm curious, is there any way to dope the exterior of aged concrete with an alkaline product that could soak in and neutralise the acidic buildup?

@peetky8645

3 жыл бұрын

traditional culture in the med in coastal areas would whitewash their masonry structures annually or often with lime.

@BuildingIntegrity

3 жыл бұрын

There are products that if applied to bare concrete regularly can inhibit the loss of pH in the concrete. Some products even claim to restore it but I am a bit skeptical of those for various reasons.

@BuildingIntegrity

3 жыл бұрын

There are products that if applied to bare concrete regularly can inhibit the loss of pH in the concrete. Some products even claim to restore it but I am a bit skeptical of those for various reasons.

@ianchandley

3 жыл бұрын

@@peetky8645 that’s probably more to reflect heat and light than protect any rebar. Plus it’s cheap and locally available. Steel bars were not used to reinforce concrete until the mid-19th century in France. There are modern alternatives available such as rebar made from carbon fibers or basalt, but as relatively new technology, have not caught on.

@peetky8645

3 жыл бұрын

@@ianchandley agree, but it may protect masonry from degradation due to salt, just a guess. no steel involved

While I have no background in Building Engineering, such a beautiful explanation in an easy to understand manner! Look forward to more. I do have one question that got me thinking. How does the concrete aging compare to like glass skyscrapers where the concrete is embedded in the building with glass facades? Does the concrete last longer since it's not directly exposed to the weather elements?

Rusting rebar expands to four times the origonal diameter of the rebar; causing stress force which the concrete cannot resist. Waterproof the laid reinforced concrete to prevent environmental processes changing the ph of the concrete. Very clear information on how reinforced concrete ages. The progressive creep of acidification through the concrete, a bit more complex, but still clear as an explanatory idea.

So new structural concrete in/near a salt environment would benefit from a layer or two of thick rubbery paint BEFORE the ph drops below 13 but after the crete dries through and through. Then the coating/s must be diligently maintained forever to keep ph at 13. Does that make sense? LOL, it does to me but I'm no expert.

@BuildingIntegrity

3 жыл бұрын

Pretty darn close!

@windsofmarchjourneyperrytr2823

3 жыл бұрын

I could see that working BUT, what happens when it gets older and begins to dry rot? It'll start peeling, I'd think.

@larrybe2900

3 жыл бұрын

@@BuildingIntegrity Could you touch on what the future has in store for the Hoover Dam?

@KB4QAA

3 жыл бұрын

@@larrybe2900 1. It is a massive pour. No rebar. This is standard for dams. 2. The Hoover Dam is not going anywhere! P)

@cerebraldreams4738

2 жыл бұрын

@@windsofmarchjourneyperrytr2823 - Every couple of years you strip off the paint and apply a new coat. It's an inconvenient expense, and you could probably get away with not doing it for 15-20 years, but if you want to still have a building in 30 years it might be good to go ahead and redo the protective paint layer.

Like all concrete structures, the constructing of them is just the beginning. They have to be properly maintained by vigilant owners!

@jayygmail

2 жыл бұрын

How to maintain rebar which was rusty before they pour concrete on it and after concrete harden?

thanks, well said. I was looking through the comments. Composite reinforcements such as fiberglass and resin reinforcement bars. The fibers can be glass, or basalt. This eliminates the corrosion of steel problem. How ever don't forget that the water percolating through the concrete structure selectively leaches out the concrete minerals. I would say the best way to protect concrete structures is to protect them from water. Just like we put a water proof roof on our wood frame houses.

Appreciate your explanation and illustration Josh. I once lived in a building where the concrete in hanging plant box are disintegrating and falling, exposing the corroded steel bars inside them.

Concrete can be easily protected from water and chloride intrusion using specialty admixtures which significantly lower the porosity of concrete. In fact concrete can be designed to have a permeability reaching that of granite which is ultra low. Unfortunately code officials, general contractors and owners won't spend the relatively small amount of money to make highly durable concrete. Per your examples, not all of the concrete in the building needs this level of protection. It's only needed in areas directly exposed to these corrosive environments. I've made concrete that's completely impervious to gases like is required in mining applications. It only added about $12 per yard on top of $115 per yard concrete. It's unfortunate that it takes a tragedy to even start a conversation about this. You're doing get work on this channel and keep it up.

@amenen01

3 жыл бұрын

Can you explain how to make the concrete impermeable?

@ivankuzin8388

2 жыл бұрын

Yeah, XC3 XD3 XF4 concrete is just 10~15% more expensive than XC1! (environmental factors per Eurocode, sorry, have no idea how it is called in other codes)

@georgescotsdale361

2 жыл бұрын

Hello Could you provide more information on those impervious/ low permeable concrete? Formulation, code, etc

@ivankuzin8388

2 жыл бұрын

@@georgescotsdale361 Low water/cement ratio (a lot of cement, low water), special cements (inc., e.g with Silica Fume and such), special sand, special aggregates (granite), generally these concretes are always high-strength, C35/45 and up (that's 45MPa crushing pressure on cube specimen), special additives, etc.

@gothatnocat6965

2 жыл бұрын

Research silica fume and metakaolin in terms of low permeability concrete. Also silicates which provide both surface hardening and permeability reduction.

How about home foundation slabs which are usually in frequent/continuous contact with water in the soil and from direct rain?

@TyphoonVstrom

3 жыл бұрын

One of the reasons I hate slab on ground construction. When the slab goes bad in 30 years, well, you can't repair it like a traditional floor on joists and piers. But it's cheap and quick and developers can increase profits from both those things...

@cjkotro8

3 жыл бұрын

Foundation slabs are supposed to have a layer of waterproofing and gravel underneath. Foundation walls are usually covered with a liquid waterproof coating before the soil around the walls is backfilled. Both are required by building codes, but a building inspector has to make sure it was done. After the Surfside collapse, both contractors and inspectors will probably be a little more vigilant that this is done correctly. Unfortunately, over time, many will become complacent again.

Ooh the question I asked myself while watching so much footage about Champlain and now I have a whole video to help me learn more! Thank you!

Someone's going to have to pay for that repair now!!! Seriously, thank you for the channel, and the work you do. I've gained alot of insight into engineering failures, such as failing concrete. Love your work, thank you.

Great explanation. Are there testing devices which can identify these hidden concrete cancers?

@BuildingIntegrity

3 жыл бұрын

There are ways to test the concrete, but they all involve drilling, coring, or other semi-destructive testing techniques which are not usually economical. There is a less-destructive method which measures the electrical equipotential in the steel iirc but it doesn't tell the pH and thus can't tell the whole story.

@gordonrichardson2972

3 жыл бұрын

If you seen brown iron oxide rust coming out of the slab, it's too late...

It’s nice to weave through all the KZread noise and watch some good content.

Damn. Feel like I'm getting college classes for free. Thanks so much for sharing your intelligence with us. Nice to be informed.

Nobody ever considers ph levels…I’ve had to shut down many pools at high rise hotels, some being salt water pools. When health department shows up I’m USUALLY teaching them…the MASSIVE difference between salt water pools and non salt water ones. I have been head of maintenance for years and have seen so many sketchy things, but it’s so simple to test ph and other chemical levels. Some of the pool structures have cracks in them…I’ve mentioned this to my boss many times but he says nothing. He’s younger than me and drives a bmw, I don’t think he’s ever had his hands dirty. Meanwhile many guests have no idea what I know…sad world these days.

Can you do a video on galvanized rebar and how often is it and would it reduce the need for sealing? Also I have heard there are issues with epoxy coated rebar. How much has that been used in Florida?

@welshbordergirl2476

3 жыл бұрын

I was wondering about Epoxy Coated Rebar too! I noticed (courtesy of the Blancolirio channel) that the rebuilt Oroville Dam Spillway used a lot of it!

@BuzzyStreet

3 жыл бұрын

@@welshbordergirl2476 hahah I just started watching Blancolirio for the aviation related content : D

@welshbordergirl2476

3 жыл бұрын

@@BuzzyStreetOoh, do check out Blancolirio's playlists related to the Oroville Dam for lots more concrete and engineering fun! 😄

@gordonrichardson2972

3 жыл бұрын

@@welshbordergirl2476 Oroville Dam is hundreds of miles away from coastal corrosion effects.

If I was an association or individual that owned buildings, I'd hire your firm. For sure. Edit: can you explain "Green Bar" ? The process of how its made and applications is used in?

@BuildingIntegrity

3 жыл бұрын

Thank you! That means a lot.

Good video! I really enjoy your clear presentations. One small technical quibble from a Chemical Engineer. Please pardon the jargon; 0-14 is not the range of pH. It is entirely possible to have pH14. PH is the negative log 10 of the hydrogen ion concentration. With a high dissociation acid, like a HCl, a 1.0 molar solution of acid has a 0 pH. A 2.0 molar solution would have a negative pH. The thing with 14 is that water dissociates such that the negative log of the hydrogen ion (H+) and the negative log of the hydroxide ion (OH-) will sum to be 14. This is a property of water (pkw). We normally refer to pH, but it always has a corresponding pOH with it, the sum of which is 14. At pH=7, pOH=7. At pH=2, pOH=12. A pH of -0.1 would correspond to a pOH of 14.1. 0-14 is just the commonly encountered pH range.

I have a recommendation for this problem. Require Stainless steel rebar in all salt water coastal buildings.

@obviousmaths4368

3 жыл бұрын

Carbon steel is stronger and harder than stainless steel. Is stainless steel not used so much mainly just cost, or do the physical properties influence the choice?

Has there been any study to determine the conditions of foundations in older costal high rise buildings in the U.S.?

This might seem like a dumb question but, does painted concrete offer more protection against rust as is the case in bare metal?

@crowfoot1199

3 жыл бұрын

@Big Leagues lordy what a pathetic ass response. rest assured buddy we all see exactly who you are.

@dragons_red

3 жыл бұрын

I would assume so as long as the paint forms a complete seal, is hydrophobic, and is renewed/refreshed as needed. If not, it seems like it can actually make things worse by trapping in water more efficiently.

@stevewhite3424

3 жыл бұрын

@Big Leagues apparently you are bitter cuz you never made it to the"big leagues"... But the heck the world needs dishwashers and laborers too.

It's really sad how many people ignore regular maintenance and don't understand that it will save them so much money in the long run.

Excellent presentation! As a building inspector this is so helpful to me. Thank you greatly.

So if you regularly coat the concrete with water proofing sealant the concrete will never age?

@thebigmacd

3 жыл бұрын

Never say never, but it will last a whole lot longer.

@kvs13156

3 жыл бұрын

Yes - Sherwin Williams has an excellent product called Loxon

How about anti-rust coating the rebar? How much time does that buy you? How much does it cost? Another youtube engineer I watched didn't like epoxy coated rebar (it gets damaged too easily during installation, and even though you can spray over the damage, bits always get missed) but did quite like galvanized rebar. Would stainless steel rebar ever be worth the cost?

@BuildingIntegrity

3 жыл бұрын

I've seen a lot of epoxy rebar in Florida and I quite agree, it's not a great option. I haven't seen much galvanized rebar so I can't comment on that. Stainless steel properties would not be good for reinforced concrete unless special detailing requirements exist which I'm not aware of.

@langdons2848

3 жыл бұрын

Galvanised rebar is an interesting question. Galvanised posts and the like last well inland in my experience. But after 20 years all of the galvanised steel foot bridges in the park near where I live (over salt water estuaries) are having to be replaced because of massive corrosion problems. So perhaps gal rebar might just buy you a bit of extra time?

@mjouwbuis

3 жыл бұрын

I think galvanisation has roughly the same effect on the steel as the alkaline passivation layer that forms due to the high pH. The question is, will those effects together or the galvanisation alone, make it last longer? I don't know.

@langdons2848

3 жыл бұрын

@@mjouwbuis I think the the biggest weakness for gal rebar would be the ends when lengths are cut. It becomes a point of failure/low protection, especially if the bar is cut with a grinder rather than bolt cutters. So that might negate much of the benefit of the galvanisation.

@user-sm3xq5ob5d

3 жыл бұрын

@@langdons2848 IMHO on building sites the quality of work is very low. All things get dinged and scratched. So construction material needs to be robust and be useable even in less than pristine condition. If one wanted to change that to the standards of other trades the whole industry would get very expensive.

Yeah, it's 100% true! And another "black side" of reinforced concrete - is the use of composite (instead of steel) rebar that doesn't likes an alkaline environment (wet concrete). Waterproofing is a super important thing!

I stayed in a high rise hotel in Borgos, Spain. I stepped out onto the balcony and could feel it dip. Was only there one night, but was v aware of possible issues with the building.

The Pantheon in Rome is 2000 years old and is solid concrete ….How did they manage to make it last .. Roman concrete is a different mix… so is it chemically different…?

@truckerallikatuk

3 жыл бұрын

It's also a structure designed and built around concrete alone. Concrete is very, very strong in compression, but weak in tension. The Pantheon is an unreinforced structure almost totally in compression. With no steel inside to rust and produce spalling, and no part of the structure in a shape in which concrete is weak, as well as being overbuilt, it'll stand for another 1000 years easy. Modern structures have slabs and such where there's tension on the slab, so the steel is there to take the tension loads to prevent the concrete just giving up.

@peetky8645

3 жыл бұрын

the romans used no steel reinforcement so they do not degrade and spall. also, the walls are 5=10x the thickness of modern walls. modern rc construction allows cheap airy contstruction while sacrificing durability. roman concrete is different in that it used volcanic ash as a big component in the mix. fly ash from coal plants is used as a modern substitute.

@dealsfromvirginia1773

3 жыл бұрын

Google says portland cement was invented in 1824, so it must be very different.

@stephenrickstrew7237

3 жыл бұрын

@@truckerallikatuk I read they used volcanic ash in the concrete mix as well … there was not much rebar around back in the old days

@peetky8645

3 жыл бұрын

@@dealsfromvirginia1773 cement is made by burning calciferous rocks in a kiln. the romans used volcanic ash that had been burned in volcanoes and spewed out. similar product, different processes.

8:24 So would sealing just with a clear paint on product the concrete every few years help to prevent this? I know that it can have the opposite effect as well and hold water in. Just thinking for things like driveways, patios etc that are sitting directly on the ground, or would it do more harm, based that it could be absorbing ground water and can't dry correctly?

@user-sm3xq5ob5d

3 жыл бұрын

Cover above, like in paint, and drainage below, like in porous material e.g. gravel, could be a solution.

@cerebraldreams4738

2 жыл бұрын

@@user-sm3xq5ob5d - This sounds like a winning answer. Waterproof on top so water can't get in, but leave it porous below so water can leave.

Mass timber is a better way to build mid rise these days IMO. As a commercial wood and steel framer who also does seismic retrofits and structural upgrades on mid size buildings, I wouldn’t mind getting into fixing up these old concrete structures.

Thanks for your content. Given the mind boggling quantity of cement used daily worldwide, I'm getting more curious about it. Apparently the world is running out of sand, for example. My humble contribution here is "waterproofing" and relates to epoxy and "resistance to moisture". My background incluces some boat building with a particiular interest in epoxy/wood/glass fibre/synthetic fibre composites. The Gougeon Bros. On Boat Building book (old now but still applicable in practice) spends a lot of time on moisture resistance of epoxy in various composites. They were also exploring moist. res. and fatigue in wind turbine blades. and did very many tests, some extreme. The take-away from the book is just how hard it is to achieve anywhere near "waterproof" even though epoxy in itself can be considered to be waterproof. You can, however, achieve acceptable practical levels of moisture resistance IF it's used exactly as proscribed. I can't see it being practical on a construction site and some products are now banned on same in Queensland. Maybe the whole subject of waterproofing needs more attention in the building industry.

Thanks for taking your time too explain this detailed process. Your videos are extremely helpful, and filled with in depth information. Look forward to the next one. Extremely interesting materials and presentation.