Great information

As someone who has worked around concrete that was poured 80 years ago, I don’t see the issues with the concrete we have now. Makes me wonder about the engineers of today with their”we can do it better” attitude has possibly made so many changes to the materials used that it will never hold up the same as something cast in 1930-40. Just like those same engineers who have made our cars SO MUCH BETTER AND RELIABLE.

I think it's curious that the wishes of a church almost killed tens of thousands of people. God is a malevolent prankster.

how much would galvanized rebar cost and what is the additional weight?

It's ribbed for her structural resilience.

Great educational videos! Thank you

He puts preachers to same !!

Crazy I thought rebar is always galvanized just like car bodies. I come from the automotive engineering field so I have no clue about civil engineering.

Galvanizing has a 99% eta layer which will keep oxidizing until nothing is left. I prefer thermal diffused zinc, which has a 90-10 with Zn-Fe. At about 50ums same as HDG. TDZ, works better on contact corrosion and buried items. It also does better on PH levels in the concrete or soil.

Its like glue it doesn't work if the paste doesn't penetrate into the rocks.

Great information. The information is very easily understood. I say this as an engineer contractor concrete producer and SCM supplier for over 50 years.

Great information. Thank you

😂um in Australia we use thin plastic slices cut up from old ink cartridges 😮 plastic don't rust. This minimises the amount of times you need re bar

Poured a concrete patio last summer, used galvanized hog fencing for reenforcement. Poured another pad using hundreds of metal coat hangers as reenforcement.

@Tyler Lay You mention the percentage that cracking is reduced. I'm curious to know how maximum load was is compared with regular concrete as well as concrete slump testing results. Great video!

While I admire her modesty, I feel she should not tell her story saying that she is most likely the student who questioned the flawed design, instead take full ownership of the excellent action she took! This is a fantastic story and can't wait to share. I wish she would sue for the 10k stipend they promised her almost 50 years ago.

What would happen if you poured the dry mix onto a plastic moister barrier and raised all the outer edges ABOVE the concrete and filled the resulting trough from the bottom up?

E-van-gel-li-cal

What a system that doesn’t install an inspecting structural engineer by law when issuing the planning and building permission for a building of this size!

I'm not a concrete expert but I enjoy learning. I played with my share of #4 rebar and a few times handled FRP (the 3rd example rough/smooth). It's hard to believe FRP is stronger than steel. That stuff feels so brittle I feel like it would overtime snap off for dowel applications. I do like acrylic polymer added in concrete but its too expensive and not available in my area.

You know I always figure epoxy coated rebar wasn't perfect but I didn't think you would get these frequent problems as little as 4 years.

Hemp fiber might work better.

Even if you dont tell the public, you just can't have people in the building while repairs are undergoing.

What about thermal properties, does it show monolithic properties with concrete?

Use plastic. Recycled, resilient and inert.

Does adequately watering the concrete for 7 days prevent plastic cracking? As well as microfibres.

Do not cut corners for a cheaper price! Order real concrete from an actual concrete plant!

I would like see practical guidence on low temperature pouring and in freezing temps. I need to make some concrete and pour it. What happens when it is freezing outside, how to overcome cracking within first 24hrs, what additives work best and if there is any drawbacks with them in terms of concrete hardness, rebar corrosion etc. thank you!

I have really wet/ clay soil. Putting a small building (no vehicular traffic in it), 24 x 40. Soil is soft. Graveling the pad I noticed pumping in my access point. Slab will have 12”x12” thick perimeter and 4” slab. 4’ rebar grid and 2 runs of bar in “footing”. Abut 8” gravel underneath. All the soil is kinda the same. Plastisized clay. Do I need to worry about the pumping area?

would the double dipped galvanized break off when bending? Great idea i think it will work.

He didnt think of wind in more than one direction? Lol k

Dr. Ley, have you heard of the myth/urban legend that adding a small amount of sugar to a wet concrete mix can prevent it from curing? Is there any validity to this story?

one word - ZINC

Good trick at the end

Painting the bridge continuously isn't because they're "scared". It's because they know what corrosion does, and are taking the appropriate measures to control it. Because it's a huge job, it makes sense to have a small, well-trained crew doing the job in a stable fashion with a minimum of disruption, instead of hiring a lot of people and renting a lot of equipment, doing it in one big burst, then letting people go.

Thank you so much

Good man 🕌

O.k. Try dry mixing your brownies and see how that works for you… you’ll get similar results with dry pour concrete.

@7:15 Yes! YES! People should know that kinda thing, bro. How can you even ask that?? If anything had happened, and they kept that secret, that company would be done for. No insurance could keep you afloat or recover your reputation. And the city itself would be sued for not ensuring the building was safe. Also I lived in NYC. They can't fix anything let alone in 3 months.

Telling me upfront you're going to waste my time in telling me the answer no thanks.

I am beginning to use FRP,, Stronger, lighter, cheaper

The shear wall in the actual photo looks to be an elevator shaft with the machine room on the roof of the building. Those areas are heavily reinforced torque box structures the building relies on for structural strenght, maybe im wrong, but i dont think is merely a shear wall. The other structure was a totally wrong design tieing into the main structure. Its interesting they call it a punch as the plate was forcing down, whereas a punch as in a punch die or and punching operation is the member placing fore on the item being punched. Interesting post just the same as always from you.

Would like to see the numbers on cost savings on those projects. I dont see how less flyash in the market (unless your project ate up the domestic supply hence the overall shortage) no rebar but cost, thinner slab cut cost, interested long term how the slab actually holds up, did you place more compaction materials on these slabs? These projects had to be commercial pumped so no savings there. What you are striving foe is right but cement plants how much reworking will be involved implementing this and their resistance in a run away concrete cost are they willing to add in more cost revamping their facilities? Especially now with killer concrete costs? Did those projects have on site mix plants easily configuable to these projects? I know portlan production still msde the same CO2 outputs for your portland, if not who and where are these new generation portland factories? These are all valid questions i think need answers you post again very interesting BUT nationally i dont see it happening for some times unless federally mandated for the reasons i listed. That semi conductor plant if those floors long term fail will be a national disaster as any setteling deviation on calbration of those machines and they are truning out junk. This i have first hand experiance knoledge of.

Reading flyash and slag are in low supply hence the skyrocketing concrete costs, the closures of cement plants in so cal again diminishing supply, lower CO2 due to lack of aviability of plants. Why not come up with another method of firing furnaces to make Portland as one guy commented here and you did not get it as it was being Ludacris alternative to the CO2. Electric furnace still needs fossile fuels to generate the ele tric power, also way less efficient making portland even more expensive. There comes a point where CO2 is is more important than progress and construction. Remember the dinosaurs ran around in a way higher CO2 landscape than us today as well as a way more GREEN PLANET with plantlife exploding with higher CO2 content in the atmospere as they need CO2 we need their excrement O2. Pumpers all need more mud, my last project 2700 sq ft limited access required pumper. They refuse to run anything other than pea gravel as it wears out their pumps too fast. So much for agregate mix. Commercial pumps like you show no experiance but i dout they pump coarse agregate either unless demanded on the concrete spec. Then at a higher cost wear and tear on equiptment costs. No end savings other than CO2 PR.

When concrete here is 260yrd and the concrete association claims 20% increases every quarter eco friendly anything always costs more why? I cant afford concrete projects now i guess that makes it green when you cant build only the wealthy can correct? Otherwise i find your posts interesting.

Hi Sir, Thank you so much for your videos; I really enjoy them. However, I believe the first two equations you used to find the target Fc should be applied when the modified standard deviation is 500 psi or less. The second set of equations would be used when the modified standard deviation is greater than 500 psi, as a larger standard deviation implies a greater safety factor. But you mentioned different limits-specifically, that when Fc is greater than 5000 psi, we should use the first two equations, and when Fc is less than 5000 psi, we should use the second two equations. Could you kindly clarify if my understanding is incorrect? Thanks again for your insights!

YOUR ENERGY GOT ME FIRED UP. CONCRETE BROTHER. SAY YES CONCRETE! YES CONCRETE! ¡

I brought in a ton of micro for all my slabs,freezing and cracks need to be controlled,so it worth it.

Hemp rebar

Honestly I think he did right in not telling the public. On a perfect world I'd like to know, but people are incredibly stupid and the media would've harped on it like vultures. I'm telling ya, complete panic, lawsuits, administrative collapse of the building, a lot of problems that would've made organizing such gigantic repairs even harder. The insurance company knew, the mayor knew, and the person mobilizing the workers knew. Those were the people that NEEDED to know, the mayor alone would handle an evacuation if the need actually arised. What he did was tell the relevant people and the relevant people likely judge that a public announcement would've made more harm than good.