Odell Concrete is still the most renoun and respected concrete expert on UA-cam. Whenever i want to learn or see different concrete options i always turn to this channel. It's hard to argue with the best!
Be a DIY warrior - that is the gift of YT and the Net - especially with guys like this video that are willing to show you positive things and also confess problems - I try to watch more and more video's on how to do this or that - I do everything also - it's not for everybody but it is for somebody's
What you experienced is called Plastic Shrinkage Cracking. Volume of the water lost through rapid evaporation exceeds the tensile strength of the fresh concrete. There is an evaporation chart you can use to tell you when you need to take precautions to avoid this condition. When the evaporation rate is.2/10 of a pound per square foot per hour you will likely experience plastic shrinkage. There is a finishing aid called “Confilm” that when properly applied with a sprayer during finishing will reduce the evaporation rate by 50%. Plastic shrinkage cracks are usually permanent. You covered them up with the paste but guaranteed they will come back to haunt you.
Yes agree in Australia Plastic down much bigger mesh say 8 mm chairs to hold the mesh in middle of the slab and a much higher slump. when ordered. Over hers we use 9 foot aluminium screeds' not lumps of wood. That whet out with dark ages.
Sounds like what happened to a couple of my slabs, hotter sunnier area was really the only differance i used bagged concrete bought at the same time and mixed the same way
An architect who was a friend of mine once told me the reason house slabs crack is because there was not enough water put on the ground before the pour. This was in New Mexico which is very dry, similar to the location you are at. Really nice save.
@@OdellCompleteConcrete It doesn't hurt to soak the ground prior to pouring...that's what I've always done on dry, hot days with dry ground since the 1970's. I've also had this happen with cracking every 2 feet on centre (where all my 1/2" rebar was in the slab) back in 1998 when we were pouring a large patio on an acreage where a very strong wind started after we finished placing. I had to remove it all and repour it.
@@OdellCompleteConcreteThat's tough to have to rely on them. Who knows, people are funny. They may not have done it as instructed which wouldn't surprise me.
Thanks for the video Sir. I’ve also been in and around concrete for 40 years. I’ve had that happen to me as well. And I know we don’t generally use poly on patios, driveways or sidewalks but I started using any poly after I had those cracks come up, and I haven’t had that problem again. I know you said the home owners watered it for 3 days, but I still believe that area sucked that water very quickly. I really appreciate all the jobs you do, you really take care of the customer. 👍
@@OdellCompleteConcrete 25 yrs we have been doing concrete in nj , never had this happen before but it's what keeps me up the night before thinking of things like this happening. It is odd especially since it took 6 hrs. to finish, unless the bottom half of the concrete had the water sucked out by the dry ground and somehow the surface remained wet. But I always we the ground down really good before each pour, my guys may get disgruntled thinking it will never dry, but when the water gets sucked out from dry ground it usually all dry's quickly surface and all. But i always make the slump where the Com along helps the concrete almost level and bond together with less effort. Obviously not soup slump but that fine line of good easy bond with every dump of the wheelbarrow. But all that being said, id be going home racking my brain saying something had to be up with the mix . lol maybe, maybe not, good work on that recovery brother hope all went well down the line. Concrete is stressful. if you care.
@@OdellCompleteConcrete I wonder if watering the ground a few days before the pour would have prevented this, like you said the ground may have been too dry and sucked the moisture out of the concrete too fast? Did both slabs crack or just the one next to the home? if it was both then if could have been the batch of concrete. maybe some fiber mesh would have helped? still love your videos and your honesty keep on producing bro!
Hi, enjoy your videos. Retired from the ready mix industry in the UK. It's normal practise here to compact the sub base then lay a polythene sheet down, followed by the mesh. This way there is no water loss from the concrete to the ground. Well done on the finish.
Love how you look for answers despite the thing going wrong on your watch. That’s positive attitude I like to say. One question: wouldn’t troweling only fix the concrete esthetically while leaving the deeper part of the crack present only to resurface in the future? Thanks for the great video.
Exactly my thoughts. I fear the crack is now baked-in and will sooner or later reappear. Some comments suggested the ground may not have been not wet enough before the pour.
I got cracks in my driveway and started later day. YES should have kept WETTING the finished top. My inside of cement has a wire mess plus a rebar. I put the dummy joints in PLUS. I made sure that I did sidewalk expansion joints. The cement guy said that with dummy joins, "O" did not need the sidewalk expansion joints. My cement was already hard, so I could NOT rework the day of pour. I have filled cracks with the Home depo crack repair filler. I learned from you and the comments that I should have spent time on after pour and broom finish. 😊
As a retired conductor for Southern Pacific I know that a railroad tie is good for 50 years before the company plans to replace them in mainline service. Branch lines and yard track will last longer, sometimes 75 to 100 years. /// Regarding the cracking, perhaps you should have put down 3" of gravel over the dirt.
Pea Gravel was originally designed for grouting block walls. Everybody likes the way that it finishes and it’s easy to work with, but it’s junk for flat work. Use a big rock mix design and pour a 4 to 5 inch slump. Your finisher will hate you but big rock will always provide you with a much better slab. Also, the wire mesh doesn’t do any good laying in the dirt you need a man or two with a hook pulling it up into the middle of the slab. Good luck.
@@rickpress9773 the gravel doesn’t make a high psi or a strong mix. The sacks per yard does. So if you have a 1” rock 4 sack mix. It is a lower psi or strength than a 3/8 gravel 6 sack. Get out of here with your nonsense
curious.......do you add air to your exterior concrete where your located? ......this appears to be shrinkage associated with to much water in concrete but your slump appeared to be good ....the concrete cured fine and in a timely manner so mix was ok....possibly moisture being sucked out bottom due to dry soils but that usually leads to very weak concrete due to lack of curing moisture....i would lean to poor prepared soil base (ie soil expansion/contraction) ( expansive soils) might read up on expansive soils
@@OdellCompleteConcrete Love watching your channel. Retired painting/wallcovering contractor here. My pure guess was a bad batch. Is there any test you can do to prove it was bad batch? Sure hope it holds up, you guys do a beautiful job.
I agree. It's the concrete. Not enough cement powder. Looks like a lot of sand too, but may just be that I'm used to a gravelly mix. I'm surprised he doesn't make test cylinder samples for every job. Then if something goes wrong, send it to the lab for load testing. Then you can prove the concrete was bad and get them to pay you for it.
If it was the concrete, would spraying it down and running a power trowel fix it? Adding water? Was the slump correct? I don't know about concrete but have questions that might find the answer.
The plate compactor was not as powerful (vibrations) as the gas one, and did not fully compact the soil. After the concrete hardened, there was settlement in the soil, which caused it to crack.
@@OdellCompleteConcrete LOL you ask people to give their two cents in the comments then call them an idiot. Of course not everyone will have the correct answer, but definitely not a good look man.
Love the channel, congrats on the 500K scribers, I've been watching for a long time and love working with concrete, I even wore out my Imer mixer just doing family yard projects......but anyway, it wasn't anything you did on this pour, something in the mix didn't sit right, possibly not uniform in the mix or a chemical reaction occurred, really appreciate your time in sharing the good and the bad, peace out!
Ground probably choose that time to start shifting, and since the concrete was not near close to being cured it started to pull apart in spite of the reinforcement. Where I live we have a high clay content in our soil which like to swell and shrink with changes in moisture. That is one reason we usually put several inches of sand under concrete slabs to create a sort of disconnect between the concrete and the soil. Give the concrete the ability to slip when the soil moves.
was the ground to dry(?) causing the slab to dry unevenly as water was wicked away? after watching your videos for years now, it didnt look like you changed your techniques any, so the failure has to be in the environment or the concrete that was ordered
Arizona-Sonora Desert Museum Creosote Bush or Larrea tridentata, greasewood, gobernadora, hediondilla, chaparral, ṣegai Creosote bushes are a flowering evergreen shrub, which means that year-round they are green and have leaves. They have tiny, pointed leaves and tiny yellow five-petal flowers. Plant leaves have microscopic “mouths” called stomata, which is how a plant breathes in carbon dioxide and exhales oxygen. Creosote’s little leaves are great water savers because they release less moisture than a big leaf. This is very helpful in a desert where it doesn’t rain very often. The waxy coating on their leaves helps prevent water loss as well. Chemicals on the leaf’s surface are released when it gets wet - this is where their iconic scent comes from! These fragrant chemicals can drop into the soil and inhibit other large plants from growing too close. Creosote’s roots spread deep into the ground so that they can suck up water from the water table and having a protected area around the plant prevents competition from other deep-rooted plants (but allows shallow-rooted wildflowers to pop up in that space). That means more water for the creosote’s roots to slurp up! Creosote lives in the Mojave, Sonoran, and Chihuahuan deserts of North America and can be found in southeastern California, Arizona, southern Nevada and Utah, as well as New Mexico and Texas. In Mexico they can be found in the states of Chihuahua, Sonora, Coahuila, Nuevo Leon, Zacatecas, Durango and San Luis Potosi. These plants grow in well-drained soils, and flat plains.
It looks like this is on the south side of a very light colored wall, on a sunny day. Even though temps were in the 70s, I bet the direct sun plus the reflected heat off that bright wall was cooking the slab and evaporating the water much faster than normal. Also I bet that wall did the same thing to the area of dirt before the pour, so it was bone dry and sucked the water out of the slab like a sponge.
You've been doing this 40 years and already a few out there dealing with the soil conditions and weather. I was thinking maybe soil pulled too much moisture outta the mix, but I'm sure it was just a bad mix as youve never had this happen before. Complain to S&S. They should make it right 👍
Decades ago they use to wet down the forms and wet the ground so the concrete slowly cured. Also cover the slab after being poured with hay and a sprinkler. Then placed a tarp on top. So the top was a still damp to allow curing..
It looked like the pour went well. Did not look like the wind was an issue. So, the question is, could it be a bad mix, or did the homeowner really get it wet for the 3 days? I guess that's something we will never know. Glad you got it. Keep up the good work. 👊🏽
My son had a 40x80 poured in Utah 5600 ft elevation, second week of September. Temps were fine, fiber in the mix, initially the finish looked totally pro. Within 6 hrs the entire pour cracked into approximately 4 ft pieces also. Kind of bizarre. I think the to quick to dry is a very good theory. Arizona and Utah suck the moisture out of everything. Thanks for the poly suggestion, it makes good sense.
I don't know anything about concrete, but my 2 thoughts.. 1. Do you think water reducer in the mix might have helped? It was really a low slump. 2. What if the forms were tapped/beat while you rodded it, and the forms were left up longer?
Would you happen to know if the company that was running the pump had any superplasticizer added to the mix onsite ? I know that too much plasticsizer can cause cracks, just not sure if the cracks would show up while you were finishing the concrete.
Doing concrete on the East Coast one thing we do differently is laying down a barrier between the ground and concrete . We always used 6mil poly plastic sheeting for the barrier. Your finishing looked spot on.
@@OdellCompleteConcrete sounds like you've already decided what caused the cracking in spite of the fact that most of the comments from actual mud guys are telling you that you need to put down plastic.
Wind can also cause this. In summer in Australia we would either give the base a good wetting down before pouring or even sometimes lay plastic barrier down first to slow up the drying process. Rather than expensive curing compounds we mix boncrete ( which is really wood glue ) or a cheaper wood glue product ,one part to four parts water and spray that on the surface immediately after finishing.
Just had this happen over the summer 110 yards of concrete, everybody concurred that it was caused from the concrete drying too quickly. The batch plant did not keep the substrates at the right moisture content. It was a very unusually dry summer and on my end, they said I should’ve put 3 to 4 times as much water on the ground before I poured the concrete. We had to tear it all out and re-poured two days later. The Concrete company would not help me out on it so I use a different company that helped me out on that job to get my business. Definitely the Concrete is what went wrong on your end.
Dry aggregates, hot/expanded aggregates, maybe too much flyash, subgrade to Dry, hot load, too many revolutions, dead cement? Core the slabs and break it. It ain't going to fix itself. Those cracks don't appear to be surface only? Hot materials are expanded, high evaporation rates cool materials and thus shrinkage. Shame that these problems visit good contractors. Best of luck.
Been doing concrete for 48 years. It’s the concrete, if you got a load from a different Conrete plant for the same job, same prep, good chance you would be fine , silt in the concrete mix creates a natural cold joint. However, I noticed it was a somewhat of a windy day, which can pull out moisture as well. Watering the dirt sub grade prior to pouring concrete is a given. One vital thing overlooked is that you used wire mesh , which means if an when the concrete cracks the concrete can separate, we would use 1/2 inch steel rebar 16 inch on centers, thus reinforcing the slab. Hope that helps.
I've always done much the same, compact and soak the ground under the slab, pour, float and trowel. I got a tip and I seem to like the results, when you give it the final trowel, garden sprayer with clear concrete sealer, coat the surface well, its like a permanent poly sheet. I haven't tried pouring concrete in the desert though. Maybe thermal shock, concrete of course gets hot and its hot out? cool water and evaporation leading to contraction?
Most likely reason: the concrete did not cure but dried in hot/dry weather. Did you pour the concrete in not-to-hot conditions, e.g. like at most 20-25 degree at the hottest time of the day? Did you spray the concrete with water to keep it wet? Did you cover it with a plastic sheet to reduce evaporation?
Probably has already been mentioned but the creosote they soak those railroad ties in isn't derived from creosote bushes like the homeowner said. It's a preservative made from distilling coal. Love your videos!
Batch plant probably sent a truck that arrived way too hot. When we pour down south, there are a lot of times you get a hot load. So I've had them batch with ice chips. Some larger substation pours we had sent with liquid nitrogen. Sounds like BS but you'll see it on massive continuous pours. If the temp out the chute was above 140, failure is pretty much guaranteed
I'm not a concreter but I know with cement render if it is finished too quickly shrinkage cracks appear next day has to do with the outside drying faster because of the floating finishing trapping moisture. I'm not sure the reason for concrete but I've come across 2 driveways being poured same day hot weather both cracking, concreter blamed concrete but was unsure. Surely they would teach about this at technical college
Probably more than one thing happening here. If the subgrade is too wet the water has no choice but to head for the surface, and if it's sealed too early it will cause cracking. Concrete bleeds whether or not you can see it, especially in the desert. A clue is that after the surface was troweled, you could still get on it to save it, meaning the top was hard, but subsurface was still plastic and it came back together. Sometimes in the heat we will actually use a little accelerator to ensure consistent set thru the vertical section. Line pump mixes are notoriously high in mortar (cement and water) and only mortar shrinks. Lower mortar content lowers shrinkage-use more water reducer...
We use a “slip’ plastic membrane under our pours here in the UK. It prevent any water loss from the concrete into the base, any movement between the sub and concrete is mitigated and also acts to prevent freeze/thaw damage (not that you would experience freeze/thaw!). I’ve never seen you guys in the US use membrane. As you’re extremely good at your job, there must be a simple reason? Cheers
I have been a concrete contractor for over 30 years in the Central Valley of California where is hot and dry. The biggest thing that I see first is weather the breeze was blowing. You can use a finishing aid like Eucobar to help with initial evaporation. The other problem that I noticed is that you used a magnesium float initially and sealed it up to soon. We use only a wood bull float and then folllow up later with an orange thunder bull float. Good luck hope that helps.
There is no way using a mag float caused the concrete to crack like that. You say he sealed it up with the mag float, if that were the case the water would have stayed in the concrete. Mag brings water and cream to the surface to allow a steel trowel to compress the fines and give a durable finish. A mag float or trowel doesn't seal/finish the concrete that's what the steel is for.
What guarrantee from cracking/ other defects do you provide? ... does the concrete provider give any warranties ?... if the mix is bad who is the last to approve its application?, you or the supplier?...looks like a redo is coming down the road at some point? Will it fail again?.. hummm... is the homeowner gonna get stuck with it?...hope not.❤
How much different are the soil conditions where you are now compared to where you did most of your work over here? That same for weather conditions? Maybe you need to tweak your finishing timing or the prep or … does this happen to other contractors in the area? Love the videos…
Possible causes are the concrete temperature and the total time from batch time to the last drop of concrete that came of the truck. If it goes higher than 90 min, probably your concrete was already too hot (hydration process).
Out here in Washington state, when we had very sandyfill or very dry, we compacted the fill with water and put down plastic to stop the concrete from having the moister pulled out
Man, I love that little vermeer 😊 track loader. Perfect for this size job. 😊 did not know that .ade Battery-powered plate wackers. On my outdoor, she that has no cement floor It's one of those pre fabs on skid planks. My wife said we don't need to rent a plate compactor. I got one anyhow. She thought the backhoe bucket could compact it good enough. When we layered are 5/8s. And lazered the fill lifts. She then understood WHY it's so important to plate wack the foundation. 😊
Here in Colorado Springs, CO, the city replaced curbs/gutters and sidewalks in my neighborhood in 2022. The curbs/gutters and drain pans are now severely pitted with fine and course aggregates showing in all the pits. The city says the finishers are not permitted to excessively trowel the concrete in order to force the aggregates deeper into the mix because that would affect the strength of the concrete. I guess they would prefer the pitted concrete. What say you?
I would agree with the comment about premature drying. The water was sucked out by a dry substrate before the concrete had a chance to cure. A layer of plastic sheeting over the gravel would I believe have prevented the problem. The curing compound should have been applied sooner also.
Is the wire mesh even necessary if there is fiber strands in the concrete? I don't recall seeing anybody pulling the wire mesh up into the concrete during the pour. Maybe I missed it in the high-speed video footage.
I had a basement floor poured, rained for several days before the pour, compacted, poly and mesh. The next morning there were cracks everywhere. This area in TN has a lot of rock in the ground, so the rain went right into the ground not affecting the pour time. still mad about those cracks. Talked with other concrete pros and they all said there are a million reasons why concrete will crack.
Cracking happens usually after it fully dries doesn't it???? Could it have been a too dry mix, or dried too fast, or not enough cement in the mix??????? Is it also possible there was a big temperature change????? Here in Michigan, we have to watch the temperature as well as the mix. Another possibility is an unseen flaw in the dirt under the slab. The weight of the concrete causing a settling in spots. "Just guessing???? "
If we are pouring directly on the ground we use vapor barrier to keep it from drying to fast and crack. Even retarder sometimes isn’t enough if the air is too dry and there is a slight wind. You gotta babysit the pour longer but plastic certainly helps slow it down.
My two cents with my experience, excelled water evaporation. Sub-grade Prep looked solid, place and finish looks solid. to me it looks like ambient temperatures were working against you guys. And maybe the subgrade was not wet enough, but I’m in a completely different climate than you guys so it’s hard to say from my perspective. I am in the PNW. Been following your channel for years now and really love the videos! At the end of the day, this is a great case study. My concern would be the cracks ghosting. Would love to see a follow up. ✌🏽
Retired Civil Engineer - Simple, too much water in the concrete mix caused your problem, water either added at the plant or in the field. I have field tech's measure the temperature because hot concrete causes the chemical reaction to speed up and associated quick shrinkage but you were able to still work the surface so not so likely not the problem. For flat concrete work, 3 to 4 inch slump is what the final product needed not self leveling concrete which it looked like in your video. If you need additional slump for pumping or placing then work with the concrete plant to use water reducer admixtures during the plant mix.
Ironic, I ran into this myself on a job in DC back in the 70's. I worked directly under the GSA inspector doing slump tests/samples on a federal project. A spandrel beam on the 2nd level of a 5 story building cracked after being stripped. GSA tested samples from that pour and found oil in the batch. The GSA inspector went out to the batch plant and found that the mechanic had changed oil into the sand used in the mix which was not visibly detectable but caused the pour to crack. Some crete companies quality control is sporadic which leads to what you experienced. And no amount of prep and finish will prevent the cracking. The beam on our job had to be jack hammered out and replaced, of course and the feds backcharged the concrete company for all damages.
I think it was a bad mix and being a Saturday reinforces that belief. As shown on the edge of that slab, the cracks run top to bottom. I do not think that the additonal trowing will heal the concrete deeper than an inch. I think the cracks will reappear soon.
The dirt foundation. Was it packed dirt? Maybe the concrete mix. You look very diligent and professional. You sound experienced. Maybe it was curing oddly. Is strange
Had a driveway done a few years ago at my home in Vegas. After a few weeks the concrete started to curl up like a potatoe chip, not bad, maybe like a 3/8", but still noticable. Oddly, the only cracks were on the control grooves, I don't think the mix was right.
I poured a lot of concrete in my youth building bridges for both state and county inspectors. I finished that career as a forman and crane operator. Inspectors would do slump test on concrete,, too wet equals fast moisture loss and cracks. When I watched you pour that I thought man that is too wet. Easy to pour it wet as it self levels, but you will have more cracks. Should pour dry so that you have to actually rake,shovel, and vibrate it into position. Most people won't work that hard at pouring concrete,, but if it is a bridge and state inspectors there, you do it correctly.
I had it happen. It was hot as hell with the sun out. The driver admitted to me later he loaded 5-6 yards on some from a previous job and mixed it in. I saved it like you I thought. 6 months later I tore it all out. It did EXACTLY like what happened to you. Hot sunny weather too. A 4” pool deck.
Was it 3500 or 4500psi mix? Looks like a bad mix to me, maybe to much cement, and had water reducer left in hopper...but it didnt flash off fast, so maybe they used sugar too...who knows. That was a mess though.
I believe you got a bad batch. I had the exact same thing happen this summer. Fairly cool day (80 deg or less), no wind, under roof, but open air. We poured two 12x36, one on each side of a pole barn. One 6 yd truck for one side, another 6 yd truck for the other. Both trucks were on their second load of the day. The first truck finished out perfect and still doesn't have a single crack. The second truck ended up like yours. I believe the second truck didn't empty out on the first job they went to and then batched my load on top of the leftovers. I can't prove that, but there were no other differences between the two slabs.
@@OdellCompleteConcrete haha yeah, blame the concrete. Crap carpenters blame the nails. It was a stiff mix, you knew that going in, you didn't put down plastic in an extremely arid environment. btw, you know as well as I do that those cracks are still there. Sorry, this one's on you, Bro.
Have a test from reputable laboratory done on both slabs you'll find your problem is the mix was out of time or mix was wrong not S &S can do there own but don't use a independent lab
I am just a DIY guy who watches you for lessons. Just curious but with the vey hot sun and breeze there could this have been caused by a simple expansion and contraction when the water hit it? maybe needed a tarp over for shade??? Just a thought but probably just a bad mix since you have been doing this for so long.
My concrete guy, who I've been using for 17 years, and has only ever done concrete his entire life, said to me on our latest pour, 6 days ago, that the concrete formulations, at least in our area, have changed in the last few years. They are using different fillers and it is much harder to properly finish than say 10-15 years ago. I don't actually know too much about that myself, just repeating what he said to me.
As an engineer, it seems like the most logical reason is the mix. I suspect them getting some dirt into that batch or they really watered it down for transit, or something to this effect. The cracking is uniform, not just the surface. Of course their are the obvious reasons like soil wicking the moisture, the low humidity and high sun of AZ, etc... but you deal with these conditions all the time without this result and I don't find anything out of the ordinary in this video. You had very mild conditions for it being AZ and had the homeowners water the pads down regularly in the days before the pour.
In Australia we would pour this using 8 mil mesh black plastic down so moisture not go into ground the mesh on chairs in the middle of the slab.. high slump on a very windy day . Get the owner to lightly wet it down each day as well as the concrete dries.
Brother not sure if you have a white cap out there but they have 5x10 mesh sheets all different thickness and prices from 9$-20$ Home Depot sells smaller sheets and they are 23$ I think… Now I’ll just get a huge order of mesh at beginning of season on the form trailer since the white cap is out of the way saves me 1.5hr round trip especially when it’s a small pour don’t need to always spend the 23$/piece on those small sheets plus you’ll need more from Home Depot since they are smaller
There are only two types of concrete, the type that’s cracked and the type that’s going to crack….more than likely the ground sucked the water out of it quickly which will lead to cracking. Was it fiber mixed concrete ?
I poured concrete for 45 yrs. The problem is probably a very hot dry base or you got a load of hot mud. You need to soak the base with water before you pour. Or put down a layer of Tyvec over the sub base.Not plastic. Hot mud happens when the concrete is old mix that has been temperd with water too much. Some batch company's remix batches that come back to the plant from previous pours. Another factor is a hot dry wind.
I'd never seen a battery-powered plate compactor before now. I'd seen just about every outdoor power tool powered by batteries, but never a compactor. Very cool!
I’ve never seen that happen and I’ve on my own Concrete business for several decades and only thing I can think of is that the Earth underneath it moved I’m not sure where your exactly located at but maybe I’ve had some kind of small earthquake or something you got me. I’d like to know.
I believe the issue lies with the soil, as the concrete cracked completely through and doesn’t appear related to the finishing or surface process. Observing your team dig for the form ties, it’s clear the soil far below the surface is very dry and uncompacted. From what I can see of the other lots, this looks like a recently built-up and graded subdivision. It’s possible the grading wasn’t compacted properly at the necessary depth for the lifts. I don’t think you did anything wrong-sometimes, things like this just happen.
Odell Concrete is still the most renoun and respected concrete expert on UA-cam. Whenever i want to learn or see different concrete options i always turn to this channel. It's hard to argue with the best!
Thanks
Wood screed that went out with stone age. Would like to see them do a shopping centre slab. That would be interesting
Elementary
I am a DIY warrior and this is the stuff that keeps me up at night. Thank you for the video and presenting the good and bad.
Glad to help
Find a ood finisher. Dont weekend warrior a concrete fishing job.
Your the standard of that
Be a DIY warrior - that is the gift of YT and the Net - especially with guys like this video that are willing to show you positive things and also confess problems - I try to watch more and more video's on how to do this or that - I do everything also - it's not for everybody but it is for somebody's
What you experienced is called Plastic Shrinkage Cracking. Volume of the water lost through rapid evaporation exceeds the tensile strength of the fresh concrete. There is an evaporation chart you can use to tell you when you need to take precautions to avoid this condition. When the evaporation rate is.2/10 of a pound per square foot per hour you will likely experience plastic shrinkage. There is a finishing aid called “Confilm” that when properly applied with a sprayer during finishing will reduce the evaporation rate by 50%. Plastic shrinkage cracks are usually permanent. You covered them up with the paste but guaranteed they will come back to haunt you.
Yes agree in Australia Plastic down much bigger mesh say 8 mm chairs to hold the mesh in middle of the slab and a much higher slump. when ordered. Over hers we use 9 foot aluminium screeds' not lumps of wood. That whet out with dark ages.
Sounds like what happened to a couple of my slabs, hotter sunnier area was really the only differance i used bagged concrete bought at the same time and mixed the same way
@@jamestanner9198 you’re doing it right
@@williamhughes6051 Bagged concrete hardly ever turns out well.
@@meflyfish Why does this guy use lumps of wood as screed. Don't you get the proper aluminium ones there. ?
An architect who was a friend of mine once told me the reason house slabs crack is because there was not enough water put on the ground before the pour. This was in New Mexico which is very dry, similar to the location you are at. Really nice save.
I had the Homeowner wet for three days prior to pour
@@OdellCompleteConcretewonder if he did or did enough
@@OdellCompleteConcrete It doesn't hurt to soak the ground prior to pouring...that's what I've always done on dry, hot days with dry ground since the 1970's. I've also had this happen with cracking every 2 feet on centre (where all my 1/2" rebar was in the slab) back in 1998 when we were pouring a large patio on an acreage where a very strong wind started after we finished placing. I had to remove it all and repour it.
Good question
@@OdellCompleteConcreteThat's tough to have to rely on them. Who knows, people are funny. They may not have done it as instructed which wouldn't surprise me.
Thanks for the video Sir.
I’ve also been in and around concrete for 40 years.
I’ve had that happen to me as well. And I know we don’t generally use poly on patios, driveways or sidewalks but I started using any poly after I had those cracks come up, and I haven’t had that problem again.
I know you said the home owners watered it for 3 days, but I still believe that area sucked that water very quickly.
I really appreciate all the jobs you do, you really take care of the customer.
👍
Possibly but it did take 6 hours to finish
@@OdellCompleteConcrete 25 yrs we have been doing concrete in nj , never had this happen before but it's what keeps me up the night before thinking of things like this happening. It is odd especially since it took 6 hrs. to finish, unless the bottom half of the concrete had the water sucked out by the dry ground and somehow the surface remained wet. But I always we the ground down really good before each pour, my guys may get disgruntled thinking it will never dry, but when the water gets sucked out from dry ground it usually all dry's quickly surface and all. But i always make the slump where the Com along helps the concrete almost level and bond together with less effort. Obviously not soup slump but that fine line of good easy bond with every dump of the wheelbarrow.
But all that being said, id be going home racking my brain saying something had to be up with the mix . lol maybe, maybe not, good work on that recovery brother hope all went well down the line. Concrete is stressful. if you care.
Bad concrete mixes are rare, but it's happened to me 3 times in 40 years, you're lucky you got to see what bad concrete mixes do
@@OdellCompleteConcrete I wonder if watering the ground a few days before the pour would have prevented this, like you said the ground may have been too dry and sucked the moisture out of the concrete too fast? Did both slabs crack or just the one next to the home? if it was both then if could have been the batch of concrete. maybe some fiber mesh would have helped? still love your videos and your honesty keep on producing bro!
I don't know nothin' about concrete, but I still love your videos. Thank you.
TY
Thanks for sharing and showing the problems you’ve encountered not just the successes. That would’ve been nerve wracking, so glad you saved it.
My pleasure!
I blame the funny trowel for telling jokes. It makes me crack up.
Lmaoooo full circle dad joke comment
Good one
your always in good hands with Odell Complete Concrete
TY
Hi, enjoy your videos. Retired from the ready mix industry in the UK. It's normal practise here to compact the sub base then lay a polythene sheet down, followed by the mesh. This way there is no water loss from the concrete to the ground. Well done on the finish.
TY
no
Love how you look for answers despite the thing going wrong on your watch. That’s positive attitude I like to say. One question: wouldn’t troweling only fix the concrete esthetically while leaving the deeper part of the crack present only to resurface in the future? Thanks for the great video.
Exactly my thoughts. I fear the crack is now baked-in and will sooner or later reappear. Some comments suggested the ground may not have been not wet enough before the pour.
probably depending how deep they were.
I think the wire will hold it together minimizing the cracks
Thanks!
Using the power trowel was a great idea, really helped to consolidate the concrete and minimized the cracks
I think all the power trowel did was work up enough cream to fill the crack but I bet the cracks come back !
Yes it definitely helped
@michael74556 no owner wants concrete with minimized cracks.
I got cracks in my driveway and started later day. YES should have kept WETTING the finished top. My inside of cement has a wire mess plus a rebar. I put the dummy joints in PLUS. I made sure that I did sidewalk expansion joints. The cement guy said that with dummy joins, "O" did not need the sidewalk expansion joints. My cement was already hard, so I could NOT rework the day of pour. I have filled cracks with the Home depo crack repair filler. I learned from you and the comments that I should have spent time on after pour and broom finish. 😊
Next time.
TY
As a retired conductor for Southern Pacific I know that a railroad tie is good for 50 years before the company plans to replace them in mainline service. Branch lines and yard track will last longer, sometimes 75 to 100 years. /// Regarding the cracking, perhaps you should have put down 3" of gravel over the dirt.
I more decomposed gravel base that was previously under the turf
Pea Gravel was originally designed for grouting block walls. Everybody likes the way that it finishes and it’s easy to work with, but it’s junk for flat work. Use a big rock mix design and pour a 4 to 5 inch slump. Your finisher will hate you but big rock will always provide you with a much better slab. Also, the wire mesh doesn’t do any good laying in the dirt you need a man or two with a hook pulling it up into the middle of the slab. Good luck.
But he has 45 years of experience.
Pea gravel is a 2500 psi and up mix You are wrong and pea gravel is just as strong
@@rickpress9773 the gravel doesn’t make a high psi or a strong mix. The sacks per yard does. So if you have a 1” rock 4 sack mix. It is a lower psi or strength than a 3/8 gravel 6 sack. Get out of here with your nonsense
I've did many of these the same way with no problems.
Only thing that changed was the concrete quality
bad batch of concrete
It seems the water from the concrete was absorbed into the ground too quick. Wetting the area more/plastic should help you avoid this.
I had the Homeowner soak for 3 days prior to the pour.
@@OdellCompleteConcrete I guess the question is what is the homeowner's definition of soaking is?
@OdellCompleteConcrete Do you think maybe that ground is extra efficient at wicking moisture?
@@AdmimistratorDG is a very absorbing material.
I have two locations with different subgrades, but both location with the same load of concrete had the same problems
Another video from Odell complete concrete still does not disappoint
Ty
curious.......do you add air to your exterior concrete where your located? ......this appears to be shrinkage associated with to much water in concrete but your slump appeared to be good ....the concrete cured fine and in a timely manner so mix was ok....possibly moisture being sucked out bottom due to dry soils but that usually leads to very weak concrete due to lack of curing moisture....i would lean to poor prepared soil base (ie soil expansion/contraction) ( expansive soils) might read up on expansive soils
I would say 1 of 3 things, 1) the mix was off, 2) the ground sucked the moisture from the concreate, 3) ground/concreate shifted somehow
I've narrowed it down to bad mix after checking off the other things
@@OdellCompleteConcrete did u warrenty that? surely its going to just crack later
no, but if I have to do again, I'll need the concrete company to pay me.
@@OdellCompleteConcrete Love watching your channel. Retired painting/wallcovering contractor here. My pure guess was a bad batch. Is there any test you can do to prove it was bad batch? Sure hope it holds up, you guys do a beautiful job.
@@OdellCompleteConcrete
I'm assuming after they watch your video that can't say you didn't do it right?
I doing hardscaping and concrete jobs in DC area for almost 20 years, yes I had same problems at least 5-6 times, every time it was BAD mix!
I concur
I agree. It's the concrete. Not enough cement powder. Looks like a lot of sand too, but may just be that I'm used to a gravelly mix.
I'm surprised he doesn't make test cylinder samples for every job. Then if something goes wrong, send it to the lab for load testing. Then you can prove the concrete was bad and get them to pay you for it.
I can still send a core sample to the lab it just cost more now.
If it was the concrete, would spraying it down and running a power trowel fix it? Adding water? Was the slump correct? I don't know about concrete but have questions that might find the answer.
Probably not
The plate compactor was not as powerful (vibrations) as the gas one, and did not fully compact the soil. After the concrete hardened, there was settlement in the soil, which caused it to crack.
Not likely
You have no idea what your talking about...
idiot
@@OdellCompleteConcrete LOL you ask people to give their two cents in the comments then call them an idiot. Of course not everyone will have the correct answer, but definitely not a good look man.
🤣🤣🤣🤣
Love the channel, congrats on the 500K scribers, I've been watching for a long time and love working with concrete, I even wore out my Imer mixer just doing family yard projects......but anyway, it wasn't anything you did on this pour, something in the mix didn't sit right, possibly not uniform in the mix or a chemical reaction occurred, really appreciate your time in sharing the good and the bad, peace out!
Thanks for watching.
I think you are right on
Ground probably choose that time to start shifting, and since the concrete was not near close to being cured it started to pull apart in spite of the reinforcement.
Where I live we have a high clay content in our soil which like to swell and shrink with changes in moisture. That is one reason we usually put several inches of sand under concrete slabs to create a sort of disconnect between the concrete and the soil. Give the concrete the ability to slip when the soil moves.
was the ground to dry(?) causing the slab to dry unevenly as water was wicked away?
after watching your videos for years now, it didnt look like you changed your techniques any, so the failure has to be in the environment or the concrete that was ordered
I had the Homeowner soak for 3 days prior to the pour.
I have no idea how to concrete, but could it be the extreme low humidity? ...which excelled the evaporation of water?
Bad concrete but good guess
Arizona-Sonora Desert Museum
Creosote Bush or Larrea tridentata, greasewood, gobernadora, hediondilla, chaparral, ṣegai
Creosote bushes are a flowering evergreen shrub, which means that year-round they are green and have leaves. They have tiny, pointed leaves and tiny yellow five-petal flowers. Plant leaves have microscopic “mouths” called stomata, which is how a plant breathes in carbon dioxide and exhales oxygen. Creosote’s little leaves are great water savers because they release less moisture than a big leaf. This is very helpful in a desert where it doesn’t rain very often. The waxy coating on their leaves helps prevent water loss as well. Chemicals on the leaf’s surface are released when it gets wet - this is where their iconic scent comes from! These fragrant chemicals can drop into the soil and inhibit other large plants from growing too close. Creosote’s roots spread deep into the ground so that they can suck up water from the water table and having a protected area around the plant prevents competition from other deep-rooted plants (but allows shallow-rooted wildflowers to pop up in that space). That means more water for the creosote’s roots to slurp up!
Creosote lives in the Mojave, Sonoran, and Chihuahuan deserts of North America and can be found in southeastern California, Arizona, southern Nevada and Utah, as well as New Mexico and Texas. In Mexico they can be found in the states of Chihuahua, Sonora, Coahuila, Nuevo Leon, Zacatecas, Durango and San Luis Potosi. These plants grow in well-drained soils, and flat plains.
Very informative
TY
Great video! Thank you for not adding unnecessary background music.
You're welcome!
It looks like this is on the south side of a very light colored wall, on a sunny day. Even though temps were in the 70s, I bet the direct sun plus the reflected heat off that bright wall was cooking the slab and evaporating the water much faster than normal. Also I bet that wall did the same thing to the area of dirt before the pour, so it was bone dry and sucked the water out of the slab like a sponge.
I didn’t catch it but did you wet the ground first sometimes the ground will suck the moisture right out of the concrete
You've been doing this 40 years and already a few out there dealing with the soil conditions and weather. I was thinking maybe soil pulled too much moisture outta the mix, but I'm sure it was just a bad mix as youve never had this happen before. Complain to S&S. They should make it right 👍
Im fairly sure the mix was off. Saturday new batch man.
Uncle David , this has happened to me multiple times in Hawaii. The ground sucked up all the water and bad mix🙏🤙 your prep was cherry 🍒
Bad loads happen
Decades ago they use to wet down the forms and wet the ground so the concrete slowly cured. Also cover the slab after being poured with hay and a sprinkler. Then placed a tarp on top. So the top was a still damp to allow curing..
It looked like the pour went well. Did not look like the wind was an issue. So, the question is, could it be a bad mix, or did the homeowner really get it wet for the 3 days? I guess that's something we will never know. Glad you got it. Keep up the good work. 👊🏽
Good question!
I'm leaning towards bad mix.
My son had a 40x80 poured in Utah 5600 ft elevation, second week of September. Temps were fine, fiber in the mix, initially the finish looked totally pro. Within 6 hrs the entire pour cracked into approximately 4 ft pieces also. Kind of bizarre. I think the to quick to dry is a very good theory. Arizona and Utah suck the moisture out of everything. Thanks for the poly suggestion, it makes good sense.
Dirt in the mix
I don't know anything about concrete, but my 2 thoughts.. 1. Do you think water reducer in the mix might have helped? It was really a low slump. 2. What if the forms were tapped/beat while you rodded it, and the forms were left up longer?
I think there no way to make a rib eye out of ground chuck
Would you happen to know if the company that was running the pump had any superplasticizer added to the mix onsite ? I know that too much plasticsizer can cause cracks, just not sure if the cracks would show up while you were finishing the concrete.
Doing concrete on the East Coast one thing we do differently is laying down a barrier between the ground and concrete . We always used 6mil poly plastic sheeting for the barrier. Your finishing looked spot on.
No freeze and thaw here
@@OdellCompleteConcrete sounds like you've already decided what caused the cracking in spite of the fact that most of the comments from actual mud guys are telling you that you need to put down plastic.
I've laid down more concrete than most people have walked on
@@OdellCompleteConcrete never heard that one before :) buts its probably true!
Wind can also cause this. In summer in Australia we would either give the base a good wetting down before pouring or even sometimes lay plastic barrier down first to slow up the drying process. Rather than expensive curing compounds we mix boncrete ( which is really wood glue ) or a cheaper wood glue product ,one part to four parts water and spray that on the surface immediately after finishing.
Just had this happen over the summer 110 yards of concrete, everybody concurred that it was caused from the concrete drying too quickly. The batch plant did not keep the substrates at the right moisture content. It was a very unusually dry summer and on my end, they said I should’ve put 3 to 4 times as much water on the ground before I poured the concrete. We had to tear it all out and re-poured two days later. The Concrete company would not help me out on it so I use a different company that helped me out on that job to get my business. Definitely the Concrete is what went wrong on your end.
Yes it's the only that makes sense
Dry aggregates, hot/expanded aggregates, maybe too much flyash, subgrade to Dry, hot load, too many revolutions, dead cement? Core the slabs and break it. It ain't going to fix itself. Those cracks don't appear to be surface only? Hot materials are expanded, high evaporation rates cool materials and thus shrinkage. Shame that these problems visit good contractors. Best of luck.
Been doing concrete for 48 years. It’s the concrete, if you got a load from a different Conrete plant for the same job, same prep, good chance you would be fine , silt in the concrete mix creates a natural cold joint. However, I noticed it was a somewhat of a windy day, which can pull out moisture as well. Watering the dirt sub grade prior to pouring concrete is a given. One vital thing overlooked is that you used wire mesh , which means if an when the concrete cracks the concrete can separate, we would use 1/2 inch steel rebar 16 inch on centers, thus reinforcing the slab. Hope that helps.
Bad loads happen.
TY
I've always done much the same, compact and soak the ground under the slab, pour, float and trowel. I got a tip and I seem to like the results, when you give it the final trowel, garden sprayer with clear concrete sealer, coat the surface well, its like a permanent poly sheet. I haven't tried pouring concrete in the desert though. Maybe thermal shock, concrete of course gets hot and its hot out? cool water and evaporation leading to contraction?
It's not hot here right now, average temperature is 75 f.
Curing compound does that.
Most likely reason: the concrete did not cure but dried in hot/dry weather.
Did you pour the concrete in not-to-hot conditions, e.g. like at most 20-25 degree at the hottest time of the day?
Did you spray the concrete with water to keep it wet? Did you cover it with a plastic sheet to reduce evaporation?
can you leave a fresh pour with a misting hose above it?
Probably has already been mentioned but the creosote they soak those railroad ties in isn't derived from creosote bushes like the homeowner said. It's a preservative made from distilling coal. Love your videos!
good to know TY
Batch plant probably sent a truck that arrived way too hot. When we pour down south, there are a lot of times you get a hot load. So I've had them batch with ice chips. Some larger substation pours we had sent with liquid nitrogen. Sounds like BS but you'll see it on massive continuous pours.
If the temp out the chute was above 140, failure is pretty much guaranteed
I thin k the mix was contaminated with dirt
I'm not a concreter but I know with cement render if it is finished too quickly shrinkage cracks appear next day has to do with the outside drying faster because of the floating finishing trapping moisture. I'm not sure the reason for concrete but I've come across 2 driveways being poured same day hot weather both cracking, concreter blamed concrete but was unsure. Surely they would teach about this at technical college
Probably more than one thing happening here. If the subgrade is too wet the water has no choice but to head for the surface, and if it's sealed too early it will cause cracking. Concrete bleeds whether or not you can see it, especially in the desert. A clue is that after the surface was troweled, you could still get on it to save it, meaning the top was hard, but subsurface was still plastic and it came back together. Sometimes in the heat we will actually use a little accelerator to ensure consistent set thru the vertical section. Line pump mixes are notoriously high in mortar (cement and water) and only mortar shrinks. Lower mortar content lowers shrinkage-use more water reducer...
Alot of potential issues, but I've narrowed it down to contaminated materials
Do you think the Milwaukee plate compactor is worth the cost compared to a gas powered?
I like it because it does the same thing with less potential problems and 0 maintenance
Nice save Dave! Experience saves the day.
We do the best we can with what we are dealt with
Isn't the fiber mesh supposed to prevent cracking?
We use a “slip’ plastic membrane under our pours here in the UK. It prevent any water loss from the concrete into the base, any movement between the sub and concrete is mitigated and also acts to prevent freeze/thaw damage (not that you would experience freeze/thaw!). I’ve never seen you guys in the US use membrane. As you’re extremely good at your job, there must be a simple reason? Cheers
Plastic is only good for 20 to 30 years.
I don't see the point in plastic unless it's indoors.
@@OdellCompleteConcreteafter 35 years I can say that the benefits outweigh the the time restraints but as ever it’s only my opinion.
I have been a concrete contractor for over 30 years in the Central Valley of California where is hot and dry. The biggest thing that I see first is weather the breeze was blowing. You can use a finishing aid like Eucobar to help with initial evaporation. The other problem that I noticed is that you used a magnesium float initially and sealed it up to soon. We use only a wood bull float and then folllow up later with an orange thunder bull float.
Good luck hope that helps.
I had the Homeowner soak for 3 days prior to the pour.
@@OdellCompleteConcrete You ever watch old people water anything... He probably sprayed it down in the hot sun and it all burned off. 😅
Yes I have and watering is what they love to do, including me.
There is no way using a mag float caused the concrete to crack like that. You say he sealed it up with the mag float, if that were the case the water would have stayed in the concrete. Mag brings water and cream to the surface to allow a steel trowel to compress the fines and give a durable finish. A mag float or trowel doesn't seal/finish the concrete that's what the steel is for.
What guarrantee from cracking/ other defects do you provide? ... does the concrete provider give any warranties ?... if the mix is bad who is the last to approve its application?, you or the supplier?...looks like a redo is coming down the road at some point? Will it fail again?.. hummm... is the homeowner gonna get stuck with it?...hope not.❤
I'd love to see the 1 year update on this as to how it held up. My guess is the ground gave away and let it settle on one side.
How much different are the soil conditions where you are now compared to where you did most of your work over here?
That same for weather conditions?
Maybe you need to tweak your finishing timing or the prep or …
does this happen to other contractors in the area?
Love the videos…
two locations same load with different base, but same results
Possible causes are the concrete temperature and the total time from batch time to the last drop of concrete that came of the truck. If it goes higher than 90 min, probably your concrete was already too hot (hydration process).
Also, if you have a windy day and your ground is dry, it will create dry shrinkage cracks
Bad load
Out here in Washington state, when we had very sandyfill or very dry, we compacted the fill with water and put down plastic to stop the concrete from having the moister pulled out
Soaked for 3 days prior
Man, I love that little vermeer 😊 track loader. Perfect for this size job. 😊 did not know that .ade Battery-powered plate wackers. On my outdoor, she that has no cement floor
It's one of those pre fabs on skid planks. My wife said we don't need to rent a plate compactor. I got one anyhow. She thought the backhoe bucket could compact it good enough. When we layered are 5/8s. And lazered the fill lifts. She then understood WHY it's so important to plate wack the foundation. 😊
cant go wrong with a plate compactor
Here in Colorado Springs, CO, the city replaced curbs/gutters and sidewalks in my neighborhood in 2022. The curbs/gutters and drain pans are now severely pitted with fine and course aggregates showing in all the pits. The city says the finishers are not permitted to excessively trowel the concrete in order to force the aggregates deeper into the mix because that would affect the strength of the concrete. I guess they would prefer the pitted concrete. What say you?
Air entrained concrete for freeze and thaw
@@OdellCompleteConcrete Please explain. Was air in the mix the cause of the pitting or was a lack of air in the mix the cause?
I would agree with the comment about premature drying. The water was sucked out by a dry substrate before the concrete had a chance to cure. A layer of plastic sheeting over the gravel would I believe have prevented the problem. The curing compound should have been applied sooner also.
Is the wire mesh even necessary if there is fiber strands in the concrete? I don't recall seeing anybody pulling the wire mesh up into the concrete during the pour. Maybe I missed it in the high-speed video footage.
Yes you probably did.
I had a basement floor poured, rained for several days before the pour, compacted, poly and mesh. The next morning there were cracks everywhere. This area in TN has a lot of rock in the ground, so the rain went right into the ground not affecting the pour time. still mad about those cracks. Talked with other concrete pros and they all said there are a million reasons why concrete will crack.
Cracking happens usually after it fully dries doesn't it???? Could it have been a too dry mix, or dried too fast, or not enough cement in the mix??????? Is it also possible there was a big temperature change????? Here in Michigan, we have to watch the temperature as well as the mix. Another possibility is an unseen flaw in the dirt under the slab. The weight of the concrete causing a settling in spots. "Just guessing???? "
Im leaning towards dirt in the concrete mix from the batch plant
@@OdellCompleteConcrete Makes sense, foreign matter could do it.
I believe dirt
just curious what the humidity levels were that day along with the wind when pouring and when curing?
7
If we are pouring directly on the ground we use vapor barrier to keep it from drying to fast and crack. Even retarder sometimes isn’t enough if the air is too dry and there is a slight wind. You gotta babysit the pour longer but plastic certainly helps slow it down.
I wonder why you laid the reinforcing mesh exactly like this and why exactly this one.
Perfection is all I know
My two cents with my experience, excelled water evaporation. Sub-grade Prep looked solid, place and finish looks solid. to me it looks like ambient temperatures were working against you guys. And maybe the subgrade was not wet enough, but I’m in a completely different climate than you guys so it’s hard to say from my perspective. I am in the PNW. Been following your channel for years now and really love the videos! At the end of the day, this is a great case study. My concern would be the cracks ghosting. Would love to see a follow up. ✌🏽
Me too, at the lab
How much to have an engineer on site to take a sample of the concrete for testing?
Retired Civil Engineer - Simple, too much water in the concrete mix caused your problem, water either added at the plant or in the field. I have field tech's measure the temperature because hot concrete causes the chemical reaction to speed up and associated quick shrinkage but you were able to still work the surface so not so likely not the problem. For flat concrete work, 3 to 4 inch slump is what the final product needed not self leveling concrete which it looked like in your video. If you need additional slump for pumping or placing then work with the concrete plant to use water reducer admixtures during the plant mix.
5 gallons added on site ordered at 4 inch slump
Ironic, I ran into this myself on a job in DC back in the 70's. I worked directly under the GSA inspector doing slump tests/samples on a federal project. A spandrel beam on the 2nd level of a 5 story building cracked after being stripped. GSA tested samples from that pour and found oil in the batch. The GSA inspector went out to the batch plant and found that the mechanic had changed oil into the sand used in the mix which was not visibly detectable but caused the pour to crack. Some crete companies quality control is sporadic which leads to what you experienced. And no amount of prep and finish will prevent the cracking. The beam on our job had to be jack hammered out and replaced, of course and the feds backcharged the concrete company for all damages.
I think it was a bad mix and being a Saturday reinforces that belief. As shown on the edge of that slab, the cracks run top to bottom. I do not think that the additonal trowing will heal the concrete deeper than an inch. I think the cracks will reappear soon.
Saturday, different crew at the plant
The dirt foundation. Was it packed dirt? Maybe the concrete mix. You look very diligent and professional. You sound experienced. Maybe it was curing oddly. Is strange
Contaminated mixes happen, its rare. I've only personally deat with it 3 times in 40 years
The railroad ties in this project at the concrete edges look good. I didn't think they would look good when you first started.
Nice touch
Had a driveway done a few years ago at my home in Vegas. After a few weeks the concrete started to curl up like a potatoe chip, not bad, maybe like a 3/8", but still noticable. Oddly, the only cracks were on the control grooves, I don't think the mix was right.
or hydraulic pressure
I poured a lot of concrete in my youth building bridges for both state and county inspectors. I finished that career as a forman and crane operator. Inspectors would do slump test on concrete,, too wet equals fast moisture loss and cracks. When I watched you pour that I thought man that is too wet. Easy to pour it wet as it self levels, but you will have more cracks. Should pour dry so that you have to actually rake,shovel, and vibrate it into position. Most people won't work that hard at pouring concrete,, but if it is a bridge and state inspectors there, you do it correctly.
Thing about the jobs you're on, the concrete company knows it will be tested, so you get good materials.
I had it happen. It was hot as hell with the sun out. The driver admitted to me later he loaded 5-6 yards on some from a previous job and mixed it in. I saved it like you I thought. 6 months later I tore it all out. It did EXACTLY like what happened to you. Hot sunny weather too. A 4” pool deck.
Unfortunate
YUP, that load was bad, I agree with you that this is the most likely cause.
Was it 3500 or 4500psi mix? Looks like a bad mix to me, maybe to much cement, and had water reducer left in hopper...but it didnt flash off fast, so maybe they used sugar too...who knows. That was a mess though.
3000 psi.
I think dirt got in to the gravel or sand at the plant
@OdellCompleteConcrete you did well salvaging it. Need to do a follow up vid on it
Could be a series
I believe you got a bad batch. I had the exact same thing happen this summer. Fairly cool day (80 deg or less), no wind, under roof, but open air. We poured two 12x36, one on each side of a pole barn. One 6 yd truck for one side, another 6 yd truck for the other. Both trucks were on their second load of the day. The first truck finished out perfect and still doesn't have a single crack. The second truck ended up like yours. I believe the second truck didn't empty out on the first job they went to and then batched my load on top of the leftovers. I can't prove that, but there were no other differences between the two slabs.
I concur 100%
@@OdellCompleteConcrete haha yeah, blame the concrete. Crap carpenters blame the nails. It was a stiff mix, you knew that going in, you didn't put down plastic in an extremely arid environment. btw, you know as well as I do that those cracks are still there. Sorry, this one's on you, Bro.
idiot
Have a test from reputable laboratory done on both slabs you'll find your problem is the mix was out of time or mix was wrong not S &S can do there own but don't use a independent lab
Sounds like a hot load
I am just a DIY guy who watches you for lessons. Just curious but with the vey hot sun and breeze there could this have been caused by a simple expansion and contraction when the water hit it? maybe needed a tarp over for shade??? Just a thought but probably just a bad mix since you have been doing this for so long.
Same load of concrete two locations on different bases, but the same results.
Hmmm 🤔 do you think it was from removing the forms to soon
just about right
My concrete guy, who I've been using for 17 years, and has only ever done concrete his entire life, said to me on our latest pour, 6 days ago, that the concrete formulations, at least in our area, have changed in the last few years. They are using different fillers and it is much harder to properly finish than say 10-15 years ago. I don't actually know too much about that myself, just repeating what he said to me.
It doesn't surprise me, probably hazardous waste being used for disposal.
Could it be the overly dry compacted dirt and the resulting suction draining the water out of the concrete to fast?
Not likely since I've did it the same way many times.
I've decided that it's a bad concrete mix.
did you wet down the base before the pour , ??
for 3 days
dry weather IMO caused this.....I dont really know. Maybe if you wet the dirt more.....Maybe soak the dirt so the moisture does not go down.
I had a small pour crack big time because it got so hot, I’m assuming that it just shrinks too quickly
As an engineer, it seems like the most logical reason is the mix. I suspect them getting some dirt into that batch or they really watered it down for transit, or something to this effect.
The cracking is uniform, not just the surface.
Of course their are the obvious reasons like soil wicking the moisture, the low humidity and high sun of AZ, etc... but you deal with these conditions all the time without this result and I don't find anything out of the ordinary in this video. You had very mild conditions for it being AZ and had the homeowners water the pads down regularly in the days before the pour.
Sounds like you watched the whole video and came to the only correct answer.
Thanks
In Australia we would pour this using 8 mil mesh black plastic down so moisture not go into ground the mesh on chairs in the middle of the slab.. high slump on a very windy day . Get the owner to lightly wet it down each day as well as the concrete dries.
Yes the homeowner is right about the Creasote Bushes. Also never go near the smoke when burning a Creasote it's toxic.
Good point
Brother not sure if you have a white cap out there but they have 5x10 mesh sheets all different thickness and prices from 9$-20$
Home Depot sells smaller sheets and they are 23$ I think…
Now I’ll just get a huge order of mesh at beginning of season on the form trailer since the white cap is out of the way saves me 1.5hr round trip especially when it’s a small pour don’t need to always spend the 23$/piece on those small sheets plus you’ll need more from Home Depot since they are smaller
There are only two types of concrete, the type that’s cracked and the type that’s going to crack….more than likely the ground sucked the water out of it quickly which will lead to cracking. Was it fiber mixed concrete ?
Ground soaked for 3 days by the Home owner
I poured concrete for 45 yrs. The problem is probably a very hot dry base or you got a load of hot mud. You need to soak the base with water before you pour. Or put down a layer of Tyvec over the sub base.Not plastic. Hot mud happens when the concrete is old mix that has been temperd with water too much. Some batch company's remix batches that come back to the plant from previous pours. Another factor is a hot dry wind.
I'd never seen a battery-powered plate compactor before now. I'd seen just about every outdoor power tool powered by batteries, but never a compactor. Very cool!
It's pretty sweet
Bad mix ?.. was it a premix or mix on site ?..digging the rail road sleeper border
Yed
Could it be too high of a fly ash content in the mix?
I think dirty materials
I’ve never seen that happen and I’ve on my own Concrete business for several decades and only thing I can think of is that the Earth underneath it moved I’m not sure where your exactly located at but maybe I’ve had some kind of small earthquake or something you got me. I’d like to know.
No more than a 4 and a half slump, what happens to water when it evaporates? Turns into air, then your left with cracked slabs
Could he but not in 6 hours
I think polythene underneath to prevent moisture loss into the ground too quickly. I don’t do much concrete, but I do put polythene underneath.
I believe the issue lies with the soil, as the concrete cracked completely through and doesn’t appear related to the finishing or surface process. Observing your team dig for the form ties, it’s clear the soil far below the surface is very dry and uncompacted. From what I can see of the other lots, this looks like a recently built-up and graded subdivision. It’s possible the grading wasn’t compacted properly at the necessary depth for the lifts. I don’t think you did anything wrong-sometimes, things like this just happen.
I had the Homeowner soak for 3 days prior to the pour.