A link to this video needs to be put in the comments of every dry pour concrete video.
@s0david
18 күн бұрын
Agreed. At least the people doing dry pour videos (the ones I’m watching at least) recognize they aren’t making anything of structural substance.
@fedogma8407
Ай бұрын
Finally someone does the test that I wanted to see and I wasn't surprised by the results since I was responsible for concrete pours in the commercial construction industry. I would never dry pour concrete for a home project.
@Jonathan-mk1ju
Ай бұрын
Here in the UK, we have a product called "Ready To Use Postcrete" by Blue Circle, targeted at fencers. You dig the hole, pack the dry pre-mix around the fence post, and then add water. This method works well because it holds the post pre-set, allowing you to move on quickly. However, I'm guessing Blue Circle has formulated this mix specifically for this application, and I think some people mistakenly believe this is how you can lay concrete using standard cement. People often don't read labels. On the techical sheet its states "POSTCRETE may not be used for general concreting, screeds, mortar, grout or render. If a specified compressive strength is required, POSTCRETE should not be used." Maybe in the US, you have a similar product you can try as an experiment. Keep up the great work on your channel; it's fantastic !
@TechOne7671
Ай бұрын
That’s exactly what I was thinking. Although I thought you out the water in the hole first which would help with the air issues.
@markdoumert
Ай бұрын
We do have this in the states as well. I think it works because it just needs to compact itself densely enough to hold the post in. Denser than the dirt around it essentially. It doesn’t need wear resistance on the surface or a high amount of compressive strength as a unit. I would use it for fence posts, but always steer people away from “dry pouring” and concrete for anything exposed and especially anything structural. Its a lame diy trend aimed at people that dont know any better. I always tell people its easier to just mix it anyway, and it costs the same either way. And try to explain the benefits of using the concrete the way it is meant to be used.
@TylerLey
Ай бұрын
I agree with @markdourmert I think this is find for fence posts but I would mix the material if I was making anything important.
@mikemorgan5015
Ай бұрын
Folks report excellent, lasting result using only packed gravel or crushed stone around fence posts. I wouldn't try that with a foundation wall, or even a curb for that matter. If the reason doesn't seem obvious, please try it. Make sure you post a video of the results for us.
@bradcavanagh3092
Ай бұрын
We have the same stuff down here in Australia and it's definitely not meant for load-bearing/structural applications. I've pulled out some posts in the last year that were set in it and also some set in proper concrete. The concrete around the post mix posts just crumbled away as I pulled them out of the ground, while the proper concrete posts required the use of a demolition saw and sledge hammer+wedge to get off the posts after I'd pulled them out.
@nobreighner
Ай бұрын
Wow, very comprehensive testing of a somewhat fringe practice! There is another reason dry pour is always going to be inferior: Cement powder loses MOST of its volume when you wet it. This means that dry pour will have very extensive voids just for that reason, as well as voids because you didn't vibrate it either.
@DACVL4U
Ай бұрын
huge voids because on extraordinarily high air entrapment.
@TylerLey
Ай бұрын
Thanks for the comment. That is a good point. Let me do some calculations on how big of a deal that is. Take care!
@nobreighner
Ай бұрын
@@TylerLey Alright!! More science! From fuzzy memory: If you take 2 cups of cement powder and mix it with 3/4 cup of water, it all fits into one cup. So this would be in the range of an 8x reduction in volume of cement dry-to-wet. That is a huge deal. Had this issue with the local batch plant, where they would reduce a yard of concrete by a cu ft when adding an extra sack of cement - but it really doesn't add any volume (just takes up voids), so that yard now becomes 26 cu ft (and costs more).
@DACVL4U
Ай бұрын
@@nobreighner that's why i do weight batching instead of volumetric batching.
@otallono
17 күн бұрын
what about when vibrating the dry pour when using a complete form? would have been easy to test in the examples in the video
@jacobframe8769
Ай бұрын
Thank you for bringing clarity to this subject
@TylerLey
Ай бұрын
Thanks for watching!
@arthurmoore9488
Ай бұрын
Yet, as is often the case with real science. We now have more questions.
@eugenetswong
Ай бұрын
@@TylerLey Thanks for this info, Tyler! You are an authoritative source.
@tienglongmy
Ай бұрын
On wood privacy fences, where the posts last 10-15 years before rotting out, you might not want high-strength concrete that will be difficult to remove.
@walsakaluk1584
Ай бұрын
Fence posts only...somtimes. Not having a way of mixing is the only advantage of this drymix over wet. You can get superior finishes and compaction with wet mix. I've watched off gridders in stunned amazement making more work for themselves with dry mix and feeling so great about it at sunset, still spraying, when they could have finished the same job by morning tea with wet mix and had the rest of the day off to do something else.
@Dingleberry1856
Ай бұрын
And they pour right on the grass.
@nspro931
Ай бұрын
Setting fence posts in concrete is setting them in a cup to hold water and rot them out later. Set fence posts by tamping the rocks and dirt that came out of the hole back in, that is all it takes. No water or imported materials needed.
@walsakaluk1584
Ай бұрын
@@nspro931 yes, tamping in the fence post is perfectly fine if done correctly. Concrete provides a reasonably predictable outcome. When concrete is used to set posts, the bottom of the post sits on a permeable layer first and the concrete poured over tat and around the post provides stability. The top of the concrete should be crowned for drainage too. Not all soils are suited to tamping alone. Not all poles are fence posts. Directly driving posts is preferred in rural settings where soil type allows. Anyway, this is about dry mix V wet mix concrete not a fence post setting tutorial. I hear you on the rotten fence posts.
@mtraven23
28 күн бұрын
not having a way to mix? shovel & wheel barrel ? hell, I've seen people make a mound on the ground & mix it with their feet....always a way.
@AlphaCharlieFour
Ай бұрын
Awesome video. Clears up myths I had heard about dry pour. Your energy is contagious. This made my day!
@mr.shannon6137
Ай бұрын
Absolutely great content! The volume of this video ranges between about 35 decibels to about 100 decibels. I feel sorry for any one trying to watch this wearing earbuds. Once again absolutely top notch content.
@LuminairPrime
26 күн бұрын
Conclusion: even the WORST MIXED concrete is better than dry pour concrete. Just mix it.
@ianbelletti6241
20 күн бұрын
I'm glad someone is finally giving us some concrete numbers to the standard knowledge that wet pour is better than dry pour for strength.
@a104917
15 күн бұрын
It's cemented in my brain now, that's for sure.
@Maulakus
Ай бұрын
Fantastic information!! Very well explained and the photos were very helpful.
@TylerLey
Ай бұрын
Thanks for watching!
@DeusKDuo
Ай бұрын
I had my suspicions this was the case glad it was confirmed.
@prbmax
Ай бұрын
I like that you showed a practical use case for dry pour. I wish you would have tested a few samples with a freeze/thaw cycles for the dry pour. I have used dry pour on fence posts more than ten years ago and the posts are still solid.
@TylerLey
Ай бұрын
I do a lot of freeze thaw testing and I don't think the dry pour would do well in the "standard" freeze thaw test. If concrete stays dry then it is not damaged by freezing and thawing. If you went out and kept water on your fence post and then let it freeze then I think it would start to be damaged. If water does not pond around the fence post then that might be why you don't see any damage. We are doing a massive study on freeze thaw environments around the US. We have learned a ton about why concrete fails rapidly in some areas and not in others. We are writing the papers now. Videos should follow after that.
@mikeiver
Ай бұрын
I recently reset some fence posts that had been pushed up by freezing thaw over many decades. They each had a small amount of concrete around them, maybe a 50lb bag at most, with the post protruding out the bottom. I left the concrete on the post since it was holding on to the post very well. I cleaned off all the dirt very well and where necessarily brushed to clean pockets androids in the surface. I then redug the holes making them about 8" larger than the existing concrete post slug and about 12" deeper as well. I did a modified dry pour in that I spray water as I pour it in the hole and then used a #5 rear to tamp the mix and get out air pockets as well as compress the mix. I added about 160lbs of concrete at each post. The last 6" gets a proper mix concrete with minimal water used. This has been my "method" for years including protective bollards. In the case of the bollards couple got tested and faired well. But I sure as hell would never dry pour a slab.
@peters6850
27 күн бұрын
@@TylerLey As someone in the northern US, im lolking forward to those freeze/thaw videos!
@stevenmiller6725
12 күн бұрын
Have done dry pour a couple of times not on fence posts. Works for posts. Add an inch and wet it with a hose until about 4 or 5 inches thick then wet it hard and let it sit until it is soaked in. Then, run a plate compactor over it until it gets soupy top and finish it. Seems to work fairly well. But was just a quick fix sort of thing. Wet much better.
@Dadnatron
5 күн бұрын
I am so glad you did this work, as I have been arguing this over an over again with my friends and neighbors. Now I can finally send them data to back up my assertion.
@ziyuanwang5332
Ай бұрын
Thx! Interesting! Concrete needs proper vibration and mixture then!
@senseisecurityschool9337
2 күн бұрын
Great video and something to keep in mind - dry ppur is still pretty damn strong. 600-800 PSI, 800 pounds per inch is still pretty strong! Even dry pour may be 5-10X as strong as the soil it's sitting on or in. If you need maximum strength, you need to measure and mix properly. If you DON'T need 3,500 pounds per inch strength, dry pour may be fine for that project. Fence posts are the canonical example - the soil around the concrete will move before the concrete breaks. Another example - my air conditioners are on pads made of FOAM. Dry pour is 20X stronger than you need for an air conditioner pad.
@snazy7777
29 күн бұрын
Love the enthusiasm for your profession
@josephvanderlinde6062
2 күн бұрын
I watched a large amount of videos about dry pour concrete and noticed a major difference in method of pour. I think that their might be one more sample that you might want to test regarding strength of the concrete. 1 - People dry pour the concrete and level it without any compacting. 2 - The dry pour mix are compacted in layers in order to make sure that there are as little air molecules as possible. *** I think that this could potentially prove to be a much stronger sample during testing than what you have. My gut feel is that it would most probably still not be as strong as wet pour, but significantly higher strength than the dry pour sample you had.
@3beltwesty
Ай бұрын
In the South sometimes "readymix" concrete bags are placed in deep ruts on dirt driveways in the bag. Then with rains they solidify to be giant pavers so your vehicle does not bottom out. You try not to drive over them until hard. This crude hack actually works OK. If you make the bag conform to the valley of the rut then the cured bag has less unsupported voids below so they they last longer. ie concrete has about zero strength in tension. ;) If you have as source of water you can poke holes in the top so the bags keep moist longer so they cure better. With 3 expensive rapid set 25 buck bags I had left over(from a job) they cured to be insanely great. With the basic lost cost concrete Mix bags the results have a wide scatter.; great to broken since another drove up a private driveway thru the flagged area of bags When I have a water source I wet the rut if dry beforehand. Then place the bags to fill the ruts. Poke holes in the tops of the bags only and dump water on the bags and "TRY: :) to mix the water in the bag. Do this on a road to a rural cabin in the woods. Then rewet the bags with water hours later and keep the cure going. If you have the time and water supply you can add rebar and uses the rut as a concrete form and just properly mix it with a shovel and use part of the bags at the top to delay the crust curing too fast. ie do not offend the concrete curing Gods wrath!
@TylerLey
Ай бұрын
This sounds like a good application. I think mixing the concrete up may do even better.
@mckenziekeith7434
29 күн бұрын
I see people use bags of concrete in similar ways here in California, too. Typically farmers or people living in rural areas. Stacked concrete bag construction can be useful for a lot of things. I have seen a lot of people build up a driveway over a culvert using this technique. Also sometimes they build low retaining walls this way. Seems to work well.
@jjackle6431
Ай бұрын
People think they've figured out some novel way to do something that has literally been developed over the last 150 years with countless millions having been spent on researching and perfecting mix designs. Thank you for putting this out there.
@activemanishere
29 күн бұрын
Despite the... concrete info... put out in this video, there are people who will still argue that dry pour is just as good as wet pour. I actually didn't need this video to tell me dry pour was garbage, but now when i am doing a project and the customer or my friend asks why we can't do dry pour, i can just point them to this video. The why is much easier to explain now, thank you. I always knew, but now i know!
@rogermccaslin5963
17 күн бұрын
When I first saw a couple of these dry pour videos, my thought was "Is this as strong as mixed concrete?" My guess was probably not because I figured there was no way to ensure that all the cement got evenly wet out. Some parts would get too much water and other parts wouldn't get enough. This was a great video that confirmed my suspicion.
@OrenTirosh
Ай бұрын
Sounds like a bit of surfactant might make a big difference in the way air gets out of the concrete and change the air channel structure
@TylerLey
Ай бұрын
That is an interesting idea! I agree that the surfactant will lower the surface tension and cause the channels to be smaller after the air leaves. This could be another idea to try in future testing.
@johnmea5140
10 күн бұрын
@@TylerLey Wouldn't a concrete vibrator remove all of the air channels as well?
@mebordernoneya8484
Ай бұрын
Another way I've seen dry-pour concrete used is around posts dug into the ground. When you dig the hole, put the post in the ground and fill the hole with dry concrete mix. This presumes there is enough water in the surrounding soil to hydrate the cement. I've seen this done often and have always wondered how strong that concrete mix gets.
@maudiojunky
Ай бұрын
I think this application works because the concrete isn't subjected to particularly high stresses, acting largely as a mass ballast and to increase the friction as the post is torqued out of the ground. The primary load is still transferred from the post to the soil since the post is placed in direct contact with the ground prior to packing dry concrete mix around it.
@TylerLey
Ай бұрын
I agree with Maud!
@mariuscsernik5884
Ай бұрын
A milion thanks from Transilvania! You answer so many questions and i learned sooooo much from you! Love your videos!
@charlesviner1565
Ай бұрын
Hello ✌️
@matthewthompson7012
14 күн бұрын
Waiting for someone to do this and I expected these same results. Excellent work and thanks for doing this. 👏👏
@richardmorris4734
Ай бұрын
Great Job, you are a credit to your school.
@TylerLey
Ай бұрын
Thank you!
@trafficsignalman
Ай бұрын
Been waiting for you to weigh in on this topic. Good to see an ASTM C 39 test run on the dry pour. You confirmed my suspicions on poor bonding, poor paste quality, and poor durability. Would be interesting to do a follow up on Alite and Blite formation with dry pour. Thoroughly enjoy your videos.
@TylerLey
Ай бұрын
Thanks so much! I agree that hydration product investigation would be cool. Take care!
@Georgewilliamherbert
14 күн бұрын
Are you and your freaks…team publishing these results? Always love to follow up in more detail. Thanks!
@qret-dv5ym
10 күн бұрын
Try adding water gel beads in between layers when laying down the concrete mix. That way it will release water to create a tighter bond.
@williammorton8555
21 күн бұрын
Professor Ley, you never fail to impress.
@patrickcallahan2210
Ай бұрын
Really awesome explanation!
@falcon02012
Ай бұрын
It would be intriguing to investigate how raising the Portland cement content in the mixture influences the binding properties and overall strength. Since dry pour concrete is easy to use for those living in remote locations, incorporating Portland cement adds only a small expense for greater convenience.
@TylerLey
Ай бұрын
I see what you are saying. That is an interesting idea and could help. I don't think it is that hard to get a mixer and make the material with that. Another option is hoe and water. Concrete has been poured in remote locations for decades.
@GRUBB-MUDD
10 күн бұрын
U still down to talk on a podcast
@mtraven23
28 күн бұрын
one of my biggest issues with the dry pour is the lack of mixing of ingredients. While its safe to say a bag of concrete has all the ingredients, in the right proportions, there is no telling where those ingredients are in the bag. Those bags ride who knows how far on trucks & then get moved all around the store....ingrediants settle. If you dont mix it, theres no way to ensure proper distribution of cement & aggregates.
@chrisglenn2096
Ай бұрын
Great content. Because the air is going UP, it stands to reason that the more shallow the mold, there would be a slight increase in strength as you step downward
@chrisglenn2096
Ай бұрын
The further the air has to travel to get out of the mix, the more pronounced the air pockets have to be to release the air. The shorter the travel, the air pockets can and will be more constricted. If you did a compressive test of a 2-4 inch pour I guarantee the strength profile would NOT hit the PSI of WET MIX, but it should be closer than the 8 inch deep sample
@legacyofbob
Ай бұрын
I have seen a fair bit of videos about dry pour and always understood it to be meant for low-load applications. Like the examples you mentioned and maybe fenceposts or floor for a shed, etc. I'm sure there are some people out there trying to make a driveway with dry pour and based on this video that seems like a bad idea. The "saturated" idea of the dry pour seemed to be 3x as strong as the "same water" dry pour you used for the majority of the tests. I would like to see the saturated method tested to see if it strengthens over time and if it bonds at all to the rebar. Thanks again for taking the time to make this video it was very educational and you do a great job keeping attention.
@dscrive
Ай бұрын
ouch, with that PSI there goes my thinking about making a dry pour car pad, I think jack stands might punch right through the concrete. I want more safe, not less haha
@TylerLey
Ай бұрын
I agree that jack stands would put a lot of stress on the pad. Thanks for watching.
@registromalplena2514
17 күн бұрын
You had me at " I'm a freak."
@climbming
10 күн бұрын
Loved your video, however I really want to know if you have any results for the misted or saturated dry mix concrete compressive strength as it ages? I can imagine that with the equal water content to wet mix, much of the water is lost to transpiration/evaporation, so there is not enough left to saturate the cement in the mix to allow for crystalline growth over time, but the saturated mix may differ. I also had a thought experiment - what if we used a hybrid method for a reasonable thickness slab of 2-3 inches: 1) Lay and level the premix concrete dry for ease (most people’s issue) 2) Fully saturate with water with misting without waiting for the top to form a crust (if we wait for a crust to form before saturation we define the volume of end product and rule out additional compaction or agitation) 3) Vibrate and tamp the formwork (using something like a sander attached to a 2x4) to compact the concrete, remove air gaps and encourage closer bonding between the aggregate and itself, as well as any rebar present. 4) Add more premix if needed if the casting compacts enough to be lower than the formwork. I think this would probably combine the ease of set up with the dry mix, and offset some of the bonding and hydration issues due to lack of agitation of the paste to ensure better coverage/coating of the aggregate than by capillary action alone.
@RePeteAndMe
Ай бұрын
After watching (thumbs up) I'd suggest a different approach to dry pour: Pour half. Add rebar in a grid pattern, nestled in so it is covered. Lay pieces of plastic in the center of each grid square. Mist. The air will escape from the middles, away from the rebar. Remove the plastic bits, pour the rest of the dry mix, replace the plastic bits, and mist. Remove the bits and keep the surface oversaturated 😊
@t_c5266
4 күн бұрын
Other tests I saw it say to use as little water as possible to make the wet mix for the strongest results. Just enough to make it workable
@aetius31
Ай бұрын
Now a question for curiosity alone , does the dry mix gets stronger if it is hydrated from the bottom? (no air channel created)
@TylerLey
Ай бұрын
I like that idea! Someone else asked about vacuuming the water in from the bottom. I think it should do much better. That would be a fun experiment to try.
@arthurmoore9488
Ай бұрын
@@TylerLey Similarly, I wonder what happens if you replicate a real world fence post scenario: * Dry mix surrounded by a porous material. (dirt) * Flooded with water. * That porous material is misted continually. * One to three times a day that porous material is flooded with water. This replicates someone setting up a sprinkler and it being in an area where it rains constantly. I know it still won't be as strong as mixed concrete, but for that situation does it really need to be?
@MoneyManHolmes
11 күн бұрын
Also try splitting the concrete mix into fourths and the water into fifths, and pouring it into the cylinder like a multi layer sandwich.
@gnsdgabriel
21 күн бұрын
Great video, very accessible for the regular person.
@anoopster
10 күн бұрын
I'm curious how this relates to the findings researchers had when they analyzed the ancient roman/greek concrete structures. If I recall, they theorized that their wet concrete was mixed somewhat clumpy (not well mixed with clumps of dry cement) when poured. The dry cement (lime?) would eventually activate when small cracks occurred over time and thus become "self-healing". The result was concrete that would last thousands of years. Based on this video, I would guess that the ancient concrete probably had poor load strength.
@christopherestewart
29 күн бұрын
Imagine how bad the dry pour would look in northern areas with lots of freeze/thaw cycles in a typical year.
@diytwoincollege7079
9 күн бұрын
It worked great for my shed base. 3 years and no cracks. I live in a cold climate too. Would I use it for my house foundation? No, but for most little projects it makes a lot of sense. I wet the soil before I poured the concrete bags into the form.
@Bentleymetalworx
20 күн бұрын
Even ACI requires rodding cylinders when testing to consolidate them and thats been mixing in the truck with midrange and the proper water to cement ratio. I knew this was basically compacted sub grade that can take the rain . But to each their own.
@sasankasekhar9735
Ай бұрын
It (Dry-pour based) can use for less volume of jobs, but for case of bulk volume of concrete jobs, I think that durability might be a concern, as wet mix well proportioned concrete perform better in all kinds of durability testing rather dry pour based concrete. Porosity of dry based concrete may be higher, as more volume of air will be present in the mix & after providing the water content into the mixed, the pores will be get connected through this which is concert into permeability issue.
@sasankasekhar9735
Ай бұрын
@Tyler, sir please provide your valuable advice regard this, although it's a very nice presentation.
@khalidsalah8482
Ай бұрын
Hank you very much professor. Fantastic and useful video, thank you very much.
@TylerLey
Ай бұрын
Thanks!
@dchall8
Ай бұрын
Thank you so much for doing this. I have a lot more confidence in dry pour (for small projects) now after seeing this. I have a feeling there will be some movement in Big Bagged Concrete to incorporate additives to make dry pour more mainstream.
@sumguysr
Ай бұрын
It'd be neat to develop a recipe that does work well as a dry pour. I wonder if superplasticizer would improve the permeation. I wonder if hammered cellulose would improve it.
@yamatsukami987
24 күн бұрын
I'm curious if watering from the bottom up somehow could get better results.
@CamaronesFuegos
10 күн бұрын
Have you tried dry pour with adding water while adding the mix? Like dumping bags while water is spraying to minimize air channeling and hydrate the mix better without the need to mix?
@notaregistereduser3446
19 күн бұрын
I use dry pour under first course of retaining wall instead of compacted gravel. 1000 psi is higher than gravel so I'm glad to see that. I just do it because it is really fast to get first course level and prevent it from moving
@matt45540
6 күн бұрын
But again why not just mix it
@chrisdaniel1339
Ай бұрын
Tyler could you test a machine called the Mud Mixer to see if there is enough mixing to properly hydrate and form a good quality paste as the mixed concrete leaves the chute? I like the idea that the MM save time in mixing, but if the concrete is not as strong as concrete mixed in a rotary drum, then the time savings is not worth it.
@TylerLey
Ай бұрын
Good idea! I would have to get one. I have done a lot of testing on volumetric mixers. They use augers to mix the concrete and they do a good job of mixing in a short period of time and so I think there is a chance that this machine would work well.
@chrisdaniel1339
Ай бұрын
@@TylerLey Volumetric mixers are incredible machines, the ability to easily adjust the slump, strength, or 'recipe' on the fly, no worries of how far a jobsite is from the concrete plant, ability to do complex/ time consuming pours that are in backyards with limited access and having to use wheelbarrows or jump form silo construction with a skip bucket on a donkey winch. One difference the volumetric mixers have an auger that is 8 - 9 feet long with different shaped flights at certain locations in the mixer. If you could do some compression testing videos with the Mud Mixer that would be amazing.
@NickJuliano-W1NRJ
Ай бұрын
I do wonder if the strength of dry pour would improve when exposed to repeated soaking over time (like in a stormy climate or rainy season)
@richw2615
Ай бұрын
By far the best video I have seen on this topic. It left only one question that I had wondered about unanswered. Dry mix in a bag usually is not well mixed. The aggregate and sand seem to settle out of the mix during transport. I'm curious if mixing it well while dry to redistribute the components `evenly would make a difference. I think dry mix is garbage, but as someone who has fumbled his way through finishing concrete I can see the allure. So if you're desperate for content you could do a supplement to this video and try it.
@The_AntiVillain
12 күн бұрын
What about dry pouring concrete and using a concrete vibrator to see if it is better than just dry pour by itself
@user-uk7uu9us1w
Ай бұрын
Your testing is cool, but i still wonder how the container changed it. i think it might be different if you used a cardboard tube on top of gravel
@user-xk5so7wb2t
Ай бұрын
Awesome Video..... Q Wonder when they're bagging the cement. it's Not fully mixed together, but it's more in parts (Quality control) or after it's bagged then it's haled hundreds of miles away, the mix settles and separates. So I'd Love to see If you can/would pour full bag of dry cement into a mixer/lrg bowl then mix contents fully, then put in your clear tube & add the water and see if that will increase strength. I'm betting it would.
@aleezy1983
13 күн бұрын
This is really good information. Did you test the 20+ day strength of the dry pour that got the maximum amount of water? It appear that it was the strongest of the dry pour methods, so I'm curious about how it ended up after the full cure time?
@scorpio6587
29 күн бұрын
Awesome information, I have been wondering about this. Question: What if you fill it from the bottom?
@jalyukon
Ай бұрын
I have had great success with dry pour but I do it differently, first I only add about an inch of dry concrete at a time, wetting the layer down until the water is absorbed then adding another inch or so of dry concrete, wetting that layer and so on until the form is filled, I also add a little bit of soap to the water and it really helps the water absorption,
@tilleryinnovations592
Ай бұрын
I was thinking about doing every two inches. How long have you had your slab completed for? I was also going to tamp between lifts
@HiwasseeRiver
Ай бұрын
Dry pour might make a good base for DIY pavers or any low load temporary pad - it would be easy to bust up and re-use as fill.
@markdoumert
Ай бұрын
This might be the best use case Ive heard. It would compact like abc and be at least as strong, most likely quite a but stronger. Surface density doesnt matter. Its common in my area where pavers are desired for the look for concrete to be used under the pavers in a high load application. This might be an upgrade over abc. My only problem is that with this application i can pump standard concrete, bull float, and leave. Id pay the extra money to not mess with the bags lol. In my area the readymix price equals the bag price at right around 1 yard. So might not even be a cost incentive. I could see it in certain areas though for sure
@TylerLey
Ай бұрын
Thanks for the comment. This is a cool idea. People commonly use cement treated base for this application. You mix cement in with soil at a pretty low percentage and it can be compacted and smoothed. This would be less expensive then dry pour but you would save some labor by directly placing the dry pour.
@keithezard
16 күн бұрын
Did you try a dry pour sample in a vacuum chamber? It might be a way to test the hypothesis that air returning to the surface is she causes the weakness as you could theoretically achieve complete saturation. If still performs less well then there may also be other factors at play.
@tony39572
Ай бұрын
Great info. The dry pour advocate I know is claiming it allows self healing. I believe it stems from a misunderstanding of the news articles that refer to the papers from the research on Roman concrete. In particular “Hot mixing: Mechanistic insights into the durability of ancient Roman concrete” The claim was made that crack formation would allow better water penetration over time. There’s some flaws in this argument and it’s also still limited to the ultimate strength of wet mix concrete.
@minhducnguyen9276
29 күн бұрын
I can see the obvious problem with dry mixing here is as the water penetrates the mixture, it'll create a gradient of moisture, creating uneven hydration. It also drag along the cement particles, again creating an uneven distribution of cement. You need to mix the cement to create a homogeneous structure.
@joshuahuman1
23 күн бұрын
Interesting video Id be interested to see if doing something like tamping or some other way of manipulateing the concrete while in the form after you wet concrete would effect the strength. I mean its still not going do be as good as wet mixed concrete but it would be interesting to see if it improves strength by 10-20%.
@aaronlee3955
10 күн бұрын
Thanks so much for this video! It would be great if you or your students could do a video where you give instructions for maximizing the strength of a dry pour concrete slab given your expertise. In essence, is there a way to get to 2000-3000 psi with dry pour (the recommended psi for concrete patios)? For example, if you started with high-strength concrete that's rated for 4000 psi, did a dry pour, and continuously added water for X days would it consistently reach 2000 psi, making it a reasonable substitute for wet mixing for a DIYer who wants to do a simple patio?
@bashnalak
Ай бұрын
I imagine using a concrete vibrator, or tamping would help eliminate the air/water channels
@41istair
Ай бұрын
I would like to see the wet-mix sample testing with and without vibration / de-gassification to see what % strength increase can be gained.
@AnWe79
Ай бұрын
Makes sense, but got me curious: What if you'd flood *and* vibrate the crap out of the dry pour? Should help reduce the air channels to the absolute minimum. Also, could the poor bonding to the rebar be partially that the dry pour was so weak the rebar was gouging out a channel due to the lateral force pulling it along, and not only poor packing? (I'd imagine vibrating would help either way.)
@Barnaclebeard
Ай бұрын
Great video. Edited it yourself, didn't you.
@guillermorodriguez836
29 күн бұрын
I wonder if tamping the dry mix in layers of 3”-4” would help reduce voids. All the same, seems like a larger amount of effort just to make a viral method compare to the tried and tested
@realvanman1
26 күн бұрын
I wonder how the dry placed concrete would perform if the water was slowly added at the bottom of the mold? Still looks like you'd have lots of voids, but at least you'd get all the air out.
@dennispope8160
Ай бұрын
I’m not a fan of dry pour, but have you considered that dry pour is usually done atop a dirt/gravel base? Could the test results differ if the dry pour was atop a gravel base that allowed the excess water to go below the mix?
@TylerLey
Ай бұрын
I don't think there is excess water. We found that the more water you added, the better the performance is. If you are going to dry pour concrete then I would add all the water you can to it.
@dennispope8160
Ай бұрын
@@TylerLey I was suggesting that it’s possible the results might have been better if above a base that could “store” some of the water and keep the moisture level high.
@elbuggo
Ай бұрын
Thank you for reporting!
@TylerLey
Ай бұрын
Thanks!
@AllimuddinAlli
13 күн бұрын
Need information about how to make concrete cubes?
@wojomojo
Ай бұрын
How well does the cylinder test result apply to the horizontal and shallow pad, do you think? There are much higher ratio of surface area for water absorption and more area for air to escape.
@TylerLey
Ай бұрын
That is a good point. We did a 4x8 cylinder because that is the standard way to test the compressive strength of concrete. We could build modify molds for future testing. I agree that if the cylinder is not as tall then the air channel effect may not be as detrimental to the dry pour but I still think it is there because the air needs to escape as the water is added.
@johnmea5140
10 күн бұрын
What if you do a dry pour and use a concrete vibrator? Shouldn't this produce the same results as pre-mixing?
@Pistonstrokes
9 күн бұрын
Why does the first imagine of the cracked open dry pour still looks wet? How long were these allowed to dry?
@jetcontracting4244
16 күн бұрын
So where was the tamping of the dry pour? By taking a stake or other implementation doesn’t make a difference?
@cm.5023
Ай бұрын
Can you explain why a bag of concrete left outside with no mixing is so strong once it solidifies?
@TylerLey
Ай бұрын
Portland cement is hydrophobic. That means it will absorb water from the air. This will cause it to hydrate in the bag but I don't think the material that is produced will be as strong as if you mixed it with water. The dry pour material that I show in the video is "strong". 1000 psi is nothing to sneeze at. It can hold up a pickup truck but it won't be as strong as if you mixed it.
@noneentered1
Ай бұрын
@@TylerLey hydrophilic?
@Iowa599
Ай бұрын
If the water is replaced with vinegar will the concrete rise as curing, like biscuits (or bread)?
@imconsequetau5275
Ай бұрын
So the next question is: how strong does concrete get if you remove all that air with a vacuum pump? Does dry mix get still stronger? I know removing air from a slab, form, or hole is hard, but try capping the test cylinder and connecting a vacuum pump. Have plenty of standing water above the mix, so it invades the pores where air escapes.
@eriksteele2810
19 күн бұрын
What if you vibrate the dry pour sample? Could that help eliminate the air channels forming?
@dlloyd6300
21 күн бұрын
I think the core reasoning behind dry pour is to avoid using a mixer. What about something like a "Mix in place" method? Something like where you pour the dry mix into the mould, add water, and then maybe agitate and stir with a metal rake or something equivalent? How would that compare to something like a traditional wet mix?
@mleachx1
21 күн бұрын
Good luck. It's hard enough to mix in place like in a wheelbarrow. After doing 2 dry pours at my house, there's no way I'd wet mix in place in the form itself, that would be more work that people are trying to avoid. I actually have walkway slabs next to each other both dry and wet poured that's been thru 2 years of freezing. Both have held up great. For walkways or low load projects, dry pour works fine. The only difference at my place is appearance basically.
@13squier
18 күн бұрын
Doing that works fine in a post hole but doesn't really work in most applications. It still leaves dry pockets and it pulls dirt/mud/debris into the concrete mix.
@jpfortin12
Күн бұрын
Can you test a dry pour with concrete reinforcing fibers? 🤔 Nice video btw!
@mckenziekeith7434
29 күн бұрын
Great video. What if you added the water to the cylinder first? Also, do you think mixing the dry-pour in the dry state would be beneficial? Is it possible that the components get stratified in the bag and need to be mixed back up?
@user-nc3tr2le4q
Ай бұрын
Great video! What I haven’t seen though, is someone that follows the Cajun country livin instructions to the letter. And I wonder if they end up filling more of those air gaps doing it their way? The explanation here suggests it’ll still be weaker, but I wonder if the factor can get reduced from 2.2x and if so, how much?
@perstaffanlundgren
Ай бұрын
Can you do a in depth video on air pour additives in concrete? And the diffrens in ordinary cement and construction cement.
@TrogdorBurnin8or
12 күн бұрын
If I make a "dry pour" slab at the bottom half of a 5 gallon bucket full of water, if I drown the thing before curing, does it do the same thing?
@PeteOfDarkness
12 күн бұрын
Would it work for shallow things like sinks/countertops/garden tiles? Possibly with rebar/fibers?
@JeffBattleFish
Ай бұрын
The dry pour has too much air in it. Mixing takes the air out. Air is bad in concrete especially if there is metal mesh or rebar inside.
@greatnate29
28 күн бұрын
Cool video. I kinda hated all the water sound effects, but it is a good video anyway.
@brandonb9452
Ай бұрын
What about floating/working the surface? Would that make a difference?
@Droningonuk
Ай бұрын
Did the dry pour not get aroud the rebar or did it pull through making it smooth? Because it looks like a wider channel to me.
@TylerLey
Ай бұрын
I think it is both. The pictures are the failed concrete and so the concrete was damaged when it pulled out. I do think the dry pour didn't pack as well around the bar and that is why there is such a big difference between the two.
@losttownstreet3409
9 күн бұрын
If you see the prices for concrete slap of 1m x 1m with 9000$ with a contractor you use dry mix. The problem are the insane prices for 1h of work, you pay $2000 without material. The dry mix used by ancient civilization had some not wet dry mix in the cast and the dry particles close any cracks.
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