What is Concrete Slump?
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- เผยแพร่เมื่อ 5 ก.ค. 2024
- In this week's update, Deco-Jeff Hershberger shows you a concrete slump test!
The term "slump" is commonly used in the industry to describe the consistency or flowability of concrete.
So the question is, how do we measure it, and how can we change it?
Even if we were to limit this to just decorative concrete, we would still use a different slump for different applications.
When you place your order for the concrete, you will need to tell the ready-mix plant how stiff or flowable you want the concrete to be. This is done by associating a number to it. An example of these numbers might be 4, 5, 6, and so on; referring to inches of slump.
In order to measure slump, we are going to need: a testing cone kit, the concrete, and a tape measure. First, fill the test cone with concrete. This should be done in thirds, packing the concrete the same amount each time. After the cone is full, we can level off the top and pull the cone. As we do this, the concrete will start to sag, or “slump”, from gravity. Now all we have to do is pull up the handle and measure the distance the concrete slumped from where it started. If the measurement is 4", we would have a 4" slump. If it is 6”, we have a 6" slump, and so on. You probably won't be performing this kind of test on every one of your residential jobs, but it is important to understand what a 4",5", and 6" slump actually looks like. In decorative concrete, we would rarely pour tighter than a 4" slump. With the exception of walls or fire pits, it would not be beneficial to pour looser than 5 ½”- 6". We get a lot of comments at our training classes on how tight we pour decorative concrete. We are not just trying to make everyone work harder! A common theory is that it's helpful to pour wetter on hot days. This is not necessarily true for stamped concrete. While pouring a high slump might buy you some time getting the concrete down, concrete poured at a 6.5" slump will be more problematic and never texture as well as that poured at 5". Keep in mind that Mini Delay packs will increase your slump by approximately 1", so if you are planning to use them you will need to start at a lower slump than normal. In cooler weather, a 5” slump is the wettest we would ever pour. All the problems that come along with stamped concrete in cold weather get magnified when pouring a high slump.
It is important to know how to change or affect the slump of your mix. The common practice is to order the concrete at a lower slump than you intend to pour (keep in mind you can only increase slump on a job site and there is no good way of lowering it). This means you will need to add something onsite to bring the slump up the desired consistency. The most common way of doing this is with water. A good rule of thumb is one gallon of water per cubic yard will increase the slump by 1". If you have 8 yds of concrete in the truck at a 4" slump and you add 8 gallons of water, your slump will be approximately 5". You may still need to fine-tune the mix after that, but this formula is a great way of deciding how much water to add when the truck first gets there. Keep in mind that every gallon of water you add to your concrete will affect the water to cement ratio. Too much water could lower the strength of the concrete beneath its intended PSI.
Another way to effect concrete slump is with an admixture. Water reducers and plasticizers are very effective in increasing slump without adding excessive water. A mid-range water reducer will help you manage pours at any time of the year. High-range water reducers and superplasticizers will allow you to pour at a high slump in the case of poured walls or even fire pits.
Just remember, most residential decorative concrete jobs will not require any certain slump, nor will there be a certified tester onsite. This means it is up to you to decide what slump will be the most beneficial to both you and your customers. Understanding the basics of what slump is and the best way to affect it will go a long way in creating the highest-end stamped concrete possible.
Please don't hesitate to contact us if you have any questions about slump or anything else relating to decorative concrete.
Thanks for watching! www.Deco-CreteSupply.com/
-Jeff Hershberger - บันเทิง
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This is great, I'll be using this to Help train out new dispatch employee's. Thank you for the Content!
You are welcome!! Thanks for watching Deco-Crete TV!
I now understand slump...and I'm not even a concrete guy. Thanks and great job
Thank you!!! Glad we could help!
Have wondered about this in the past. Thanks for the explanation.
I love it.
It's clear, concise and straight to the point.
Thank you for sharing the knowledge!
None of this was clear
Um if he says 'Um' one more time I swear 🤣
I hate that I read this comment before I finished (the video) 🤣, but's he's very articulate and given that he's knows this much about concrete, there's a lot of f**ks and s**ts that normally roll of the tongue, that are definitely not being said. However, I still hate that I can't rewatch this and not hear "um" everytime he says it.
Still a great video and as a new ready mix driver, this is 100% on my radar to help me slump up and not get railed by the pump operator or swamper or 19yr kid with an ego on site
Edit: (the video)
Sounds like normal talking to me. He makes sense, he’s knowledgeable and enunciates clearly.
I um read this um before I um watched it and UM was all I um heard
🤣 yeah, he said it a lot!!
Im new to the field, and Im glad you took the time, Thank you.
You're welcome!! Thank you for watching!
Fantastic video Sir!
Great explanation! Short, sweet, and to the point!! Thanks for making this helpful video!!!
I've been studying for a building contractor license and this keeps coming up, thanks for explaining this!
Um thanks
Excellent demonstration!
Thanks for watching!!!!
Great explanation!
Thanks Joe!
Great video!
Dude, my wife was right I should’ve watched these videos before I started training this week because Tuesday he’s rattling off all this shit and I had no idea what he was talking about but now when I go back today I got a better understanding. Thank you.
You are welcome!!! Thanks for watching!👍
This is an explicit explanation.
Thanks very much.
God bless you.
I'm a civil engineering student at polytechnic
You are welcome!! Thanks for watching and leaving the comment!
Very helpful!! Didn't know there was a device for measuring slump; interesting 😊
THANKS FOR THE DETAILED EXPLANATION WHO DETERMINES THE FLOW REQUIRMMENT FOR A ICF OR ICCF ?
Great job
Nice explaination
Thanks for watching Anthony!
Awesome stuff.
Glad you enjoyed it, thanks for watching Gage!
Great information sir. Appreciate you sharing your knowledge. Do you have any videos explaining water-cement ratio???
Thanks for the comment!!! We don't have any videos on that right now. We do plan on making one in the future though, stay tuned👍
Thank you
thanks for the video. I've been pouring small areas of concrete for years and I knew that a 6 vowed better than a 4. I also knew that add mixtures were stronger than adding water, But that official measuring cone was really cool. I'm totally serious when
Glad we were able to help!
Great video.. chill on the um
Thanks for the comment!! Jeff was around 15 ums per minute in this one🤣🤣
Thanks for this info! If I want to use an 80lb bag of Quikrete concrete mix, how much water would I need for a 2-3in slump?
Follow the instructions on the bag and mix accordingly!
Cool, I never knew!
Great video. So if I were to be screeding a 8 foot driveway by myself, would that be a good reason to increase my slump? Also, with a higher slump, would that generally increase the time between floating and finishing?
6in slump would be a good average for pouring a driveway. pouring a little tighter than that will increase strength but will be harder to work. pouring wetter than a 6in slump might make things easier but you will lose strength
Hello. Getting ready to pour 5 yards over poly (garage floor). My order recipe will be L10/ 6.5 sacks. Because of the poly, I would like to use a water reducer to minimize bleed water as well as improve workability. Would like a 4" slump with a 6" or 7" workability. How would that be ordered? Or will the supplier know just what to do? Thank you for your videos!
That is a good way to go about it. Explain the situation to the ready-mix plant and request mid-range water reducer. Thanks for watching Anthony!
Great video. You explained what I was looking for in a perfect way. If I had a drink for every time you said “uhh” or “ummm” I would be dead drunk though. 😂 No offence though. Super great video.
Thank you!
Could you please tell more about the measurement we need to take? What cm is perfect?
The perfect slump is going to depend on the application, that's where the measurement comes in! measure from bottom of the bar to the center of the slumped concrete
I just started working with Ozinga as a ready mix driver and i am having such a difficult timing fully understanding the conversions of slump on the PSI meter and calculating water to the mix. it has to "click" soon but i think if i had a chart or something maybe I'll understand.
Thanks for the comment!!! Hopefully, the new job is going well for you👍 We don't have much experience with the conversions on a psi meter, our background is more in pouring & finishing the concrete rather than the ready mix side. You might be able to find a chart online somewhere, or maybe someone at your company would have something for you. If not, my advice would be to talk to some of the drivers who've been driving for a while to see how they do the conversions. You could even make your own chart to follow based on their info. It could just be a handwritten thing to keep in your truck, or you could make it look nice and share it with the other new drivers. As for calculating how much water to add, a good rule of thumb is: 1 gallon of water per yard of concrete will bring the slump up 1 inch. So, say you have 6yds on your truck and it's at a 4-inch slump. The contractor says he's looking for a 6-inch slump, you would need to add 12 gallons of water. Hope this helps you out. Thanks for watching!!!
The um but other than that. Awesome video.
Hard to get an explanation like that from your superiors.
Every time he says “Um” take a drink 🍺
Im wasted 30 seconds in.
I'm dead of alcohol poisoning, and I was drinking O'Doul's.
Did anybody count the umms?
Take a shot every time he says um 😅 🍻
I um wanted um to learn um about slump um thanks for um the video.
Um thanks for uh watching!
So adding more water to your concrete would increase the fluidity of the concrete, but then it would also lower the strength of the concrete?
Correct! 👍
If i got a dime every time he says "um" id be doing pretty good financially 😂😂😂
Haha......he was around 15 ums per minute in this video!😂😂
@DecoCreteTV Thats 2 games of pool at the bar, lol
I wish I could count how many "um"s were in the video. Not sure I I can count that high? 🤔 but seriously man you obviously know your, um, shit and um, can actually speak really well. You articulate and get your point across amazingly well. 👏 Thank you!
“I don’t know what to do with my hands”
-Ricky Bobby
I swear you said "Uh" or "Um" like a thousand times hahah
So if i have 7 yards I’d need roughly about 7 gallons to bring up the sump one inch?
yes that is correct!
Can you explain the calculation?
One gallon of water into one yard of concrete will bring the slump up one inch
I think our local concrete plant needs to watch this we never get what we order always order 4 comes as a 6
is it safe to say that adding 10 gallons to 10 cy, the slump would increase by 1 inch ?
Yes that is correct!
a gallon... per YARD of concrete will change the slump that much?
yes it will👍
so its like viscosity?
kinda yes
I have seen for the first time on youtube a 100 slump.....it was so much water it would probably shrink 3 inches while drying. totally slumped out. like self leveling all these guys with rakes just standing there as the concrete flows like a mudslide.
😂😂
You guys in Orrville Ohio?
Yes sir, 133 N Kohler Rd. Give us a visit!
@@DecoCreteTV I will have to do that! Thanks
This was umm a very umm informative video. Thank you for umm taking the time to uhh explain.
Umm, thanks for watching!!! 👍
Dude um that my um thought exactly.. um
uh, you too!? uhmmmm.
12" slump
Um
Educational video but this guy puts the “um” in slump lol.
Ummm
Ummmm uhh great umm video uhh really ummm enjoyed umm it umm uh ummmmmmmm.
In reality, I never use this test to predict how workable my concrete is, I just use my good workmanship standard. :)
Umm and umm ah umm
Slump is only in specs so you can tell who doesn't know what they are talking about on the job
ummmm... what was i going to say..ummm...
horrivel
Thanks but this video is not done by an engineer explaining how slumps are related to water/cement ratio, workability, permeability and target strengths of concrete using various methods of placements on site e.g. by skips, pumps, etc... not satisfied with this video
um sounds like um vegetable oil... dude covered everything i was looking for but the promo at the end made it all untrustworthy
I lost interest with too many UMs. better videos out there.
You would fail an aci test if you pulled a slump and measured off your handle.
Um lol um
Cheese charcuterie tray = poo with zero slump
Taco Bell = 32" slump
I still have no idea what slump means when it comes to your concrete. 😂😂😂 wtf
Brother work on your speech skills. Be consciousness of the word "um". It's an undesirable word when speaking or writing. Your content however is excellent.
Thanks for the feedback!!!
A #2 slump of shit.
Eh bad pull bad pull…
Great video!
Thanks for watching!!!