How to run a Concrete Slump Test! Steel Slump Cone Kit - amzn.to/2yGiFXf Huge thanks to - www.holteng.com Make sure your following Jordan Smith - bit.ly/2xQ0Fg8
the slump test is to measure consistency not amount of water, do not add water to your equipment! you are supposed to dampen, not wet! it may give you false high results, you cannot use a rebar, the cone must be lifted in 3 to 7 seconds for a heigth of 12 inches, then you measure to the original displaced center. that is if you want a test result that follows the ASTM procedure.
No, you cannot use rebar. Must use the smooth 5/8" bullet nosed bar to meet the test requirements. And you have to rod the concrete 25 times. Fill in 3 lifts. No more, no less. C'mon Matt, for someone who is telling people how to perform a slump test, at least get this very basic test procedure correct...
The question is how much does it throw off your results, I have no idea but Wiki agrees with you, en.wikipedia.org/wiki/Concrete_slump_test Thanks for pointing that out.
I have an interview next week for a job that focuses mainly on concrete testing. This video helped me get a better understanding so i'll be more prepared for the interview.
Sigh, 2" additional slump over spec can be a critical design problem depending on the application/mix and should not be a "field decision" unless made by very experienced personnel with authority to make such decisions - otherwise the load should be rejected. Nobody should be adding water to the mix at the job site if the concrete slump is within spec without a very good reason - just because it makes it easier to place and finish IS NOT a good reason.
As an engineer, adding water on site is fine. But never ever go over spec. You as a contractor are now not following the engineered specification and creating a weaker mix. We design for a reason. The seal on the plans is a liability for us that you do not want to take on. Please respect the legal seal and follow our specifications.
ArthurDentZaphodBeeb slump in the field is negligible. +1 over spec isn’t going to ruin anything. Some times you need to add water especially in summer
Could you create a video that explains the reason why you want a low slump vs high value and how too much water affects that test and value of concrete? And, concrete poured in a hot vs cold climate and humid vs dry climate? There is a story in each of these situations and tied with the slump or cone test. Love the videos!
Curbs, sidewalks, walkways, driveways, retaining walls, foundations and foundation walls all have its specific slump values needed for the type of job.
Love your Videos Matt, always informative. F.Y.I. you should not use a piece of rebar for rodding as it could introduce air to the test. a smooth 5/8" tamping rod with a rounded end is best. concrete in three additions rodded 25 times per addition.. keep
Matt, you might add a water to cement ratio (w/c) specification. If the w/c ratio gets over 0.5, water can easily move through the concrete (you know I'm the water/moisture/mold guy!).
Simple and useful. I am going to be doing a job soon, using extreme strength concrete... 2" slump max, and pond curing. 18000PSI, micro rebar and kevlar reinforced. Pretty cool job. Quartz aggregate.
It is crazy expensive but creates some of the toughest and thinnest creations. Ductal UHPC, LafargeHolcim is the company here in the US. I think it is rated up to 22.5 ksi for structural applications. It can be used for cast in place or precast. My use was a cast in place barrier. Something 4" thick that can stop incredible threats and forces (hurricanes or tornadoes), yet still maintains a good surface finish. There are not many use cases that justify a 4-8 times cost compared to everyday concrete, but impact resistance and strength per volume or cross section are critical. 3/4" cured can have an effective strength similar to that of a 4" thickness depending on the use and goal. Static loads, or architectural, it opens many doors. I wouldnt be surprised if Matt has worked with it, or another UHPC in the past on some of the more modern jobs.
pretty primative test honestly. youd think we would have a simple device to just stickinto concrete to test it by now. better than carting around a testing cone of that size !
the guy commentating is a bit clueless about the little technicalities lol it's not a rebar and it's not in "3 or 4 pours", the construction guy is doing it correctly though. It does look like a smooth rod with a round end and he did it in 3 pours and struck off the top at the end.
You didn’t run a slump, buddy. Not sure what you call that. Your increments were off on each depth, you rod each lifts 25 times using a 24 inch tamping rod with a 5/8” hemispherical tip-not rebar- and you lifted too fast.
we pour at a 6 in. skunk bare minimum 😳 when it’s just two guy, we like it more wet so we don’t have to be throwing up by the time we’re done vrooming haha.
@@yourmomsuncle2953 Adding water to concrete weakens it exponentially. Super plasticizer reduces the need to thin with water and makes the mix very sloppy (for flatwork not walls) so it's very easy to move and work. It lasts for a couple hours then the mix sets up as normal. So your placing and screeding window is when it's active.
You could have a 5 second video of Bob Villa saying "This is a brick." holding up a brick to the camera and people would come out of the woodwork to specify ATSM masonry standards for what actually classifies as a brick and how poor old Bob didn't cite 10 references to support his statement like he's writing a PhD thesis.
A veteran taught me about this, he was in charge of making sure this test passed, if it didn't he sent it back the truck. He got beat up a couple times by union workers because he was a hard ass in making sure things were right.
Thats a total false story. Union workers dont “beat you up” for doing your job. As an concrete tester myself, that is just not true. They need you. If theyre building falls apart because you didnt send the mix back than its all on you, and they know that. Your job is to send it back to the truck whenever anything is wrong. Your friend is not a “hard ass” for sending it back. Thats our job. 🤦♂️
If a Union Worker Ever had something negative to say about his mix failing my test, I will have the foreman get him off the jobsite immediately. Thats how that works.
@@KiLLJOY1056 This Vietnam Veteran I'm talking about, may he rest in peace, was a non-union worker in charge of the construction for the government. This was back in the day 70's and 80's. They just happen to be union. It could have been a bad culture at that certain company. Though he made it sound like it was because they were union.
You miss the point Hans.............It's not the homeowner who needs to do the test............It's YOU.The idea being any specification for a particular job must meet the quality and strength required by law........You could wait for the crush test or intill the car hoist falls over and kills someone...........If you do the crush/slump test ( similar to gas and electrical testing ) you will not end up in jail. Unlike your poor clients who will end up in hostpial or worse. The slump test may be crude...........but there aint nowt better to protect eveyone, including the supplier.......Have you seen the about of structures falling down due to dodgey corrupt people.The building near the centre of Baku, which was still under construction, collapsed on Tuesday. Officials said they believed shoddy building work was to blame. uk.reuters.com/article/uk-azerbaijan-building-collapse/death-toll-from-azeri-building-collapse-reaches-12-idUKL3128599420070831
the slump test is to measure consistency not amount of water, do not add water to your equipment! you are supposed to dampen, not wet! it may give you false high results, you cannot use a rebar, the cone must be lifted in 3 to 7 seconds for a heigth of 12 inches, then you measure to the original displaced center. that is if you want a test result that follows the ASTM procedure.
No, you cannot use rebar. Must use the smooth 5/8" bullet nosed bar to meet the test requirements. And you have to rod the concrete 25 times. Fill in 3 lifts. No more, no less. C'mon Matt, for someone who is telling people how to perform a slump test, at least get this very basic test procedure correct...
Rebar will add air pockets with its deformed sides and skew the tests. Use smooth bar only!
You can use rebar.
lol, scold the man
The question is how much does it throw off your results, I have no idea but Wiki agrees with you, en.wikipedia.org/wiki/Concrete_slump_test
Thanks for pointing that out.
Thank you for explaining this, as a home owner I had no idea what this meant as they delivered concrete many times for various projects. Thx again.
I have an interview next week for a job that focuses mainly on concrete testing. This video helped me get a better understanding so i'll be more prepared for the interview.
Sigh, 2" additional slump over spec can be a critical design problem depending on the application/mix and should not be a "field decision" unless made by very experienced personnel with authority to make such decisions - otherwise the load should be rejected.
Nobody should be adding water to the mix at the job site if the concrete slump is within spec without a very good reason - just because it makes it easier to place and finish IS NOT a good reason.
As an engineer, adding water on site is fine. But never ever go over spec. You as a contractor are now not following the engineered specification and creating a weaker mix. We design for a reason. The seal on the plans is a liability for us that you do not want to take on. Please respect the legal seal and follow our specifications.
ArthurDentZaphodBeeb slump in the field is negligible. +1 over spec isn’t going to ruin anything. Some times you need to add water especially in summer
We got a shovel for you and your 4” slump going to a 3 in about 15 minutes..you can drag it outta the chute for us when it’s 90 out
Could you create a video that explains the reason why you want a low slump vs high value and how too much water affects that test and value of concrete? And, concrete poured in a hot vs cold climate and humid vs dry climate? There is a story in each of these situations and tied with the slump or cone test. Love the videos!
Collective Construction INC if he had to rake that stuff in 90 degree weather he’d want it at a 7
Curbs, sidewalks, walkways, driveways, retaining walls, foundations and foundation walls all have its specific slump values needed for the type of job.
Love your Videos Matt, always informative. F.Y.I. you should not use a piece of rebar for rodding as it could introduce air to the test. a smooth 5/8" tamping rod with a rounded end is best. concrete in three additions rodded 25 times per addition.. keep
Rebar is not allowed. Smooth 5/8” rod is required. Fill the test cone in 1/3rds
What is the acceptable minimum value of the concrete slump fall when carrying out a slump test?
Matt, my question is what other tests is the engineer doing besides the slump test?
Joe Faucon Air entrainment with an air meter is a better test to determine the quality of the concrete. Slump test is more for workability.
Matt, this is good. However, a small amount of info on slump for a patio and slump for a stairs would be good info.
My cat 🐱 is slumped to a 3 on the couch. 🛋 this is good catcrete...
Might need a little more water.
I used to do this at Taylor Woodrow Construction Back in early 80's.
Matt, you might add a water to cement ratio (w/c) specification. If the w/c ratio gets over 0.5, water can easily move through the concrete (you know I'm the water/moisture/mold guy!).
+Wynn White excellent comment!
Simple and useful.
I am going to be doing a job soon, using extreme strength concrete... 2" slump max, and pond curing. 18000PSI, micro rebar and kevlar reinforced. Pretty cool job. Quartz aggregate.
John Doe 18 ksi concrete? Holy crap
It is crazy expensive but creates some of the toughest and thinnest creations.
Ductal UHPC, LafargeHolcim is the company here in the US. I think it is rated up to 22.5 ksi for structural applications.
It can be used for cast in place or precast. My use was a cast in place barrier. Something 4" thick that can stop incredible threats and forces (hurricanes or tornadoes), yet still maintains a good surface finish. There are not many use cases that justify a 4-8 times cost compared to everyday concrete, but impact resistance and strength per volume or cross section are critical. 3/4" cured can have an effective strength similar to that of a 4" thickness depending on the use and goal. Static loads, or architectural, it opens many doors. I wouldnt be surprised if Matt has worked with it, or another UHPC in the past on some of the more modern jobs.
John Doe damn what are you building the hall of justice
pretty primative test honestly. youd think we would have a simple device to just stickinto concrete to test it by now. better than carting around a testing cone of that size !
Agreed...............we are all waiting to see what you come up with..........Crush test is too late.
I just taste it
He mentions you could use rebar instead of a 5/8" smooth rod. Never. You do not use rebar. The rough bar would push the large aggregate to the bottom.
Thank you. I had a bet you would say the word "basically."
Redo this video. Next time show the actual test and stop waving the camera round. Keep it on the tester. And he lifted that cone way too fast.
$250.00 for a steel cone!! Just steal one of those rubber ones off the side of the road.
You did your slump test different than a cement truck company.
Why just a slump test? Why not an air entrainment test as well? You would get a better idea of the quality of the concrete that way.
marcus dixson some regions have zero freeze thaw so no air test required
Do not add excessive water to your concretr
That is not the ACI way of measuring that
the guy commentating is a bit clueless about the little technicalities lol it's not a rebar and it's not in "3 or 4 pours", the construction guy is doing it correctly though. It does look like a smooth rod with a round end and he did it in 3 pours and struck off the top at the end.
You didn’t run a slump, buddy. Not sure what you call that. Your increments were off on each depth, you rod each lifts 25 times using a 24 inch tamping rod with a 5/8” hemispherical tip-not rebar- and you lifted too fast.
we pour at a 6 in. skunk bare minimum 😳 when it’s just two guy, we like it more wet so we don’t have to be throwing up by the time we’re done vrooming haha.
Because you never heard of super plasticizer admixture.
@@2drsdan you would be correct
@@yourmomsuncle2953 Adding water to concrete weakens it exponentially. Super plasticizer reduces the need to thin with water and makes the mix very sloppy (for flatwork not walls) so it's very easy to move and work. It lasts for a couple hours then the mix sets up as normal. So your placing and screeding window is when it's active.
In every single comments sections of constructon howtos, there's always the knowitalls
You could have a 5 second video of Bob Villa saying "This is a brick." holding up a brick to the camera and people would come out of the woodwork to specify ATSM masonry standards for what actually classifies as a brick and how poor old Bob didn't cite 10 references to support his statement like he's writing a PhD thesis.
A veteran taught me about this, he was in charge of making sure this test passed, if it didn't he sent it back the truck. He got beat up a couple times by union workers because he was a hard ass in making sure things were right.
Thats a total false story. Union workers dont “beat you up” for doing your job. As an concrete tester myself, that is just not true. They need you. If theyre building falls apart because you didnt send the mix back than its all on you, and they know that. Your job is to send it back to the truck whenever anything is wrong. Your friend is not a “hard ass” for sending it back. Thats our job. 🤦♂️
If a Union Worker Ever had something negative to say about his mix failing my test, I will have the foreman get him off the jobsite immediately. Thats how that works.
@@KiLLJOY1056 This Vietnam Veteran I'm talking about, may he rest in peace, was a non-union worker in charge of the construction for the government. This was back in the day 70's and 80's. They just happen to be union. It could have been a bad culture at that certain company. Though he made it sound like it was because they were union.
Too much hand gesticulation! Keep your hands away from the guy trying to do the work; annoying.
$250 !!?? No thanks, I'll just grab that traffic cone over there.
This test technician is not qualified for several mistakes.
if a homeowner came out with a cone and started trying to slump test my concrete while i was pouring they'd get a forming stake in the ocular cavity
With that attitude, Hans, I would no doubt have fired your sorry posterior before we even got that far.
scottutube1 nah i'm just kidding, i actually really respect a homeowner who cares to know what's going on
I bet you would have given them a real Hans job but NO reach around.
Hans Russell lol
You miss the point Hans.............It's not the homeowner who needs to do the test............It's YOU.The idea being any specification for a particular job must meet the quality and strength required by law........You could wait for the crush test or intill the car hoist falls over and kills someone...........If you do the crush/slump test ( similar to gas and electrical testing ) you will not end up in jail. Unlike your poor clients who will end up in hostpial or worse. The slump test may be crude...........but there aint nowt better to protect eveyone, including the supplier.......Have you seen the about of structures falling down due to dodgey corrupt people.The building near the centre of Baku, which was still under construction, collapsed on Tuesday. Officials said they believed shoddy building work was to blame. uk.reuters.com/article/uk-azerbaijan-building-collapse/death-toll-from-azeri-building-collapse-reaches-12-idUKL3128599420070831
So much wrong with this video! Google another video! Please don’t learn from this one. I thought it was a joke at first.
And your advice is ?..........As the saying goes " Anyone can criticise the Monalisa....." etc
true slump test is when you leave it overnight and measure the slump