Calling Griz,

 

Depends on the mix design & purpose....

But 60 minutes & back to the plant to wash out & re-batch...:thumbsup:

 

A builder here had a 5,500 sq ft poured an hour and fifteen from the plant in august. Last truck was a 11 am, probably 100 degrees. Had a structural crack that the client sued for, and won.

Not a lesson to forget

 

Depends on the mix design & purpose....

But 60 minutes & back to the plant to wash out & re-batch...:thumbsup:

The mud was very workable, not warm. What would be the consequence of a hot batch, that's if you have knowledge on that. I'm not trying to put you on the spot, thanks

 

For what you're doing....

you're ok....:thumbsup:

My current stuff the inspector looks at the time & the drum counter...

testing Engineer looks at Temp, Time, Slump & does break tests...

 

The driver wasn't stupid, they add water in any emergency so they don't get it all stuck in the drum.

90 minutes is the rule around here, so when it nears two hours it's still usually borderline good.

 

Thanks gentlemen, the only thing I have to give the inspector is a trip ticket reflecting 4500 psi. Just didn't want to get a lot of cracks. Thanks again

 

4500 PSI....no cracks?

What is the mix design?

You trowel it coming out the chute?:whistling

 

No it had 0.45 water to cement ratio. Had to be pumped so it had 3/8 PG flowed pretty well

 

Sounds ok....great water/cement ratio...:thumbsup:

Plasticizer or retarder added?

Why 4500 PSI? Slump?

Talked to the engineer he said the 4500 psi isn't necessarily for bearing reasons it's because the soil is very acidic and 2500 isn't Dense enough to prevent decay like 4500 will.

 

Sounds ok....great water/cement ratio...:thumbsup:

Plasticizer or retarder added?

Why 4500 PSI? Slump?

No slump test required, just a trip ticket

 

Yes I know of Lusardi, pretty good company from what I've heard.

I don't recognize that truck but don't tell me it's robertson's....

 

independant guy he has 5 trucks, he sent me an old one

 

Lucky he did not blow the other two tires on that side or would of really been a mess.

 

He scraped up the street pretty good I suppose the city will come down on him

 

You would need a thermometer, when it hits 80 degrees is when it brings up some concern. But on a residential job, there's no definitive way to tell the integrity of your concrete since you have no special inspectors around. There's several other factors which will affect your concrete other than temperature; slump, w/c ratio, mix design, consolidation, time on tickets, proper placement, properly adding water, control joints, reinforcement, air entrainment, proper curing.

If you're ever concerned about a pour, you can always hire special inspectors to monitor your pour for you. I used to work as one, and we would get a residential job every now and then where they hired us to check the pour even though they weren't required to.

When the concrete gets old before it even comes out of the chute. Usually the three hour mark is where we draw the line. As an inspector, if I saw that someone was about to pour three hour old concrete I would tell them "It's your concrete, use it if you want but if you do I have to make cylinders and test this, if they don't meet the minimum compressive strength then you will be liable". I test the concrete, I do it very well, is the message I try and get across, then I leave it on them.

 

It depends on what you do to the concrete. The NRMCA did tests where they mixed concrete for months adding super to the mix to keep it plastic & taking samples once a day. The last samples taken broke higher than the 1st ones.

 

Be careful when ordering small amounts of concrete. Around here they like to send out a truck with left over concrete from another job making it older than you think.

Another tip if you’re concrete has to meet certain specs especially on commercial jobs. You order concrete to meet a certain spec you pour and fails strength hardness test. Now somebody has a big bill to break all that cement out and redo who’s liable. An old timer told me never tell them to add water because now you changed the mixture making you liable. No wonder they keep asking if you want to add water gets them off the hook. Whether he was right or works the same every ware is a question for a lawyer I guess.

 

Most specs require concrete to be poured on the job within 90 minutes or about 300 spins of the truck's barrel after the time when water is added to the concrete mix at the plant.
ASTM Specs for engineer controlled jobs also indicate time requirement on delivered concrete... the discharge time should be completed within 1 1/2hrs after adding water. At the same time if I'm not mistaken, there is a paragraph that says that these limitations can be waived by the customer if the concrete slump as it should be, then concrete can be placed without adding water.
You can get all the information HERE for future use or Read the ASTM-94C

 

When I was told the about the adding water thing I was just a worker running an excavator. But even then I took the every opportunity to learn something such as B.S.ing at lunch. He was a super that was about to retire. I was digging out the foundation and learned a lot about running a jobsite.

Thanks for the info I don’t deal in concrete much that’s why I’m on here to gain knowledge. I’m fairly new to running my own show the more I know the more opportunity I got to grow my business.

 

Why not order a ready mix truck for a little job like that and avoid the hassle?

 

It was a ready mix truck

 

from my experience with concrete and posts like these i wonder how so much concrete has been placed successfully. working with a time bomb...

sometimes i work with CSA cements and accelerators for countertops. that gets even crazier.

 

With your warmer climate I would have send the load back.


After 90 minutes that stuff is kicking off, pretty quick too, not sure how you got a finish on it

 

Wasnt even warm, it finshed great, easy to work. air temp about 75. Im glad I didnt send it back. Slab came out great

 

i'm wondering if the truck driver didn't add a bunch of extra water, perhaps off the books.

i could see an inexperienced guy doing that right off, hopefully he was in contact with the plant immediately for advise.

 

i'm wondering if the truck driver didn't add a bunch of extra water, perhaps off the books.

i could see an inexperienced guy doing that right off, hopefully he was in contact with the plant immediately for advise.

I think if their was going to be problems I would no about it by now. We snapped out walls, straightened bolts, and demoed stucco on existing, and didn't see any problems. I checked with concrete company and they said 90 minutes is usually the max, however 2 hours is not going to create a problem for a bedroom addition. The mix is 4500 psi for sulfates in the soil. The engineers reasoning was the denseness of the 4500 keeps the acidic reaction of the sulfates from breaking down the concrete, whereas 2500 psi is not dense enough.

 

Since, you did not get a batch ticket that meets ASTM C94/C94M-09.14 & you did not preform any tests you have no idea what you got. All you have is a delivery ticket that says 4500 psi & 0.45 w/c.

 

I was referring to the mobile mix trucks that mix and dispense everything on site.

Mix the concrete on site to your spec and you only pay for what you get. No concrete statues on your lawn and no shortages, perfect fresh concrete...greatest thing since sliced bread for small jobs.

Thanks Inner10, That's sounds cool, we poured out twenty yards might of been a little much for that situation, I am not familiar with that process, so correct me if I'm wrong. Can you give a few more details on that I'm definitely interested for my next pour. My company does a lot of small stuff. They come out to your site and mix it on site? What type of mixer do they use.

 

They are incredibly popular in Ottawa, I always refer to the those trucks as ready mix and the old kind as transit mix. I've used them for doing slabs a couple times, my old neighbor runs a pool install company and uses nothing but.

They show up with a big truck like this:

You tell the operator on site how you want the mix and he turns a few dials and it comes pouring out. The mix is metered so you only pay for the exact amount that you use.

One time the truck was running low so the guy radioed another truck and he arrived before the first one was empty to finish the job. Couldn't be simpler...and you don't have to do any calculations really, you just pay for what you use.

 

You already cut control joints?

Cracking can/may be an issue down the road.

Even if water was added in this application you should be fine.

What is the finish floor material? & Time frame to install?

 

Just a dumb question here.

Why can't they put the dry mix in the truck and when they get to the sight add the water? That way it is fresh every time.

 

That's how mobile mix works...but it adds metered amount of water to a metered amount of aggregate as it comes out the chute.

 

You already cut control joints?

Cracking can/may be an issue down the road.

Even if water was added in this application you should be fine.

What is the finish floor material? & Time frame to install?

Finish floor material is click together floating wood. Time frame could be a month or two I'm remodeling the whole house, it's getting fire sprinklers and all new drywall, whole new kitchen, and two new baths.

 

They are incredibly popular in Ottawa, I always refer to the those trucks as ready mix and the old kind as transit mix. I've used them for doing slabs a couple times, my old neighbor runs a pool install company and uses nothing but.

They show up with a big truck like this:

You tell the operator on site how you want the mix and he turns a few dials and it comes pouring out. The mix is metered so you only pay for the exact amount that you use.

One time the truck was running low so the guy radioed another truck and he arrived before the first one was empty to finish the job. Couldn't be simpler...and you don't have to do any calculations really, you just pay for what you use.

Wow that is awesome, we learn something new everyday, I will do some research in my area thanks for sharing that.