# How To Keep Your Concrete Mixer Driver Happy



## Termite

Thanks for contributing that Mort! I think a lot of DIYers don't understand how easy it can be to deal with concrete companies and having the concrete delivered to their project. I often walk on homeowners' jobsites and find 3 or 4 pallets of sackrete, and it makes me wonder why they're so resistant to calling and ordering it ready to place. 

It can also be very cost effective compared to the bagged stuff too!

Good info. :thumbsup:


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## rjordan392

Mort,
Can you give us more information on pours. How does a homeowner know that his sidewalk pour is the right type of pour. Or how can he tell if the contractor is working the pour correctly.
My sidewalk is spalling but not as much as the first season after it was poured. I did patch it up last Spring and put down some sealer on it but I noticed anothers piece broke away this winter. About 8 years ago, I had my rear driveway re-done and never did any thing to protect it and it has not spalled. Years ago, in Philadelphia, Pa, sidewalks had 1/2 to 3/4 inch gravel mix and now I noticed that they don't seem to use it anymore. My sidewalk has about 1/4 inch pieces of stone material that reminds me of slate. I don't think this is as strong as the gravel mix. Your Thoughts?


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## gma2rjc

This is a great idea for a how-to subject. I didn't know I knew so little about pouring cement.

You said cement mixer trucks occasionally tip over. As you are driving one of these trucks down a road, are there things other drivers (of cars, SUV's, etc.) should be aware of or do differently when we're driving near a cement truck? For example, for our own safety, Semi truck drivers don't want us driving in their blind spot or pulling up on the right side of their truck at an intersection when they are trying to make a wide right turn.


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## Termite

Gma2rjc, just be aware that their weight is staggering. The weight of the concrete in an 11 yard load is nearly 40,000 pounds. That doesn't stop on a dime in traffic, and it will leave nice ruts in your yard! 

Rjordan392, placing concrete is a science and an art. Mix design, time frame, placement methods, finishing practices and weather all can greatly effect the end result. For example, exposing freshly finished (wet) concrete to wind/breezes can be catastrophic to the slab, even on what appears to be a perfect day. Extremes of cold and heat can be damaging if precautions are not taken. The spalling you're experiencing could be caused by a number of things having to do with the mix, the finishing, salt damage, etc.......
I'm hoping that in the near future we can get a "how to place a concrete driveway/sidewalk/patio" thread started, and can cover all the do's and don'ts and the how's and why's of why people have concrete problems like you're having. I did 5 years of college that was highly focused on concrete construction, have worked around it for years, and I still don't claim to understand everything about it.


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## joasis

I nearly had to laugh....this is great advice for people dealing with a ready mix truck for the first time, but as a contractor, it is the other way around. The driver keeps me happy or they loose the account.:laughing:

Just a little humor there....:thumbsup:


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## Nathan

Great write up Mort... thanks!


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## Willie T

thekctermite said:


> Thanks for contributing that Mort! I think a lot of DIYers don't understand how easy it can be to deal with concrete companies and having the concrete delivered to their project. I often walk on homeowners' jobsites and find 3 or 4 pallets of sackrete, and it makes me wonder why they're so resistant to calling and ordering it ready to place.
> 
> It can also be very cost effective compared to the bagged stuff too!
> 
> Good info. :thumbsup:


Amen to the cost part. I had a complex, section-by-section job that just wasn't set up for a one-time quick pour with a truck. I elected to do it with bagged conctete and a small job site mixer. I sure wish there had been any other way, but.....

Cost me almost 2/3 more. But the time I would have tied up a truck just wasn't workable, I just had to bite the bullet. Was a heck of a lot of work, too.


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## Mort

rjordan392 said:


> Mort,
> Can you give us more information on pours. How does a homeowner know that his sidewalk pour is the right type of pour. Or how can he tell if the contractor is working the pour correctly.
> My sidewalk is spalling but not as much as the first season after it was poured. I did patch it up last Spring and put down some sealer on it but I noticed anothers piece broke away this winter. About 8 years ago, I had my rear driveway re-done and never did any thing to protect it and it has not spalled. Years ago, in Philadelphia, Pa, sidewalks had 1/2 to 3/4 inch gravel mix and now I noticed that they don't seem to use it anymore. My sidewalk has about 1/4 inch pieces of stone material that reminds me of slate. I don't think this is as strong as the gravel mix. Your Thoughts?


Without knowing the specifics on how it was placed, my guess would be that the contractor put too much water in the concrete. The more water you add when mixing it, the easier it is to work with, but that has the disadvantage of making it weaker. 

As far as the rock size, standard sidewalks that I pour are a 4000psi 3/4 rock mix. They mix it that strong because the cost of putting rebar in all that would be restrictive. If your sidewalk is exposed aggregate or stamped, it is most likely 3/8" pea gravel, which is standard.

gma2rjc - Just remember, they don't turn, they don't accelerate, and they don't stop. If you want to get an idea how they drive, rent a 26' cube truck and load everything in the top left side. Then turn a corner.

joasis, I'm glad I could make you laugh. Just remember that it goes easier if everybody is happy. There's a lot of contractors, but how many redimix companies...?


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## yesitsconcrete

wish it were mort who always show'd up on our pours,,, more'n once i've call'd dispatch & put a driver on the bann'd list.

mort, you just listed all the stuff from your common sense list ',,, if more people used it, we wouldn't have 1/2 the problems not on

ly in conc but in the world.

thanks for the smiles, btw - enjoy'd reading it !


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## BillyCement

*Some great advice there, Mort. By keeping the driver happy, the contractor actually makes his own job easier.*


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## BillyCement

rjordan392 said:


> Mort,
> Can you give us more information on pours. How does a homeowner know that his sidewalk pour is the right type of pour. Or how can he tell if the contractor is working the pour correctly.
> My sidewalk is spalling but not as much as the first season after it was poured. I did patch it up last Spring and put down some sealer on it but I noticed anothers piece broke away this winter. About 8 years ago, I had my rear driveway re-done and never did any thing to protect it and it has not spalled. Years ago, in Philadelphia, Pa, sidewalks had 1/2 to 3/4 inch gravel mix and now I noticed that they don't seem to use it anymore. My sidewalk has about 1/4 inch pieces of stone material that reminds me of slate. I don't think this is as strong as the gravel mix. Your Thoughts?


*I agree that it could be that too much water was added to the mix. Although, was any type of ice melter used on the sidewalk? That will also make concrete peel.*


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## rjordan392

I believe so too. The cement company probally added too much water. But the contractor should have known this and rejected the mix. I placed Ice melter on both my driveway and pavement 4 to 6 months after the pour and only the pavement has spalled. The contractor who work the pour let me know he was annoyed that he had to make two trips to install new concrete. I had a problem with a large tree root that was in the way and needed to be cut out. I told him initially that he would have to break the concrete first and then I need to rent a tree stump remover to cut it out. Then afterwards, he would be allowed to come back and order the concrete and install it. When he complained on the day of the pour, I reminded him of what I wanted done before he took the job.


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## Mort

rjordan392 said:


> I believe so too. The cement company probally added too much water. But the contractor should have known this and rejected the mix.


Its been my experience (and I bet BillyCement could back me up on this) that it is the contractor that often wants the concrete a lot wetter than the specs allow. They'll order a 4" slump and want to pour around a 6-7" slump, so its easier to work with (afterall, they'll be long gone when it starts to crack). Personally, as long it comes out of my drum, I don't really care how stiff you pour it.


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## rjordan392

Mort,
I am a bit confused on the concrete terminology. For Instance; the truck driver pours the concrete and the contractor directs the pour. So how does a contractor order a 4 inch slump and turn it into a 6 or 7 inch slump. I watched the pour and do not recall my house supply water being used to water down the pour. I think the only time I seen water being used was by the truck driver to clean the chute. I believe he had his own water supply.
I am just slightly familiar with the word slump as I did a search a way back and there is a commercial tool thats used to measure slump I believe. Is that correct? The contractor did not use any tool to measure slump. He just used the regular tools to smooth out the concrete and then strike lines into it to form blocks.


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## Mort

You don't need a hose to add water. There is a valve on the back of the truck that adds the water directly into the drum from the onboard water tank. If you ever saw the drum rotating at full speed, that means the driver was adding water (because the contractor told him to). 

As far as slump, to test it they use a slump cone. 










It is precisely 12 inches tall, and is filled with concrete. When you pull it up, the concrete falls, and the slump is the measure of how far it falls. For example, if you pile it in the slump cone, pull up the cone, and the pile of concrete is now 8 inches tall, it has fallen 4 inches, so its a 4 inch slump.

I have never seen a contractor use a slump cone. I only see them on State jobs or huge commercial projects. Contractors can pretty much tell by looking at it (and mixer drivers too), and depending on the quality of their work, they will often pour it wetter so its easier to work with.


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## yesitsconcrete

morty, you do know your stuff ! ! !  :yes:


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## concretemasonry

Many ready-mix companies require the driver to write down if water was added and the approximate amount. Some trucks also meter the amount added and used before "wash-out, if a site wash - out is permitted locally. The notation is usually on the copy/receipt the driver keeps and must be returned.

The reason for the notation on the water addition is that the mix placed was not the same as the mix that was batched for guarantee purposes.

Batch weights and water addition at the plant are usually kept for each batch automatically for accounting purposes also.

Tipping the driver for extra maneuvering and moving to minimize labor savings by the customer is frowned on by the concrete companies and the customers waiting for the truck to get back and reload for them.

Dick


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## rjordan392

Thanks Mort, 
So in the future, what can a homeowner say or demand from the contractor to avoid overwatering? Is it too much to ask for a warranty for one year after installation? In my area, I have seen more cracks in concrete then spalling. I suspect they did not dig out the full 4 inches of dirt.


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## concretemasonry

In most areas, a ready-mix supplier will guarantee the concrete if used as batched. Here if it is for a driveway. it must be 4000 psi, 5% air entrained. Some people will sell anything, but others will not deliver if it is not that spec and they know it is for a driveway. - We have some tough winter conditions (ice melting daily at below zero up to 32F) and the absorbed water freezing nightly, so the producers have to establish tight requirements for a guarantee.

The suppliers guarantee does not extend to the placement. A contractor or concrete placer is the make-or-break item in the responsibility chain.

Any good contractor can give a guarantee (one year is a little short for durability issues). Shrinkage cracks should be taken care of by the control joints done by the contractor. Spalling is normally due to poor placement/finishing or curing. Spalling due to aggregates is rare since most producers use aggregates and mixes that are approved by the state/county/city. Cracks due to setting (structural) are the responsibility of whoever compacted and prapred the base.

Dick


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## Mort

rjordan392 said:


> Thanks Mort,
> So in the future, what can a homeowner say or demand from the contractor to avoid overwatering? Is it too much to ask for a warranty for one year after installation?


As a homeowner, I would say to the contractor that he must not go over the allowable water.

What is allowable water? Glad you asked.

When concrete is batched (mixed together at the plant), the batchman usually batches it drier than spec allows. They do this because the driver needs to wash off the top of his truck, the top fins of the drum, etc. They also allow for the contractor to add a bit of water, so that if it is drier than they ordered (happens all the time), the can add some to adjust the slump. The allowable water is printed on our tickets, along with the computer-controlled batch weights.

Our company will guarantee the concrete if the water allowed is followed.

If they must have it wetter, due to the nature of the pour or whatever, they can use a super plasticizer (aka High Range Water Reducer). I know basically nothing about chemistry, but suffice it to say that it is a chemical that makes the concrete wetter without compromising the strength. It costs a bit to add it, but it will make everybody happy.

And we are required to write down the water added (you get written up at my company if you don't), and every other company that I've heard of is required to also.

And concretemasonry is right, a lot of the responsibility also lies with the contractor. We will guarantee it if it is placed properly (which includes watering).


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## rjordan392

Good Responces.
Thank you both.


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## BillyCement

Mort said:


> Its been my experience (and I bet BillyCement could back me up on this) that it is the contractor that often wants the concrete a lot wetter than the specs allow. They'll order a 4" slump and want to pour around a 6-7" slump, so its easier to work with (afterall, they'll be long gone when it starts to crack). Personally, as long it comes out of my drum, I don't really care how stiff you pour it.


*Happens all the time, Mort. Sometimes the inspector takes his readings and leaves. That's when the contractor says "Soup it up.". I say "No problem". :thumbup:*


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## BillyCement

rjordan392 said:


> Thanks Mort,
> So in the future, what can a homeowner say or demand from the contractor to avoid overwatering? Is it too much to ask for a warranty for one year after installation? In my area, I have seen more cracks in concrete then spalling. I suspect they did not dig out the full 4 inches of dirt.


*Cracking is usually the result of water getting underneath the concrete. When the water freezes it pushes up against the slab and cracks it. Everything I've poured at my own house is deeper around the edges. The only crack I have is from an earth tremor we experienced years ago. And much of my concrete is well over 20 years old.*


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## yesitsconcrete

while there're many reasons conc crks, wtr isn't the leading cause of any i've ever seen,,, while a ' thicken'd edge ' is an accept'd method of placing slabs/aprons/etc, it doesn't add any strength to tension rqmts,,, look to an incorrect jnt pattern OR jnts placed at the wrong time, instead.

wtr can exacerbate other causes, of course, but alone isn't the cause,,, many think placing's conc's not difficult but, altho it doesn't look like it to many, it is a specialty trade,,, just my $.03 ! ! !


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## cocobolo

Hi Mort: excellent thread.
Glad you mentioned the air entrainment. We used to have to use 6% up in the Yukon.
In case folks don't know, this air is to allow the concrete to expand and contract a little without breaking. And of course, it is the cold weather in which most of the problems arise.
As to the discussion regarding the contractor adding more water, I have always found that when you get to the final finish, too much water plays havoc with the concrete. The surface appears to get far too weak. A stiffer concrete always seems to finish better. Maybe not easier, but better.
And cost versus pre-mix bags!!! Here one bag of premix is $8+ with taxes. It takes 54 bags to make a yard. That's $432+ for one yard! Gimme the truck anytime!


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## Mort

cocobolo said:


> And cost versus pre-mix bags!!! Here one bag of premix is $8+ with taxes. It takes 54 bags to make a yard. That's $432+ for one yard! Gimme the truck anytime!


I heard a great saying the other day at work, when the contractor said they weren't going to get a pump to do their slab, "We never have enough time to do it right, but we always have enough time to do it over."


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## yesitsconcrete

finishers ' LOVE ' to bless their work - that's why they carry the mason's ( blessing ) brush - especially when its HOT  & they're a guy short on the crew,,, trouble is the finish'd product winds up craz'd & of lower strength than the rest of the slab - even on my own :furious: after i specifically told the guy ' NO EXCESS FINISHING WATER ' & ' SAW JNTS THE SAME DAY ! ! ! ',,, he did bless too much & he saw'd the next afternoon in HOT sun so now i've got crazing to shotblast & repair PLUS a couple random crks,,, they only measure .002 after 1 year but they will be a pita to repair as they become working joints.

sick part's i was placing driveways in augusta at the time for 2 1/2 X's the $$$ so i guess i can't really complain as its my fault ' those got pd & they're gone ! ' :no:


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## shumakerscott

*Self mix*

I still try and mix my own. Haul in my sand gravel mix. Cement in a bag and mix in a mixer. Larger projects need a truck for sure in certain situations. I will be pouring my slab in my house by hand. I will be asking for advice as things go along. It will be a radiant slab. Dorf Dude...


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## Knucklez

wow, great post. in 2 years time i will be needing a basement pour and it is good to be educated DIY before i call the pro in to assess the job. 

Knucklez


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## BillyCement

yesitsconcrete said:


> while there're many reasons conc crks, wtr isn't the leading cause of any i've ever seen,,, while a ' thicken'd edge ' is an accept'd method of placing slabs/aprons/etc, it doesn't add any strength to tension rqmts,,, look to an incorrect jnt pattern OR jnts placed at the wrong time, instead.
> 
> wtr can exacerbate other causes, of course, but alone isn't the cause,,, many think placing's conc's not difficult but, altho it doesn't look like it to many, it is a specialty trade,,, just my $.03 ! ! !


*Actually, I only said that water is "usually" the cause of concrete cracking. I didn't say it was the only cause. As for making the edges thicker, I didn't say that it adds strength to the concrete, it only helps to prevent water from getting under the slab and rising (and thereby possibly cracking the concrete) when it freezes.*


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## yesitsconcrete

billy, didn't mean to pee in your wheaties but i disagree completely,,, excess water'll reduce the compressive, flexural, AND tensile strength of conc,,, under the slab, it can cause base to ' pump ' thereby promoting random cracking,,, imn-s-hfo, tho, the LEADING cause's still incorrect an jnt pattern OR jnts installed incorrectly,,, a thicken'd edge won't satisfy my ' keep your base dry ' wish's, either... water still seeks its own level - gravity OR hydraulics.


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## BillyCement

*You may be right, but I can only speak from experience. My entire 12' X 40' patio is made from extremely wet left-over concrete. I took no extraordinary measures to make sure it didn't crack except for making the edges deeper than the rest of the slab. And I've had no cracks except for one that occurred when we had a severe earth tremor many years ago.*


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## change0070

Mort. i am very interesting in the front discharge truck, which is widely used in America. Many china companies also produce front discharge type.but price is really expensive. about $200,000. and how much is it in U.S ? here is the front discharge mixer truck in china .














































is there any big different from the mixer truck made in U.S ? and how much is the truck in U.S ?


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## Mort

change0070 - I'm not up on the pricing on various mixers, but $200,000 sounds about right for a front discharge. There are two main companies producing them in the U.S., OshKosh and Terex, which sells them under the Advance name. You can get them with a lot of different options, 3-7 axles, hydraulic chute extensions, water tanks, engines, you name it. As far as I know, they aren't available with manual transmissions anymore, which is just fine by me. 

The one you have pictured looks similar to some of those made in the U.S. The one I run is a 7-axle, steer, two sets of duals, 3 sets of belly axles (two in front and one behind the drivers), and a Load Span Tag Axle behind the engine.


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## Mort

One other thing, in the sue-happy USA, they wouldn't even think about producing a truck without the safety railing going all the way around the catwalk.


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## Mort

I don't suppose a moderator could allow me to edit my first post so I can fix some broken picture links, and maybe add some things? Apparently, after a few years, you can't click a button on the bottom of the post anymore.


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## dusty247

*Transit Mix driver*

I have drove for over 30 years and the story remains the same. Granted many things have changed over the years, but the safety part can totally agree. 
You say you have been only driving for a couple of years, well it sounds as if you will be a good driver. 
People think that it is just an easy job, I guess it is if you have been doing it for a while, There is a whole lot of responsibility just driving to the job no to mention once you get on the job always watching, pouring it out in the grade not put down to much,or to little, looking out for the workers,cars, people in general. 
Hope you are getting paid well for the job you are doing??????

O yea and that comment you made on the last 2" to go, now I can see why you would have said that. It would be nuts to top the wall with just 2" to go you are showing your drivers smart alikeness. Got to love it.:thumbup:


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## Mort

Dusty, I wrote the original post in 2009, I got about 7 years of mixer driving before I gave it up (long story). I loved doing it, though. I suppose its like anything else, it gets easier after you do it for a certain amount of time. We got paid pretty well for a Class B job, I wish I made as much doing what I'm doing now (again, long story).


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