Rookie Mixer Driver (Front Discharge) Questions

At every company I usually ask other drivers or a supervisor this kind of question. If they won't help then I ask online.

 

Mixer motion is in a regular pattern.

Large volume single chem tanks hauling 7500 gal in an 8000 gal space with a very light product 'kinda' rocks back n forth from side to side while in motion.

Stuff like alcohols and solvents like acetone require the driver to be accustomed to that motion and we taught to not 'fight it' & never swerve quickly.

We also taught speed limit or less AND half or less the exit ramp posted speed to avoid rollover.

The sloped mixer shape keeps most of the weight in the larger portion but it still moves in a regular pattern as the flights mix the aggregate and cement while the slope is how you reverse to unload in a controlled fashion.

Continue to to be cautious and you will become used to the rock and roll as you travel.

The water tanks usually have a calibrated sight to measure water used to mix.

 

I was taught to fill 5 gallon buckets with water and time it out. 2 seconds per gallon in old mixer 19, a gallon took 1 second at the slump rack. Air pressure drops in your water tank and it slows down a bit.
I never ran a front discharge mixer...I'd be scared to panic stop in one of those.

 

When a mixer is in mix mode inside the drum the mix is forced downward. During transport you want the drug rotating as slowly as possible. This gives the mix time to drop. Mixers have really bad reputations for rollovers. I have seen many do so.

I am going to say this as clearly as I know how. Incorrectly slumped concrete can be expensive. You can save a lot of problems after the mix is batched if while on the slump stand you slump the load correctly. If you don't know how to slump or don't understand how to measure water I suggest you get back with your employer and get some extra training. Slumping concrete is not something you are going to learn in a few days.

It's been years since I last knew what a cubic yard cost. I can only imagine that 8 or 9 yards are in the $500 to $700 range based on what's in it. My only advice is to talk to somebody.

I was about to hit enter and finish my comment when I remembered a rule my company had back years ago on this adding water thing. We were not supposed to add water at the job until we called it in on the radio and had the person requesting it sign the ticket. This is because during the batch process the concrete is batched per the customer's requests. I did not operate a mixer much, but when I got finished blowing off the cement and they needed help I would carry a load. Most of the time at the slump stand I was just making sure the slump was right (99% of the time it was) and making sure the fiber added was mixing well.

 

Slow and easy.
Don't be like this guy
7yds of concrete set up all on the driver's side of the drum.
Worst pulling load ever.

 

It happens quite often, but definitely can be avoided. A company I worked for many years ago had so many turnovers in a short period that they made drivers stop the drum briefly while making turns and ramps. Supposedly there was a transfer of 6,000 lbs while the drum was turning fast. Generally the slowest speed you should be fine under normal conditions. Many companies want a signature before adding water and you need to learn the truck to accurately measure flow. On the older trucks you needed to turn the air off to the water while in transit or a good bump could cause the valve to open dumping all your water in the ready mix ruining the load.

 

Talk to batch dispatch and see if they can’t put you on a big pour to follow some senior drivers— if they can, watch what they do carefully— maybe chum them a little with a box of donuts. May not seem like it, but if you’re trying and don’t whine to much, the older hands want you to learn and most will help you out