Classes for Contractors?

[raymond]

Here's a question for management...
So, how often do the contractors try to out-smart the concrete they are buying buy putting additives in the mix that they have no clue what and how the concrete will react when the mix they've dreamed up reaches the pour point. Who gets the phone call when the concrete either lights up like the sun - or lays there not setting up for 6 hrs...etc...etc...etc..
I was wondering if a class for the contractor, that explains in detail, all the additives and the effects they have to the mix during and after placement would be beneficial. The class would have a test and a passing grade would be necessary before you could purchase concrete with additives. Maybe it could be in addition to General Contractors licensing process???
Then,upon completion of the test, you have them on record as being knowledgable to the product and it would be easier to deal with the angry contractor that wants to back-charge for a pump, his crew and possible replacement of work completed...poorly

[dwfnga]

Sounds like a smokin idea, I can't tell you how many times I've had to listen to crackhead finishers tell me what additives ect will do to a mix, when it's obvious they have no clue. (2% Calcium added to load forecast 78deg)

[BillyCement]

Apr 23, 2008 18:35:25 GMT -5 dwfnga said:

Sounds like a smokin idea, I can't tell you how many times I've had to listen to crackhead finishers tell me what additives ect will do to a mix, when it's obvious they have no clue. (2% Calcium added to load forecast 78deg)

I hear you about that 2% calcium at higher temps. So many times I've had to deliver a load of 4500psi with 2% on a warm day in June to a customer who wouldn't know a bull float from a pocket knife. Then when he starts to lose it he accuses me of having some 'crete left over from my previous load. I really need to retire.

[gant]

this big job we are on they put all kinds of chemicals in the loads.. its not the contractors its the inspectors and engineers..cant use calcium because in 200 years it will eat the steel out of the concrete.. we have to us NCA instead of calcium.. we have to use a chemical called eclipse.. I believe it is a non shrinking admix.. we use xypex.. its a waterproofer..our company has the quality guys that just make up different mixes all day..we did one that had so much slag in it that it took over a week to cure.. it was called 5000 mass and it broke at over 16000psi.. pretty crazy stuff they can do these days

[Mort]

I can just hear the responses to that now. "I've been doing this for over ___ years, I know what (expletive) concrete does with (expletive) calcium in it! (expletive) you!"