Required to tell?
Required to tell?
(OP)
Well, I wanted to see what others thought of this situation:
We are performing QC for a contractor/supplier for a concrete highway project overseen be the local DOT (USA). We performed a concrete mix design for our client. When they set up the plant, an error was made and the sand and coarse aggregate quantities were swapped. There is a third, intermediate aggregate.
This third aggregate has helped maintain the requirement for the percentage of coarse aggregate (in spec), and all other aspects of the mix are within spec. The flexural breaks have been outstanding. The only thing we see is that the standard specs call for a new mix when proportions change
The error was discovered half way through the project, and they shut down for the holidays at the same time.
We have told our client they should notify the DOT, but they are reluctant. They are meeting all specifications, with the exception of a new mix design due to the changed proportions.
How hard would you push?
We are performing QC for a contractor/supplier for a concrete highway project overseen be the local DOT (USA). We performed a concrete mix design for our client. When they set up the plant, an error was made and the sand and coarse aggregate quantities were swapped. There is a third, intermediate aggregate.
This third aggregate has helped maintain the requirement for the percentage of coarse aggregate (in spec), and all other aspects of the mix are within spec. The flexural breaks have been outstanding. The only thing we see is that the standard specs call for a new mix when proportions change
The error was discovered half way through the project, and they shut down for the holidays at the same time.
We have told our client they should notify the DOT, but they are reluctant. They are meeting all specifications, with the exception of a new mix design due to the changed proportions.
How hard would you push?





RE: Required to tell?
That's my opinion. Others may vary.
Good on ya,
Goober Dave
RE: Required to tell?
Did you do trial batch mix designs and develop the proportions for the mix or did you do a mix design verification where you mixed the proportions done by someone else to check the strength and workability parameters?
Are you really doing "QC" work for the contractor? I would suggest that at most you are doing "QA" work. Since you don't set policy or hire/fire contractor personnel, you're not really doing QC...seems like just a semantic argument, but it does have some important liability implication for you. Further, whether you are doing QC or QA, someone should have noticed the mix variation before so much time and placement went by.
Do you tell? Of course you do. It might turn out to be just a paperwork exercise to get it all straightened out, but one that needs to be done for documentation purposes.
Don't get lulled into the premise that only strength counts in concrete. Durability, particularly in pavement applications, is equally important. What has the aggregate change done to the durability? You need to assess that or help your client assess that.
This is a public project. What you have is a potential technical "scandal" if anything goes even slightly wrong. Bad news does not get better with age....tell your client you are legally and ethically bound to disclose this and you would prefer that he do it first or that you do it together, otherwise you will have to do it without regard to his position. Even though you are paid by your client you are working for the public (the owner of the roadway).
RE: Required to tell?
David
RE: Required to tell?
We did a verification mix.
We are performing QC testing for the contractor, who is self producing the mix, and thus deemed to be QC. True, we have the typical limited control. QA is another firm that is working for the DOT.
We are well aware of the different issues with concrete, beyond strength. The mix, as used meets all the DOT requirements that have been set in place for durability, strength, etc. Four entities on the project look at the tickets, and not one saw the issue, until we were asked to look at a revision to the mix (to increase slump) based on field produced material.
The way we see it, it is just a paperwork issue. The mix was placed in an area of town that would require a serious issue to make the contractor replace it, and there is nothing that would alter their pay for the item.
We agree that the DOT needs to be informed. We notified our client first to give them a chance to come forward. We did not really expect this much resistance, since there are not really any issues with the actual material.
So I guess the feeler was to see how hard people would press their client to expose the fact that they are still in spec, even though they made an error.
Also, I totally agree, and have always thought, "I work for the project, my client only pays the bill."
RE: Required to tell?
RE: Required to tell?
But I'm just a sparky...
Dan - Owner

http://www.Hi-TecDesigns.com
RE: Required to tell?
Not looking over your shoulder or walking around with your fingers crossed is a nice feeling. If brought out into the sunshine, this could be identified, tested and a deviation authorized by DOT- it's in their interest not to tear it up as well.
I questioned my part of a large design & production order w/ the guy who entered the order, and was essentially told 'STFU and design to the order as entered'. Ran it by a peer, he said 'you done what you should, now design to the order'. The order was incorrectly entered for ~50 units, new package designed in a hurry, replaced by 3-5 guys in the field & off the shop floor for a week or two. Cost of the screwup exceeded my salary, probably increased the count of layoffs that followed a few months later.
RE: Required to tell?
Also, the reality is that the DOT is getting exactly what they specified for the project. They determined the parameters for this Class of Concrete, and both the mix designed, and the mix used meet the requirements of the specification.
It would be like me asking you to build me a table out of wood. The wood must have a certain density, hardness, strength, and a limited amount of expansion due to humidity variations. You submit oak to me to be used, and I approve this choice, but build it out of ash. Both woods meet the requirement. Your finisher notices the wood is not the same as the description, and tells you about it. Is he obligated to go over your head (as a PE)?
RE: Required to tell?
Regards
Pat
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RE: Required to tell?
TDAA..I agree with you, but you're missing my point. This is a public project. If a problem comes up with the pavement, without regard to its validity or severity, the mix design and placement then become a big red herring that will take more of your time than you'll want to give.
Resolve it with appropriate communication now. It doesn't sound like it is a functional issue at all...just a project deviation that needs to get approved and summarily dismissed as an issue.
RE: Required to tell?
I know a moulder who was the world leader in moulding surf board and sail board fins. The trend moved to GF PC. He could not mould it without a fine orange peel finish.
He solved the problem by promoting HIS Porpoise skin finish. He promoted the finish improved water flow over the surface just like a Porpoise. After that all competitors had to try to match his moulding fault to meet the demand for that fashion.
Highlighting a mistake or fault as a benefit can work.
Regards
Pat
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RE: Required to tell?
RE: Required to tell?
TDAA...good luck. You're heading in the right direction. Look out for the CYA DOT employees!!
RE: Required to tell?
Yes, the Microsoft business model.
Good Luck
--------------
As a circle of light increases so does the circumference of darkness around it. - Albert Einstein
RE: Required to tell?
Microsoft just make false claims about it's capabilities.
Regards
Pat
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RE: Required to tell?
"make false claims about it's capabilities"
Seem about equivalent to me...
TTFN
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RE: Required to tell?
I would say no your not. QA/QC is as much about the process as it is about the product.
Sounds like you specified the mix.
Are you testing and inspecting at the point of placement? ie: checking slump, tmeperature, air content, batch tickets, time in the truck etc etc.
And yet the mix going on the road is bad?
Doesn't the batch plant have a QA/QC program? IF so do they have a process to identify non-conformitiess? IF so did they write one?
Most state DOTs have a detailed requirement for QA/QC programs. Who is responsible for seeing that it's followed?
I would assume it was in the contract and somebody took public money to impliment and follow that program, they didn't so it's like stealing.
Were it me I would kick the whole job over, tell them to get out the jackhammers and do it right. The principle is not wheather the road is good or not but that they took money to do a job that wasn't done.
Would you like to fly in airplanes that were built the same way?
RE: Required to tell?