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RE: Spec needed for 3000 psi concrete

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Joe,

It is not as out of control as your concern appears. In fact, the spec was supplied by the concrete company to the testing lab who, as I stated in my last e-mail, called me to inform me that what they provided was not adequate. The Architect did not provide the specs originally – they were indicated on my drawings, but only as a 3,000 psi concrete for grade beams with special deputy inspection required. This was pretty typical of how we did things in the 80’s for URM buildings where we placed moment frames in soft-story structures.

When the inspector called me, I asked him to recommend the mix that he believed was best for the job since he refused to accept what the concrete company sent to him. I was uncomfortable as the mix was not clearly called out – only the weight of concrete and ratio of water. I still was missing the aggregate and this is when I turned to the List.

Randy Collier sent me an example of what they used – which is what I would consider to be a complete specification used for a public works type project. We modified this as I said and now everyone seems happy.

I respond almost immediately to most of the issues with this job and don’t pay too much attention to whether or not I am needed on the site more than I anticipated in the contract. I profited pretty well on the job and figure that I am more concerned with the contractor installing the retrofit parts as they should be. I don’t believe he has the experience I had in URM buildings and because of this, he needs some extra hand holding.

I don’t worry about liability – but about getting the job right. I know and like the inspector – I’ve dealt with his company for years and have faith in their ability to lead me where I might be weak. The design is conservative on the grade beam.

 

My opinion is that there is always a concern about being sued for something on a job. The worst I’ve done is lose a small claim suit in nearly 20 years in private practice. I respond quickly, fix what might be done wrong before the client has to pay for the work to be redone and I make myself accessible. Unfortunately, this is the reason I lost a suit in small claims – my additional time on another job after discovering the designer’s error in overall building height that needed a redesign delayed another project and I had to return the entire retainer after doing more than 50% of the work. You win some and lose some, but I think the majority of clients are happier for it.

 

Thanks for your concern, Joe. I agree with Scott on this one and feel that we do have a responsibility as we wood in specifying the welds we use in steel or the connectors we call out in wood. There is a minimum responsibility to provide as much information as you can to make sure that the concrete, after being placed, will test as we expect or better.

 

Regards,

Dennis

 

Dennis S. Wish, PE

California Professional Engineer

Structural Engineering Consultant

dennis.wish(--nospam--at)verizon.net

http://www.structuralist.net

 

-----Original Message-----
From: Jnapd(--nospam--at)aol.com [mailto:Jnapd(--nospam--at)aol.com]
Sent: Friday, October 08, 2004 5:23 PM
To: seaint(--nospam--at)seaint.org
Subject: Re: Spec needed for 3000 psi concrete

 

Scott & Bill:

From the sounds of Dennis's email the arch  and/or client if it is a city put together the specs without his input and now Dennis is answering questions and concerns that were not his doing.  If he jumps in and corrects the errors in the specs now all fingers will point to him as the screw up. The various parties will want compensation for job delay and new added cost. Dennis may be stuck with this and will probably not be compensated for his time all for something that was not his fault.  Othwise I agree with both of you. Dennis will be walking on eggs.

 

Joe Venuti
Johnson & Nielsen Associates
Palm Springs, CA


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