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Re: PT Construction

[Subject Prev][Subject Next][Thread Prev][Thread Next] Gail,

Yes, they certainly do look like multi-strand tendons. No wonder no-one does bonded PT in buildings in the USA if this is their idea of an economical way to design bonded parking garages. But then, as I understand it, the formwork profiles used for the beams in parking garages in USA are fairly fixed, thus limiting designers to produce a design that can fit logically within the beam shapes available.

I have recently returned from a trip to Middle East and UK where several discussions with PT companies and post-tensioned floor designers all confirmed that bonded PT floors are cheaper in their markets than unbonded floors which is why these markets have moved predominately to bonded systems. We decided this about 25 years ago in Australia.  But none of those markets would never use those tendons in a standard parking garage.

At 09:44 AM 3/05/2005, you wrote:
Well, I certainly wouldn't want to name any names, publicly refer to any vendors, or insult anyone,  but if you call up the article below and scroll down to page five,  you see a drawing of what looks darn-like a multi-strand anchorage.
 
http://www.vsl.net/news/media_coverage/ci2505loper.pdf
 
And the pictures I have of these anchorages (in-situ as it were) look darn-like the pictures in this article. 
 
I took pictures of this garage only because I had nothing else to do while waiting for the shuttle bus.  I have other pictures (from other structures) from litigations.  The beam anchorages always kind of look big and round,  not little and rectangular.
 
 
Gail Kelley
 
 
 
-----Original Message-----
From: Gil Brock <gil(--nospam--at)raptsoftware.com>
To: seaint(--nospam--at)seaint.org
Sent: Tue, 03 May 2005 09:06:51 +1000
Subject: Re: PT Construction

Gail,
 
I have never, in 30 years, used multi-strand tendons in anything other than a very heavily loaded transfer member or a bridge.
 
I have never used one in a parking garage or other normal building member. The jacks used are standard single strand jacks. If the US PT industry uses multi-strand tendons in this type of bonded member, it is no wonder bonded PT has never taken off there as it has in many other areas of the world.
 
At 12:22 AM 3/05/2005, you wrote:
 
>Problems with getting the beams stressed has pretty much make grouted PT >construction a non-viable option for parking garages in this >country. The beam tendons in grouted one-way slab and beam construction >are multi-strand tendons which require a special jack. Usually, the >stressing is done by the p-t supplier, and there are always problems with >getting them out to the site in a timely fashion.
>
>In other countries, where it is standard construction, grouted PT works >fine. Grouted pt works fine in bridges, too, except the presentations I >have seen on the new cable-stay bridge in Boston were not >confidence-inspiring, as far as the quality of the inspection on >construction of the deck.
>
>Gail Kelley
 
Regards Gil Brock
Prestressed Concrete Design Consultants Pty. Ltd. (ABN 84 003 163 586)
5 Cameron Street Beenleigh Qld 4207 Australia
Ph +61 7 3807 8022 Fax +61 7 3807 8422
email: gil(--nospam--at)raptsoftware.com
email: sales(--nospam--at)raptsoftware.com
email: support(--nospam--at)raptsoftware.com
webpage: http://www.raptsoftware.com
 
 
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Regards  Gil Brock
Prestressed Concrete Design Consultants Pty. Ltd. (ABN 84 003 163 586)
5 Cameron Street Beenleigh Qld 4207 Australia
Ph +61 7 3807 8022               Fax +61 7 3807 8422
email:            gil(--nospam--at)raptsoftware.com
email:            sales(--nospam--at)raptsoftware.com
email:            support(--nospam--at)raptsoftware.com
webpage:         http://www.raptsoftware.com