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Post-tensioned or reinforced ?

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Daniel, since you have a lot of experience with PT, I would like to ask you something I have been wondering about for a long time : What are the bottom-line advantages and disadvantages of PT vs RC slabs ?
In Quebec, I have never seen PT slabs being used, so there is little current field experience, although that could be brought in if it was worthwhile. 
Is there an appreciable cost difference ?  Advantage PT or RC ?
Deflection control ?
Slab thickness ?

What are the green aspects ?


On Nov 16, 2007 8:26 PM, Daniel Popp < drp181(--nospam--at)> wrote:

Our office has done a great deal of high-rise PT design recently.  We use both ADAPT and RAM Concept, which was known as Floor before being bought by RAM International (which is now owned by Bentley).  Both programs have their strengths and weaknesses.

ADAPT is considered by many to be the industry standard, and is very good for two-dimensional design (design strips).  I would recommend using the program to become more familiar with the design process, as it gives the user a simple two-dimensional design interface which makes adjusting the design easy.  ADAPT has more recently introduced a three-dimensional finite element analysis option, which we have not used much yet.  ADAPT Support is also beyond compare -- they even offer to model your slabs for you for a fee.

For complete design of two-way PT slab systems, RAM Concept is hard to beat.  It performs a full three-dimensional analysis of the slab, including beams, drops, thickened areas, and support.  The meshing of the slab is the best I've seen in any structural program.  All design checks can be performed by the program, as well as punching shear checks and stud rail design.  Concept is now integrated with RAM Structural System, meaning that geometry and loads can be sent both directions.  This has not benefited our office, as we do not use RAM Concrete;  I have been told by RAM that their Structural System cannot handle two-way slabs, meaning that extraneous beams must be added to the RSS model.  Another downside:  preliminary design is not as simple as in ADAPT, especially if the engineer does not have a good feel for the design.

Feel free to email me directly for more specific observations on the programs and PT design in general.

Best regards,

----- Original Message ----
From: Stan Caldwell <stancaldwell(--nospam--at) >
To: SEAINT Listserv <seaint(--nospam--at)>
Sent: Friday, November 16, 2007 1:20:13 PM
Subject: ADAPT or POSTEN ??

For the last few years, my practice has mostly been bridge design.  However, every now and then, a significant building project comes along.  This is one of those times.  By the end of the year, my staff will start designing two building projects with a total of more than 40 floors.  Most of the floors will likely be post-tensioned concrete construction.  Both projects are located in Texas, well away from the Gulf Coast, so seismic and wind are not anticipated to be major issues.
The last time we maintained licenses on P/T software was back in the days of DOS.  I assume that the two leading options today are the same that they were back then, ADAPT and POSTEN. 
From recent hands-on experience, do any of you have recommendations on either of these programs?
Are there any other reasonable options that I am not yet aware of? 
Thank you in advance for sharing your wisdom on this subject.
Best regards,  
Stan R. Caldwell, P.E.
Richardson, Texas