|Jeffrey Leemhuis, AIA, CSI, CCS, LEED-AP|
Post Number: 26
|Posted on Friday, December 17, 2010 - 11:34 am: |
Where would be the best location to specify an integrally colored concrete interior monumental stair? 03 33 00 - Architectural Concrete?
Post Number: 395
|Posted on Friday, December 17, 2010 - 12:06 pm: |
I am certain opinions will be varied, but if cast-in-place, use Section 033000. You are only specifying the integral color. Section 033300 will repeat most if not all of 033000 with the exception of the integral color. What is the most logical location? Do you have separate sections for formwork and reinforcing? I think 033000 is correct even for concrete "where appearance is of prime importance."
|Mark Gilligan SE, |
Post Number: 347
|Posted on Friday, December 17, 2010 - 03:33 pm: |
Agree the integral color should be specified in 033000.
If you try to repeat much of infor in 033300 there will be a potential for inconsistencies. I would suggest that 033000 reference 033300 which would focus on the mockup and the differences.
If you want good architectural concrete you need a contractor who knows how to produce a good result and who is motivated. If you do not have the contractor no specification can guarantee sucess. You then need to require mockups so that the problems can be sorted out ahead of time.
I know of one high profile concrete project where everybody was impressed by the architectural concrete and there was talk about copyrighting the concrete specification because it obviously must be the cause. The reality was that the concrete specification was only a fair concrete specification. The secret was the contractor.
I would investigate the impact that fly ash and slag will have on both the color and the finish texture.
|Anne Whitacre, FCSI CCS|
Post Number: 1083
|Posted on Saturday, December 18, 2010 - 04:14 pm: |
first, I agree that the contractor is the key to the whole thing, and a good spec will not make a bad contractor any better.
However, it has often been my experience that for "good" visible concrete, its pretty tough to get good performance out of the typical cast in place concrete section. And if you have other concrete on the project, then you need to make a distinction between the high visibility, tighter tolerance concrete versus the stuff that will be covered up with some other material. For that reason alone, I would be inclined to pull the monumental stair out into an architectural concrete section.
For this type of visible thing, you want a couple of things to go right: the formwork has to be very well made, with tight tolerances and smooth joints. The concrete mix has to be well consolidated, and if there is integral color, well blended so there aren't any streaks and puddles. The concrete itself has to be well mixed, and poured without visible joint lines.
Another thing to think about: depending on the color additive, you may be adding a lot to your project, especially if you need to use white cement to get a good color. (delete this whole issue if your stair is going to be black). Have you considered using stains instead? Since you didn't ask that question, we can save for another forum.
|Mark Gilligan SE, |
Post Number: 349
|Posted on Sunday, December 19, 2010 - 03:35 am: |
One of the reasons for there to be a separate architectural concrete specification section is to deal with the different approaches by the architect and the structural engineer. Concrete specifications written by architects or specification writers emphasize different things and typically do not handle the structural issues well. Trying to make one section reflect the conflicting perspectives is not likely to be satisfactory. Each party is convinced that other is ignoring many critical issues. We all have control issues and only see those things important to us..
Having the engineer edit the architectural master does not work well since it typically results in the engineer making compromises and letting the architect do pretty much what he wants. What is the percentage in having a fight with your client? This is different from working with the architect so that he gets what he wants and needs.
Assuming the engineer cares about his specifications he has customized his master. When the Architect becomes interested in the concrete specifications because there is architectural concrete he wants to modify the specification sections to reflect his idea of what should be said and in the process causes mischief with the structural section. The question is who owns the concrete specification section and thus who will organize the section and make the edits.
When you have an architectural concrete section that complements the regular concrete section each professional can control his section. This allows the structural engineer to be responsible for the structural aspects of the architectural concrete while the architect gets to control his issues in the architectural concrete section.
The question then becomes how do you divide up the content and coordinate the sections. First remove everything from the architectural concrete specification that you do not feel strongly about. If you do not understand what something says and why it is there remove it. Focus on what you want not how the contractor does it. Those detailed provisions about how the work is done are probably not that critical and may at times may make things more difficult if strictly followed.
|John Regener, AIA, CCS, CCCA, CSI, SCIP|
Post Number: 496
|Posted on Monday, December 20, 2010 - 10:39 am: |
The converse is true: cast-in-place concrete sections written by structural engineers do not address "architectural" concerns well. All that superfluous, non-structural stuff about appearance and constructibility tends to get ignored, in my experience, in specs produced by the structural engineer.
It seems like what's really important to the structural engineer and building official can be concisely stated in the general notes on the Structural Drawings. THOSE seem to take precedence over all other documentation and contractual considerations, including the "book specs."
It isn't a matter of leaving in or taking out things what one "feels strongly about" but doing collaborative design and stating or showing all requirements for the work to be performed. Those requirements, especially for other than light construction (in my opinion), need construction specifications to be written to fully communicate with all parties. This is especially true when there's a competitive bidding process involved.
Cast-in-place concrete is one topic that many members of the project team have concerns to express. That includes the architect, structural engineer, civil engineer, landscape architect, mechanical (plumbing) engineer, mechanical (HVAC) engineer and electrical engineer.
Who is responsible for the spec for "housekeeping" pads in the mechanical and electrical rooms or the base to mount an irrigation controller on or the reinforced concrete slab-on-grade pad in front of the trash enclosure? These are "non-structural."
Should the contractor have to cope with separate structural and architectural sections for interior concrete slabs-on-grade because floor flatness (FF) and floor levelness (FL) are just for pretty architecture and not structural integrity? Is it more important to segregate design disciplines or to integrate information?
How are sustainable design considerations for cast-in-place concrete (e.g., use of fly ash and VOC requirements for curing and finishing compounds) to be handled under a parochial separation of design responsibilities?
There's a reason why architects must take structural engineering (and landscape architecture, civil engineering, mechanical engineering and electrical engineering courses) in school and that is to be able to "speak engineer" and manage the collaborative design process. I am not aware of similar requirements for the engineering disciplines. Perhaps that's why the architectural curriculum requires 5 or 6 years.
|Ellis C. Whitby, AIA, PE, CSI, LEED® AP|
Post Number: 84
|Posted on Monday, December 20, 2010 - 11:58 am: |
Of course there are engineers who “wear blinders” and only want to deal with their specialty, ignoring the big picture. But saying architects are the sole solution is way too glib.
Plus your educational facts are incomplete. Architectural Engineers take the engineering courses, plus architectural courses. At least at Penn State we did. And it takes 5 years. (full disclosure: PSU AE 1974.)
My Dad graduated in Architecture from Penn State (1948) and he said that at that time the AE program and Architecture program was in the same department. A good arrangement in my opinion.
Today they are in separate colleges.
As long as I am on a rant, a lot architects must have slept through the engineering classes, at least based upon the number who I have had to show how to calculate basic geometry (arches and domes, you know that basics), or determine the dew point in an insulated wall without a computer program. Oh, and lets not forget setting the building in the low point of the site (“better views”, not withstanding the added costs for fill and flood risks).
|Anne Whitacre, FCSI CCS|
Post Number: 1084
|Posted on Monday, December 20, 2010 - 12:21 pm: |
and back to my point: the contractor will bid the concrete section as though its all underground and/or covered up with some finish material. I typically pull the architectural concrete and the architectural structural steel out into separate sections to emphasize that we have different visual requirements for this work and smaller tolerances. It has been my experience that if you try to specify two versions of tolerances in one spec section that the bidder/subcontractor will ignore the tight tolerances on some portions of the work unless you really draw their attention to it.
I've worked with structural engineers who do a very good job of reviewing/editing/producing their spec sections and in most cases they have agreed with me on this approach. The problem isn't the language in the specifications -- its getting the subcontractor to believe that you're going to enforce different standards for some portion of the work.
|Mark Gilligan SE, |
Post Number: 350
|Posted on Monday, December 20, 2010 - 05:16 pm: |
I agree that structural engineers are often not focused on the architectural concerns and that collaboration needs to occur. I also suggest that collaboration can be facilitated it everybody understands what they do not know. I am not promoting a parochial attitude but rather a framework for more collaboration because in the typical approach there is little collaboration.
Collaboration is not enhanced when the architect of specification writer insists upon some magic language without understanding the issues. Collaboration cannot exist unless there is some mutual trust. If you have some magic language that you do not understand the reasons for but are afraid to change then it is difficult to collaborate.
To suggest that the items really important to the structural engineer be placed on the general notes, while often done, reflects a lack of appreciation of structural engineering specifications besides being in conflict with a basic tenant of the Project Resource Manual. This really discounts the structural issues. I recently came across an article that made the point that because of our biases and filters we often cannot see the other parties paradigm. True of architects and specification writers as it is of engineers.
Regards the housekeeping pads in mechanical room and the site pads. If the mechanical pads are to be placed on concrete that was placed on the project, the concrete for the pads should be in 033000. If the pads are placed on existing concrete and there is no other concrete on the job I would defer the solution to others.
Site concrete which would include work designed by landscape architects and civil engineers and would include concrete in front of trash enclosures is often in a separate specification sections even when similar concrete finishes. Not only are the requirements often quite different the time needed to reach consensus among the different professionals is typically not worth the effort to make a unified section.
I would use a separate architectural concrete section only when there are special issues. Normally issues such as floor flatness and levelness would be addressed in 033000. Put the general requirements related to floor flatness or levelness in 033000 and list the specific FF and FL values in a schedule on the drawings. In my experience I have been lucky if the architect even thought of the issue let alone knew what the numbers meant.
I remember a discussion with a big name architectural firm that prided themselves on sophistication with concrete. They had no appreciation of tolerances for concrete columns and beams
There is misunderstanding on what I propose. You do not want the architectural concrete specifications repeating the technical requirements related to fly ash and other similar issues. The “architectural concrete” is often cast integral with other non-architectural concrete. You cannot separate the sustainable design requirements from the mix designs in 033000. But you can separate the finish requirements. Where fly ash and admixtures impact finishes there needs to be some coordination.
You cannot address the concrete requirements in CalGreen, the new green code in California, without dealing with the structural concrete provisions.
Curing compounds would be addressed in 033000 while finishing compounds would be addressed in some other section similar to paint.
The bottom line is that architects and specification writers need to appreciate what the structural engineer can bring to the table and be willing to engage in some real give and take collaboration. Similarly engineers need to step up to the plate but this will only happen if such behavior is rewarded.
Actually I started out in architecture and my BS is in Architectural Engineering. While architects get exposed to the other disciplines this all too often does little good. It is my observation that the individual’s personal interests and what happens after school that is often more relevant.
I agree with Anne in that the key is “getting the subcontractor to believe that you're going to enforce different standards for some portion of the work.”