| Author |
Message |
Lynn Javoroski FCSI CCS LEEDŽ AP SCIP Affiliate
Senior Member
Username: lynn_javoroski
Post Number: 1644
Registered: 07-2002
| | Posted on Thursday, May 23, 2013 - 11:44 am: |    |
Does anyone have a spec section for AAC that they'd be willing to share? |
Brian E. Trimble, CDT
Senior Member
Username: brian_e_trimble_cdt
Post Number: 65
Registered: 08-2005
| | Posted on Thursday, May 23, 2013 - 12:01 pm: | |
I would contact your local IMI rep, Pat Conway. He might have something already worked up. pconway@imiweb.org |
Lynn Javoroski FCSI CCS LEEDŽ AP SCIP Affiliate
Senior Member
Username: lynn_javoroski
Post Number: 1645
Registered: 07-2002
| | Posted on Thursday, May 23, 2013 - 12:06 pm: | |
Thanks, Brian. I've done that, too |
J. Peter Jordan
Senior Member
Username: jpjordan
Post Number: 568
Registered: 05-2004
| | Posted on Thursday, May 23, 2013 - 12:13 pm: | |
There is a group selling a "plank" wall system in our area, but getting good technical support has been a problem. A lot of the literature talks about how energy efficient it is, but under the latest ASHRAE guidelines, continuous insulation will be required. Am not at all sure that it is cost effective when the entire wall assembly is considered. |
Jeffrey Wilson CSI CCS
Senior Member
Username: wilsonconsulting
Post Number: 101
Registered: 03-2006
| | Posted on Thursday, May 23, 2013 - 01:08 pm: | |
I have a project spec for Arriscraft msry veneer: Jeff at WilsonConsultingInc dot com. |
Mark Gilligan SE,
Senior Member
Username: mark_gilligan
Post Number: 566
Registered: 10-2007
| | Posted on Thursday, May 23, 2013 - 01:22 pm: | |
Check with your structural engineer. My impression is that building code provisions, specifically with respect to earthquake, are in question. |
J. Peter Jordan
Senior Member
Username: jpjordan
Post Number: 569
Registered: 05-2004
| | Posted on Thursday, May 23, 2013 - 01:27 pm: | |
Arriscraft is calcium silicate masonry complying with a ASTM C73 and with a compressive strength 3 times CMU and a density around 130 pcf. It is made without using lime. Autoclave aerated concrete(AAC)is a portland cement product with a compressive strenght of appoximately 1/4 to 1/3 that of ASTM C 90 CMU and a density of 30 to 40 pcf. This offers advantages (very light weight and ability to shape with carpentry tools) and disadvantages (low strength). I am unaware of any ASTM standard or specification governing AAC products. |
Lynn Javoroski FCSI CCS LEEDŽ AP SCIP Affiliate
Senior Member
Username: lynn_javoroski
Post Number: 1646
Registered: 07-2002
| | Posted on Thursday, May 23, 2013 - 01:42 pm: | |
It has been determined that AAC will be used for the project, which is not in the US. Thanks for the advice; Pat has sent what he has. |
Jerome J. Lazar, RA, CCS, CSI, SCIP
Senior Member
Username: lazarcitec
Post Number: 980
Registered: 05-2003
| | Posted on Friday, May 24, 2013 - 10:50 am: | |
Lynn, I sent you copies of the last AAC specs we prepared in 2005/6 for several projects in Florida (also not in the US, Florida is its own bizarre country that I call home). If you don't get it email me at lazarcitec@msn.com |
Jerome J. Lazar, RA, CCS, CSI, SCIP
Senior Member
Username: lazarcitec
Post Number: 981
Registered: 05-2003
| | Posted on Friday, May 24, 2013 - 11:22 am: | |
ASTM C1692 - 11 Standard Practice for Construction and Testing of Autoclaved Aerated Concrete (AAC) Masonry |
Jerome J. Lazar, RA, CCS, CSI, SCIP
Senior Member
Username: lazarcitec
Post Number: 982
Registered: 05-2003
| | Posted on Friday, May 24, 2013 - 11:27 am: | |
ASTM C1386 - 07 Standard Specification for Precast Autoclaved Aerated Concrete (AAC) Wall Construction Units |
John McGrann
Senior Member
Username: jmcgrann
Post Number: 101
Registered: 03-2002
| | Posted on Friday, May 24, 2013 - 01:01 pm: | |
There's a good article on p. 66 of the 2013 Awards Issue of Fine Homebuilding about a house constructed of ACC. The sidebar piece notes that tolerances are tighter with ACC (units are uniform and joints are thin) as compared to regular masonry.
John T. McGrann, Jr., AIA, CSI, CCS, LEED AP
|
Mark Gilligan SE,
Senior Member
Username: mark_gilligan
Post Number: 567
Registered: 10-2007
| | Posted on Friday, May 24, 2013 - 03:42 pm: | |
ASCE 7-10 makes it clear that ACC lateral systems cannot be used in regions of high seismicity.
Since the use of ACC will almost always be specified by the engineer on the project I find it disturbing that the engineer is not given the responsibility of providing the specification section.
All too often when I received a specification for a structural section from architects the specification has had significant flaws that could not be corrected by changing a reference or two. In many instances the specification section was obviously out of date.
Commercial master specification sections often are based on certain types of projects.
My sense is that many engineers upon receiving these specification sections make minimal changes. Sometimes this is out of ignorance but other times this is partially the result of the owner or architect instructing the engineer to use a given master.
Providing the engineer a specification section to use does not solve the problem and in many cases only supports these bad practices. |
Phil Kabza
Senior Member
Username: phil_kabza
Post Number: 526
Registered: 12-2002
| | Posted on Tuesday, May 28, 2013 - 10:21 pm: | |
Mark: I can't help but think that your posting above begs for a whole new thread. The basis for the conversation could be how specification sections are produced by the responsible discipline as complementary to their drawings and as part of their "instruments of service." Where portions require collaboration are when components of the structural system have architectural implications; experienced consultants are accustomed to working these issues out, but creators of commercial masters still tend to lump all of these components together (such as selection of face brick in the same section as the specification of reinforced concrete masonry.) This results in confusion regarding who writes what, and who is responsible at the end of the day. |
Mark Gilligan SE,
Senior Member
Username: mark_gilligan
Post Number: 568
Registered: 10-2007
| | Posted on Wednesday, May 29, 2013 - 04:18 am: | |
Phil: I agree with your characterization of commercial masters. The specification section will reflect the perspective of the author. A structural steel specification section for a high rise steel building is a different thing from a specification section written for a low rise building with concrete block exterior walls.
A fundamental mistake is made when it is assumed that the individual who has specification writing experience should take the lead as opposed to someone who is knowledge regarding the technical content of the specification section. In some cases they may be the same individual but all too often they are not. |
Ronald Barnett (Unregistered Guest)
Unregistered guest
| | Posted on Wednesday, May 29, 2013 - 09:45 pm: | |
I appreciate the discussion on AAC [not ACC :-) ] in this forum. I worked directly for two AAC manufacturing companies for many years, but moved into prestressed concrete manufacturing several years ago. However, during my 8 years in the industry, we tested the product at Underwriters Laboratories for fire ratings, at Oak Ridge for thermal ratings, at the University of Texas at Arlington for material properties and behavior, and at the University of Texas at Austin for seismic performance. We worked through various committees in ASTM to have several standards issued for both masonry and reinforced panel products. We worked with the Masonry Standards Joint Committee (MSJC) to publish building code provisions that are referenced in the International Building Code. We worked with ACI to publish a document specific to AAC. We also worked with the IMI to train masons to install the products correctly. One source of information can be found at www.aerconfl.com.
As was correctly stated above in this thread, no one product is perfect for all applications, but I can say from personal experience, this is quite a unique and versatile product. It can provide a 4-hour UL rating for corridors and fire walls with a thin, lightweight, solid, cement-based product. It can be reinforced and designed to withstand hurricane force winds in Florida. It successfully performed in seismic testing that exceed the current building code requirements. By the way, when this testing program was developed, a method of determining seismic design criteria and coefficients for new building materials did not exist. A methodology was successful developed by Dr. Richard Klingner (UT Austin) and Dr. Jennifer Tanner (currently at the University of Wyoming) using reinforced AAC masonry.
All this to say, there are countless projects including residential, commercial, schools, military and hotels that have been constructed with AAC as the structural system and are performing fine - including "lots" that have been through multiple hurricanes.
Understanding the product and its limitations, like any product, is extremely important - and writing the specification with an understanding of the products and design requirements will allow the product to be used to everyone's benefit. |
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