Autoclaved Aerated Concrete (AAC) from ACI 530-05

[STR04]

I'm working on a project that has switched out masonry for Autoclaved Aerated Concrete (AAC). I have searched the manufactures, looked in ACI 530-05, Appendix A and found an ES report by ICC which all having great information about the product but I have no experience designing with AAC. Has anyone ever used this product and/or know if any pit falls or things to watch out for?

TIA,

STR04

 

[jechols]

I spoke with an engineer in my office who recently designed a structure with AAC. Here are few items of concern he mentioned:

1. Do not anchor to it (e.g. shelf angle) unless at concrete filled bond beam.

2. Find out how they are planning to run electrical wire and/or plumbing. (i.e. don't let them take a router and start cutting 1 1/2" deep continuous groves every where, especially if the wall is interior they might try to do it on both sides.)

3. Masons don't like to work with it (they are use to putting 3/8" thick mortar on faceshell, AAC uses a thin full mortar bed) so they use framers which sounds scary.

4. Have to use Strength Design

5. Not sure about this one but can't use as shearwall unless in SDC A or B?

Hope this helps, if anyone sees any inaccuracies please point 'em out.

J

 

[wrightd]

Is your project Residential or Commercial? If it is Commercial most of the Manufacturers I deal with will assist the local Engineer. Have you identified the Supplier.

Wrightd

 

[concretemasonry]

The other scarry thing about AAC is that the compressive strength varies with the orientation the units as used with regard to the orientation during the manufacturing process. - Particualrly difficult with soild units.

The tie-down detail requiring a routed channel for a cable in a 2 story structure is a challenge.

Dick