Return to index: [Subject] [Thread] [Date] [Author]

RE: Slabs On Grade

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Michael,

The 2" sand blanket between the vapor barrier and the concrete slab is to
prevent curling.
The 2" sand blanket between the vapor barrier and the subgrade is to serve
as a capillary break for wicked or perched ground water.
The imported fill may be due to expansive soil.

When I have built slabs on grade on expansive soils, I prefer to use a slab
reinforced with rebar which requires a 5" or 6" slab.  I also like to key
all joints with dowels to prevent differential movement at joints with will
create tripping hazards and wear points.  After watching many slabs being
constructed, I use 3" blankets of crusher fines which compact easier and
won't displace when equipment runs over them.  Sand will displace even under
foot traffic.

Regards,
Harold Sprague


> -----Original Message-----
> From:	Michael Bryson [SMTP:bryson(--nospam--at)civil.ubc.ca]
> Sent:	Friday, September 01, 2000 11:25 AM
> To:	seaint(--nospam--at)seaint.org
> Subject:	Re: Slabs On Grade
> 
> 
> Just for your information, I'm looking at a job that is calling out a
> reinforced 4" SOG, on top of a vapour barrier, on top of 2" of sand, on
> top of another vapour barrier, on top of another 2" of sand, on top of 20"
> of "imported fill"! This was dictated by the soils engineer, and I assume
> because the site is on expansive soils?
> 
> 

******* ****** ******* ******** ******* ******* ******* *** 
*   Read list FAQ at: http://www.seaint.org/list_FAQ.asp 
*   This email was sent to you via Structural Engineers 
*   Association of Southern California (SEAOSC) server. To 
*   subscribe (no fee) to the list, send email to 
*   admin(--nospam--at)seaint.org and in the body of the message type 
*   "join seaint" (no quotes). To Unsubscribe, send email 
*   to admin(--nospam--at)seaint.org and in the body of the message 
*   type "leave seaint" (no quotes). For questions, send 
*   email to seaint-ad(--nospam--at)seaint.org. Remember, any email you 
*   send to the list is public domain and may be re-posted 
*   without your permission. Make sure you visit our web 
*   site at: http://www.seaint.org 
******* ****** ****** ****** ******* ****** ****** ********