Need a book? Engineering books recommendations...

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

RE: Keyway Details

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Option 3 is what I have used for many years. It has been the standard in our water division for a long, long time. There are good performing water faciities all over the world and the US using this detail. I know that contractors love to complain about it, but it has given good performance over the years. When it comes down to it, contractors do not charge any differently for option 3.

Option 2 does not give you a lot of embedment of your water stop.
Option 1 would cost a lot more because of the increse in thickness required, and reducing the moment capacity at that point is not a good idea.

Regards,
Harold Sprague


From: "Michael L. Hemstad" <hemstad.ml(--nospam--at)tkda.com>
Reply-To: <seaint(--nospam--at)seaint.org>
To: <seaint(--nospam--at)seaint.org>
Subject: Keyway Details
Date: Wed, 16 Jun 2004 16:28:58 -0500

We do a fair amount of wastewater and water treatment work involving
concrete tanks.  We go round and round about the joint between the slab
and the bottom of the wall.  These joints need to resist shear and
moment.  Basically we have three options we keep arguing about.

1. Finish slab flat, with keyway.  Put waterstop in bottom of keyway.  1
1/2 inch key plus half a 6 inch waterstop makes 4 1/2 inches.  Thus,
either make the slab 3 inches thicker than needed and hold the top mat
down, or bend the bars down under the wall (reducing their depth just
where it's most needed).

2. Finish slab flat.  Roughen under wall, dispensing with keyway.  Use a
4 inch waterstop, touching the top mat; tie it to the inside vertical
rebar.

3. Hang a 3 1/2 inch tall wall form, placing joint, key, and waterstop
up above the base slab.

I like option 2 myself; it's the simplest.  The wall will be rough there
anyhow because of the dowels sticking up in the way of the finisher.
Does anyone have any better ideas, or opinions on which of these options
is best?  Please weigh in with opinions and reasoning.

Thanks,

Mike Hemstad, P.E.
TKDA
St. Paul, Minnesota

P.S.  I've tried to send this several times.  By coincidence I notice
that the Digest was very short yesterday.  Has anyone else had trouble
sending to the List?

******* ****** ******* ******** ******* ******* ******* ***
*   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) or UnSubscribe, please go to:
*
*   http://www.seaint.org/sealist1.asp
*
*   Questions 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
******* ****** ****** ****** ******* ****** ****** ********

_________________________________________________________________
FREE pop-up blocking with the new MSN Toolbar ? get it now! http://toolbar.msn.click-url.com/go/onm00200415ave/direct/01/


******* ****** ******* ******** ******* ******* ******* ***
*   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) or UnSubscribe, please go to:
*
*   http://www.seaint.org/sealist1.asp
*
* Questions 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 ******* ****** ****** ****** ******* ****** ****** ********