Need a book? Engineering books recommendations...
Return to index: [Subject] [Thread] [Date] [Author]
RE: Thickened Edge Slab - Jointing
[Subject Prev][Subject Next][Thread Prev][Thread Next]- To: <seaint(--nospam--at)seaint.org>
- Subject: RE: Thickened Edge Slab - Jointing
- From: "Rich Lewis" <seaint04(--nospam--at)lewisengineering.com>
- Date: Wed, 6 Sep 2006 19:00:26 -0500
Dave, First, I don’t know anything about
the environment. If this is a building slab with normal use then it is very
easy. If it is a freezer building then it is something different. I will explain what I do for a typical warehouse
or retail building. Joint spacing should not exceed the 3*T
value. In your case it is 18 feet. That is where I start. I then divide the
slab dimension by 18 to come up with the number of panels. In your case it is 2
panels by 4 panels. Now here is where it gets confusing. The first panel is ½
and the last is ½ in size. The reason it is ½ in size is the turned down edge
becomes an anchor point, the point of zero movement. If you were to mirror a factitious
slab outside the building with the center located on the turned down slab section,
that is how the flat slab with no turn down edges would behave. It is also how
this slab will behave since it is anchored at the edge. So the distance to the
first joint must be ½ the typical spacing. So here is the spacing of the joints I
would use; 7.5 ft., 15.0 ft., 7.5 ft. 7.5 ft., 15.0 ft., 15.0 ft., 15.0 ft., 7.5
ft. These can slide some if for some reason it
is better not to use the exact numbers. If you are using a pre-engineered metal
building then I like to adjust my joint spacing so the joints do not fall on a
column line. For light thrust loads I use a hairpin and I like as much continuity
of the slab reinforcing as possible spanning between the rigid frames. Depending
on the rigid frame spacing, I locate the joint midway between the rigid frames
or at ¼ points between frames. You can only get away with no control
joints if you add reinforcing to handle it, or you use shrinkage compensation. HTH Rich From: David Maynard
[mailto:DMaynard(--nospam--at)kfx.com] Here’s what I got. It’s an insulated, reinforced,
thickened-edged concrete floor slab. It’s 30 ft wide, about 60 ft
long, and 6 inches thick in the middle, with the edge thickness of 24 inches. Should I put in control joints??? If
so, at what spacing??? Is there a way I can get away with no control
joints??? The thing that is throwing me off is the
thickened edge (I know what to do with a regular flat slab). Any help
would be greatly appreciated. Dave Maynard, PE |
- References:
- Thickened Edge Slab - Jointing
- From: David Maynard
- Thickened Edge Slab - Jointing
- Prev by Subject: Thickened Edge Slab - Jointing
- Next by Subject: RE: Thickened Edge Slab - Jointing
- Previous by thread: Thickened Edge Slab - Jointing
- Next by thread: RE: Thickened Edge Slab - Jointing
- About this archive
- Messages sorted by: [Subject][Thread][Author][Date]