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RE: concrete parapet

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I did not keep the entire article so I am not sure, but I don't think that
it was for swimming pools because one of the paragraphs in the part I kept
says "For walls with protection to the weather in the form of exterior earth
fill, the chart will provide reasonable control of cracking. The chart may
not be adequate for structures where the exterior wall surface is fully
exposed to the freeze thaw cycle while the interior surface is maintained at
a reletively constant temperature."  The chart also shows .0018 as the
minimum factor to use in calculating steel area.

ACI 350, a guide for water-tight structures, indicates a minimum factor of
.0028 and for the 60' spacing I mentioned in my earlier message, ACI 350
recommends a factor of .005.

In any event, if this wall is to be exposed to view and if appearance is
important, I would be just as concerned with shrinkage cracks as I would be
in a swimming pool.  They may be even more of a concern. Small cracks in a
pool can be repaired and the repair probably would not be noticeable.  Small
cracks in a concrete parapet will look like large cracks every time they get
wet if the concrete is left exposed.

Roger Davis
SDS Architects, Inc
205 N. Dewey Street
Eau Claire, WI 54703

-----Original Message-----
From:	Hasan Hindawi [mailto:hasanh(--nospam--at)]
Sent:	Wednesday, November 03, 1999 11:59 PM
To:	seaint(--nospam--at)
Subject:	Re: concrete parapet

Does that apply to swimming pool floors and walls, where crack control
requirements are more stringent?
Hasan Hindawi
----- Original Message -----
From:	Roger Davis <rdavis(--nospam--at)>
To:	<seaint(--nospam--at)>
Sent:	ÇáÎãíÓ, 04 äæÝãÈÑ, 1999 12:43 AM
Subject:	RE: concrete parapet

> In the October 1984 issue of Concrete International there was a chart that
> indicated that for a control joint spacing of 60 feet (end of chart) you
> should use .004 * AREA.  The author said this may not be adequate for the
> wall is exposed to the full freeze-thaw cycle.  I read someplace that the
> Wisconsin DOT uses .007 * AREA for highways with out control joints, but
> most DOT's use .006 * AREA.  I don't think I would use less than .007 *
> unless I found a good source that indicated a lower value worked.
> Roger Davis
> SDS Architects, Inc
> 205 N. Dewey Street
> Eau Claire, WI 54703
> 715-832-1605
> rdavis(--nospam--at)
> -----Original Message-----
> From:	Randy Hamilton P.E. [mailto:rh-eng(--nospam--at)]
> Sent:	Wednesday, November 03, 1999 4:05 PM
> To:	Seaint
> Subject:	concrete parapet
> I am currently reviewing a project with cast in place concrete parapets
> integral with thicker concrete walls and a concrete roof.  This structure
> located in high elevation snow country.  I am concerned about longitudinal
> temperature and shrinkage reinforcement that should be included in the
> parapet.  The parapet is likely to have over 100 ft. run without control
> joints.  With the temperature cycle that the parapet is likely to go thru
> and the continuous restraint to the wall and roof is there additional
> reinforcement recommendations beyond that recommended for typical
> wall reinforcement of .002xArea.
> Can anyone recommend a reference dealing with this subject?
> Thanks in advance for your help.
> Randy Hamilton, P.E.