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RE: Minimum Temperature Reinforcement

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Dear Joseph :

Thanks for your questions. First your are right, houses are intended to be
built by the owners with very little technical supervision. The specimen
built in the laboratory was made considering this and no control was taken
on the details. By the way, it is a 4 inch wall with only one welded wire
reinforcement in the middle so it's very difficult to get it wrong. And
about the concrete, we told the people building the lab specimen to use as
much water as they felt comfortable. Results gave a 1400 psi concrete which
supported 8 times the expected lateral load. The design controled mix with
required water gave2500 psi and some tests more.
I know it is very difficult for you to understand why we are trying to skip
the codes and do something really CHEAP, but we have also checked the
reliability of the structure and it's beyond the beta indexes expected, so
this means we are really making them a favor, because they are going to
change cartboard houses for concrete houses, and by the way, this people
make around $ 1,700 A YEAR, so they need something NICE, CHEAP and GOOD,
being cheap the most important.

Thanks for your comments,

At 12:03 PM 03/09/1999 -0700, you wrote:
>I could be way off base; But, (IMHO) the following questions come to mind
>when I consider this post.
>A.	Are the walls which will become part of the structure also going to be
>built in the laboratory by engineers or are they going to be built by the
>lowest bidder who may not be able to achieve the same quality of wall in the
>field as was achieved in the lab?
>B.	Is it ethical to skimp on materials.  The recipients of these homes would
>probably be grateful for any king of housing. But, if you're going to do
>them a favor, aren't you obligated to do them a favor.
>Joseph M. Otto
>Ireland Engineering
>Fremont, CA
>-----Original Message-----
>From: Walter Sheen Paoli [mailto:wsp(--nospam--at)]
>Sent: Friday, September 03, 1999 9:27 AM
>To: seaint(--nospam--at)
>Subject: Minimum Temperature Reinforcement
>Dear Fellows:
>We have been working developing a small house for poor people. This one is
>made out of four inch reinforced concrete walls. We have been able to prove
>that a 1400 psi concrete is enough for the expected lateral forces and also
>for dead and live load. We have used the minimum specified steel
>reinforcement for temperature and tested a natural scale module in a
>laboratory. We have found that it resists 8 times the expected lateral
>force. Now since we made the cement contents as low as we could, now we
>want (if possible) to put less steel reinforcement. Now I'd like to ask:
>1.- Temperatures between summer and winter have a 25 Celsius degrees, which
>is not a lot. How is this minimum steel reinforcement determined ?
>2.- In your opinion, for cracking control, would it be bad to use less
>3.- We are planning to use welded wire reinforcement. If we specify small
>distance between wires, would it be possible to use less amount of steel ?
>Thanks for your help.
>Walter E. Sheen
>Civil Engineer
>Paseo de la Republica 6403. Lima 04
>(511) 446-6237 (511) 446-9407
>Lima, Peru

Walter E. Sheen
Civil Engineer
Paseo de la Republica 6403. Lima 04
(511) 446-6237 (511) 446-9407
Lima, Peru