Path: utzoo!censor!geac!torsqnt!lethe!yunexus!ists!helios.physics.utoronto.ca!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!pacific.mps.ohio-state.edu!linac!att!cbnews!cbnews!military From: andrem@pyrman2.pyramid.com (Andre Molyneux) Newsgroups: sci.military Subject: Pouring concrete (as regards Iraqi shelters) Keywords: concrete Message-ID: <1991Feb9.025948.389@cbnews.att.com> Date: 9 Feb 91 02:59:48 GMT Sender: military@cbnews.att.com (William B. Thacker) Organization: AT&T Bell Laboratories Lines: 34 Approved: military@att.att.com From: andrem@pyrman2.pyramid.com (Andre Molyneux) In response to: >>From: MEDELMA@CMS.CC.WAYNE.EDU (Michael Edelman) >Message-ID: <1991Feb8.012544.15685@cbnews.att.com> >Thos Cohen asks "how long does it take for 36m of concrete to cure?", >with regards to Iraqi shelters. The answer: No longer than it takes >1m to cure. I thought I'd relate some information I received on a tour of Hoover Dam about 5 years ago: During the tour, the guide asked how many people had heard that workers on the dam had been killed by being buried during the pouring of concrete. When several people raised their hands, he told us that such stories were hogwash since concrete won't cure correctly if it is poured more than 8 inches at a time. To emphasize this, he pointed out pictures showing the building of the dam. Sure enough, you could see concrete being poured into wooden-sided molds that couldn't have been more than 1 foot high. On a related note, I recently saw a BBC show on Greek and Roman architecture that mentioned the use of concrete in Roman projects. The host told how the Romans poured the concrete in layers, and how they had to pour each layer a little before the one before it had completely cured. In this way the many layers of concrete effectively became one piece. Anyone have experience with recent techniques for pouring large quantities of concrete? ------------------------------------------------------------------------------ Andre Molyneux - KA7WVV - andrem@pyrman2.pyramid.com PYRAMID TECHNOLOGY CORPORATION 1295 Charleston Road, Mountain View, CA 94043 "Insert your favorite corporate disclaimer here."