Egon, I would beg to differ on your comment that "Once the concrete is set, there is very little, if any, water absorption". I have water wicking through the concrete floor in my basement quite regularly. Having seen the salts that are washed out of the concrete by water wicking through tells me that concrete really does absorb (or pass) water. The only way to stop that is to seal it somehow.
Scott [email protected] -----Original Message----- From: [email protected] [SMTP:[email protected]] Sent: Saturday, August 21, 1999 8:57 PM To: [email protected] Subject: RE: Concrete as an insulator??? >>And it is still a good insulator during a rain storm?????? Or would the >>torturous path of the water molecules embedded in concrete be too much to >>create a free flowing conductive path? Wouldn't it depend upon the >type of >>concrete and/or the process??? ... Before we get too carried away, it might be appropriate to remind ourselves that water, in itself, is an excellent insulator. Pure water is not a conductor, until you dissolve some free ions into it (eg. salt). I'm not a civil engineer, but I suspect that concrete does not dissolve each time it gets rained upon. This would make for some very poor housing; not to mention falling bridges and other nasty things. Also, most civil engs strive to keep salt out of the concrete mix, since it doesn't do the rebar much good. BTW, all that water that is used to mix the concrete reacts with the cement and forms a solid compound. It's not just sitting in there, sloshing around. Once the concrete is set, there is very little, if any, water absorption. Any further water that may be added, just stays on the surface. Of course, if I used cement or any other insulator on my 200 kW power supply, I would tend to refrain from hosing it down very often. Egon :-) ______________________________________ Egon H. Varju, PEng E.H. Varju & Associates Ltd. North Vancouver, Canada HAVE MODEM Tel: 1 604 985 5710 Fax: 1 604 273 5815 WILL TRAVEL E-mail: [email protected] [email protected] ______________________________________ --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators). --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators).
