Date: Thu, 5 Nov 1998 16:14:49 +0200 From: Jeremy Lea <reg@shale.csir.co.za> To: Kris Kirby <kris@airnet.net>, "Jason C. Wells" <jcwells@u.washington.edu> Cc: FreeBSD-chat <freebsd-chat@FreeBSD.ORG> Subject: Re: Why SGML for docs? Message-ID: <19981105161449.A303@shale.csir.co.za> In-Reply-To: <3641959C.4E755EF1@airnet.net>; from Kris Kirby on Thu, Nov 05, 1998 at 06:10:04AM -0600 References: <Pine.BSF.4.05.9811042329560.10124-100000@s8-37-26.student.washington.edu> <3641959C.4E755EF1@airnet.net>
next in thread | previous in thread | raw e-mail | index | archive | help
Hi, On Thu, Nov 05, 1998 at 06:10:04AM -0600, Kris Kirby wrote: > University of Alabama at Huntsville (UAH) is appearently known for a > concrete and composite carbon fiber watercraft of some type. The entire > idea of a boat out of concrete... Do a search for "concrete canoe competition" on your favourite engine one day. It's one of the main events on the ASCE national calendar, although there are other similar competitions around the world. They're actually extremely difficult to build well, but an excellent lesson in concrete mix design. The concrete is normally fibre reinforced, which lowers the workability, along with the low water:cement ratio to get high strength, so you have to add superpasticisers to get the mix in between the reinforcing. Plus you need to have the concrete cure quickly but have a low shrinkage else the hull will crack, and if the curing is not uniform then it will warp. Choice of aggregate is also important. You new something which floats, but which binds well to the cement paste, because you need a high tensile strength. Plus you have to design, build and paddle the boat... -Jeremy -- | "In this world of temptation, I will stand for what is right. --+-- With a heart of salvation, I will hold up the light. | If I live or if I die, if I laugh or if I cry, | in this world of temptation, I will stand." -Pam Thum To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-chat" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?19981105161449.A303>