Hi Ken and Kim Good grief... those are the names of my nephew and niece! You're not my nephew and niece, are you? I'll break out in boils or something if you start called me Uncle, LOL!
>On Wednesday, July 14, 2004, at 10:46 AM, Kim & Garth Travis wrote: > > > > it appears that all the recipes and uses I am finding use either > > portland > > or lime, so I am wondering what the advantage to adobe could be? > > > > > > From my understanding of the chemistry, there wouldn't be much. >RHA is a pozzolan, which means it forms calcium silicate hydrates >in the presence of CaO, which of course is lime, and which is also >produced as a byproduct of the portland reactions. Unless the >soil (or the RHA itself) contained significant amounts of CaO or >calcium hydroxide Ca(OH)2, there wouldn't be a pozzolanic reaction. > >The RHA would then be serving as just another filler material >(a silty aggregate), rather than contributing to the binder fraction >of the mix. -K But it's not just a filler, it definitely does set. I have some right here in front of me. Set. Not very strong, but definitely set. Much stronger with some lime and/or portland though, up to full cement strength. So it's refractory, an insulator, a binder and an extender. It's important how you burn it though, temp must be in the right range. It does contain some calcium, potassium, sodium. Have they solved the slow fire problem with papercrete yet? Boron they were adding, IIRC. RHA might help to decrease that risk, dunno. Sure doesn't burn and it's a really good insulator, about the best we've worked with. The traditional Japanese charcoal stoves we've been working with are great for 3rd World use, with the disadvantage that they're best carved from solid diatomaceous earth. So they're exported, not made there locally, and they're not very cheap. Cheapo ones here are made of clay, inferior, though also exported. Not big exports, the very good design is rather lost for 3rd World use unless they can be made locally with good quality. RHA seems to be more or less the equal of diatomaceous earth. Earlier I did try using papercrete, mixed with woodash and also some boron, as insulator for IDD woodstoves, and got the STOVES crowd interested, but I couldn't get it right and I don't think they could either. Regards Keith ------------------------ Yahoo! Groups Sponsor --------------------~--> Yahoo! Domains - Claim yours for only $14.70 http://us.click.yahoo.com/Z1wmxD/DREIAA/yQLSAA/FGYolB/TM --------------------------------------------------------------------~-> Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuels list archives: http://infoarchive.net/sgroup/biofuel/ Please do NOT send Unsubscribe messages to the list address. To unsubscribe, send an email to: [EMAIL PROTECTED] Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/biofuel/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
