Replies

1. 
   caseyr | Jun 16, 2007 02:28am | #1

   If you haven't already, do a Google search on "lightweight concrete mix" - you should get several hits with some good info.

2. 
   ponytl | Jun 16, 2007 02:28am | #2

   start with lightweight  sand... then if you can find light weight rock and portland... you can cut your total weight way down...

   p

   really you can only find.. light weight "rock"   as far as  know... and it has to presoak or it will float...... only way i've seen it done... i've heard of some moss type fillers for molding... but...

3. 
   McDesign | Jun 16, 2007 02:28am | #3

   Use vermiculite for aggregate?

   Forrest - got a bunch of vermiculite, never used it for concrete, but it's amazingly light

1. 
   brownbagg | Jun 16, 2007 02:49am | #4

   really you use slag and furnace blast. also you can use the rocks in BBQ grills

4. 
   splintergroupie | Jun 16, 2007 02:49am | #5

   You might be interested in HYPERTUFA:

   http://en.wikipedia.org/wiki/Hypertufa

   http://faq.gardenweb.com/faq/lists/hypertufa/2003052859024911.html

5. 
   WayneL5 | Jun 16, 2007 04:23am | #6

   This is just speculation, but incorporating vermiculite and fibers in the mix.

    

6. 
   jackplane | Jun 16, 2007 06:47am | #7

   for planters, i've seen a lot made with styrofoam covered with chicken wire, then coated with concrete...lightweight and looks more formidable than it is.

   Expert since 10 am.

7. 
   Lapun | Jun 16, 2007 10:13am | #8

   I have used an air-entrainment additive liquid coupled with an increased mixer speed for a crusher dust mix. The result was a 20-25% weight reduction.

   I have also heard of an experiment using crushed coral and sawdust to produce non-load bearing panels which could be sized by handsaw.

   It was a situation where development depended upon experimental nouse more than funding power.

   Lapun.

8. 
   peteshlagor | Jun 16, 2007 05:28pm | #9

   I've heard of pumice being used as agg.