Lightweight Concrete ?

[MountainDon]

Does anyone have any experience with lightweight concrete, specifically concrete made from vermiculite and portland cement, nothing else?  I have a project that includes a shallow pan that should slope to a drain near one end. It should also be as lightweight as possible, hence the desire to stay away from the usual type of concrete.

Thanks.

[flyingvan]

  I have pictures somewhere....It was rated to 800 degrees C so I used it to form the part of my outdoor fireplace that transitions from the burner box, which was refradtory cement, to the chimney blocks--- a kind of molded pyramid.  My notes on the stuff---

--You have to moisten the aggraegate before mixing or it never really hydrates
--it takes more water
--it takes longer to dry
--mix it really well to get air entrainment

[Don_P]

Michelle has made pots of hypertufa: portland, vermiculite and peat as a fiber. I wonder if some of the fiber available in bags at the ready mix plant would be worthwhile.

[tommytebco]

I used that type of concrete for the floor of my workshop. I bought it off of craigs list for cheap.
I wanted my money back when I opened the first bag. The seller came over and did a demo small square. (as follows)
1.fill form with the powder
2.Sprinkle with hose until wet through.
3.finish it off with a float.

It's now 6 or 7 years in service and has no cracks. My sections were 10 x 10 foot.

I was amazed.

Hope this helps

[Alan Gage]

How big is this pan? How light weight would you like it? How strong does it need to be? How about building it out of fiberglass cloth and epoxy. Very light, strong as you want it to be (determined by core and thickness) and not too bad to work with.

Alan

[MountainDon]

24 x 32 to 36.    I was trying to avoid f-glass as I am not sure of my glassing skills at this point. Past repairs made to f-glass things have required a lot of post 'glassing smoothing. Probably poor technique.