getting ready to pour foundation for my house. It’s basement foundation sitting atop some very nice undisturbed structual sand. The sand I pulled out I was planning to use as structal back fill over top of crushed rock that sits above and around the drain tile. But I can’t decide if I should go with crushed rock for the basement slab or use the stuff I got on site being sure to compact it well. If I didn’t have the sand I’d be buying the rock, but the sand I have is mine and free.
edit: not too mention if I can’t find someone to buy it off me I’ll have to get it trucked out.
so…..who votes for what?
Edited 7/28/2005 11:44 pm ET by nails2
Replies
I have built in a lot of areas around the world where confined compaced sand was used successfully under slab. As for backfill, You mention that you have some large material for drainage. I would be inclined to protect the interstices between these pieces with a geotextile or filter fabric, and then use the sand as compacted fill over this. Sand drains, but is slower depending on size of all of the particles in it ( smaller is worse for drainage). If it is dry it doesn't cause any expansion problems. I repeat... if it can be kept dry... Do you have access to some clays to place over the top of the sand to keep out the water from the ground surface (assuming this is the perimeter you are backfilling)?
Thanks for reply warren. I definately am planning for fabric over the crushed rock. The sand itself is fairly fine I'd say. The undisturbed stuff looks like clay until you dig it up. Don't have any clay around just lots of sand and good top soil.