does sand cement slurry penetrate gravel base ? does sand cement slurry penetrate gravel base ? andy2175 (Civil/Environmental) (OP) 14 Oct 13 13:36 I am placing a bottomless vault in a pit on a two foot bed of compacted aggregate, the backfill of vault will be 2 sack sand cement slurry, any chance the slurry will soak into the gravel and prevent it from draining ? Any journal article or other quotable sources available ? thanks Andy RE: does sand cement slurry penetrate gravel base ? Ron (Structural) 14 Oct 13 19:08 Yes. Journal article not necessary RE: does sand cement slurry penetrate gravel base ? cvg (Civil/Environmental) 14 Oct 13 19:14 place geosynthetic or 8 mil poly in the bottom to separate and your problem solved RE: does sand cement slurry penetrate gravel base ? Althalus (Structural) 5 Nov 13 08:42 What is the gravel like? What is the slump of the slurry? If it is an open graded gravel only, then it will penetrate upto a couple feet depending on the size, gradation, and shape of the gravel. If it is a sand/gravel mix, then it should only penetrate a few inches. If your vault is big enough, it should be such that it will still drain even with some slurry penetration around the edges. This is not a journal or calculation thing. It's just experience and common sense. Slurry is a fluid. The soil at the bottom is a sort of filter. The more viscous the fluid and the tighter the filter, the less it will penetrate. The opposite is true with less viscous and more open respectively. RE: does sand cement slurry penetrate gravel base ? concretemasonry (Structural) 5 Nov 13 11:39 What is the exact definition of "gravel". - There many factors like gradation and particle shape. Dick Engineer and international traveler interested in construction techniques, problems and proper design.