How is compaction done for fills under slabs in buildings
How is compaction done for fills under slabs in buildings
(OP)
I was just curious. I know that rolling is used to compact soil fills under road pavements and slabs on grade covering large area. Someone told me that in buidings you would use ramming.
I need further info on this whole thing, including typical subgrade materials used.
I will appreciate if you help
Thanks
I need further info on this whole thing, including typical subgrade materials used.
I will appreciate if you help
Thanks





RE: How is compaction done for fills under slabs in buildings
RE: How is compaction done for fills under slabs in buildings
Ramming perhaps refers to a pogo-stick like compaction device known in our parts as a "jumping jack". It is primarily used for hard-to reach areas where a vibratory plate would have difficulty in maneuvering around.
Subgrade materials used: There is really no typical material used as it depends upon your locality, availability of materials, and quality of in-place soils. Generally, you will find most engineers/geotechs will specify a removal of all organics from you subgrade, a discing up of perhaps 6 to 12 inches of material with re-compaction to 95% optimum density. Then any fill may be added using either a well-graded granular material or existing soils from the site if they are suitable. Finally, a uniformly graded granular material is placed as a direct subgrade to the slab. This material provides a capillary water barrier under the slab to minimize moisture movement from the soil to your slab. Compaction, again is per KAM's response.
RE: How is compaction done for fills under slabs in buildings
Chuck
cgopperton@stantec.com
http://www.stantec.com/
RE: How is compaction done for fills under slabs in buildings
This gives a suitable density of material for constructing on.
Regards
SC
(Mildura, Australia)
RE: How is compaction done for fills under slabs in buildings
Thanks in advance
RE: How is compaction done for fills under slabs in buildings
are cast.
BTW, I get the 95% MDD part & material may vary based on locality. So what's the criteria for selecting a fill material? Insitu CBR value at the source? plasticity index?
sieve size of the granular?
If the ground slabs are supported by ground beams, the soil beneath isn't carrying
any load. Is it still necessary to compact to 95%mdd, if so why & if not then what's the
appropriate treatment?
RE: How is compaction done for fills under slabs in buildings