On this subject, it is written a lot of material with enough contradictory conclusions. In this article I would like to disclose that question ...
To date, the builders are doing everywhere sand cushion under the foundations, and in response to the question "? What, "say:" Everybody does it, "" Will not be worse "or anything else without specific justification of this! technology!
Generally speaking, all of the discharge "I hear a bell, but I do not know where he is!"
Where does it come from?
In the old Soviet times, when private construction virtually marked time, it went on by leaps and bounds development of precast concrete, so to say it was aimed at industrialization, when a huge economic exhaust from the use of reinforced concrete, as it is fast, cheap enough qualitatively. Therefore, since the Soviet era we've got a lot of non-Reinforced Concrete.
So, while private construction - is a completely different sphere, and here there is an incident, the school remained the old. All seen as the construction of high-rise buildings standing today was erected on a sandy base, this sand was put the foundation of all kinds of RC elements, and then constructed the higher floors.
So for what it used Sand? And in order to level the ground on a plane to equal enough factory RC structure stood "in his place" (for uniform distribution load) without any gaps between the ground base and RC product (in order to eliminate the point loads on the convex place after excavation and compaction ground).
A monolithic reinforced concrete, which is poured in place, it is unnecessary no cushion of sand or something else, he perfectly fills the irregularities of ground and running at 100%, transferring and distributing the load from the higher buildings on priming the entire bearing area.
Good luck building!
See also my article "How to stand before the construction of the foundation."
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