What is the procedure for floor PCC by sand filling? Need for compaction for sand filling necessary

Your question is not clear, providing more information on what actually you want describe will help other to assist you on it.
Photo of it could make more visualization on it.
sir,actually after filling the sand from plinth level to ffl level,
procedure for filling sand in each layer or directly filling upto 1.5mtr height for sand
also need compaction for sand required or not
 

Dnyan Deshmukh

Staff member
I have not done a sand filling yet in any of my project. sand is non cohesive type so does not have idea about how the compaction is done.

For murrum or a soil available in your area need to be used as backfilling material in plinth area.

Before proceeding to back filling work, the test need to be carried out in third party laboratory for its properties like MDD, OMC, Plastic Limit etc. and the report should also confirm in writing that, the material can be used for back filling purpose.

The thickness of layer is depend on the type of machinery use for doing compaction.
Plate compactors are effective up to depth of 150 to 200 mm.
2 MT rollers (Mini Rollers) are effective for depth of up to 600 mm.

Again it also dependent of the material properties.

Back filling is generally done in layers and each layer is tested for achieved compaction ( denoted as compaction factor). upon getting above 95% of compaction factor the work of next layer is done.

In case when there is no work is to be carried out above the fill for almost a year (considering 4 months of monsoon) the filling may be done in uncontrolled way i.e. - without doing compaction.

During monsoon due to rain water the fill get saturated and settle down on its own which leads to maximum compaction.
To achieve the 100% saturation, normally the water is poured in fill area by tankers.
 

Dnyan Deshmukh

Staff member
Hello Sir,

Can we fill water by tankers in back fill areas instead of Layer wise compaction?
Yes you can do that, but need to ensure the backfill is completely saturated.

Such thing only done to achieve the progress but need to keep in mind, other than RCC works, no works should be done at ground or plinth and should left as it is till one rainy season, this ensures complete saturation and full compaction.

While doing RCC, specifically first slab above ground extra precautions need to be taken to ensure no settlement of forms during concreting.
 
sir,actually after filling the sand from plinth level to ffl level,
procedure for filling sand in each layer or directly filling upto 1.5mtr height for sand
also need compaction for sand required or not

Generally, sand filling does not requires compaction with rollers (as we are doing for soil compaction) as it is non-cohesive material.
Only watering (flooding) is required for compaction of sand. Better to fill it in layer wise i.e. 500 to 700mm.
 

Jayant Joshi

Senior Member
Sand filling does not require any compaction.
Normally sand is filled in layers of say 500 mm to 600 mm and sprinkling of water.

For soil filling compaction is required, but excess quantity of water is not desirable, Can lead to void once water evaporate.
Some times people fill water and creating pond of water, wastage of water as well as you will not get desired density.
Normally 15% quantity of water by volume is recommended for soil filling

As rightly mention by @Dnyan Deshmukh soil filling must be in layers and after each layer we have to test compaction factor.