How To Sand Concrete Slab. Make sure to keep your pressure even. This is a volumetric calculation.
As they say, it will get hard and crack. Bad weather) during construction of the laying work of paving slab/interlocking blocks. If you want to build a road, use gravel, but this does not mean you will not have issues.
Therefore, cement quantity = (cement part / concrete parts ) * concrete volume
Construct the form with 2×4 or 2×6 lumber and secure in place by wood stakes and deck screws. Choosing not to use sand or gravel underneath a slab does not necessarily guarantee it will sink. If you sanded it effectively, you should see a bit of exposed aggregate on your surface. In m20 ratio of sand cement and aggregate is 1:1.5:3 ,in this ratio 1.5 part is sand total proportion =1+1.5+3=5.5.