Concrete voidness is an important indicator that indicates the number of pores inside. So the strength and durability of concrete structures directly depend on the voidness indicator. And concrete structures need to withstand temperature drops, high humidity, the passage of time and soil pressure.

But how to achieve fewer pores in the solution?
A number of factors affect this indicator:

The fraction of the filler and its type. The filler that you use must belong to one faction. You can pre-sift and sort it.
If you use the first available filler, it will affect the quality and strength of the solution. First of all, it concerns the secondary rubble obtained by crushing construction waste.

I know from experience that secondary rubble is an extra headache, the material is heterogeneous, it absorbs moisture in different ways, so a normal solution will never work with it.

The quality of cement. For less voidness, a fine cement mixture is used, which will ensure the formation of a balanced and homogeneous mixture.

Water quality Water should be clean, with an acceptable level of acidity. Water should not contain sulfates, impurities, salts. All these additives will adversely affect the quality of concrete.

It is clear that with the independent production of the solution, these requirements can be met only in part. Nevertheless, it is important to ensure that impurities do not get into the solution, such as grass, dirt, earth. Buy only high-quality materials, because cheap is never reliable.