Compactness is a main feature of concrete tiles.

Compactnessess increase influence positive mechanical resistance of tiles while reducing their permeability to water before and especially improves reaction time to gelivity processes.

To obtain greater compactness of tiles is used:

a)     an aggregate (sand) with optimal characteristics;

b)     the addition of ultra fine powders, hydraulic active, able to better fill the capillary and crazing pores of cement stone (fly ash);

c)     the use of added superplasticising, whose complex action lead to increased growth workability concrete and concrete compactnessess.

      The results clearly show that the use of sand or cement mixtures are substituted with ash from thermo present consisting advantages in better mechanical resistance, more uniform texture, better reaction to gelivity, lower cost price, and not least solveing environmental problems by using the waste ash resulting from coal combustion.