- Depends on water / cement ratio;
- M 100; M 150; M 200.M 550 and so on.is displayed
- Mainly depends on the amount of water
- Depends on the amount of additives
- Depends on the size modulus (IM) of the filler.
- Divides into classes (S1; S2; S3; S4; S5)
- Each of the classes has certain conical depressions; (S4 = 16 - 21)
- Displayed as W2, W4, W6
Sulfate – resistance
There are two degrees:
- resistance to sulfate;
- high sulfate - resistance
- The degree of sulfate resistance is determined by "sulfate ions" in groundwater or in the soil itself (dry soil).
- CaSO4, Na2 SO4; - SO4 - here is the part that breaks down the concrete. (SO4)
Frost – resistance
- It is marked with the letter "F"
To increase frost resistance:
- concrete must be very dense
- must draw a minimum of water to itself
- Amount of cement should be a lot
- concrete must have closed micro-pores (through special additives)