How to classify concrete hardness?

Before choosing the diamond tools, it is essential to know the hardness of concrete

The hardness of concrete is referenced by its compressive strength measured in Pounds per Square Inch (PSI). Cured concrete slabs vary widely in compressive strength; with moisture, temperature, design of mixture additives, cementitious materials and curing processes often determining their measured level of strength. The higher the compressive strength, the harder the material.

Concrete HardnessPSIIn MpaTypical Application
Very hard8000 or more60Mpa or MoreNuclear Plants
Hard6000-800040Mpa-55MpaBridges, Piers
Medium4000-600028Mpa-40MpaRoads
Soft3000 or less20Mpa or lessSidewalks, Patios, Parking lots

After we know how to classify the hardness of concrete, we will how to choose the right grinding cup wheels or grinding shoe, see the blow table

Concrete HardnessMpaBond Types
Very hard60Mpa or MoreVery Soft
Hard40Mpa-55MpaSoft
Medium28Mpa-40MpaMedium
Soft20Mpa or lessHard