Why are there different concrete grinding segments of different bonds?
When grinding concrete floors you may realize that when you purchase concrete grinding shoes that the segments are either soft, medium, or hard bond. What does this mean?
Concrete floors can be of different densities. This is due to the temperature, humidity, and ratio of the concrete mix. The age of the concrete can also play a factor in the hardness of the concrete floor too.
Soft concrete: Hard bond segments
Medium Density concrete: Medium bond segments
Hard dense concrete: Soft bond segments
The purpose of different bonds
The purpose of the bond is to hold the diamond particle in place so it can grind the concrete. As the diamond particle scrapes across the concrete, There is a large amount of friction as you could imagine. The metal bond needs to hold the diamond particle in place to grind the concrete without breaking off the bond until the diamond particle has worn away.
Extra hard concrete is harder to grind as we all know. The metal bond needs to hold the diamond particle exposed so it can grind the concrete. The bond needs to be soft to wear away to have the diamond particle exposed. The problem with soft bond diamond particles is that it will wear away the diamond particle faster and the whole segment will wear down quicker and the harder bond segments.
A hard metal bond holds the diamond particle stronger as the soft concrete grabs onto the segment creating more friction. Due to the increased friction, the diamond particle does not need to be as exposed as on harder concrete.
Further reading: Epoxy School. Grinding Concrete