The only two things we know for sure about concrete are: it gets hard and it cracks. Evaluating concrete is essential as no two slabs of concrete are the same. The variation in the aggregate, the sand, cement to water ratio along with several other factors will determine the exact hardness of this.
In order to best determine the proper method needed for surface preparation (shot-blasting, diamond grinding etc.), it is important to test the Measure of Hardness (MoH) with the proper tool kit.
The kit pictured includes four pencil like instruments that each have a different tip. You simply try and scratch the concrete starting with tip #1. If it doesn’t leave a scratch proceed upward to tip #2 and so on, until a scratch is made in the concrete. That is the MoH rating for that slab of concrete.
Knowing in advance how hard your concrete substrate is will help you determine the right method of surface preparation to insure long-term adhesion and many years of service from your epoxy floor.