Construction cutting blades

For maximum cutting speed and blade life, you should match the blade as closely as possible to the material you're cutting. Characteristics of the concrete you need to know include the compressive strength, the size and hardness of the aggregate, and the type of sand.
Blade manufacturers consider concrete with a compressive strength of 3000 psi or lower a soft material and Diamond cutting discs with a strength above 6000 psi a hard material. Therefore, you should use a blade with a hard bond to cut the lower-strength concrete and a blade with a soft bond to cut high-psi concrete. Similarly, hard aggregate (such as trap rock, basalt, and quartz) dulls diamond particles quickly, so use a blade with a softer bond to allow new diamonds to be exposed as needed.
The size of the aggregate in concrete primarily affects blade performance. When cutting through larger aggregate (3/4 inch and up), construction cutting discs and wears more slowly. Pea gravel (smaller than 3/8 inch) is easier to cut, but the blade will wear faster.
The type of sand determines the abrasiveness of concrete, with sharp sand being the most abrasive cutting wheel and round sand the least. To determine the sharpness of the sand, you need to know where it's from. Crushed or river bank sand is usually sharp while river sand is round and nonabrasive. The more abrasive the sand, the harder the bond requirement.
What if you will be cutting more than one type of concrete? As a general rule, manufacturers recommend choosing the blade based on the material you'll be working with most often or the material for which top blade performance is most important. Most diamond blades can cut a range of materials.