The “age”, or length of curing time, greatly affects how the diamond saw blade performs on cutting concrete. Before choose the right diamond blades, it is important to know something about the curing of concrete. The “state” of concrete from initial pouring to a period of 72 hours and over can be divided into 3 types, temperature, weather, moisture, aggregate, time of year, admixtures and composition also influenced the concrete state.
Type 1 – 0 to 8 hours
normally, this is the “green concrete” we always talk about. The concrete is considered in its “green“state 0 to 8 hours after the pour, meaning it has set but has not hardened completely. With green concrete, the sand in the mixture has not bonded to the mortar blend firmly and will cause extreme abrasive action once the physics of sawing begins. Further, the slurry generated by green concrete is equally as abrasive and will require special undercutting protection for the steel core of the diamond blade, the Soff-cut blades are specially designed blade for green concrete cutting, with the special designed skid plate, it can effectively prevent the chipping during cutting. Typically, sawing control joints of highways, industrial flooring, driveways, runways and similar projects is performed during this state.
Type 2 – 8 to 24 hours
the concrete is considered as cured 8 to 24 hours after the pour. The sand is held firmly adhered to the overall mixture. Generally, control joints established in State 1 are widened during this time.
Type 3 – 24 to 72 hours
The concrete is considered as cured 24 to 72 hours after the pour. The sand is held firmly in the mortar mixture, and the overall abrasive actions and properties of the concrete are greatly diminished. Now, consideration of the aggregates, compression strength and steel content of the concrete become important factors in determining proper diamond-blade selection.