The expansive pressure of Bustar is progressive and proportional to the time elapsed since loading. Power increases as time passes. Although fragmentation takes place within 12 to 24 hours, the progressive action of Bustar expansive grout continues for four days in warm weather and eight days in cool weather, reaching a pressure of over 7000 T/m^2 (rock and concrete break at between 1500 and 3000 T/m^2). Note that core temperature, water temperature, or ambient conditions may effect cracking time.
Maximum spacing is 10 times the actual hole diameter.
Minimum recommended depth is 20 inches. Minimum hole depth is 12 inches.
Maximum recommended depth 19.5 feet. Maximum hole depth is 32.8 feet.
Hole depth must be always deeper than the distance between holes.