Fracture Mechanism

The crack time of traditional types take 6-8 hours after the completion of loading. The crack time of the universal type of RockFrac® NEDA can be controlled from 30 minutes to 24 hours by the dose of inhibitor added into water. The speed of splitting is determined by the reaction speed, which is up to the temperature of the job site. The higher temperature, the shorter the reaction time.

The rock tensile strength is 4-10 MPA and concrete tensile strength 2-4 MPA. Mixed with appropriate water and poured into pre-drilled holes in stone or concrete, NEDA® starts hydration reaction. The solid expansion produced after coagulation and rigidification exerts pressure in the hole-walls exceeding 50 MPA (500 kg / cm²), which is far stronger than the tensile strength of the stone and concrete. Therefore the stone or concrete is cut or demolished easily.