ROCBOLT Technologies and ROCBOLT Resins

Torque Tension Rebar

  1. A hole of 1" diameter (or appropriate diameter for size of bar) is drilled into the mine roof strata approximately 1" longer than the torque tension rebar or j-bar used by the mine. Measure from where the plate touches the roof to the top of the bolt. Adjustment to be made to accommodate header boards, crossbars, plank, etc.

  2. Insert resin cartridge into hole. Length and type of resin as specified in the roof control plan.

  3. With the bolt in the bolt wrench, insert the torque/tension bolt into the hole to a point where the roof plate is just slightly off the roof line and no excessive boom pressure is applied. Now rotate the bolt rapidly for 5-10 seconds (or as per resin manufacturers recommendations for type of resin being used) to insure proper mixing of the resin. The delay mechanism built into the nut (shear pin, dome, or jmtt* nut) will allow the bolt assembly to rotate as a single unit during the resin mixing process. Always keep hands away from rotating parts.

  4. Now hold the bolt assembly in place (do not apply any up-thrust) for a minimum of 10-30 seconds (depending what resin is used) to allow the resin to set up properly.

  5. Recommended torque: 150-250 ft-lbs for 5/8"; 175-325 ft-lbs for 3/4", and 200-350 ft-lbs for 7/8".