(1) Small diameter drilling of sheath detection type

(Patent No. 6170088)

1) Since the equipment is an ultra-low vibration drill (long bit drill), there is no damage around the drilled area.

２） 削孔時の鋼材損傷を防止するため、電流計と鉄粉センサでシース接触を監視し、自動停止します。

3) Since the inspection hole and the injection port are both used with a small diameter hole of φ15.5mm, the burden on the structure can be reduced.

②Estimation of the amount of cavity in the sheath

(Patent No. 5997864)

1) The amount of cavities in the sheath can be accurately estimated based on the pressure change of the decompression vessel communicating with the sheath.

2) Approximate correction of measured values reduces errors due to air leaks.

3) Accurate injection control can be performed to grasp the amount of cavities.

③ Grout re-injection method

(Patent No. 5824588)

1) Reduce the pressure inside the sheath with a vacuum pump, and use the negative pressure to naturally aspirate the grout. After that, close the By-pass and pressurize with the snake pump.

2) By controlling the injection speed by switching the injection method, air entrapment and blockage can be prevented.

錆 Rust prevention grout material

(Patent No. 6262979)

1) Immobilize harmful soluble chloride ions by adding calcium aluminate.

2) Immobilization of chloride ions suppresses steel corrosion.

3) Excellent filling properties can be expected due to the use of super viscous grout.