Description
1. Nut
2. Dome-shaped grouting adapter With grouting hole and welded-on sleeve
3. Polyethylene sleeve Corrugated, with inner centralizers
4. Plate Incl. bore for grout discharge
5. Rebar rock bolt Cold rolled threads on both sides for mounting expansion shell and nut
6. Expansion shell
Field of Applications
Main applications of the CT-Bolt™:
- Systematic permanent reinforcement of underground excavations
- Ground support for areas with limited or no access during operational lifetime
- Mining: permanent roadways and excavations
- Hydropower and underground oil or gas storage caverns
- Sub-sea and sewer tunnels
Installation Procedure
- Drill 43-45mm hole diameters. The drill hole length must be longer than the bolt by approx. 50mm.
- Domed washer plate is fitted to the bolt.
- The bolt is inserted into the hole.
- After placing the bolt in the hole to its full length, the bolt is then rotated to set the expansion shell to the required tension.
- Attach grouting adaptor to anchorage.
- Mix 0.33 to 0.35 W/C grout. Pump grout. Grout is pumped through the inner annulus to the bolt end and returns along the outer annulus.
- Terminate grouting with visible grout return.
- Detach adaptor and proceed to next bolt.
Technical Features
- Combination rock bolt
- Active reinforcement by pre-stressing of the expansion anchor
- Allowance of a certain amount of elastic deformation of the rebar induced by displacements of the rock mass
- Flexible grouting behind the working face allows an optimum adoption of the CT-Bolt™ to given ground and operating conditions
- Optimum alignment and assurance of complete grout coverage of the of the rock bolt by the polyethylene sleeve
- Unique choice of the corrosion protection level
- Protection of the load-bearing components of the CT-Bolt™ according to given levels of corrosive environments
- Bolts are available black, hot dip galvanised, or black with a stainless steel head detail
- Rock bolt testing equipment
- Rock bolt testing provides a quality control of the rock bolt system behaviour in combination with given ground conditions
- Bolt load indicators and custom-specific pull test kits are provided upon request
1) After grouting
2) Expansion shells for larger borehole diameters available on request
3) Delivery lengths up to 12.0 m are available on request
Prime Advantages
- Combination rock bolt
- Efficient, practically proven, and reliable rock reinforcement system
- Combination of an immediate point anchorage and a fully grouted rock bolt
- Immediate load-bearing capacity after installation by the mechanical anchor
- Fast installation and flexible post-grouting behind the working face
- Double corrosion protection by the polyethylene sleeve and grout coverage
- Easy adjustment of the corrosion protection level to costumer demands
- Fully automated or manual installation procedure
