Rock Bolts – Cable Bolts 15.2mm
Product Code Guide
| Designator | No. of Strands | Bulbs/m | Bulbing Type | Cable Length | Tail Type | Packaging | Tail Length | Coating |
|---|---|---|---|---|---|---|---|---|
| CB | D | 1 | B | 060 | D | C | 05 |
| Physical Properties | Minimum | Typical |
|---|---|---|
| Yield Load at 0.2% Elongation | 212kN | 250kN |
| Tensile Strength | 250kN | 265kN |
| Elongation on 600mm Gauge Length | 3.5% | 6.5% |
Key Features
- Manufactured from stress relieved, low relaxation, high strength 15.2mm diameter 7 wire steel strand, the cable bolt is formed by bulbing the strand into small cages, typically 26 to 28mm diameter, and up to 6 bulbs per metre.
- The cable bolt bulbs can be modified, in frequency and diameter, so that geotechnical engineers are able to design specific reinforcement products to suit ground conditions being encountered. In some cases, de-bonding tube can be added to the lower section of the bolt to allow for pre-tensioning.
- The bulbed cable bolt is supplied in either single, double or in combination forms. Single bulbed plus single plain cable. They are supplied in nominated lengths for grouting into holes from 35mm to 105mm diameter.
- Can be used with cementitious grouts as well as resin anchors when early support is required.
- For up hole applications, cable bolts are fitted with a spring wire "fish hook" to hold the cable bolt up the hole.
- Surface confinement is provided by flat or domed plates and barrel and wedge anchors. Please refer to appropriate pages for slotted or multiple hole plates, barrel and wedge anchors, grout and breather tubes.
Standard Lengths & Packaging
- Standard bolt lengths range from 3000 to 30000mm in 300mm increments.
- Non-standard requirements are available by negotiation.
- Bulbed cable bolts are normally supplied in straight lengths up to 6 metres and bundled. Cables over this length are usually coiled.
Installation Guide Lines
- In coal mining applications, the preferred hole diameters are 35/36mm for single bulbed cable bolts and 50mm for double bulbed cable bolts.
- Holes are drilled approximately 200mm shorter than the bolt length. If the bolts are to be tensioned, a tail of between 200 to 500mm is required dependent on the type of tensioning unit to be used.
- The bulbed cable bolt is prepared by attaching a breather tube to the full length of the bolt. Allow an excess of breather tube, say 2 metres, to protrude from the hole mouth.
- Similarly attach approximately 1 metre grout tube to the bottom of the cable with sufficient tail to connect to the pump.
- The bulbed cable bolt is inserted into the hole & the hole mouth sealed to eliminate lose of grout when pumping.
- Connect the grout tube to the pump. The air bleed (breather) tube is placed into a container of water and pumping commenced. Air bubbles will exhaust from the breather tube while pumping and be visible in the water container. When the hole is full of grout, these air bubbles will cease to flow.
- After the grout has cured, the bolt can be tensioned if a de-bonding tube has been fitted.
