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 | S | - | P | 060 | S | C | 20 | - |
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
- Plain cable bolts are manufactured from stress relieved, low relaxation, high strength 15.2mm diameter 7 wire steel strand and are commonly used as long tendons in strata reinforcement.
- Plain cable bolts are supplied in various lengths to customers' requirements.
- Load capacity can be enhanced by simply doubling up from single strand, to double, or treble as the need arises.
- Can be used with cementitious grouts as well as resin anchors when early support is required.
- For up hole applications, plain cable bolts are fitted with a spring wire "fish hook" to hold the cable bolt up the hole prior to grouting.
- Multiple strand cables are usually supplied swaged on the up hole end.
- Surface confinement is usually provided by flat or domed plates and barrel and wedge anchors. For accessories, refer to appropriate pages for slotted or multiple hole plates, barrel and wedge anchors, cable bolt spacers, grout and breather tubes.
Installation Guide Lines
- In metal mine or civil applications, the diameter of the hole is governed by the type of drill string available and the length of hole to be drilled. For coal mining application, refer to bulbed form data sheet.
- Holes are drilled to approximately 200mm shorter than the bolt length. If bolts are to be tensioned, a tail of between 200 to 500mm is required, dependent on the type of tensioning unit to be used.
- Plain cable bolts are prepared for installation by attaching a breather tube to the full length of the bolt. An excess of breather tube, approximately 2 metres, to protrude from the hole mouth.
- These cables can also be installed using an alternate "retreat" grouting method by withdrawing the grout tube from the hole.
- Approximately 1 metre of grout tube is attached to the bottom of the cable with sufficient tail provided to connect to the pump.
- The cable bolt is inserted into the hole and the hole mouth sealed to eliminate loss 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 hole whilst 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 cable bolt can be tensioned, provided sufficient free length of cable is available. Note that HDP tubes are often used to provide a de-bonded section to allow tensioning.
Standard Lengths & Packaging
- Specialised requirements are available by negotiation.
- Plain cable bolts are normally supplied in straight lengths up to 6 metres and bundled. Cables over this length are usually coiled.