Rock Bolts – Solid Bar
|Yield Strength||500MPa / 200kN||540MPa / 220kN|
|Tensile Strength||540MPa / 220kN||635MPa / 260kN|
|Calculated Shear Strength||145kN||170kN|
|Elongation (After Fracture)||5%||20%|
|Tensile Strength of the Threaded End||200kN UTS|
|Mass Per Metre||3.46kg|
|Bar Core Diameter||23.0mm|
|Major Bar Diameter||27.0mm|
|Cross Sectional Area||415mm²|
|Rolled Thread||M24x3.0mm Pitch|
- This slot and wedge bolt is manufactured from hot rolled reinforcing bar which has rib deformation generally in a "herringbone" form. It has a 150mm long slot cut into the up hole end of the bolt and M24x3mm pitch rolled thread on the other end.
- The 150mm long slot is designed to accept a steel wedge which acts as a mechanical type point anchor. Refer to Data Sheet WE for details of steel wedges.
- The solid deformed slot and wedge bolt parent bar is reduced in diameter to allow forming of the M24 rolled thread. The threaded section of the bolt accordingly has reduced physical properties to that of the parent bar.
- The 24mm solid deformed slot and wedge bolt can be pre or post grouted if required with cementitious grouts.
- Corrosion protection may be provided by hot dip galvanizing or alternative coatings.
- 34mm hole diameters are preferred. Larger diameters than these can be used but anchorage capacity may be reduced. Holes larger than 36mm and smaller than 32mm are not recommended.
- Hole depth is critical and should be approximately 50mm shorter than the bolt.
- The wedge is assembled into the slot, just sufficient to support the wedge, for entry into the bolt hole. The nut is also rotated along the bolt thread to leave approximately 50mm of thread exposed.
- The bolt with the wedge is entered into the hole and the nut end of the bolt is fitted into a special spanner contained in a rotary percussive rock drill.
- Using both the thrust of the machine and full impact the bolt is driven onto the wedge to set the bolt. The spanner is then changed and the nut rotated to tighten the bolt.
- Standard bolt lengths range from 600 to 3000mm in 300mm increments.
- Non-standard lengths are available by negotiation.
- Bolts are packaged in bundles with threads protected by heavy duty polyethylene bags.
- Bolt fittings, such as nuts, anti-friction washers and dome balls, are supplied fitted to rock in the configuration requested.