The "posimix" bolt is manufactured with the addition of a specially designed spring wire attached to the up hole end of many of DSI rock bolts.
The "posimix" bolting system was designed to assist in the installation of rock bolts with chemical anchors in larger diameter holes (31-33mm) by providing:-
substantially enhanced mixing of the chemical anchors,
Increased load transfer capabilities,
the ability to be installed with a face jumbo as well as hand held machines.
The "posimix" device centralises the bolt in the hole allowing an even distribution of the chemical anchor around the bolt. It also acts as an Archimedes screw pump forcing the chemical towards the back of the hole, assisting in mixing whilst consolidating the anchor for improved load transfer properties.
In addition to improved mixing properties the "posimix" device also tends to pump the plastic skin of the chemical anchor to the back of the hole which eliminates the ‘gloving’ effect.
Most DSI conventional chemical bolts can be manufactured as "posimix" bolts and supplied to suit either left or right hand bolt rotation.
Recommended hole size is 31-33mm in diameter.
Corrosion protection may be provided by hot dip galvanizing (refer to Section G). Alternate coatings are available by negotiation.
Australian Patent Number 717939 is applicable to the design of DSI "posimix" bolts and components.
Installation Guidelines
The rock bolt hole is drilled as per mine support designs.
Hole depth is critical. Hole depth should be shorter than the bolt to allow for the height of the washer and nut.
After insertion of the chemical anchors, the bolt is rotated through the anchors while being pushed to the back of the hole. In the case of full encapsulation, anchors of different setting times are often used and the higher speed anchor is to be inserted first, followed by the slower speed anchors.
It is important to follow the chemical manufacturer’s recommended mixing and hold times as printed on the chemical anchor cartons. DO NOT OVER-MIX.
Standard Lengths & Packaging
Standard bolt lengths range from 1500 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 bolts in the configuration requested.
Notes
Only DSI rock bolt components should be used in order to obtain full performance of the bolt system.
Assistance should be sort from DSI Technical Services Engineer’s in selection of the correct Posimix bolt for the application together with its product code.
DSI's Mining Products Division is Quality Assured to ISO 9001:2000, Registration No.QAC/R61/0315.
