Once the quarry has been sited, the environmental restoration plan agreed, and the preliminary clearing work completed, the method of quarrying the rock is chosen.
Depending on the type of deposit encountered, whether granite in the form of boulders or in benches from several centimetres to several metres high, the quarrying method chosen will involve the use of a crowbar, quarrying wedges, plugs and feathers, explosives or calmmite (1) to detach blocks of rock from the solid rock mass.
Primary cutting is the process by which a fracture is created in the rock mass to detach a block, or in a block of rock to cleave it, by successive breaks, into blocks of manageable dimensions.
The size to which blocks must be cut will thus be determined by the handling system used. In determining a block's dimensions, it is important to relate it to the size of the finished product (paving-blocks or curbstones) which will be made from the block.
If pavement curbstones 100 cm long and with a 20 × 20 cm section are to be produced, one should obtain an initial block of multiple dimensions to those of the curbstones/edging blocks (adding a small margin to allow for material lost in dressing).
For example, after the first cutting stage, the block could measure 105 × 63 × 42 or 105 × 85 × 21 cm.
Granite block from which curbstones measuring 100 × 20 × 20 cm are to be produced.
It will be possible to cut six curbstones from this block with a minimum of waste.
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