Graymont New Zealand sites manufacture thermally rated chip. This material has been tested to meet relevant standards as a high voltage cable bedding material.
Other specialised materials are available including stemming stone and selected fill.
Thermally Rated Chip
Did you know?
Limestone is composed of the mineral calcite (calcium carbonate) and/or the mineral dolomite (calcium and magnesium carbonate) along with small amounts of other minerals.