GSB

GSB is defined by the Department of Transport Specification for Highway Works clause 803 and is typically known as GSB Sub Base or Type 1

Type 1 GSB is produced by crushing stone to create a material containing a range of sizes from 40mm down to Dust, which naturally interlocks when compacted to provide excellent load bearing capacity and qualities.

Sub Base is produced from crushing whatever type of stone is natural to the part of the country you live in. In addition it can be produced from crushing slag, rubble and concrete from demolition projects and is referred to as a recycled Type 1 GSB.