Fibre reinforcement shotcrete in coal

Fibrecrete Reinforced Shotcrete (FRS), a cement-based mixture pneumatically applied at a high velocity onto coal surfaces. The material component of shotcrete is essentially cement and fly ash blend in a mixed powder form combined with sand, gravel and water. This wet process of shotcrete application is unique to coal, but has been used in the civil industry and hard rock mines for many years. This process allows a good compaction of applied ground support liner that allows penetration into the strata giving a bonded liner with stability, compared to cast-in-place concrete. The advantages of the shotcrete process are related to the reduction of the installation time for ground support, compared with the traditional mesh and bolts system, with the added advantage being a reduction of labour required to place the same work load. The logistics are advanced with a better safety factor, environmental conditions, improved ventilation and reduction of roadway gases. FRS is considered as a primary and secondary support material particularly suitable and used in underground coal mining. The current use of FRS wet mix, which has significant resistance to segregation and benefits as a ground support system as implemented in Queensland mines particularly within the Bowen Basin.