Admixtures and Other Factors Influencing Durability of Sprayed Concrete (Shotcrete)
CIM Montreal 2003
Knut Garshol, Michael Rispin,
Quality and durability of sprayed concrete depend on the concrete mix design, the raw materials therein, the type and use of accelerator, and all aspects of the placement onto the rock surface in the tunnel. A large number of influence factors are involved and they must be managed for a successful and durable permanent sprayed concrete structure to be produced. This paper discusses some of the central issues, including how to view the long term effects of chemical admixtures and accelerators in wet-mix sprayed concrete. The ITA WG-12 Shotcrete Recommendations about how to manage durability evaluations are also highlighted. Permanent lining sprayed concrete for rock support is increasingly being used today and the durability can be equally achieved as for any other concrete.
sprayed concrete, durability, Shotcrete, accelerators, admixtures