A reference to an article at TRB (Transportation Research Board) mentions a new method of spraying concrete for tunnel linings is being used on the railroad tunnel in Vancouver, B. C.  Originally developed in Switzerland and in use in Europe for over 4 years, now it is being used in Canada.

Details of the Swiss way of spraying tunnel lining (hereafter I shall call it "SWSTL") is not given; article instead refers to another article ( The link http://worldcat.org/oclc/1586268 gives the list of the libraries where the article is available). The summary given at TRB site says the new SWSTL method is different from shotcreting. It says "Larger aggregates can be used. The dry mix is delivered to the nozzle by compressed air, at which point the water is added and adjusted by a valve...." Please read the full abstract at TRB link below.

https://trid.trb.org/View/100314