The reputation of Sika is well known in tunneling, because the company has from the beginning in 1910 always worked for the future of tunneling. The company was founded in the same year, where also the first patent for a spraying machine was applied. Probably a symbolic coincidence, due to the fact that the history of Sika in tunneling was clearly driven by the development of sprayed concrete technology. Four milestones have to be mentioned:
- During the electrification of the Gotthard railway line the decision was made to use for all the tunnels between Lucerne and Chiasso the sealing concept of Sika with the product well known -Sika Sigunit.
- With the first sprayed concrete applications Sika was supplying the machines and the setting accelerators, as well as the first rapid setting ready-for-use mortars in the dry process.
- Sika was the promoter of the wet process sprayed concrete and was supplying the admixtures to the first tunnel using this method and aluminate based accelerators.
- Sika again was the first admixture supplier bringing an alkali-free product into the market. Due to this development it was possible to go from temporary to permanent support with the promotion of the single shell tunnel lining method, where the 19km long Vereina tunnel has to be mentioned.
In tunneling the NATM (New Austrian Tunneling Method) and other classical tunneling methods are still very popular, using a temporary rock-or ground support, a tunnel membrane followed by a pumped inner concrete lining with the application of exaggerated construction dimensions with an enlarged excavation profile. The whole construction sequences are based on empirical experiences from earlier tunneling construction sites. Tunneling in the future will require the most economical processes. In this regard Sika’s products range cover the whole requirement existing in underground construction..
Pioneer in underground chemical supplier as well as in construction method (wet/dry shotcrete) Sika worldwide with its high quality products and systems has supported has been involved with several hundred tunnel around the world.