Tunnel Information

The Brattås tunnel is located in E18 in Porsgrunn municipal. The tunnel is 524 meters long where the tunnel linings consists of prefabricated concrete elements with a relatively smooth surface. The Brattås tunnel is positioned near a curvature making it somewhat unsafe for oncoming road-users. This is one of the contributing factors to the high accidents rate. The Norwegian pubic roads administration wanted to brighten the tunnel making it safer and chose therefore to spray it with Lightcems Whitecoat with a height of 3,5 meters on each side.

Method

The project was carried out during autumn 2011 under favorable working conditions. The tunnel was washed using high-pressured water to remove old oil, dirt, salt, etc. This proved a difficult task as the oil, dirt, and salt had during the course of many years attached itself into the concrete pores, giving it a smooth and almost polished surface. High-pressure water was not sufficient and the tunnel had to be sand blown giving the walls a rougher surface increasing the bond strength with Lightcems Whitecoat. The tunnel walls were sprayed using a specially designed spraying truck which automatic settings, spraying the entire 3,5m height in one application. To acquire the correct thickness, the walls where sprayed 3 times.