An Aquajet hydrodemolition robot is cutting away decayed concrete from pylon foundations in a Swedish ski resort so a replacement surface can be laid.
The ski lift system in Åre, around 350 km (220 miles) south of the Arctic Circle, takes skiers and holidaymakers up the side of the 1,420 m (4,659 ft) high Åreskutan mountain.
It was built in phases starting from the late 1970s, and has helped turn the village into one of the country’s leading winter sports resorts.
The contract to renovate the foundation blocks on the pylons has been awarded to Corvara Industri & Skadeservice, a specialist in repairing damage to industrial installations and a supplier of high-pressure, suction, hydrodemolition and blasting services throughout the Nordic region.
A 410A Aquajet Aqua Cutter , a remote controlled machine specially designed for applications in confined and inaccessible areas, is being used on the concrete foundation blocks.
“The robot is so light and compact that we are able to lift it up the side of the mountain on the cableway itself, and then lower it onto the block,” says project supervisor Mattias Carlsson.
“Each block is between 3 and 4 m (10 and 13 ft) high and there is a ledge, between 700 and 750 mm (27 and 29 inches) in width, that the robot can stand on.
“The machine is so compact and manoeuvrable that it can be driven along the ledge and even around the corners, so that it can reach all surfaces on the foundation without the need for any lifting devices,” added Mattias.
The foundation blocks had aged to the point where Corvara had to use the water cutter jet to remove 200 mm of decayed concrete, and the entire surface of the top two stages of each foundation must be removed.
“Jack hammers could of course have been used for this job, but they cause noise and dust, which in this environment is not desirable,” says Mattias.
“It would also have caused critical vibration damages to the foundations and the pylons. With the hydrodemolition technique it was possible to keep the cableway open during the complete restoration.”
Corvara’s contract, which covers 12 foundation blocks in total, runs until the end of 2016.