The original Raffles Hotel with the new towers behind; note the folded up placement boom adjacent to the crane on the far tower.
The original Raffles Hotel with the new towers behind; note the folded up placement boom adjacent to the crane on the far tower.

Western Australian concrete contractor, G & N Conform, is completing the concrete work on two major high-rise projects in Perth. To provide air power in a “pigging” application to clean concrete delivery pipes, the company has purchased and is using two Atlas Copco XATS 156 portable air compressors. This is thought to be the first time Atlas Copco compressors have been used in Australia for this application, which is providing an environmentally friendly solution for cleaning concrete delivery pipes with less water.

The compressors, rated to provide a free air delivery of 352 cubic feet per minute at 150 psi, are being used at the Raffles Waterfront development in Meleville, South Perth, and the Peninsular development at Burswood close to the city center. On completion of concrete pours using a concrete pump and placement boom, the flexible boom hose at the concrete placement end is removed and replaced with a 6-inch inside diameter “pig launcher” with an approximately 8-inch-diameter high-density foam ball squeezed inside the pipe. This pig launcher has the same inside diameter as the rest of the concrete delivery pipework.

Compressed air from the Atlas Copco compressor blows the pig through the pipe and into the concrete delivery truck at ground level, removing any concrete inside the pipe; G & N repeats the operation if necessary, to ensure that the pipe is clean for the next day's delivery of concrete. According to Nando Spera, with G&N Conform, the technique is perfect since it leaves no waste material onsite and does not require large volumes of water.

The pig launcher is attached to the delivery end of the hose on the placement boom to force unused concrete back into the ready-mix truck.
The pig launcher is attached to the delivery end of the hose on the placement boom to force unused concrete back into the ready-mix truck.

The Raffles site is on the Swan River in Perth; the A$125 million (approximately $100 million US) development includes an 18-story tower and three 6-story buildings. It also incorporates the 1937 art deco Raffles Hotel. A hotel has been on this site for more than 100 years since the Canning Bridge Hotel was built there in 1896. In 1937, the single-story art deco hotel was remodeled and renamed Raffles after its famous namesake in Singapore. The new development will provide 147 luxury apartments and two-level basement car parking. The old Raffles hotel will be converted into a restaurant, tavern, and function center.

With only a single concrete boom, workers must transfer it to either tower as needed for concrete pours, which may continue several hours each day, pouring up to 280 cubic meters. The compressor is then lifted alongside the placement boom for the pigging application.