BASF saved construction time on CLEM 7 Tunnel
When it comes to underground construction, the performance of the waterproofing solution used is of paramount importance, particularly if the project is being constructed under one of Australia’s major rivers. The spray-applied polymer membrane provided by BASF sprayed concrete machine saved time and effort on the construction of the 3 billion Dollar Clem Jones 7 Tunnel (Clem 7) in Brisbane, Australia. The project was completed seven months ahead of schedule.
With a tunnel length of 4.8 km, at its lowest point Clem 7 runs approximately 70 meters below sea level, so the responsibility of supplying a water-tight tunnel installation was a real challenge.
“We were given a very short delivery time,” says project director Adam Hudson for the Contractors and Baulderstone Bilfinger Berger Joint Venture (LBBJV), “beginning work in August 2006 and with a completion date for October 2010.”
Whilst the original specification of a traditional sheet membrane system was initially utilized, the installation of the sheet system was proving a time-consuming exercise. This was particularly evident in areas such as the cross-passages linking the south-bound tunnel to the north-bound, where extensive detailing of the applied membrane was necessary.
A membrane system with a fast rate of application was required because the delays were hampering the fast-track construction program. The project’s engineers needed to find a replacement waterproofing solution that was quick and easy to apply, while also being capable of providing the long-term waterproofing performance required.
Quick and easy
The ideal solution was found in a spray-applied polymer membrane from BASF Construction Chemicals. MASTERSEAL 345 delivered the required combination of outstanding waterproofing performance, with extremely fast application. Once trained in the application of the product, it was possible for the LBBJV crew of four to apply up to 2,000 square meters of complete membrane in a day.
The product was applied with one of BASF’s MEYCO Piccola dry-mix sprayed concrete machines. These machines were already being utilized on site, so the infrastructure required to adapt it to spraying was minimal.
MASTERSEAL 345 is a single-component spray-applied powder product, which once applied, bonds layers of sprayed or cast concrete, offering a good bond strength on both sides of the membrane. When mixed automatically with water at the nozzle and delivered to the substrate via compressed air, it provides a tough, elastic membrane layer. The flowable nature of the freshly applied product ensures all irregularities in the porous profile of the tunnel wall are coated evenly, providing a positive waterproof seal.
The inner final layer of sprayed concrete on Clem 7 was applied over MASTERSEAL 345 within days of the membrane’s application, again creating massive construction cycle time efficiencies.
Over 68,000 square meters of the product was applied in various sections of the project, supplying the contractor with the quickly applied, high quality waterproofing option they required.
Clem 7
Clem 7 comprises twin 4.8 km road tunnels, excavated using two 12.4 m diameter TBMs and 10 roadheaders, to link the Brisbane suburbs of Woolloongabba in the south to Bowen Hills in the north. The tunnel includes cross passages approximately every 120 m, a cable tunnel beneath the tunnel floor, a smoke duct in the tunnel soffit, five underground substations, two low point sumps in the mainline tunnel and M&E fit out that uses the latest technologies to achieve one of the safest road tunnels in the world. Extensive surface works were required to tie the tunnels into the existing road network at six portal locations. The total route length of the bypass toll-road, including on-ramps, is 6.8 km. The tunnel was designed to ease inner-city congestion and is now a quick alternative to the route with over 24 traffic lights.
In the near future, Clem 7 will link with the Airport Link tunnel, offering even greater convenience for the Brisbane motorist.
About the Construction Chemicals division
BASF’s Construction Chemicals division is the leading supplier of chemical systems and formulations for the construction industry. Continuous innovation and tailor-made solutions ensure its customers are more successful. In the MEYCO Underground Construction unit, international tunneling and mining specialists work closely with contractors, design engineers and mining organizations around the globe. They permit the seamless transfer of their state-of-the-art MEYCO® technology and services with complete packages that solve all underground engineering problems, safely and cost and time effectively: Expanding Horizons Underground. www.meyco.basf.com
BASF Construction Chemicals operates production sites and sales centers in more than 50 countries and achieved sales of about €2.1billion with approximately 6,900 employees in 2010.
About BASF
BASF is the world’s leading chemical company: The Chemical Company. Its portfolio ranges from chemicals, plastics, performance products, and agricultural products to oil and gas. As a reliable partner BASF creates chemistry to help its customers in virtually all industries to be more successful. With its high-value products and intelligent solutions, BASF plays an important role in finding answers to global challenges such as climate protection, energy efficiency, nutrition and mobility. BASF posted sales of more than €63.9billion in 2010 and had approximately 109,000 employees as of the end of the year. Further information on BASF is available on the Internet at www.basf.com or in the Social Media Newsroom at newsroom.basf.com.