While it may not be as famous as Sydney’s Opera House or Harbour Bridge, there can be no doubting the ‘iconic’ status of Melbourne’s Flinders Street Railway Station. Completed in 1910, Flinders Street Station is not only nationally recognised as a Melbourne ‘icon’, for many Melbournians ‘under the clocks at the Flinders Street Station’ is still the preferred place to meet in the Melbourne CBD.
While the station continues to serve as the ‘central access point’ for rail services in the Melbourne CBD, nearly 100 years of continual use was beginning to take toll on the structure. With that in mind, the Victorian Government implemented a $13 million program to strengthen the deck of the station concourse, together with an additional $10 million refurbishment and upgrade program to improve facilities, make it more accessible and enhance its visual appeal.
Developed with a focus on enabling the concourse to cope with the increased loads associated with current activities – including increased patronage, additional shops and facilities, and access for emergency services an other vehicles – the concourse level upgrade incorporated the use of a state-of-the-art MBrace® Fibre Reinforcement System from BASF Construction Chemicals. Based on Carbon, Aramid and Glass fibre technologies, MBrace® provides the ideal combination of high strength, lightweight materials and corrosion resistance. The Flinders Street Station application involved the application of MBrace® CF120 unidirectional carbon fibre sheets to the underside of the concourse structure.
Perhaps not surprisingly – considering the building’s age and the fact that it is one of Australia’s busiest railway stations – the Flinders Street Station MBrace® application offered some additional challenges when compared to most projects, including work scheduling amidst an operating railway station, and over 100 years of built-up dirt and grime on the concrete surface.
The contract for the MBrace® application work was awarded to Sydney-based company Eptec Pty Ltd. In order to minimise the impact of the works on commuters and the day-to-day operations of the station, Eptec worked closely with Connex (the operators of Melbourne’s train and tram network) to schedule the work in a manner that allowed Connex to re-route trains away from the tracks directly below the area where the work was being carried out.
Once the build-up of dirt and grime had been removed from the underside of the concourse slab through grit-blasting, exposed cracks were injected with Concresive® 1375, a low-viscosity, high strength epoxy injection resin also from BASF Construction Chemicals. The surface was then levelled with BASF’s Concresive® 1444 - a thixotropic epoxy mortar paste binder and adhesive - prior to the application of the MBrace® CF120 sheets, which are held in place using the specially-formulated MBrace® Saturant. Over 2,000m2 of MBrace® sheets were used in the Flinders Street Station project.
The concourse strengthening project also included filling the hollow cast iron columns that support the slab with Masterflow® 870 flowable grout, resulting in solid columns with a strength of over 70MPa.
The final stage of the concourse works saw an application of BASF’s Masterseal® 160D to the concrete arches under the slab and the steel beams. Specifically developed to provide protection for concrete, mortar, masonry, natural stone or wood against aggressive environmental attack from carbon dioxide and chloride ions, Masterseal® 160D delivers the ideal combination of protection and aesthetics. The Masterseal® 160D used on the concourse project was colour-matched to the ‘Flinders Street Heritage Yellow’ colour that is so prominent throughout the station.
In addition to the concourse strengthening project, BASF Construction Chemicals’ products were also used to waterproof the historic station awning that forms the interface between the station and the adjacent taxi rank on Swanston Street. Following profiling with Barra® Mortar HL (a lightweight polymer modified repair mortar) to provide adequate fall for drainage, the roof behind the famous dome was waterproofed with Sonoshield® Sonoguard.
Specifically developed for vehicular and pedestrian traffic areas, Sonoshield® Sonoguard is a liquid applied moisture-cure polyurethane membrane with an integral aggregate surface that combines long-term waterproofing protection with continuously elastomeric properties and a non-slip surface.
About the BASF Construction Chemicals
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. Its Admixture Systems business unit specifically helps customers in the ready-mix, precast and manufactured concrete and underground construction industries. The Construction Systems unit offers a wide range of products for sports and industrial flooring, external renders and wall insulation, expansion joints, wood preservatives as well as specialist repair mortars, tile adhesives and waterproofing membranes. The division operates production sites and sales centers in more than 50 countries and achieved sales of €2.2 billion with approximately 7,500 employees in 2006 .
BASF is the world’s leading chemical company: The Chemical Company. Its portfolio ranges from chemicals, plastics, performance products, agricultural products and fine chemicals to crude oil and natural gas. As a reliable partner to virtually all industries, BASF’s high-value products and intelligent system solutions help its customers to be more successful. BASF develops new technologies and uses them to meet the challenges of the future and open up additional market opportunities. It combines economic success with environmental protection and social responsibility, thus contributing to a better future. BASF has approximately 95,000 employees and posted sales of €52.6 billion (approximately $66.1 billion) in 2006. Further information on BASF is available on the Internet at www.basf.com