When it comes to providing quality road and bridge infrastructure, one of the biggest challenges being faced by Australia’s road authorities and Councils is that of ever increasing vehicle loads. A large percentage of the nation’s aging bridge infrastructure was neither designed or constructed with the intention, or physical capabilities, to support the types of vehicles and massive loads that are now commonplace. As such, many Councils are now faced with the task of ‘upgrading’ these bridges to meet the needs of modern road users.
Following on from its success in a series of Australian trials, as well as thousands of successful international applications, MBT’s remarkable MBrace™ Composite Strengthening System has been used to strengthen two bridge structures in Tasmania. This has given them a new lease of life ensuring their continued long term viability.
Both projects were carried out for Tasmania’s Department of Infrastructure, Energy and Resources , with the contract for the structural engineering and design work awarded to Pitt and Sherry, and the construction works contracts awarded to Tasmanian based company Van Ek Contracting Pty Ltd.
As the first Australian bridge projects to utilise the MBrace system, they have already generated a significant amount of interest from engineers, contractors and road authorities around the country. The first of the two Tasmanian projects involved the use of the MBrace Composite Strengthening System to improve the load bearing capacity of a rail underpass bridge along the Bass Highway at Devonport.
Constructed in 1970, the 140 metre long bridge required upgrading and strengthening in order for it to meet the increased vehicle mass limits that have been introduced along this section of the national highway.
MBrace carbon fibre laminate strips were applied to the underside of the bridge deck along each of the bridge’s eight spans. The strengthening process first involves the application of the low viscosity epoxy MBrace Primer, followed by the use of the MBrace Levelling Mortar to level uneven surfaces and the application of MBrace Adhesive. At this stage the carbon fibre strips are also coated with adhesive, aligned, and then pressed into position using a hard roller.
The second project incorporated the use of the MBrace Composite Strengthening System along the Ouse River Bridge on Tasmania’s Lyell Highway. Constructed in 1947, the Bridge appeared to be in relatively good condition. However, due to the age of the structure, and the nature of concrete materials that were used in its construction, the initial cleaning work exposed some areas of material deficiency which were repaired prior to the application of the MBrace carbon fibre laminates.
“The use of the MBrace Composite Strengthening System for the Devonport Rail Overpass and the Ouse River Bridge provided us with a cost effective solution that has significantly improved the strength and load bearing capacities of both bridges,” said David Coe, Director, Pitt and Sherry. “Not only will they be able to withstand the increased traffic loads, they’ll be able to continue to stay in service for many more years.”
For further information contact Andrew Sarkady, at MBT (Australia) Pty Ltd, telephone (03) 9569 4855 or visit www.mbtaus.com.au.
* Copy provided by MBT
