Bridges: The weakest link or the strength of the Australian economy?
ARRB’s National Leader of Asset Performance Nigel Powers writes about the evolution of bridges and how important it is to continuously monitor and assess these structures to ensure they are well maintained.
The road network is critical for the Australian economy through the movement of freight and for quality of life.
Bridges are a critical part of the Australian road network, but they are sometimes taken for granted. They connect people, businesses and communities – making it possible for us to safely and reliably cross rivers, creeks and other obstacles.
Bridges have undergone significant change through history. They have been designed to varying standards, based on the best available knowledge, experience and technology available at the time. In the late 1800’s and early 1900’s, bridges were made from timber and masonry and designed to safely transport 15-tonne steam rollers.
Throughout the 1900’s, the design loads increased as technology and materials improved with modern computing and analysis, enabling the use of materials like steel, concrete and more recently carbon fibre in bridges.
At the same time, the mass of the freight being carried has increased with vehicles more than 80 tonnes now regularly using the road network. This creates a major challenge for road authorities, especially for local government, which has many bridges designed to much lesser loading still in service.