USQ Delivers Technology Workshop on Composite Rebars
The University of Southern Queensland (USQ) has partnered with Composites Australia to provide Australian civil and composite engineers with access to the latest knowledge on an innovative reinforcing solution to the costly corrosion of concrete infrastructure.
The workshop was delivered by internationally-renowned leader on the use of fibre-reinforced polymer (FRP) composite materials in construction, USQ Adjunct Professor Brahim Benmokrane from the University of Sherbrooke, who was joined by USQ Civil Composites Group Leader, Associate Professor Allan Manalo.
It provided practising Australian engineers, civil engineering firms and engineering students with the knowledge necessary to design concrete structures with FRP bars.
Civil and structural engineers from some of Australia’s major engineering consultant and construction companies including SMEC, AECOM, Wagners and EIC Activities, were among the 40 delegates representing more than 20 organisations and five states who attended the workshop in Brisbane.
The use of FRP bars has gained considerable worldwide interest and growing acceptance in the construction industry, as internal reinforcement to concrete structures, particularly in highly aggressive environments where corrosion of traditional steel reinforcing bar is a major problem.
Professor Benmokrane explained corrosion resistance was the main motive and attraction for the choice of FRP over steel bars in public infrastructure such as roads, bridges, and parking garages in Canada, where tonnes of salt are spread throughout city streets each winter.
His comprehensive and generous presentation covered recent developments and field applications; specifications and design codes; design considerations and principles supplemented with many practical examples and fundamental theories of concrete member behaviour; all of which was evidence-based using in-situ design examples of his pioneering applications.
Professor Benmokrane also absolved concerns about the durability of FRP bars – including moisture uptake, elevated temperature, stress corrosion, creep, fatigue, fire ratings, adhesive bonding and UV resistance – by sharing the results of accelerated aging tests.
Associate Professor Manalo highlighted that in Australia, the environments were severe to use steel as reinforcement to concrete structures from the viewpoint of corrosion damage.
“The great interest in non-corrosive reinforcements such as FRP bars is increasing as most concrete bridge infrastructure start to deteriorate only after 30 years of service. Repair or replacement costs associated with this steel corrosion in Australia is estimated at AU$13 billion per year,” he said.
FRP bars are also increasingly specified for electromagnetic neutrality and sensitive electrical research equipment.
The Molecular Horizons Building at the University of Wollongong uses over 50 tonnes of FRP bars in 14 mm deep piles, pile caps, ground slabs and first floor suspended slab, and columns and walls through to the second story.
Since 2012, there were more than 1.5 million meters of GFRP bars installed in actual construction projects in Australia and the market for GFRP bars increases by 13% per year, and with an estimated market value of around AU$2.5 million in 2017.
“There is no doubt that the body of work undertaken by Professor Benmokrane and his team, coupled with our work at USQ, provides an excellent framework for reference in the development of design criteria and specifications for FRP bars so that Australia can more widely benefit from this composites option for our concrete infrastructure projects into the future,” Associate Professor, Manalo said.
Published: 14th December 2018