Researchers at Deakin University (Geelong, Australia) have designed a pedestrian bridge over Cowies Creek at Deppeler Park in North Geelong that uses sustainable materials. Designed by Deakin researchers Mahbube Subhani and Kazem Ghabraie, the bridge is made from concrete with a durable carbon and glass fiber-reinforced polymer that will not require maintenance over its 100-year lifespan.
Subhani and Ghabraie designed the bridge on behalf of North-Geelong based engineering firm Austeng, which submitted the winning bid to build two pedestrian bridges for the City of Greater Geelong (COGG). As opposed to steel-reinforced concrete requires regular maintenance about every five years, the reinforced concrete design “should not require any maintenance for the whole of its design life,” says Subhani.
Subhani notes that the reinforced concrete design offers improved corrosion protection that steel-reinforced concrete designs do not. “We have replaced the steel reinforcing bar normally used in steel reinforced concrete with more durable carbon and glass fiber reinforced polymer,” he says.
Not only is this carbon and glass fiber-reinforced polymer five times lighter than reinforced steel, it is also stronger. In addition, it only requires 25% of the energy used to produce steel, thereby reducing both maintenance costs and CO2 emissions. “Instead of cement, the concrete has been made using fly ash, a by-product of coal combustion,” according to Subhani.
Pre-testing for the bridge shows that the pedestrian bridge can handle the design load. Over the long term, the Deakin researchers hope the reinforced concrete used on the Cowies Creek bridge can be used to make new and replacement bridges throughout COGG.
Source: Deakin University, www.deakin.edu.au.