UC engineers develop in-situ damage detection for building steel

An award-winning, pioneering technique for assessing earthquake damage to steel in buildings or bridges will allow engineers to give faster, more reliable information to engineers, with tangible flow-on results for insurers and building owners.

After the major Christchurch earthquakes, many steel-reinforced concrete buildings were deemed irreparable and demolished due to lack of information about the extent of damage to building materials. Often, disagreements between building owners and insurers continued for extended periods.

New University of Canterbury (UC) research may help to resolve these issues. Architectural Engineering lecturer Dr Giuseppe Loporcaro and Mechanical Engineering Professor Milo Kral’s research into a new technique for assessing damage to steel rebars (the steel reinforcing rods contained within concrete slabs of substantial buildings) has been awarded $20,000 in UC’s annual Tech Jumpstart competition.

Dr Loporcaro says earthquakes are unavoidable natural events, but when they occur in urbanised areas they can cause excessive damage. If this damage is not detected immediately, it extends the recovery phase.

Steel rebars are built to stretch during severe shaking, enabling the concrete they are housed in to crack while the rebars remain intact. This work determines how much the rebar has already stretched and how much capacity it still has before breaking if further shaking occurs.

Their method enables engineers to test the rebars on site rather than in a lab – a lengthier and more costly process. The other advantage of their method is more reliable results.

“Disruptions cost time and money, as well as impacting the entire community,” Dr Loporcaro says.

“The in-situ damage detection method aims to speed the assessment phase, and consequently reduce the impact on the community in terms of disruption, down-time and costs for repair and/or demolition.

“It will also allow information to reach owners and insurance companies more quickly, so issues can be resolved in better time.”

The researchers will use the award to take their innovative research towards commercial reality.