Dr Stefano Pampanin of the University of Canterbury explains how new materials consisting of small metallic or composite fibres can be added to concrete to help dissipate the energy of an earthquake, and so reduce damage.
DR STEFANO PAMPANIN
Concrete is made of aggregate – we call them stones, but aggregate - and sand. So concrete takes compression properly but does not like to be stretched in tension: it will be crack. So we typically have some steel, and steel takes tension very well. Instead of using major bars, we’re using these minor fibres, that can be very advanced and not necessarily are made of steel, can made of very advanced materials like carbon, like glass fibres. They are extremely strong in tension, so what happen is that if they are steel fibres they are going to stretch back and forth and they are going to dissipate, in a plastic way, the energy that we are going to input.
It’s interesting because this use of, for example, small fibres, has been widely investigated around the world in the last, I would say, 20 years. But not for seismic application - has been investigated to be implemented in buildings, not in seismic region. So there’s a not - lot of knowledge about how to use these material in standard application but not for seismic application.