Researchers from the Universitat Politècnica de València, belonging to the Concrete Science and Technology University Institute (ICITECH, in Spanish), have developed a new construction element that improves earthquake protection for buildings and bridges. Its name is “Smart Seismic Concrete Connection” (SSCC). It improves the connection between the structural materials and stands out for its high capacity to change shape without breaking. In addition, it allows the structure to recover its original shape after an earthquake and it barely needs subsequent repairs. The team working at the ICITECH UPV includes José Luis Bonet, Javier Pereiro and Alberto Navarro.
“The use of this system permits having self-centering structures. The invention comes from the desire to solve a need for today’s society: constructing seismic-resistant structures for people, and maintaining their operating capacity after an earthquake, without major repairs or economic losses,” says José Luis Bonet.
Patented by UPV, this new element aids to improve structural resistance against any combination of events. It is also notable because it is easy to install. It barely requires maintenance and does not need additional space like other systems—such as the huge pendulums in some Asian buildings—because it is placed inside columns, beams and walls.
Regarding its installation, researchers explain that it is put in strategic areas inside the structure with the aim of improving its performance. “Our philosophy is not constructing more solid structures, rather the contrary. Just as the wind splits a trunk, a reed is flexible enough to bend, adapt to movement and recover its position when the wind stops blowing, without scarcely suffering damages and splitting,” explains Bonet.
The device is specially designed for bridges, hospitals, power stations, institutional buildings and any other construction that, because of its importance during an emergency, requires higher protection. It is also intended for crowded places, such as athletic and shopping centers. “Of course, it can be used in residential buildings when the developer wants to have an added plus of safety and reduce the possible future repair or demolition costs. In fact, during the lifespan of structures it could be a convenient initial investment as it permits saving costs in the future in the event of an earthquake,” adds Bonet.
High technology components
The connection device consists of two materials that symbiotically resist the earthquake. First, there are shape-memory alloy bars (SMA) that can develop something known as “superelasticity”—the capacity of those metals to recover their shape after stretching and bending, something that steel reinforcements in concrete structures cannot do. Second, there are high-performance concretes developed by ICITECH at UPV, that accompany and complement SMA. “These concretes are much less fragile than conventional ones and are able to adapt to major SMA deformations during an earthquake,” concludes José Luis Bonet.