The Department of Earthquake Engineering, NED University on Saturday performed shaking table test of buckling resistant bracing (BRB) system here at department's lab. The BRB system test was conducted for the first time in Pakistan under the supervision of Dr Muhammad Masood Rafi, Chairman Department of Earthquake Engineering of the varsity.
Talking to Business Recorder, Dr Masood Rafi said the Buckling-Restrained Brace (BRB) system is a seismic retrofit technique that is intended to upgrade existing reinforced concrete or steel frame structures to the state-of-the-art practice.
He said the purpose of a BRB system is to avoid buckling of the supporting brace during a seismic event. He said this system has been manufactured by Steel Canada Limited with University of Ottawa, Canada for the retrofitting the seismically deficient structures. "The BRB test was earlier performed on steel structures and now technology has made possible to retrofit/fix the deficiencies in concrete structures/buildings", Professor Masood said.
He said a fully buckling-restrained brace system that can be assembled on-site for seismic reinforcement. The BRB system can eliminate failure from buckling of the brace under compression, forcing the failure if any to take place, as desired, from elongation of the core.
It assembles quickly reducing costs as well as measurement errors and installation time on the jobsite. Low cost assembly allows for the use of higher ductility core materials, improving the energy absorption and therefore performance of the system. The system is cost savings, more ductile special steel materials (stainless steel) can be used as a yielding core to provide much greater energy absorption and significantly improve the performance of the brace. This unique system can be used not only for seismic retrofits of concrete structures but can also be applied to steel structures as well as construction of new buildings.