Seismic Retrofit of Central Opening Partial Infilled Frame by Expanded Metal Ferrocement

Abstract

This paper presents the retrofit of partial infilled frame with central opening by ferrocement and expanded metal.  Theoretical models are suggested to design the lateral resistance of the retrofitted frames.  Experimental tests on the prototype frames were carried out to verify the design method.   Four specimens were built to the full scale, which were divided into two groups: a) the bare frame and the retrofitted frame, and b) the partial infilled frame with window opening and the retrofitted frame.  It was found that the retrofitted frame with window opening showed satisfactory behaviors including the lateral strength, lateral stiffness and energy dissipation capacity.  The observed maximum lateral strength of the retrofitted frame with opening achieved the design strength.  The proposed model predicted the lateral strength with a good accuracy when it was compared with the experimental result.  The strengthened columns for the opening infilled frame prevented brittle shear failure due to the behavior of short column. The retrofitted column exhibited a ductile behavior with the developed flexural crack at the constrained level.