ABSTRACT
The objective of this paper is to report the result of an experimental program conducted on the strengthening of nonductile RC frames by using external mesh reinforcement and plaster application. This type of strengthening technique is recently added to the new Turkish Earthquake Code (2007). The main objective was to test an alternative strengthening technique for reinforced concrete buildings, which could be applied with minimum disturbance to the occupants. Generic specimen is two floors and one bay RC frame in 1/2 scales. The basic aim of tested strengthening techniques is to upgrade strength, ductility and stiffiness of the member and/or the structural system. Six specimens, two of which were reference specimens and the remaining four of which four of which had deficient steel detailing and poor concrete quality were strengthened and tested in an experimental program under cyclic loading. The parameters of the experimental study are mesh reinforcement ratio and plaster thickness of the infilled wall. The results of test on these frames were compared with reference specimens. The effects of the mesh reinforced plaster application for strengthening on behavior, strength, stiffness, failure mode and ductility of the specimens were investigated. Premature and unexpected failure mode has been observed at first and second specimens failed due to inadequate plaster thickness. Also third strengthened specimen failed due to inadequate lap splice of the external mesh reinforcement. The last modified specimen behaved satisfactorily with higher ultimate load carrying capacity. Externally reinforced infill wall composites improve seismic behavior by increasing lateral strength, lateral stiffness, and energy dissipation capacity of reinforced concrete buildings, and limit both structural and nonstructural damages caused by earthquakes.
