Experimental Evaluation of the Cyclic Behaviour of Scaled (1:3) Reinforced Concrete Frames

Abstract

This paper presents laboratory test results for two-column one-bay reinforced concrete (R/C) bare frames with or without masonry infills for 1:3 scale prototypes when the top beam is subjected to horizontal cyclic loading using 50kN axial load per column. It is well documented that infills affect the dynamic characteristics of building structures. At the same time, their uncertain behaviors have also been recorded. Many parameters, such as the infill materials, reinforcing of infills, connection to the surrounding frame by means of surrounded joint contact, local techniques, and others affect structural system behavior. The masonry infills increase the overall horizontal lateral strength and stiffness and partially structural strength; hence, proper use can positively affect the general seismic behavior. Masonry infill benefits were tested using several specimens: one virgin bare frame, one virgin bare frame with masonry infills, and one virgin frame with masonry infills and reinforced cement plaster. In this experimental series, the aim was to investigate and study the following parameters concerning the general problem of the frames and masonry infills under the influence of cyclic horizontal loading: the frame type, the masonry infill type and, the strength of mortars and coating used to construct the brick walls. The obtained results align with the results of similar studies in Greece. All results address the influence of the infills concerning stiffness, strength, and energy dissipation of the infilled R/C frames, which are significant parameters that should not be neglected.