Seyed Masood Hassanzadeh Shirazi - University of Tehran, Tehran, Iran
Mohammad Sadegh Marefat - University of Tehran, Tehran, Iran
Rasool Rostam Shirazi - University of Tehran, Tehran, Iran
Mohammad Khanmohammadi - University of Tehran, Tehran, Iran

There are many reinforced concrete structures throughout the world that have been built in the past decades and lack appropriate seismic details and reinforced by plain bars. To study the behavior of such buildings, seven beams have been tested under cyclic and monotonic load. The specimens include substandard beams and beams with standard details reinforced either by plain bars or by deformed bars. The tests indicate that the substandard specimens sustain relatively large slip of longitudinal bars, separation of specimen relative to foundation and sliding at large deformation phase. The standard specimens reinforced by plain bars perform almost similar to standard specimens with deformed bars, in terms of elastic stiffness and lateral displacement ductility; but, they sustain larger slip, smaller yield strength. The damage index defined by (Park and Ang 1985) has been used and the index has been correlated to experimental results.

plain bar, cyclic test, slip, damage assessment, average curvature