Experimental research on the seismic behaviors of corroded RC frame beams failed in flexure-shear mode under the artificial climate

8 RC frame beams with shear span ratio as 2.67 were tested in artificial climate until the deigned corrosion crack widths were reached for the specimens, and then the quasi-static tests were carried out to study the seismic behaviors of corroded RC frame beams with stirrups and longitudinal steel bars failed in flexure-shear action. The 8 specimens were divided into two groups. The structural design parameters of the specimens in the first group remained unchanged, but the corrosion crack widths of steel bars were changed. The specimens in the second group were designed with the same corrosion crack width, but the stirrup ratios were changed. Six performance indicators, such as bearing capacity, ductility and plastic rotation, displacement restoring capacity, stiffness degradation and cumulative hysteretic energy dissipation parameters, were used to evaluate the deterioration law of seismic behaviors of RC frame beams with different corrosion crack widths and stirrup ratios. The conclusions were given as follows: corroded RC frame beams with lower stirrup ratio are more sensitive to the corrosion rate. Based on the skeleton curves of RC frame beams, it is seen that both flexural capacity and shear capacity may degrade with the increase of corrosion rate of stirrups and longitudinal bars. It is proved that the indices of ductility coefficient, stiffness degradation and cumulative hysteretic energy dissipation are most sensitive to the corrosion rate. With the increase of corrosion loss ratio, the failure mode would transit from flexure-shear failure to shear failure. ©, 2015, Editorial Office of China Civil Engineering Journal. All right reserved.