The Earthquake Engineering Online Archive

Stiffness degradation of reinforced concrete members subjected to cyclic flexural moments

Bertero, Vitelmo V.; Bresler, Boris; Liao, Huey M.

UCB/EERC-69/12, Earthquake Engineering Research Center, University of California, Berkeley, 1969-12, 115 pages (530/B37/1969)

A method of testing and evaluation of stiffness degradation in the inelastic regions of reinforced concrete beams is presented. Selection, fabrication, instrumentation and testing of specimens are described in detail. Four beams having rectangular cross sections were subjected to different deformation histories including reversed loadings. Test results are presented in terms of hysteresis loops for steel and concrete strains, curvatures and deflection. Effects of deformation history on stiffness, strength, ductility and energy absorption and dissipation are discussed. This report constitutes the first phase of a continuing program of investigation and recommendations for further research are indicated.

Available online: http://nisee.berkeley.edu/documents/EERC/EERC-69-12.pdf (14 MB)