Title: Failure of Small Reinforced Concrete Beams Under Repeated Loads
Author(s): Jonn R. Verna and Thomas E. Stelson
Publication: Journal Proceedings
Appears on pages(s): 1489-1504
Sixty reinforced concrete beam specimens were tested to destruction under repeated loading. These specimens were 78 in. long, 5 in. wide and 4, 5 1/2, or 7 in. deep. They were simply supported over a 72- in. span and loaded at the third points. The test data are for the loading conditions of repeated cyclic loading from 10 percent of ultimate static load to a maximum until failure or 1,000,000 cycles. If no failure occurred the maximum load was in-creased and the program was repeated. The data are presented with parameters for nominal shear stress, nominal bond stress, concrete compression stress and steel tension stress. The interaction of the different modes of failure were interpreted in terms of these stresses. The tests indicated that bond is the mode of failure most susceptible to fatigue damage and that shear or diagonal tension failures are likely to occur if the specimens are not weak in bond. They showed, also, that the mode of fatigue failure depended on the load level as well as the static failure mode.