Influence of loading history on the response of a reinforced concrete beam

Abstract

An investigation considering the influence of loading histories on the performance of a reinforced concrete beam plastic hinge is described. Twelve loading histories were considered, including conventional procedures employed in the United States, Japan and New Zealand, and artificially generated histories derived from recorded earthquake ground motions. Details of the prototype structure and the test beam are described, followed by comprehensive reporting o f experimental data. Performance descriptors and further treatment of the experimental data are presented in a companion paper.

Effects of variation in loading protocol on the strength and deformation capacity of ductile reinforced concrete beams

“…Consideration of the number of large-drift cycles can be essential for the collapse limit state, as evidenced by other experimental programs. [16][17][18] Based on the results of this and previous studies, it is the authors' opinion that the number of loading cycles prior to damage localization is not a major contributing factor to the deformation capacity of flexural members. Damage localization is dependent on the failure mode of the component in question and could take the form of bar buckling, degradation of core concrete, or yielding of transverse reinforcement.…”

“…A number of experiments have previously been carried out that investigated the effects of loading history on the performance of reinforced concrete components with ductile seismic detailing. [12][13][14][15][16][17][18] These studies have demonstrated both the limited effect of preyield cycles as well as the importance of large-displacement cycles on the assessed deformation capacity; however, questions remain about the effects of "moderate," but above yield, displacement cycles, and about the mechanics that lead to decay in lateral stiffness or resistance in plastic hinges. For the following summary, "failure" is defined using the commonly accepted criteria of a 20% drop in strength after reaching peak lateral load capacity.…”

An assessment of parameters describing the response of a reinforced concrete beam

“…As part of this study, a model of a ten-storey building was generated in the computer programme Ruaumoko (Carr 1998) in order to generate five simulated earthquake loading histories. The building was modelled at twothirds scale for four of the five acceleration histories to comply with the adopted scale of structural testing (Ingham et al 2001).…”

“…Table 2 presents details of the four earthquake records that were chosen to generate the five acceleration histories used in this study, with Table 3 summarising the sequence of the records. Table 3 was conducted with the objective of further expanding the suite of loading histories to be used in the structural testing programme reported by Ingham et al (2001).…”

“…A companion paper (Ingham et al 2001) outlined the rationale, test methodology, and salient results from testing of twelve reinforced concrete beams. These beams were nominally identical, but were tested using twelve different loading histories cons1stmg of: laboratory procedures common in the United States, Japan and New Zealand; fabricated histories including monotonic, fatigue, and uni-directional response; and simulated earthquake load histories.…”