Title: Behavior of Reinforced Concrete Frames Under cyclic Loads Using Small Scale Models

Author(s): Gajanan M. Sabnis and Richard N. White

Publication: Journal Proceedings

Volume: 66

Issue: 9

Appears on pages(s): 703-715

Keywords: cyclic loads; deflection; frames; lateral pressure; limit design method; load-de-flection curves; loads (forces) ; models;moment-curvature relationship;portal frames;prototypes;reinforced concrete;research.

DOI: 10.14359/7392

Date: 9/1/1969

Abstract:
Twenty reinforced concrete portal frames were tested to study their response to high intensity repeated loads. Twelve frames (10 small scale models and 2 prototypes) of identical design were subjected to gravity loading; six were loaded continuously to failure and six were subjected to repeated loading. Maximum severity of loading was 10 cycles at each of 85, 90, and 95 percent of ultimate capacity. Eight additional model frames were tested in a program involving complete reversal of horizontal sidesway loading at intensities ranging from 65 to 80 percent of the single cycle ultimate load capacity. It is concluded that the load carrying capacity of the frame is relatively unaffected by repeated gravity loads at magnitudes of up to 95 percent of the ultimate load but is substantially affected by a complete reversal of lateral load. The critical reversible load beyond which frames could not achieve single cycle ultimate capacity was found to be between 75 to 80 percent of the single cycle load. It is also shown that small scale models can be successfully used for studying the detailed behavior of reinforced concrete frames. Good agreement between model and prototype results was obtained for ultimate loads, deflections, moment- rotation characteristics, and over-all structural behavior.