Summary: | 碩士 === 國立成功大學 === 土木工程學系碩博士班 === 100 === This thesis presents analysis and design of reinforced concrete beams subjected to combined bending (M), shear (V), and torsion (T).Comparison of experimental failure load with prediction of Elfgren’s interaction equation, the requirements of reinforcement according to AASHTO-LRFD (2010) and ACI 318-08 Code, and the softened effects of concrete under various combined loads are studied.
Two series of beam specimens were tested. One is TM series including 8 beams under various T/M ratios, and the other is TV series including 13 beams with solid and hollow sections under various T/V ratios. Both have 350×500mm cross section.
Results indicated that conservative estimate of failure load were found from Elfgren’s interaction equation. The ratios of test to prediction of failure loads for TM and TV series are 1.27 and 1.29, respectively. In TM series, failure modes changed at M=0.59Mo. The volumetric ratio of reinforcement requirements based on AASHTO-LRFD is closer to actual design than ACI 318 Code. As T/M ratio increased, the softening coefficient of TM series beams decreased. The softening effect of concrete is also evidenced from the measured of softened compressive strains at failure stage.
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