SHear strength of reinforced concrete-composite beams with prestressed concrete and non-prestressed concrete

초록

Reinforced concrete (RC)-composite beams with prestressed precast concrete (PSC) and non-prestressed cast-in-place concrete (non-PSC) are frequently used for precast concrete construction. However, the vertical shear strength of such prestressed concrete composite beams is not clearly defined in the current design codes. In the present study, simply supported PSC composite beams were tested to evaluate the effect of prestressing on the shear strength of the composite beams. The test variables include the cross-sectional area ratios of PSC and non-PSC, the magnitude of prestressing force, the shear span-depth ratio, and the transverse reinforcement ratio. The test results showed that the shear strength increased when the PSC area ratio, prestressing force, and transverse reinforcement ratio were increased. However, because the prestressing force did not completely restrain the diagonal tensile cracks in the non-PSC, the effect of the prestressing force on the prestressed composite beams was not as significant as that on the prestressed monolithic beams. Based on the test results, a design recommendation was given to safely predict the shear strength of the prestressed composite beams. © 2018, American Concrete Institute. All rights reserved.

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