Shear Behavior of Concrete Beams Reinforced with High Performance Steel Shear Reinforcement

MMFX;Shear

Munikrishna, Aruna ; Dr. Sami Rizkalla, Committee Chair,Dr. Emmett Sumner, Committee Member,Dr. Rudi Seracino, Committee Member,Munikrishna, Aruna ; Dr. Sami Rizkalla ; Committee Chair ; Dr. Emmett Sumner ; Committee Member ; Dr. Rudi Seracino ; Committee Member

University:North Carolina State University

关键词: MMFX;    Shear;   

Others  :  https://repository.lib.ncsu.edu/bitstream/handle/1840.16/1618/etd.pdf?sequence=1&isAllowed=y

美国|英语

来源: null

【 摘 要 】

The current shear design provisions of the ACI 318 specifications limit the yield strength in transverse reinforcement to 60 ksi. Advancement in technology has led to the fabrication of High Performance steel. Use of HP steel in reinforced concrete could lead to cost savings by reducing the amount of steel required due to the inherited high strength and increase of the service life of structural members due to its enhanced corrosion resistance. This research is undertaken to examine the use of high performance steel as a feasible reinforcement material for reinforced concrete structures. Commercially available steel, Micro-Composite Multi-Structural Formable (MMFX), conforming to ASTM A 1035, was selected for this study. MMFX steel has minimum yield strength of 100 ksi.This experimental program comprised eighteen tests using nine large-scale reinforced concrete beams subjected to static loading up to failure. The key parameters considered in experimental program were the steel type and the amount of shear reinforcement. This research investigated crack width, modes of failure, deflection, stirrup strain, ultimate load carrying capacity and the behavior of the MMFX steel as transverse reinforcement for concrete beams.Results from the experimental program show that by utilizing the higher yield strength and consequently reducing the reinforcement ratio of MMFX steel, the beams can achieve almost the same load-carrying capacity as the beams reinforced with conventional Grade 60 steel. Also, beams reinforced with MMFX showed similar deflections at service load as the beams reinforced with Grade 60 steel. Therefore, reduction in the reinforcement ratio of MMFX steel, did not affect the serviceability of these beams.Analysis shows that the ACI 318, CSA, and AASHTO LRFD design codes can closely predict the ultimate shear strength for beams reinforced with high performance steel having yield strength up to 100 ksi. The beams were also analyzed using a well-established Modified Compression Field Theory (MCFT) to predict the shear strength of beam reinforced with high-performance steel.MCFT can be used to accurately predict the shear behavior of the beams. Based on the results and findings of the experimental and analytical research, design guidelines are proposed for the use MMFX steel as shear reinforcement in concrete beams.