Effect of Aggregate Size on Beam-Shear Strength of Thick Slabs

This study investigates the safety and accuracy of the American Concrete Institute shear design method when applied to thick slabs by focusing on the size effect in shear and the role played by the maximum coarse aggregate size in transferring shear stress across cracks. An experimental program was conducted in which 10 large-scale and 10 geometrically-similar, small-scale, shear-critical reinforced concrete slab-strip specimens were loaded to failure. It was found that the major mechanism of shear transfer in these element types is aggregate interlock, and that the maximum aggregate size plays an important role in beam-shear capacity of reinforced concrete members. The abilities of the ACI design method and a simplified design method based on the modified compression field theory (MCFT) to predict the failure loads are compared. Findings indicate that the ACI design method is unconservative when applied to thick slabs or large wide beams constructed without stirrups, but the simplified MCFT design method is both safe and accurate. The simplified method also can accurately predict the effects of decreasing the maximum aggregate size on the beam-shear behavior of lightly reinforced concrete members.

  • Availability:
  • Authors:
    • Sherwood, Edward G
    • Bentz, Evan C
    • Collins, Michael P
  • Publication Date: 2007-3


  • English

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  • Accession Number: 01046596
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Apr 17 2007 10:16PM