Title:
Effect of Aggregate Size on Beam-Shear Strength
of Thick Slabs
Author(s):
Edward G. Sherwood, Evan C. Bentz, and Michael P. Collins
Publication:
Structural Journal
Volume:
104
Issue:
2
Appears on pages(s):
180-190
Keywords:
aggregate; design; reinforced concrete; shear.
DOI:
10.14359/18530
Date:
3/1/2007
Abstract:
This paper describes an experimental program 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. 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. It was found that the ACI design method is unconservative when applied to thick slabs or large wide beams constructed without stirrups, hereas the simplified MCFT design method is both safe and accurate. It is further found that the simplified method can accurately predict the effects of reasing the maximum aggregate size on the beam-shear behavior of lightly reinforced concrete members. It is concluded that shear design methods should account for the fact that aggregate interlock plays a critical role in the beam-shear behavior of reinforced concrete members.