VIEWS: 16 PAGES: 5 CATEGORY: Engineering & Energy POSTED ON: 5/28/2010
Discussion by Evan C. Bentz ACI member, Associate Professor, University of Toronto, Toronto, ON, Canada The authors are to be congratulated for writing a comprehensive paper that summarizes the opinions of ACI Committee 446 on fracture mechanics approaches to shear design. Figure 8 shows the results of a fracture mechanics-based finite element (FE) model predicting the shear strength of members with stirrups based on a test from Toronto.11 The discusser is surprised at the predicted shear strength values shown in Fig. 8(b). The reason why empirical relations can be used for the effects of steel ratio ρ^sub w^, relative shear-span ratio a/d, and concrete compressive strength f'^sub c^ , but not for the effect of size, is the difference between interpolation and extrapolation.
the test (for example, measured crack widths are reported in curve, nonlinear dynamic analysis was used to determine the Table 3). Very little shear displacement of the crack surfaces maximum displacement of a variety of concrete walls was observed. Thus it was concluded that the diagonal cracking subjected to
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"Justification of ACI 446 Proposal for Updating ACI Code Provisions for Shear Design of Reinforced Concrete Beams. Paper by Zdenek P. Bazant, Qiang Yu, Walter Gerstle, James Hanson, and J"Please download to view full document