ACI code specifies the shear strength of deep beams based on the strength at the first diagonal crack of NSC
beams without the consideration of beam size effect. Therefore, it is necessary to evaluate if the ACI design equation for
deep beams is applicable to high strength reinforced concrete (HSRC) deep beams with main reinforcement ratio less and
more than 1% with considering size effect or not. This paper is considered a supplement to the companion paper (Part I
Comparison of Design Equations). Eighteen simple span HSRC deep beams without stirrups were tested to examine various
parameters on the shear capacity; f’cu=50 MPa, three values of main reinforcement, (ρs%), (0.73%,1.21% &1.83%) and four
values of shear span to overall depth ratio, (a/h), ( 0.84,1.3,1.7&2.3) were selected to mainly study the characteristics of deep
beams. The increase in overall depth (h) under the same a/h=1.3&1.7, led to more brittle failure with wide diagonal cracks
and high energy release rate related to size effects. HSRC deep beams exhibited more remarkable size effects with regard to
brittle behavior. It was also shown that the ACI code gives similar safety factors on the shear strength at the first diagonal
crack of HSRC deep beams, but do not specify a high enough safety factor on their ultimate strength due to the size effects.