Title: Shear Behavior of Thick Slabs
Author(s): Michael P. Collins, Phillip T. Quach, and Evan C. Bentz
Publication: Structural Journal
Appears on pages(s): 115-125
Keywords: aggregate interlock; cracking; design equations; safety; shear; size effect; stirrups; test/experiment; thick slabs
Thick reinforced concrete members not containing shear reinforcement can fail at shear stresses significantly lower than those specified by the 2014 ACI Code. This is because the traditional ACI shear provisions were based on tests of small specimens, and do not account for the size effect in shear. This paper focuses on an experimental program in which a 4000 mm (13 ft) thick slab strip specimen and a 300 mm (12 in.) deep companion specimen were constructed and tested to failure. These tests extend the range of a series of 17 such slab strip experiments previously tested at the University of Toronto. The results show that the 2014 ACI Code can give dangerously high estimates of shear capacity for very thick slabs not containing shear reinforcement. The research also shows that minimum shear reinforcement greatly increases both the strength and deformability of thick slabs.