FINITE-ELEMENT EVALUATION OF SHEAR ENHANCEMENT OF HIGH-STRENGTH CONCRETE PLATES

Five types of different shear reinforcement, namely single-bend, U-sti rrup, double-bend shear stud, and T-headed shear reinforcement are eva luated numerically. Emphasis is placed on the evaluation of their cont ribution to the punching shear capacity of high-strength concrete plat es. The numerical investigation was conducted by using finite element analysis. The finite element analysis reported herein is an applicatio n of the nonlinear analysis of reinforced concrete structures using th ree-dimensional solid finite elements. The purpose of this application is to demonstrate that three-dimensional elements represent a way to model out-of-plans shear reinforcement in the slab. Hence, the three-d imensional 20-node brick element with 2 x 2 x 2 Gaussian integration r ule over the element faces and a plasticity-based concrete model were employed in a finite element program. Single-bend and double-bend shea r reinforcements were modeled with the smeared layer method while the U-stirrup, shear stud, and T-headed shear reinforcement were depicted individually in the mesh. Reasonable agreement has been obtained betwe en the numerically predicted behavior and experimental test results. F inite element analysis confirmed the experimental test results, that t he double-bend shear stud, and T-headed reinforcements are the most ef ficient types of shear reinforcement, and the U-stirrup is the least e ffective type of shear reinforcement. Transverse shear stress was eval uated by the finite element analysis in terms of shear stress distribu tion, and compared with the ultimate punching shear resistance specifi ed by the ACI 318 design code.