Title: Experimental and Numerical Assessment of Reinforced Concrete Beams with Disturbed Depth

Author(s): A. Hamoda, A. Basha, S. Fayed1 and K. Sennah

Publication: IJCSM

Volume: 13

Issue:

Appears on pages(s):

Keywords: beam with unequal depth, shear resistance, re-entrant corner, finite element simulation, concrete damage plasticity model, beam nib, ultimate load-carrying capacity

DOI: 10.1186/s40069-019-0369-5

Date: 11/30/2019

Abstract:
This paper investigates numerically and experimentally the performance of reinforced concrete (RC) beam withunequal depths subjected to combined bending and shear. Such beams can geometrically be considered for unleveledreinforced concrete (RC) floor slab-beam system. However, it may generate critical disturbances in stress flow atthe re-entrant corner (i.e. location of drop in beam depth). This research investigates the use of shear reinforcementand geometric properties to enhance cracking characteristics, yielding, ultimate load-carrying capacity, and exhibitingductile failure mode. Ten reinforced concrete (RC) beams were constructed and tested experimentally considering thefollowing key parameters: recess length, depth of smaller beam nib, and amount and layout of shear reinforcementat re-entrant corner. Finite element analysis (FEA) with material non-linearity was conducted in two RC beams thatwere tested experimentally to validate the computer modelling. The FEA models were then extended to conducta parametric study to investigate the influence of geometric parameters (beam shape and width) and amount andarrangement of shear reinforcement on the structural response. Results confirmed that geometric properties andratio of shear reinforcement at the re-entrant region significantly affect the behavior of reinforced concrete beam withunequal depths in terms of first cracking, yielding level, ultimate load carrying capacity and mode of failure.