Impact of Aggregate Size on the Behavior of Steel Fiber Reinforced Concrete Deep Beams without stirrups

Abstract

In this paper, the influence of aggregate size on the mechanical behavior of steel fiber
reinforced concrete (SFRC) deep beams is reported. Two full-scale SFRC deep beams were
developed with conventional concrete and tested under four-point conditions at 2 mm/min
loading rate. The first beam was prepared with normal concrete of maximum aggregate size
of 10 mm (CA10), whereas, the second beam was developed by 20 mm and 10 mm mixed
coarse aggregate (CA20-10). Because of the improved fiber distribution, the ductility of
SFRC deep beams with CA10 was marginally higher and had notably higher load capacity
with respect to CA20-10. The SFRC deep beam with 10 mm CA compared to that of CA20-
10. Moreover, mutually SFRC deep beams with CA10 and CA20-10 concrete exhibited
complete asymmetric displacement response to incremental loading. Naturally, the nonuniform
fiber dispersion and aggregate interlock produced the different shear resistance on
both sides of the beam. The failure pattern of SFRC deep beam with CA10 and CA20-10
concrete have similar failure (shear) mode. The major cracks developed between in the
constant shear region were the cause of the brittle beam failure.