Abstract:
The use of recycled aggregates from construction and demolition waste (CDW) as the
replacement of coarse aggregates has increased in recent years in order to reduce the high
consumption of natural resources by civil infrastructure construction sectors. In addition, steel
fiber reinforced concrete has been used in many applications such as concrete pavements,
overlays, patching repair of hydraulic structures, thin shells and precast products over the past
several decades. Nowadays, it is well established that the incorporation of steel fibers improves
engineering performance of structural and nonstructural concrete, including better crack
resistance, increase in ductility and toughness as well as enhancement in resistance to fatigue and
impact. In this work an experimental investigation is carried out to observe the influence of
Galvanized Iron (G.I.) fiber reinforcement on the stress-strain behavior of concrete made with
brick aggregate and recycled brick aggregate. In addition, compressive strength by destructive
test as well as non-destructive test, Splitting tensile strength and Young’s modulus are also
determined. Two types of coarse aggregates, brick and recycled brick aggregates having the
same gradation and water cement ratio (w/c=0.44) are used. Hooked end G.I. wires with 50 mm
of length and aspect ratio of 55.6 are used as fiber reinforcements in a volume fraction of 0%,
0.50% and 1.00%, respectively for the both cases. The experimental results show that around
10% to 15% and 40% to 60% increase in 28 days compressive strength and tensile strength of GI
fiber reinforced concrete, respectively compared to control case (0% G.I. fiber replacement) for
both the aggregates. It is seen that effect of addition of 1% fiber on the concrete compressive
strength is little compared to that of 0.5% G.I. fiber addition for both the aggregate types. On the
other hand, concrete strain at failure of G.I. fiber reinforced concrete has increased almost 2
times compared to the control case (0% GI fiber replacement) for both the aggregate types. It is
also observed that effect of fiber reinforced concrete made with 1% fiber is more than 0.5% fiber
for the both cases of aggregates in the terms of maximum strain of concrete.
Keywords: Brick aggregate, Recycled Brick aggregate, G.I. fiber, Compressive strength,
Tensile strength, Young’s Modulus, Stress-strain behavior.
