Abstract:
Fiber Reinforced Concrete is one of the most promising construction techniques and
repairing materials of modern times. Polyester and steel fibers are, by far, the front
runner in the field of reinforcing fibers. A very recent investigation on the properties
of locally available Galvanized Iron wire (GI wire) which is basically mild steel wire
with a thin coating of Zinc has discovered that it has the potential to be a viable lowcost
alternative of commercially available steel fibers. Besides that, polyester fiber
has been used as popular reinforcing material from long ago. On the other hand,
Micro concrete technology is a new trend where the size of coarse aggregate is
reduced significantly without compromising the strength of concrete. Here along with
strength, workability is ensured using chemical admixture (Super plasticizer).Now a
days it is mainly used for retrofitting purposes for its various inherent characteristics.
Therefore, a research has been conducted to study the performance of locally
available GI wire fiber reinforced Micro concrete (GWRMC) and Polyester fiber
reinforced Micro concrete (PFRMC) and also make comparison to find the suitable
option for our country. This paper presents the findings of several basic
characteristics of GWRMC and PFRMC primarily related to strength, ductility and
durability. The prime focus of the study was on the effect of fiber content on the
foregoing properties of Micro concrete. Consequently, within the scope of the work,
fiber dosage was varied within low range (1 to 2.5% by weight for GWRMC and 0.1
to 0.5% by volume for PFRMC) while the concrete mix-design and fiber properties
were kept unchanged. A wide variety of tests including compressive and splitting
tensile strength, modulus of elasticity and water absorption test (Sorptivity) were
performed on suitable test specimens. It was observed for polyester fiber compressive
strength increases upto 43 percent and splitting tensile strengths increases upto 30
percent with respect to control. Again for steel fiber compressive strength increases
upto 47 percent and splitting tensile strengths increases upto 25 percent with respect
to control. Durability test i.e. Sorptivity revealed that water absorption rate of Micro
concrete is significantly lower than normal concrete. Furthermore, cost analysis and
comparison of both types of fiber shows that the use of GI wire fiber instead of
polyester fiber is little bit economical and convenient from the perspectives of
Bangladesh.
