Abstract:
Sudan one of the developing country in the world. In future
high strength high performance concrete required for construction
work .Concrete being the most important and widely used material
is called upon to possess of very high strength and sufficient
workability properties. Concrete made with Portland cement has
certain characteristics: it is relatively strong in compression but
weak in tension and tends to be brittle. Another fundamental
weakness of concrete is that cracks start to form as soon as
concrete is placed and before it has properly hardened. The
weakness in tension can be overcome by the use of conventional
reinforcement on the other had researchers is continues research
the possibility of prevent crack formation and develop the
concrete properties by used Fiber-reinforced concrete (FRC).
FRC is a concrete containing fibrous material which
increase its structural integrity, geometries, distribution,
orientation, and brittleness also effect on strength. Polypropylene
Fiber Reinforced Concrete (PpFRC) is an embryonic construction
material which can be described as a concrete having high
mechanical strength, stiffness and durability. Hence, this research
was interested in finding out the effects of addition of various
proportions of polypropylene fiber on the properties of concrete,
also to know the optimum quantity of polypropylene fibers.
3D Polypropylene fibre reinforcement (AdFIBRE’ III) of
different percentage (0.05%, 0.10%, 0.15%, 0.20%, 0.25% and
0.30%) was added in local concrete ( Sudanese material :cement
and aggregate)) tests fresh and hard PpFRC in : workability,
compressive strength, and flexural resistance tested at :3,7,28 days
From the exhaustive and extensive experimental work it was
found that: PpFRC enhanced performance of concrete by reducing
blending ,segregation and plastic shrinkage crack , also we
observed that : slump decreases with increases of PpF percentage,
on the other hand compressive strength increase 8% when we add
0.05 % which is the best percentage of PpF , but generally we
haven’t sufficient enhance in PpFRC due to reduce of workability
, about flexure strength it increase with increase in PpF content
the best percentage is 0.30% of polypropylene fiber that produced
improved 12% in flexural strengths , as a result of more duality
and bonding with fiber , less crack , there for the strength grown
up, which observed clearly in the failure mode was become
gradually.
