|
Advanced Composites
Composites can remediate structural deficiencies associated
with:
-
Earthquake forces and explosive blasts
-
Structural strengthening/upgrades
-
Change of use/increased loading
-
Expansion of structures and facilities
-
Deterioration remediation
Steel and polymer fibers
Deterioration and failure of concrete are closely related to
the formation of cracks due to load, creep, and environmental effects. Cracks in concrete allow ready access of corrosion-inducing
elements such as moisture, chlorides, carbon dioxide, and oxygen to attack reinforcing steel. Adding polymer fibers to the
concrete can reduce the possibility of conrete steel corrosion. The fibers serve two major functions: to prevent plastic shirnkage
cracking and to reduce segragation of the concrete components. The reduction in permeability of the concrete is an attribute
of primary importance with regard to the protective measure against corrosion. Adding the polymer fibers creates a high thoughness
index, which is the ability of the concrete to sustain a load under the initial crack. It is very important as it relates
to spalling and to steel reinforcement bonding.
Steel-fiber-reinforced concrete
This state-of-the-art composite material is made of hydraulic
cements, fine or fine and coarse aggregate, and a dispersion of discontinuous steel fibers. It may contain pozzolans and additives
commonly used with conventional concrete. The addition of these fibers can provide improvements of the engineering properties
of the concrete. Impact strength, toughness (post-crack ductility) are some of the properties that are greatly improving the
concrete slabs-on-grade. The ability to resist cracking and material disintegration, as well as fatigue resistance is also
enhanced. The steel fiber is an alternative to conventional reinforced slabs-on-grade. It provides superior performance as
well as eliminates the need for conventional reinforcement. Faster placement, lower life cycle costs and reduced labor costs
are added advantages.
|
