Fiber reinforced Concrete

Fiber reinforced Concrete

Many different properties of the fresh and hardened concrete can be effectively influenced by adding fibers. There are innumerable different types of fiber with different material characteristics and shapes. Correct selection for different uses is important. As well as the actual material, the shape of the fibers is also a critical factor.

Fiber reinforced concrete is used for

·     Industrial flooring

·     Sprayed concrete

·     Slender structures (usually in precast plants)

·     Fire resistant structures

Properties of fiber reinforced concretes

·     To improve the durability of the structure

·     To increase the tensile and flexural strength

·     To obtain resistance to later cracking

·     To improve crack distribution

·     To reduce shrinkage in the early age concrete

·     To increase the fire resistance of concrete

·     To influence the workability

Concrete production

The fiber manufacturers’ instructions must be followed when producing fiber reinforced concretes. Adding the fiber at the wrong time or mixing incorrectly can cause great problems and even make the fibers useless.

·     Comply with the manufacturer’s adding time and method (i.e. at the concrete plant or in the ready mix truck)

·     Comply with the mixing times (balling/destruction of fibers)

·     Do not exceed the maximum recommended fiber content (considerable reduction in workability)

·     Fibers generally increase the water requirement of the mix (compensate for this with superplasticizer)

Fiber types

·     Steel fiber

·     Plastic fiber

·     Glass fiber

·     Carbon fiber

·     Natural fibers