• The idea of using fibers in concrete materials dates back to Roman and Egyptians period
• Romans included bits of horsehair in the construction of wall.
• ROMAN COLISEUM which was built in 80 AD
• The Egyptians used straw in their bricks used for constructions
INTRODUCTION TO SECONDARY REINFORCEMENT OF CONSTRUCTION BY FIBRES
• Plastic shrinkage and plastic settlement cracks
• Less abrasion resistance and impact resistance of floors
• Weak construction joints
• Periodic maintenance of floors due to less durability
• Faster wearing of top floor surface
DRAW BACKS IN CONCRETE FLOORING WORKS
• Development of plastic shrinkage cracks in the initial stage of plastering
• High rebound loss of mortar
• High water and moisture absorption from external environment
• Less cohesive mix due to segregation
• Development of thermal and drying shrinkage cracks at the hardened surface
of plastering
• More maintenance of the walls required in terms of frequent waterproofing and painting of the buildings
• Ugly crack patches
DRAW BACKS IN PLASTERING WORKS
• Generation 1 - Vegetable Fibers - Straw, Jute and Cotton, Coconut Coir
• Generation 2 - Horse hair, Sheep’s Wool
• Generation 3 - Glass, Polyester, Nylon, Polypropylene and Steel
DEVELOPMENT OF FIBER REINFORCEMENT
• Glass - Expensive, Causes itching, Hazardous
• Steel - Corrosion, Dead Weight, Expensive, Mixing Problem
• Nylon - Very Expensive
COMPARISON WITH VARIOUS TYPES OF FIBERS
• Holds aggregates & does not allow separation of coarse aggregate due to
vibration /gravity
• Results move uniform concrete to concrete
• Fiber allows slow transfer of water to surface, resulting in reduction of cracks
WHAT FIBRE DOES?
ACCEPTANCE CRITERIA FOR CONCRETE WITH SYNTHETIC FIBERS
• Synthetic fibers are added to concrete to reduce plastic shrinkage cracking of reinforced concrete and structural plain concrete and/or to reduce shrinkage and temperature cracking in structural plain concrete slabs on grade.
• Consideration to be given to the volume, size and type of fibers used.
• The fibers are regarded as an admixture and are used in addition to any structural reinforcement, shrinkage and temperature reinforcement and joints as required in the applicable code.
• The fibers may be used in concrete over steel deck construction.
• The fibers may be used in fire-resistive construction on steel decks.
· Fibers were instrumental in reducing shrinkage cracks
· Rebound loss of the mortar has been reduced to 10 % instead of 30 to 40 % with out fibers in the mortar
· There is no Dampness and leakage of plastered walls
· Better finish of wall surface
· Increased strength of mortar due to which more durable and long lasting constructions
· Savings due to economic mix designs and more durable plastered surface
· Compressive strength of plaster was increased by over 15-20%
· Results in Cement savings up to 3%
· Increase in labour productivity by over 5%
ADVANTAGES & BENEFITS OF USING FIBERS IN PLASTERING
AT OUR PROJECTS
The use of fibers has improved the abrasion resistance of concrete floors to
moving loads.
· No appearance of plastic shrinkage and plastic settlement cracks on the concrete floor surface.
· Service life of the floor is enhanced due to high durable concrete produced with synthetic fibers.
· Improved impact resistance of floors to point loads
· Concrete mix with fibers was cohesive with better workability
· Compressive strength of plaster was increased by over 8-10%
· ADVATAGES & BENIFITS OF USING FIBERS IN CONCRETE FLOORING WORKS
· Use of Synthetic Fibers in all construction applications should be encouraged by the construction industry.
· Different types of fibers should be developed to address each specific need of construction applications.
· Construction industry should encourage new technologies like fibers reinforcement in construction to a larger extent for improving the durability and serviceability of the building and structures.