Reinforce concrete with plastic fibres

Why use Fibre-Force Polypropylene Macro Fibres?

Plastic fibres help reduce shrinkage and control cracking when used as secondary reinforcement.

Polypropylene fibres tend to hold the concrete mix together thus slowing the settlement of coarse aggregate and reducing the rate of bleeding. A slower rate of bleeding means a slower rate of drying and thus less plastic shrinkage cracking. In hardened concrete, polypropylene fibres act as crack arresters. Like any secondary reinforcement, the fibres tend to stop cracks from propagating by holding the concrete together so cracks cannot spread wider or grow longer. However, since polypropylene fibres are distributed throughout the concrete, they are effective close to where cracks start at the aggregate-paste.

How is Fibre Force used?

To use these fibres, the concrete mix design does not have to be altered, and no special equipment or slump modifications are required, even for pumping or shotcreting. Therefore only two simple things must be determined: how much fibre to add and what length of fibre to use? Fibre Force is manufactured in small bundles. During the mixing operation, the movement of aggregate separates these bundles into smaller bundles and individual fibres therefore mixing easily distributes the fibres throughout the matrix.

What length of Fibres should be used?

In fibre-reinforced concrete, cracks can open only if the tensile stresses in the concrete exceed the tensile strength or the pull-out strength of the fibres. The longer the fibres are, the stronger the bond between fibres and paste is and thus the greater the fibre pull-out strength is. If fibres are too long, uniform distribution of the fibres becomes difficult. Longer fibres can be used when larger aggregates are present to shear the bundles of fibre apart. Short fibres are used with small or lightweight aggregate.

Applications

•External floors & Hardstands
•Shotcrete, mining, tunnelling
•Internal Floors
•Pipe, kerbs Pipe-racks
•V-drains
•Marine Structures
•Internal floors at retail and industrial units, schools, houses, offices etc.
•External hardstands- truck & car parking areas, storage areas, distribution centres
•Precast concrete elements- lintels, beams, pipes, water retaining tanks, walls, etc.
•Agricultural waste tanks
•Sprayed concrete
•Hardstands, external floors
•Shotcrete, tunnels, mining
•Internal floors

Advantages of Polypropylene fibres offer

• Increased flexural toughness & ductility
• Higher crack & impact resistance
• Impact & abrasion resistance
• Cost saving of 30 – 50% compared to welded mesh
• Impervious to corrosion and spalling
• High early and long term strength concrete
• High workability concrete
• Low shrinkage concrete
• Marine concrete
• Sulphate & salt resistant
• Post tensioned concrete
• Concrete for sustainable development
• Extended service life
• Potential for increased joint spacing

Product Use

Bedrock’s synthetic macro Fibre Force ™ are formulated for use in ready-mix concrete. The addition of fibres to batching or the drum of the ready-mix truck is a very simple process. This can be done by conveyer belts, chutes or dispensers or simply by hand thus simplifying your reinforcement process. Fibre force is then mixed into the concrete for a minimum of 5 minutes to achieve a consistent distribution of the fibres throughout the concrete matrix.

Placing and Finishing

Synthetic fibres can be pumped and placed using conventional equipment. Normal screeding or floating with a vibrator, powerfloat or laser screeds are applied and conventional finishing techniques and equipment can be used.

Dosage Rate

Typically fibre dosage is between 4 kg to 10 kg/m3, which will be specified by the structural engineer.

The formulated "X" shape is specifically designed to increase anchorage for Shotcrete. The shape is also advantageous to reinforcement for all other concrete and cementitious mixes. Fibre Force ™ fibres are extruded from 100% virgin polypropylene and are mechanically deformed along the entire length of the fibre to achieve maximum adhesion within the concrete matrix.

Technical Data

Fibre Lengths 30mm – 65mm
Nominal Fibre Dia (d): 0.8mm
Hooking Mechanism: X Profile, Mechanically Crimped & Distorted
Specific Gravity: 0.91
Melt Point: 180°C
Thermal Conductivity: Low
Presentation: Bundled Fibres