New RAD 55 macro synthetic structural fibre has been embraced by, and readily accepted in the shotcrete and engineering industries as end users recognise the benefits of replacing steel fibre and mesh with a synthetic fibre.
Structural synthetic fibre (RAD 55) is superior to more conventional reinforcement in shotcrete as it can outperform, give greater cost savings, is easier to use and safer to handle. Radmix International has uniquely packaged the RAD 55 fibres in a 2kg water-soluble bag.
These bags of fibres are placed in the plastic concrete mix in the transit mixer right at the job site.
The bags then dissolve within a couple of minutes, leaving the fibres to disperse evenly throughout the matrix. Since the bags are light they are safer to use, and there’s no more lifting of heavy boxes or bags.
The fibres themselves are unlikely to injure the worker, compared to some of the needlelike steel fibre that can be hazardous to handle.
It has been demonstrated in round determinant plate (RDP) tests that by using synthetic fibres a dosage rate of only 6kg to 8kg per cubic metre is required to obtain higher cumulative energy absorption (measured in joules) compared to a steel fibre dosage rate of 35kg to 50kg.
The beam test shows slabs on ground and pre-cast concrete predominantly require a dosage rate of between 25kg to 40kg of steel fibres per cubic metre.
In comparison, using between 3kg to 6kg of structural synthetic fibre per cubic metre of concrete achieves greater strength and durability in the matrix.
The product has been successfully used in pre-cast, hillside driveways and other concrete roading and paving projects It’s ease of handling, corrosion resistance and increased strength are its main features.