Fiber Types
Fiber types for use in fiber-reinforced concrete applications come in a variety of sizes, shapes and colors. For additional literature and dosage recommendations, please contact the appropriate manufacturer.
Common Concrete Fiber Types:
- Cellulose Fibers: Manufactured from processed wood pulp products, cellulose fibers are used in a similar manner as micro-synthetic fibers for the control and mitigation of plastic shrinkage cracking.
- Glass Fibers: Glass fiber reinforced concrete (GFRC) has been predominantly used in architectural applications and modified cement-based panel structures.
- Macro-Synthetic Fibers: This newer class of fibers has emerged over the past few decades as a suitable alternative to steel fibers when dosed properly. Typical materials include polypropylene and other polymer blends with the same physical characteristics as steel fibers. They can be dosed from 3 to 20 lbs/yd (1.8 to 12 kg/m3).
- Micro-Synthetic Fibers: These fibers are generally used for the protection and mitigation of plastic shrinkage cracking in concrete. Most are manufactured from polypropylene, polyethylene, polyester, nylon and other synthetic materials, such as carbon, aramid and acrylics. Micro-synthetic fibers are generally dosed at low volumes ranging from 0.03 to 0.2% by volume of concrete – 0.5 to 3.0 lbs/yd (0.3 to 0.9 kg/m3).
- Natural Fibers: These fibers are used to reinforce cement-based products in non-commercial applications worldwide. They include materials such as coconut, sisal, jute and sugarcane, and come in varying lengths, geometries and material characteristics.
- Poly-Vinyl Alcohol (PVA) Fibers: These synthetic-made fibers can alter the flexural and compressive performance of concrete when used at higher volumes.
- Specialty Fibers: Covering all other fiber types, this classification generally pertains to newly manufactured or specified materials not common to these categories.
- Steel Fibers: These fibers are generally used for providing concrete with enhanced toughness and post-crack load carrying capacity. Typically loose or bundled, they are usually made from carbon or stainless steel, and then shaped into varying geometries such as crimped, hooked-end or with other mechanical deformations for anchorage in the concrete. Classified within ACI 544 as Types I through V, steel fibers have maximum lengths ranging from 1.5” to 3” (30 to 80 mm) and can be dosed at 10 to 100 lbs/yd (6 to 67 kg/m3).
