Fibers in concrete
The commonly fibers used in concrete has steel fibers, synthetic fibers, glass fibers, natural fibers, and carbon fibers.
1、 Steel fiber
Steel fiber is a high-quality concrete reinforcement material, generally using steel fibers with a diameter of 0.25-1.0mm and a length of 25-40mm; There is also a type of bidirectional steel fiber that can simultaneously enhance the tensile and compressive strength of concrete. Steel fibers have advantages such as high strength, high elastic modulus, high plasticity, and good impact resistance, and are widely used.
2、 Synthetic fibers
Synthetic fibers are high-strength, high modulus, and high toughness fiber reinforced materials that can effectively improve the bearing capacity, tensile performance, and durability of concrete. The commonly used materials for synthetic fibers include polypropylene, polyester, polyether, polybutene, and polyurethane, which vary in length and are generally 6-51mm. Synthetic fibers are lightweight and easy to construct, and are widely used in engineering such as concrete slabs, pipelines, floors, tunnels, and bridges.
3、 Fiberglass
Glass fiber is a non-metallic fiber composed of glass fiber. It has the characteristics of anti-corrosion, anti-aging, high temperature resistance, good electrical insulation, etc. Its excellent toughness and strength make it widely used in the fields of construction, safety protection, electronics, ships, aircraft and automobiles. The length of fiberglass is generally between 3-25mm, with a diameter of approximately 0.015-0.025mm. Fiberglass has excellent tensile strength and toughness, but is sensitive to thermal stress and low-temperature brittleness, which should be taken into consideration during use.
4、 Natural fibers
Natural fibers refer to fibers extracted from plant bodies, such as wood fibers, hemp fibers, palm fibers, etc. Adding these materials to concrete can improve its toughness and durability, reduce surface cracking, and also give concrete excellent properties such as sound insulation and thermal insulation. The length of natural fibers is generally around 5-50mm, and the diameter ranges from 0.1 to 0.2mm. Natural fiber has low strength and high organic matter content. When using, attention should be paid to controlling the fiber content and blending ratio.
5、 Carbon fiber
Carbon fiber is a non-metallic material with advantages such as high strength and low density, and is an important material for manufacturing high-tech products. The application of carbon fiber in concrete can improve its strength, stiffness, and impact resistance, as carbon fiber has properties such as corrosion resistance, high temperature resistance, high elastic modulus, and low coefficient of expansion, making it suitable for fields such as bridges, tunnels, subways, and buildings.
In summary,adding fibers to concrete can improve its strength and toughness, reduce the harm of cracking, and increase its seismic performance. The commonly used types of concrete fibers include steel fibers, synthetic fibers, glass fibers, natural fibers, and carbon fibers, each with different characteristics and applicable ranges.