Recently, synthetic macro fibers have been developed and introduced into the market. These fibers have many similar characteristics with steel fibers in a large number of applications. When the amount of coarse fibers is more than that of fine fibers (up to the maximum amount, about 12kg / m3, volume ratio of 1.35%), the coarse fibers can provide the bearing capacity of concrete after cracking.
the materials used in this kind of products include polyolefin, polyester, nylon, polyvinyl alcohol, polyacrylonitrile, aromatic polyamide or their mixture of polypropylene or polyethylene. At first, people mainly saw the potential application of coarse synthetic fiber in shotcrete, and then developed to some applications in foundation bearing plate and other aspects.
using the fiber can obviously improve the flexural strength and flexural toughness of concrete, increase the impact resistance and fatigue resistance of concrete, reduce the rebound rate of shotcrete, and overcome the plastic shrinkage cracks. The product is easy to operate and overcomes the defects of steel fiber, such as easy corrosion, rusting, agglomerating, mechanical wear, difficult transportation, rebound injury and so on. Moreover, its toughening and anti cracking effect on concrete is equivalent to that of steel fiber. In a variety of applications, this kind of fiber can even be used as a substitute for steel fiber. In China, crude synthetic fiber (commonly known as steel like fiber) has also been applied in tunnel spraying, bridge deck pavement, dam repair and other projects.
