Why we use pp fiber in the concrete?

Why we use pp fiber in the concrete?

In modern high strength and high performance concrete, the application of concrete is developing towards high strength and great fluidity. With the improvement of concrete strength and slump, the cement dosage increases, which brings the side effect is the intensification of hydration heat, the solidification shrinkage of concrete increases, the shrinkage stress increases, and the number of cracks increases.In addition, as the construction to the big volume, large area, shape, direction of development of complex and diverse, to the development of underground space, the internal stress of concrete is larger and more complex, the appearance of cracks are also far more than in the past, especially the current site most used merchandise pumping concrete, mixing fly ash, although kuangfen, expansive agent and so on has certain effect, but due to the construction, maintenance and artificial factor etc.,Often after pouring concrete ramming crack is still inevitable.It is reported that the above problems can be solved by adding fiber into concrete.