Experimental study on crack resistance property of fresh polypropylene fiber concrete

In this paper, through the observations experiments of plastic shrinkage cracking in 10 fiber reinforced concrete slabs constrained at the end under outdoor natural environment, and free shrinkage experiment under standard test method, the influence of polypropylene fiber length, fiber volume fraction and the fiber mixing way on the performance of fresh fiber reinforced concrete cracking was studied, and the performance of fiber reinforced concrete slabs with different mix proportion resisting early plastic shrinkage crack was evaluated. The test results about crack length, quantity and width show that, 3mm short fiber has good inhibitory effect on free drying shrinkage of concrete, while blending long and short fibers has the best inhibitory effect on the constrained plastic shrinkage and cracking of concrete. Low-volume content of fiber reinforced concrete also has a certain limit crack effect. Among them, the volume content of 0.2% of the concrete has the best crack resistance effect.