Determination of optimum fiber content in fiber asphalt mixture

Abstract：in order to determine the optimum content of fiber in fiber asphalt mixture, the high temperature rutting test, water stability test, low temperature bending test and fatigue test were carried out on the four kinds of fiber asphalt mixtures including adding no fibers and adding 0.3% fibers respectively.The low temperature bending test was carried out on the fiber asphalt mixture with different content of the same fiber, and the strain energy of the fiber asphalt mixture was analyzed.At the same time, bending tensile strength, bending strain and bending stiffness modulus within normal range or not were also analyzed.The results showed that the high temperature performance and low temperature performance of the asphalt mixture after fiber addition were obviously improved, and the optimum amount of each fiber was presented.Finally, it was concluded that the strain energy could more clearly reflect the influence of fiber change on the overall performance of the mixture and determined more accurate optimum fiber content.Under the optimum fiber content determined by the strain energy, the other technical indicators of the mixture were in an ideal state.

Keyword：fiber asphalt mixture;low temperature bending test;strain energy;optimum content;