Experimental Study on Water Stability of Asphalt Mixture

To improve water stability, we mixed asphalt mixture with cement, slag micro powders and lignin fibers, respectively. The Marshall immersion and freeze-thaw splitting tests were carried out. It is shown that cement replacing mineral powders can improve the water stability of asphalt mixture, especially at the content of 1/3 mineral powders, with a Marshall stability of 11.50 kN and a soaking residual stability of 92.46%, increasing by 10.79% and 6.58%, respectively, than those without any cement. According to the results of cement replaced by slag micro powders, its stability increases by 1.38kN, and the soaking residual stability is 90.64%, but the freeze-thaw splitting tensile strength slightly decreases. It is indicated that the water stability of the asphalt mixture can be improved by adding 0.3% lignin fibers, the soaking residual stability increasing from 86.75% to 97.41% and the ratio of freeze-thaw splitting tensile strength rising from 60.94% to 80.29%. It is concluded that the best effect can be reached by adding 0.3% lignin fibers.