不同纤维沥青胶浆抗剪切性能试验研究

Experimental Study on Shear Resistance of Asphalt Mortar with Different Fibers

在沥青路面工程中,纤维较多应用于提高沥青混合料的高温抗车辙性能,如城市道路交叉口或公路的长大纵坡路段。纤维沥青胶浆的抗剪切性能直接影响沥青混合料的高温抗车辙性能。采用沥青胶浆的直剪试验,探究不同纤维沥青胶浆的抗剪切力学性能,并对比不同纤维及纤维的掺加方式对沥青胶浆高温性能的改进效果。试验结果表明:沥青胶浆中加入纤维,其抗剪强度显著提高。玄武岩纤维+聚酯纤维胶浆的抗剪强度最高。纤维沥青胶浆抗剪强度的提升原因是黏聚力C和内摩阻角φ的增大,但主要是黏聚力C增大,其对抗剪强度的贡献率约为78%;掺入纤维的沥青混合料动稳定度明显提高,聚酯纤维+玄武岩纤维混掺地效果最好,这与沥青胶浆剪切试验结果一致。

The fiber is mostly used to improve the high temperature rut-resistance performance of the asphalt mixture in the asphalt pavement project,such as the urban road intersection or the long longitudinal section of the road.The shear-resistant performance of fiber asphalt mastic directly affects the high temperature rut-resistance performance of asphalt mixture.The direct shear test of asphalt mastic was used to explore the shear-resistant mechanical properties of different fiber asphalt mastic,and the improvement effect of different fiber and fiber mixed methods on the high temperature performance of asphalt mastic was compared.The test results show that the shear strength of asphalt mastic is significantly improved by adding fibers.The shear strength of basalt fiber and polyester fiber mastic is the highest.The reason for the improvement of the shear strength of fiber asphalt mastic is the increase of cohesive force C and internal friction angleφ,but the main reason is the increase of cohesive force C,and its contribution rate against shear strength is about 78%.The dynamic stability of asphalt mixture with fiber is obviously improved,and the effect of mixing polyester fiber and basalt fiber is the best,which is consistent with the results of the shear test of asphalt mastic.