碳纤维土工格栅加筋沥青混合料低温抗裂性能研究

Research on Low-temperature Crack Resistance of Carbon Fiber Geogrid Reinforced Asphalt Mixture

为了探究碳纤维土工格栅对沥青混合料低温抗裂性的改善效果,为新型沥青路面结构的选择提供理论依据,制作不同结构层间(AC13-AC20、AC20-AC25)的无加筋、碳纤维格栅加筋混合料小梁弯曲试件。通过低温弯曲破坏试验评价其低温抗裂性能,得到主要结论如下:(1)碳纤维格栅加筋混合料的裂缝张开度明显小于无筋混合料,试件断裂时,碳纤维格栅仍未达到极限变形;(2)在AC13-AC20试件中,碳纤维格栅试件的最大抗弯拉强度、最大弯拉应变、弯曲劲度模量与无筋混合料相比,分别提升了13.97%、48.06%和-19.11%,破坏时间延迟61.66%,而在AC20-AC25中,上述数值分别为14.39%、51.14%、-19.90%和66.95%,这表明碳纤维格栅加筋能够显著提升混合料的低温抗裂性能。

In order to explore the improvement effect of carbon fiber geogrid on the low-temperature crack resistance of asphalt mixture,and provide the theoretical basis for the selection of new asphalt pavement structure,the bending specimens of trabeculae of non-reinforced and carbon fiber grid reinforced mixtures between different structural layers(AC13-AC20,AC20-AC25)are fabricated.The low-temperature bending failure test is carried out to evaluate its crack resistance,and the main conclusions are obtained as follow:(1)The crack opening of the carbon fiber grid reinforced mixture is significantly smaller than that of the unreinforced mixture,and the carbon fiber grid still does not reach the limit deformation when the specimen is broken;(2)Compared with the unreinforced mixture,the maximum flexural tensile strength,maximum flexural tensile strain and flexural stiffness modulus of the carbon fiber grid specimens are increased by 13.97%,48.06%and-19.11%respectively in the AC13-AC20 specimen,and the failure time delay is 61.66%,while in AC20-AC25,the values are 14.39%,51.14%,-19.90%and 66.95%respectively.It shows that the carbon fiber grid reinforcement can significantly improve the low-temperature crack resistance of the mixture.