RAP掺量对AC-13再生沥青混合料性能影响研究

Study on the Effect of RAP Content on the Performance of AC-13 Recycled Asphalt Mixture

为研究沥青混合料回收料(Reclaimed Asphalt Pavement,RAP)掺量对AC-13再生沥青混合料性能的影响,本文设计了3种掺量的AC-13再生沥青混合料,分别测试其在相同级配情况下,处于最佳沥青含量时,再生沥青混合料的空隙率、浸水残留稳定度、冻融劈裂强度比、动稳定度和小梁试件的弯拉应变、抗弯拉强度和弯曲劲度模量。结果表明:RAP掺量会显著影响最佳沥青用量,并且在最佳沥青用量的前提下,RAP掺量的增加会导致浸水残留稳定度和动稳定度增大,冻融劈裂强度比和弯拉应变、抗弯拉强度和弯曲劲度模量减小,这表明,在相同级配且处于最佳沥青含量的情况下,RAP掺量的增加会提高再生沥青混合料的高温性能,降低再生沥青混合料的水稳性能和低温抗裂性能。因此,在AC-13再生沥青混合料设计过程中,建议RAP掺量不超过20%,从而使再生沥青混合料具有更好的性能。

In order to study the effect of asphalt mixture recycled material(RAP)content on the performance of AC-13 recycled asphalt mixture,three kinds of AC-13 recycled asphalt mixture were designed,and the porosity,water immersion residual stability,freeze-thaw splitting strength ratio,dynamic stability,and flexural tensile strain,bending tensile strength and flexural stiffness modulus of the reclaimed asphalt mixture under the same gradation were tested at the optimal asphalt content under the same gradation.The results show that the amount of RAP will significantly affect the optimal amount of asphalt,and under the premise of the optimal amount of asphalt,the increase of RAP content will lead to an increase in the residual stability and dynamic stability of immersion in water,and a smaller freeze-thaw splitting strength ratio and bending tensile strain,bending tensile strength and bending stiffness modulus,which indicates that under the same grade and optimal asphalt content,the increase of RAP content will improve the high temperature performance of recycled asphalt mixture,and reduce the water stability and low temperature crack resistance.Therefore,in the design process of AC-13 recycled asphalt mixture,it is recommended that the RAP content should not exceed 20%,so that the recycled asphalt mixture has better performance.