纳米TiO_(2)和SBR改性沥青混合料路用性能研究

Study on Road Performance of Nano-TiO_(2) and SBR Modifi ed Asphalt Mixture

为探究TiO_(2)和SBR改性沥青对混合料性能的影响,首先按0.5%、1%、1.5%剂量的纳米TiO_(2)和1%、2%、4%剂量的SBR粉末进行正交试验配比,用高速剪切混合乳化机制备9组改性沥青,分别测试基质沥青和改性沥青的三大指标,确定改性剂的最佳掺量。以AC-13为例,对筛分清洗好的矿料进行性能分析,确定最佳级配。最后成形马歇尔车辙试件,分析高温车辙性能和水稳定性能,对基质沥青混合料和改性沥青混合料的性能进行对比评价。结果表明:纳米TiO_(2)和SBR的改性沥青混合料在高温车辙性能和水稳定性能上都有显著提高。改性沥青混合料的动稳定度比基质沥青提高了1.3倍多,经改性过的沥青混合料的马歇尔残留稳定度比基质沥青提高了9.06%,冻融劈裂强度比提高了6.16%。

To explore the influence of TiO_(2) and SBR modified asphalt on the performance of mixture,firstly,the orthogonal test proportion is carried out according to the dosage of 0.5%,1%,1.5%nano-TiO_(2) and 1%,2%,4%SBR powder,and 9 groups of modified asphalt are prepared by high-speed shear mixing emulsification machine.The three indexes of matrix asphalt and modified asphalt are tested respectively to determine the optimal dosage of modifier.Taking AC-13 as an example,the performance of screened and cleaned mineral aggregate is analyzed to determine the best gradation.Finally,The Marshall rutting specimen is formed,the high-temperature rutting performance and water stability are analyzed,and the performance of matrix asphalt mixture and modified asphalt mixture are compared and evaluated.The results show that the modified asphalt mixture of nano-TiO_(2) and SBR significantly improves the high-temperature rutting performance and water stability.The dynamic stability of modified asphalt mixture is more than 1.3 times higher than that of matrix asphalt.The Marshall residual stability of modified asphalt mixture is 9.06%higher than that of matrix asphalt,and its freeze-thaw splitting strength ratio is increased by 6.16%.