高温多雨区硅藻土SBS复合改性沥青混合料路用性能及改性机理

Study on Diatomite and SBS Composite Modified Asphalt Mixture Road Performance and Modification Mechanism in High Temperature and Rainy Regions

为了研究硅藻土作为填料型沥青改性剂用于高温多雨区的技术可行性,提出采用硅藻土等量替代矿粉与SBS改性剂进行复配,并基于车辙、低温弯曲、冻融劈裂和四分点加载疲劳试验系统研究了硅藻土SBS改性沥青混合料的路用性能,同时揭示了硅藻土对SBS改性沥青混合料的改性机理。试验结果表明,硅藻土等量替代矿粉后,SBS改性沥青混合料在水温耦合作用下的抗车辙能力大幅度提高,同时混合料水稳定性和低温抗裂性显著提高,硅藻土SBS复合改性沥青混合料各应力水平下的疲劳寿命均高于普通SBS改性沥青混合料,疲劳寿命的提高幅度达50%,用硅藻土等量替代矿粉作为SBS沥青混合料的改性剂是可行的。硅藻土对SBS改性沥青混合料的改性机理在于,提高了沥青与集料之间粘附性和握裹力。

in order to study the diatomite as filler type asphalt modifier used for high temperature high temperature and rainy regions the technical feasibility of using diatomaceous earth equivalent substitute mineral powder with SBS modifier for distribution, and based on rutting, low temperature bending, freeze-thaw splitting and four point load fatigue test system studied diatomite road of SBS modified asphalt mixture is,at the same time reveals the diatomite modification mechanism of SBS modified asphalt mixture. Experimental results show that the diatomaceous earth equivalent substitute mineral powder, SBS modified asphalt mixture under the coupled action of water temperature anti-rutting ability increased significantly, the mixture water stability and low temperature crack resistance increased significantly, diatom- ite SBS composite modified asphalt mixture fatigue life under different stress level are higher than common SBS modified asphalt mixture, the fatigue life of increase rate of 50% , use diatomite amount instead of mineral powder as SBS modifier of asphalt mixture is feasible. Diatomite modified mechanism of SBS mod-ified asphalt mixture is, increase the adhesion between asphalt and aggregate and grip.