沥青胶浆高温及疲劳性能研究

Study on high-temperature performance and fatigue properties of the asphalt mortar

通过动态剪切流变仪,采用不可恢复蠕变柔量、不可恢复蠕变柔量差及复合模量衰减至初始模量50%时所需的时间作为评价指标,分别对不同矿粉、粉胶比和沥青组成的沥青胶浆进行了高温性能和疲劳性能试验。试验结果表明:矿粉使沥青胶浆不可恢复蠕变柔量减小,使高温抵抗变形的能力增强,但矿粉的模量增效作用有限;当不可恢复蠕变柔量差为0%时,沥青胶浆处于稳定态。建议采用基质沥青胶浆不可恢复蠕变柔量差为0%时的粉胶比作为沥青混合料粉胶比。矿粉对沥青的疲劳性能不利,不同矿粉沥青胶浆疲劳寿命的差值明显。高粘沥青胶浆的高温性能和疲劳性能均优于基质沥青胶浆的。建议:在实际道路中,矿粉的使用应通过试验,在合理比对后进行选择,且选用高温性能和疲劳性能更优的高粘沥青材料。

The index including unrecoverable creep compliance,unrecoverable creep compliance difference,the time required for the attenuation of complex modulus to 50%of the initial modulus(50%|G*|)were used to appraise the high-temperature performance and fatigue properties of asphalt binder with different mineral powder,gelatine ratio and asphalt by DSR.The test result indicates that the phenomenon,the unrecoverable creep compliance of the asphalt mortar reduced and high-temperature resistance to deformation enhanced,was happened beacause of the mineral fillers,but the effect of increasing modulus was limited.When the unrecoverable creep compliance difference descended to be 0%,a stable state occured on the bitumen slurry.The unrecoverable creep compliance difference of matrix asphalt mortar as 0%was suggested to use on the most suitable for the asphalt mixture.The effect of mineral powder on the fatigue property of asphalt was not favorable,and the difference of fatigue life of asphalt binder with different mineral powder was obvious.High-temperature performance and fatigue properties of asphalt mortar with high viscosity are superior to that of the matrix asphalt mortar.Therefore,compared to the use of mineral powder in the solid road,the asphalt with high temperature properties,high viscosity and better fatigue performance should be chosen.