矿粉-乳化沥青胶浆对沥青路面裂缝修复愈合的影响

Influence of Mineral Powder-emulsified Asphalt Mortar on Repair and Healing of Asphalt Pavement Cracks

针对乳化沥青用作沥青路面裂缝修复愈合存在着粘结强度差、高温下易流淌、封缝防水效果差、自愈合速度慢等问题,将不同类型和掺量的矿粉与乳化沥青混合形成矿粉-乳化沥青胶浆,通过其黏度随时间的变化规律和蒸发残留物DSR试验揭示了矿粉添加后对乳化沥青黏度和高温性能的影响,并建立了基于时间的黏度变化模型,以此评价用于灌缝时乳化沥青的破乳时间。进行了裂缝浸水量试验、劈裂强度试验,从宏观上验证了矿粉-乳化沥青胶浆的防水封缝效果、自愈合速度等性能,以此确定矿粉最佳掺量。试验结果表明:矿粉-乳化沥青胶浆的初始黏度相对较低,随着时间推移,黏度增长速度变快,最后逐步稳定,黏度提高近23 Pa·s,建立的龚帕斯模型可准确预测完全破乳时间,为准确确定通车时间建立基础;高温下(60℃)抗车辙因子达到837.8 Pa,裂缝间浸水量几乎为零,高温稳定且受水损坏侵蚀影响小,在对裂缝粘结的同时可有效填充裂缝,阻止水的进一步下渗,大大减缓路面的水损坏进程;沥青混合料的愈合速度成倍提高,石灰岩和玄武岩的矿粉-乳化沥青胶浆的愈合指数A可分别达到62.9%和76.1%,有利于早期强度的形成,综合确定0.9为最佳粉胶比;中性性质的玄武岩矿粉相对于石灰岩矿粉比表面积大、电位低,因此各项性能相对较优。

In view of the problems of emulsified asphalt used for repair and healing of asphalt pavement cracks,such as poor bonding strength,easy flow under high temperature,poor waterproof effect of joint sealing,and slow self-healing speed,different types and contents of mineral powder are mixed with emulsified asphalt to form mineral powder emulsified asphalt slurry.Through change rule of its viscosity with time and evaporation residue DSR test,the influence of addition of mineral powder on the viscosity and high-temperature performance of emulsified asphalt is revealed,and a time-based viscosity change model is established to evaluate the demulsification time of emulsified asphalt used for joint filling.The water immersion test and the splitting strength test on cracks are carried out to verify the waterproof sealing effect,self-healing speed and other performance of the mineral powder emulsified asphalt mortar from a macro perspective,so as to determine the optimal content of mineral powder.The test result shows that(1)The initial viscosity of the mineral powder emulsified asphalt slurry is relatively low.With the passage of time,the viscosity growth rate became faster and finally stabilized gradually.The viscosity increased by nearly 23 Pa·s.The established Gompertz model can accurately predict the complete demulsification time and establish a foundation for accurately determining the traffic time.(2)The rutting resistance factor reached 837.8 Pa at high temperature(60℃),the water immersion between cracks is almost zero,the high temperature is stable and the influence of water damage and erosion is small.While bonding the cracks,it can effectively fill the cracks,prevent further water infiltration and greatly slow down the water damage process of the pavement.(3)The healing speed of asphalt mixture is doubled,and the healing index A of mineral powder emulsified asphalt mortar of limestone and basalt can reach 62.9%and 76.1%respectively,which is conducive to the formation of early strength.It is comprehensively determined that 0.9 is the best filler-asphalt ratio.(4)Compared with limestone mineral powder,basalt mineral powder with neutral properties has a large specific surface area and low potential,so its properties are relatively excellent.