不同温拌沥青混合料降温效果研究

Cooling Effect of Different Warm Mix Asphalt

选取有机添加剂Sasobit和人工沸石两种温拌剂,采用东海70号沥青配置温拌沥青,选取AC-13矿料级配拌制沥青混合料。通过黏温曲线和马歇尔试件的体积指标分别确定两种温拌剂各自的最佳掺量;在最佳掺量的条件下通过不同温度下成型马歇尔试件和旋转压实试件,观察其空隙率的变化规律来研究两种温拌沥青混合料的降温效果。研究表明:两种温拌剂都可降低沥青的高温黏度,其黏度随温拌剂掺量的增加而减小;Sasobit最佳掺量为3%(与沥青的比例),在马歇尔击实条件下,加入Sasobit的WMA的成型温度比HMA的成型温度降低了14℃;人工沸石的最佳掺量为0.3%(与混合料的比例),在马歇尔击实条件下,加入人工沸石的WMA成型温度比HMA的成型温度降低了20℃,在旋转压实的情况下两者的温度降低了接近30℃。

The organic additive Sasobit and artificial zeolite were chosen as two kinds of warm mix agents,and Donghai 70#asphalt was adopted as the preparation of warm mix asphalt,and AC-13 mineral aggregate gradation was selected to mix the asphalt mixture. The optimum content of two kinds of warm mix agents was determined respectively by the volume indicators of viscosity-temperature curve and Marshall specimen. Under the condition of optimal dosage,the change rule of voidage was observed by forming Marshall specimen and gyratory compact specimen with different temperature,to study the cooling effect of two kinds of warm mix asphalt. The results show that both of two warm mix agents can reduce the high temperature viscosity of asphalt,and its viscosity decreases with the increase of the dosage of warm mix agent; the optimal dosage of Sasobit is 3%（ the ratio to asphalt）,and WMA molding temperature with Sasobit added decreases by 14 ℃ under the condition of Marshall compaction,compared with that of HMA; the optimum content of artificial zeolite was 0. 3%（ the ratio to mixture）,and WMA molding temperature with artificial zeolite added decreases by 20 ℃ under the condition of Marshall compaction,compared with that of HMA; in the case of gyratory compaction,the temperature of the both above reduces by nearly 30 ℃.