Study On The Influence Of Warm-mix Agent Upon The Performance Of Asphalt

Warm Mix Asphalt has been widely used in the construction of asphalt pavement,because it can decrease the temperature of asphalt mixture in the process of production,reduce energy consumption and harmful gas emissions,has the advantages of energy conservation and environmental protection.In recent years,Warm Mix Asphalt based on the surfactant has been developing rapidly in our country,warm mix technique go through the emulsified asphalt,concentrate,up to now has entered the era of finished warm mix asphalt.Finished warm mix asphalt has a series of advantages and can effectively decrease the temperature of asphalt mixture in the process of production.However,less research was done on the warm mix agent effect on the performance of asphalt,and the relevant technical specifications are still absent,which seriously restrain the large-scale popularization and application of this product.In view of the present situation of finished warm mix asphalt domestic application and research,the influence of the warm agents on asphalt,and the rheological properties and interface effects of warm mix asphalt has been studied in this paper.Besides the mechanism of warm mix agent has been briefly analyzed.The results showed that warm mix agent has a relatively small impact on asphalt penetration,softening point and ductility,can improve the aging performance of asphalt,has bad effect on the temperature sensitivity of modified asphalt.Warm mix agent has little effect on asphalt viscosity-temperature relationship.With the increase of warm mix agent,the decreased range of asphalt viscosity is small,which indicates that the mechanism of warm mix agent is not the decrease of viscosity.The addition of warm mix agent can reduce the ability of asphalt to resist deformation,and has a bad effect on high temperature performance of modified asphalt.The effect on the large dosage of SBS modified asphalt is greater than the small one,which indicates that warm mix agent can weaken the "increased flexibility" effect of SBS.High temperature performance attenuation indexes are defined according to the rutting factor and zero shear viscosity,which can be used to characterize the warm mix agent effect on high-temperature behavior of asphalt.The study found that modified asphalt is more sensitive to warm mix agent.With the increase of warm mix agent dosage,the contact angle between asphalt and water decrease and then increase,the surface free energy increase,which indicates that under the proper dosage,warm mix agent can improve wetness degree between asphalt and aggregate,and can increase the adhesion of asphalt and aggregate.The mechanisms of warm mix agent are the increase of wetness degree between asphalt and aggregate,the increase of the adhesion of asphalt and aggregate and the lubrication of Warm Mix Asphalt between aggregates.