Study On Viscosity-reducing Mechanism And Technical Performance Of Warm Asphalt Binder

Environmental awareness has been increasing rapidly over the past years, and countries all of the world sign the Kyoto Protocol successively. Extensive measures like air pollution reduction targets have encouraged efforts to reduce pollution. Warm mix asphalt (WMA) has developed due to increased environment awareness and stricter emissions regulations. WMA is one asphalt mixture technique, which allows asphalt to be mixed and compacted in a comparatively low temperature by reducing viscosity of asphalt with certain techniques and maintains the use performance not below that of hot mix asphalt (HMA).Based on thorough investigation and analysis of current warm mix asphalt technique, organic viscosity-reducer S was selected to produce warm asphalt binder, and the viscosity-reducing mechanism of warm asphalt binder and the influence of organic viscosity-reducer on asphalt technical performance were studied systematically in my dissertation.The results indicated that organic viscosity-reducer S and base asphalt didn't occur chemical reaction analyzed by infrared adsorption spectrum analysis and nuclear magnetic resonance analysis; The analytical results of four components showed that the content of four components changed in modified asphalt; The viscosity reduction effect is most closely related to saturates through grey correlation analysis; There existed a temperature transformation point between 100℃～110℃for WMA asphalt binder through viscosity analysis; Appropriate dosage of organic viscosity-reducer S reduced high temperature viscosity of asphalt effectively; The mixing and compaction temperatures were reduced by 5℃～7℃compared with base asphalt with the dosage of organic viscosity-reducer of 3%; Appropriate dosage of organic viscosity-reducer S improved the temperature susceptibility, high temperature performance and the storage stability and so on through the technical performance analysis and affected the low temperature performance tinily; Furthermore, the reasonable dosage of organic viscosity-reducer was 3% through comprehensive analysis.Meanwhile, this dissertation obtained the viscosity-reducing mechanism of organic viscosity-reducer of warm mix technique, which can provide theory instruction for the development of new warm mix modifier; The change laws of the technical parameters were evaluated, the reasonable dosage range of organic viscosity-reducer was provided by analyzing the influence of different dosage of additive on performance of warm asphalt binder, which has good reference value for the popularization and application of WMA; The mixing and compaction temperatures were obtained by analyzing the viscosity-temperature law of warm asphalt binder, which can be used in pavement construction conveniently and provide reference for the relevant technical specification of WMA.