Development and Application of Super PCR SBS Modified Emulsified Asphalt
|Course||Road and Railway Engineering|
|Keywords||tack coat modified asphalt emulsion mechanism SBS modifiedemulsion asphalt shear strength|
Interlayer bond is one of the most important factors which influence the performance ofasphalt pavement. At the present, the tack coat on sale mainly are SBR modified emulsionasphalt and common emulsion asphalt which cannot provide a good bond force for bitumenpavement layers under the condition of high temperature, overload and longitudinal slope,which lead to the early diseases of asphalt pavement such as folding, broaching and interlayerslipping, and destruct the integrity and structure stress of pavement. Consequently, it is veryimportant to develop a high-performance emulsion asphalt. Because of the SBS has a goodelasticity and high-and-low temperature performance, based on this material, a high qualitymodified emulsion asphalt was prepared which has a strong film-forming ability andadhesion, and has a good application prospects.Firstly this paper discussed the interlaminar contact mechanical response of asphaltpavement, and obtained every interlayer shear strength requirements under the influence oflongitudinal slope, overload and braking. On this basis, the relationship between softeningpoint and shear strength was established combined with the shear strength of several tack coatmaterials in different temperature. Then other index requirement of SBS modified emulsionasphalt were determined when the material reach this softening point level. The indexrequirement can provide evidence for developing high performance SBS modified emulsionasphalt. The raw materials composition and probably proportion was determined throughexperimental analysis on existing raw material. Finally, by means of the orthogonal test, theinfluence rules of emulsion asphalt properties, such as modifier, emulsifier, inorganicstabilizer and organic stabilizer etc. was analyzed, and determined the optimum content ofeach component.The SBS modified emulsion asphalt in this paper has the following properties,well-distributed, good fluidity and high viscosity, which can enhance adhesive property ofasphalt pavement interlayer. By using the self-development interlayer stress tester, adhesiveproperty of the modified emulsion asphalt was proved by contrast to shear strength andpull-off strength on other tack coat materials. Test road was paved which relying onmaintenance project at He-An expressway in Anhui Province. Through the shear tests on core samples, it was proved that asphalt pavement interlayer has the higher shear strength whenusing the SBS modified emulsion asphalt, and has a good highway performance.