The Study On Preparation And Performance Of Modified Asphalt Emulsion

This paper prepares modified asphalt emulsion using SBS emulsion as modifier and through the way of twice heat mixing. In the course of preparing SBS emulsion, it concludes the choosing of cationic emulsifiers and deciding the composition of emulsifiers. It also finds the best appropriate technics from experiment in quadrature. Through the analysis of SBS emulsion that is produced from the best appropriate technics, they show that SBS emulsion with positive charge has vary strongly stability, and the size of which accords with that of asphalt emulsion, so SBS emulsion and asphalt emulsion are compatible.Through analysis the important performances of two asphalts and asphalt emulsions, we know asphalts which are emulsified are almost not change except the decreasing of low temperature ductility. Asphalt performances are ameliorated in a large degree when asphalts are modified by SBS emulsion, through the curves of three important index of asphalts, they find that the best appropriate amount of SBS emulsion is 6%. Seeing the microstructure of modified asphalt emulsion using photics microscope can find the following: SBS disperses very well in asphalt emulsion; Two emulsions are best consistent; and it also don't have grain congregativeness and deposition. Besides those, the all emulsion's performances can satisfy the need of the JTG F40 criterion, so the modified asphalt emulsion is a good combined asphalt pavement material.Through the study of SBS,asphalt emulsified mechanism, we gain the following: The preparation of SBS emulsion is though reverse emulsified mechanism; The best important affectional factor about the result of emulsification is the numerical value of emulsifier's HLB. The factors that affect the emulsified asphalt stability are the numerical value of emulsifier's HLB,diffuse double electric layers and the intensity of interface membrane. Seeing the infrared chartes and the four ingredients changing of asphalts and modified asphalts, the following are gained: The modifying of asphalt are physical modifying and chemical modifying. Chemical modifying is the simpleness connection of two molecules, and the units of structure in every molecule is not change. Modified asphalts have lower saturate and aromatics than these in asphalts which are not modified, and the resin and asphaltene both increase in different degree. The decrease of saturate and aromatics is because they filter into the interior of SBS. The increasing of resin and asphaltene is because they can link with SBS through chemical bond, because of which the flexible of asphalts is accretion, so asphalts modifying come true.