Study Of The SBS Modified Asphalt System Phase Evolution Law And Compatibility Evaluation Technique Based On Microstructure

The features of modified asphalt,such as deformation resistance and high temperature resistance,vary depending on whether the modifiers in the SBS modified asphalt system are present in the form of scattered phase,continuous phase,or two-phase crosslinking,respectively.Fluorescence microscopy observation technique is one of the most popular methods for morphological analysis of modified asphalt due to its ease of use and low cost.But there hasn’t been enough research done on how modifiers in changed asphalt systems change morphologically.This study investigates the relationship between modifier morphology and asphalt compatibility under various preparation processes.It also demonstrates the viability of using fluorescence microscopy in the quality evaluation of modified asphalt by using a neural network model,the high-temperature performance,and fluorescence images of asphalt obtained using a fluorescence microscope.The main research contents and results are as follows:(1)This study proposes seven image parameters to measure relative area,swelling multiplier,developmental fineness,fractal dimension,dispersion coefficient,relative standard deviation,and standard deviation to evaluate the microstructure of SBS modified asphalt system for three aspects of relative content,particle morphology,and dispersion of the modifier in SBS.Fluorescence images are pre-processed using digital image processing techniques in MATLAB software.(2)This paper examines the impact of matrix asphalt,modifier,compatibilizer,and stabilizer on the compatibility of the modified asphalt system using the fixed SBS modified asphalt preparation technique.After the addition of the compatibilizer,the softening point of ZH/SBS modified asphalt rises by about 6 °C,and the difference in the softening point of48-hour dissociation falls by about 5–7 °C.After the stabilizer is added to the modified asphalt system,the softening point of modified asphalt develops at more than 80 °C,but in0.5–3h development time,the modified asphalt softening point no longer rises significantly.(3)The SBS modifier in granular and linear form does not contain any additives in the modified asphalt system.However,the stabilizer added to the modified asphalt system after the modifier cross-linking phenomenon occurs quickly,the final modifier and the matrix asphalt is easily to show "mutual solubility phenomenon";when the modified asphalt system in the process of hot storage phase separation occurs,the modified asphalt will occur in the upper part of the modifier aggregation will occur since the cross-linking phenomenon,and the lower part of the asphalt modifier to low conten(4)When the preparation temperature was 170°C,the shear rate was 5000 rpm,and the development time was 3h,the modified asphalt performed at its best.The matching fluorescent images’ respective relative areas,swelling multipliers,development fineness,fractal dimensions,dispersion coefficients,standard deviations,and relative standard deviations were 48.95%,99.83%,4.36,1.89,0.89,0.31,and 0.28.When the modified asphalt system exhibits the "mutual solubility phenomenon," the fluorescence image processing method for modified asphalt is no longer appropriate.(5)When the morphology of the modifier in the modified asphalt system changes,there is a greater correlation between the fluorescence image characteristics and softening point.The predictions of the MLP neural network prediction model are also more accurate than those of the multiple linear regression equation.