Study On Properties Of Double Modified High Viscid Asphalt Based On OGFC Mixture

OGFC mixture pavement has the functions of drainage and noise reduction due to the characteristics of large voids,and is widely used in sponge urban drainage pavement.However,the characteristics of large voids make the durability of adhesion between asphalt and aggregate easily insufficient due to asphalt aging.Rubber powder and SBS dualmodified high-viscosity asphalt can enhance the binding force between asphalt and aggregate,and improve the performance of OGFC mixture.However,the performance evaluation index and index value of dual-modified high-viscosity modified asphalt based on the performance of OGFC mixture are not consistent.The lack of uniformity and lack of evaluation methods for quantitatively analyzing the aging rate and aging degree of highviscosity modified asphalt have become urgent issues in the engineering community.This subject mainly studies the performance of rubber powder and SBS double-modified high-viscosity asphalt and its OGFC mixture performance,and compares the performance with imported TPS-modified high-viscosity asphalt and domestic finished high-viscosity asphalt.The research contents mainly include:(1)The rheological properties of the highviscosity modified asphalt before and after aging and the three major indexes and viscosity of the asphalt before and after aging to compare the advantages and disadvantages of the above-mentioned asphalt;(2)The high temperature dynamic stability of the OGFC mixture before and after aging,Freeze-thaw splitting strength ratio and water immersion scattering loss rate changes to compare the anti-aging performance of asphalt mixtures;(3)Using gray correlation theory to establish the relationship between the performance of high-viscosity modified asphalt and the performance of OGFC mixture,and put it forward through nonlinear equations Asphalt index values that meet the performance specifications of the mixture;(4)Use infrared spectroscopy to detect the changes in the functional group content of the dual-modified high-viscosity asphalt with different aging times,and fit the nonlinear aging equation through the aging model to quantitatively analyze the asphalt aging rate and aging degree,Put forward an evaluation method to evaluate the anti-aging performance of high-viscosity modified asphalt.The research results are as follows:(1)The properties of the dual-modified high-viscosity asphalt before and after aging are better than the other two high-viscosity modified asphalts;(2)The performance of the three high-viscosity modified asphalt mixtures before and after aging has little difference.In general,the performance of the dual-modified high-viscosity asphalt mixture is better than the other two high-viscosity modified asphalt mixtures;(3)The gray correlation analysis results show that the high-temperature performance of the OGFC mixture has the highest correlation with the dynamic viscosity of the asphalt at 60℃.It is 0.78;the water stability performance has the highest correlation with the softening point,with a correlation of 0.96;the scatter performance has the highest correlation with the phase angle,with a correlation of 0.97.(4)The high-viscosity modified asphalt performance index value that meets the requirements of the OGFC mixture performance specification should meet the 60℃ dynamic viscosity greater than 45000 Pa·s,the softening point greater than 75.0℃,and the phase angle less than 68.0°;(5)different heights The microscopic components of the viscous modified asphalt show that the dual-modified high-viscosity asphalt has the lowest degree of aging within the same aging time,followed by TPS modified high-viscosity asphalt,and the finished high-viscosity asphalt has the highest degree of aging.The result is consistent with the macroscopic anti-aging performance of asphalt consistency.The fitted nonlinear aging model is reliable.