Research On The Composition Design And Performance Of Recycled Asphalt With Tung Oil Composite Regenerating Agent

At present,most roads are currently facing problems such as road maintenance and reconstruction,resulting in a large amount of waste asphalt mixture.The rational disposal of these waste asphalt mixture can not only delay the shortage of natural resources,but also reduce the environmental pollution so as to achieve sustainable development.Therefore,the use of regenerating agent to regenerate waste asphalt mixture is currently the most important means.However,there are many kinds of regenerating agents,among which a single light oil regenerating agent has certain limitations on the performance recovery of aged asphalt.Therefore,the development of a comprehensive performance of a strong composite regenerating agent can restore the overall performance of aging asphalt.Firstly,the tung oil,dioctyl phthalate(DOP),C9 petroleum resin,and organic montmorillonite(OMMT)were used to prepare the composite regenerating agent,and its optimal mix proportion was determined by the orthogonal experimental design.Secondly,Evaluation of rheology by temperature scan,frequency scan and bending beam rheology experiments;Again,Analyze the anti-aging performance of recycled asphalt by rheological properties after pressure aging vessel(PAV)and ultraviolet aging(UV)aging,To determine the optimum dose of tung oil composite regenerating agent after comprehensive analysis,using the test indexes closest to the base asphalt as the benchmark;Study of asphalt-aggregate adhesion by means of surface energy theory;Finally,the differences in molecular weight and composition of characteristic functional groups between recycled asphalt and matrix asphalt with the best content were compared by Fourier transform infrared spectroscopy(FTIR),Gel permeation chromatography(GPC)and scanning electron microscopy(SEM).The results show that with the addition of tung oil composite regenerating agent,the G*/sin δ is 27.2%higher for B-8%and 44.9%higher for C-10%compared to the base asphalt,the rheological properties of aged asphalt can be effectively recovered or even better than that of base asphalt.By using the complex modulus aging index(CMAI)and phase angle aging index(PMAI),it is found that the anti-aging performance of reclaimed asphalt is better than that of base asphalt.The adhesion work of recycled asphalt increases,and limestone is 6.9%higher than basalt,indicating that limestone has the best adhesion to asphalt.With the optimal content of tung oil composite regenerating agent,the LMS content of B-8%was reduced by 3.2%and the SMS content was increased by 4.6%,indicating that the composite regenerating agent is beneficial to the dispersion and dissolution of polar substances in the aged asphalt.The incremental changes of each functional group index and each molecular content of the recycled asphalt after aging by P AV are much smaller than those of the base asphalt,indicating that tung oil composite regenerating agent can inhibit the attenuation of recycled asphalt during aging,and the anti-aging performance of recycled asphalt is significantly improved.After the aging of the matrix asphalt,a large number of wrinkles appear on the surface of the asphalt.However,the addition of tung oil composite regenerating agent can make the aged asphalt surface smooth,which indicates that the tung oil composite regenerating agent can restore the microstructure and morphology of aged asphalt to a certain extent.