Research On Preparation Technology And Properties Of Modified Petroleum Asphalt With Plastic Cracking Products

Human society produces tens of thousands of tons of plastic waste every year,leading to the "white pollution" that hinders green development.However,extensive research on waste plastics has revealed that incorporating them into asphalt can enhance its performance,resulting in improved environmental benefits and utility.Consequently,the use of plastic-modified asphalt has become a trending topic.Studies have shown that a fraction of the waste plastic’s macromolecular long chains can intermingle with asphalt,while the remainder remains segregated,leading to cracking of the plastic’s different molecular weight products.This phenomenon retains the larger molecules while also producing smaller molecules that interact well with asphalt,improving compatibility.Among the cracking products of polyethylene(PE),low molecular weight polyethylene(PE-C)stands out due to its solubility in asphalt,high melting point,large molecular weight gradient,and good storage stability.Therefore,this paper selects PE-C as the modifier agent for asphalt.Investigating the modification process and mechanism of PE-C-modified petroleum asphalt holds significant theoretical and practical application value.This article focuses on investigating the impact of polyethylene cracking product(PE-C)on the performance of asphalt.The three main areas of performance,storage stability,and aging were analyzed.The results show that the PE-C modifier can enhance the softening point of the asphalt,improve penetration,maintain optimal ductility,reduce segregation,and enhance its anti-aging properties.Furthermore,the modification process conditions of PE-C modified asphalt were investigated,and the optimal conditions were determined to be a 4 % dosage of PE-C,modification temperature of 150 ℃,shear rate of3000 r/min,and modification time of 20 min.Subsequently,the experimental data was analyzed using the gray correlation analysis method in this study,and it was found that modification temperature,modification time,and dosage are the most crucial factors that affect the performance of modified asphalt.The correlation degree of the three major performance data for each process condition group was calculated,and a weighted scoring system was utilized to evaluate and determine the process condition group with the highest score.Based on the results of the gray correlation analysis,a two-factor experiment was conducted,and a3-dimensional function prediction model was established using the experimental data to determine the optimal process condition group for modified asphalt,which included 4.08 % of PE-C,a modification temperature of 141.4 ℃,a shear rate of 3000 r/min,and a modification time of 20 min.Finally,using three characterization methods,including asphalt four-component analysis,Fourier transform infrared spectroscopy(FT-IR),and thermogravimetric analysis to investigate the structural changes and modification mechanism of PE-C modified asphalt from a microscopic perspective.The asphalt four-component analysis showed that an appropriate amount of PE-C could obtain better performance of modified asphalt,resulting in superior pavement performance in practical road applications.FT-IR results indicated that Between PE-C and matrix asphalt basically belong to physical mixing,trace aging reaction occurred;The thermogravimetric analysis shows that the modified asphalt has a higher thermal decomposition temperature than the matrix asphalt,and the structure of the modified asphalt is relatively stable.the addition of PE-C could enhance the high-temperature resistance of asphalt.Therefore,the addition of PE-C modifier can affect the quality of asphalt,thus changing the macroscopic performance of asphalt in pavement applications.Moreover,by adjusting the dosage of PE-C and the modification process conditions,modified asphalt with better performance can be obtained to meet the requirements of different construction conditions.