Abstract: The method of cracking polyethylene （PE） and polypropylene （PP） was introduced. Two kinds matrix asphalts—Maoming-90 and CNOOC-70—were chosen, and blended with cracking recycled plastics（CRP） or non-cracking recycled plastics（RP） by mass of 6% and 8% respectively. Three indexes （penetration, soften point and ductility）, storage stability, low-temperature bending property, viscosity and aging performances of the modified asphalts mixed with cracking recycled plastics were compared and studied. The component variation of RP and CRP, and the components variation of the asphalts with or without modifier were test analyzed with infrared spectrum. The modified asphalt mechanism was analyzed. Test results show that the high-temperature property of all kinds CRP modified asphalts increase greatly, the soften point of CNOOC-70 asphalt with CRP modifier addition of 6% can grow from 48.7℃ to more than 70℃，and demonstrate sound storage stability without segregation and meanwhile demonstrate their low-temperature bending property, viscosity and aging performances similar to that of matrix asphalt.

Key words: highway engineering, recycling plastics（RP）, cracking recycled plastics（CRP）, modified asphalt, segregation, infrared spectrum, mechanism

摘要： 介绍了裂化处治聚乙烯（PE）、聚丙烯（PP）类生活废旧塑料的方法。分别将原状造粒生活废旧塑料（RP）及裂化生活废旧塑料（CRP）按6%及8%掺量，掺入茂名90 ＃ 及中海油70 ＃ 两种基质沥青中制得生活废旧塑料改性沥青，对比试验研究了基质沥青及生活废旧塑料改性沥青的三大技术指标（针入度、软化点、延度）及存储稳定性、低温弯曲性能、黏度和老化性能。用红外光谱分析了裂化处治前后生活废旧塑料以及改性前后沥青的组成成分变化，研究了裂化处治生活废旧塑料改性沥青性能提高的机理。结果表明：各类裂化处治生活废旧塑料改性沥青高温稳定性显著提高，掺量6%条件下可使中海油70 ＃ 基质沥青的软化点由48.7℃提高到70℃以上；存储稳定性好，不离析；低温弯曲、黏度、老化等性能未降低，与基质沥青性能相近。

关键词: 道路工程, 裂化生活废旧塑料, 原状造粒生活废旧塑料, 改性沥青, 离析, 红外光谱, 机理