不同热氧老化环境下SBS改性沥青及其混合料性能研究

Study on SBS modified asphalt and its mixture performance under different thermal oxygen aging environment

【目的】探寻沥青及沥青混合料逐渐老化对沥青路面路用性能的影响。【方法】对不同热氧老化环境下SBS(I-D)聚合物改性沥青的常规指标、流变性能及以其制备的AC-13C沥青混合料的高温稳定性、低温抗裂性、水稳定性及单轴压缩动态模量开展试验研究。【结果】随着热氧老化程度的不断加深,沥青黏韧性及抗塑性变形的能力逐渐降低,脆性逐渐增强;随着热储存时间的增加,沥青软化点、5℃延度和针入度先升高后降低,135℃黏度逐渐升高;随着热氧老化程度的不断加深,沥青混合料高温抗车辙能力逐渐提高,低温抗开裂及抗水损害能力逐渐降低;沥青混合料动态模量随着温度的升高而降低,随着热氧老化程度的加深及加载频率的增大而升高,但温度为35、50℃时其变化趋势有所改变。【结论】随着热氧老化程度的不断加深,沥青混合料高温性能得到改善,低温及水稳定性能降低,该研究成果在实际工程应用中具有一定的价值。

[Purposes]This work aims to explore the influence of asphalt and asphalt mixture aging on the road performance of pavement exposed.[Methods]The conventional indexes and rheological properties of SBS(I-D)polymer modified asphalt exposed to different thermal and oxygen aging environments,and the high temperature stability,low-temperature crack resistance,water stability and uniaxial compression dynamic modulus of AC-13C asphalt mixture prepared with SBS(I-D)polymer modified asphalt were studied.[Findings]With the increasing degree of thermal oxygen aging,the viscosity toughness and plastic deformation resistance of asphalt gradually decrease,while the brittleness gradually increases.With the increase of hot storage time,the softening point,5℃ductility and penetration of asphalt first increased and then decreased,and the 135℃rotational viscosity gradually increased.With the deepening of thermal oxygen aging,the high-temperature rutting resistance of asphalt mixture gradually increases,the low temperature cracking resistance and water damage resistance gradually decreases,the dynamic modulus decreases with the increase of temperature,increases with the deepening of thermal oxygen aging and the increase of loading frequency.However,the dynamic modulus changes at 35℃and 50℃.[Conclusions]With the deepening of thermal oxidation aging,the high-temperature performance of asphalt mixture improved,and the low temperature and water stability reduced.The research results have certain value in practical engineering applications.