高原高海拔地区道路石油沥青再生特性及其机理研究

Study on Regeneration Characteristics and Mechanism of Road Petroleum Asphalt in High Altitude Regions of Plateau

为研究高原高海拔地区老化沥青的再生性能和再生机理,制备7种不同再生剂掺量的再生沥青,借助动态剪切流变试验(DSR)、弯曲梁流变试验(BBR)评价再生沥青性能。采用傅里叶变换红外光谱仪(FT-IR)及原子力显微镜(AFM)对老化沥青和不同再生剂掺量的再生沥青进行测试,以分析其再生机理。结果表明:随着再生剂XT-3掺量的增加,再生沥青的针入度与延度随着掺量的增加波动较大,在XT-3质量分数为7.0%时,针入度和延度达到最大值;软化点在XT-3质量分数为7.0%时,测试值最小,复数模量先减小后上升,相位角先增大后减小,车辙和疲劳因子先上升后下降,蠕变速率先下降后上升。再生沥青的表面粗糙度皆大于老化沥青,红外光谱的结果显示再生剂并未与沥青发生化学反应。综合考虑再生沥青的路用性能,再生剂的最佳掺杂质量分数为7.0%。

In order to study the regeneration performance and mechanism of aged asphalt in high altitude regions of plateau,seven kinds of reclaimed asphalt with different regenerant contents were prepared.The properties of reclaimed asphalt were evaluated by the dynamic shear rheological test(DSR)and bending beam rheological test(BBR).The Fourier transform infrared spectrometer(FT-IR)and atomic force microscope(AFM)were used to analyze the recycling mechanism of aged asphalt and reclaimed asphalt with different regenerant contents.The results show that with the increase of regenerant XT-3 mass fraction,the penetration and ductility of reclaimed asphalt fluctuate greatly with the increase of the content,and the penetration and ductility reach the maximum value when the XT-3 mass fraction is 7.0%.When the XT-3 mass fraction is 7.0%,the test value of the softening point is the smallest.The complex modulus first decreases and then increases,and the phase angle first increases and then decreases.The rutting factor and fatigue factor first increase and then decrease,and the creep speed first decrease and then increase.The surface roughness of reclaimed asphalt is greater than that of aged asphalt,and the infrared spectrum results show that there is no chemical reactions between the regenerant and the asphalt.Considering the road performance of reclaimed asphalt,the optimum mass fraction of regenerant is 7.0%.