基于流变学与黏弹性理论的温拌胶粉改性沥青的高温性能研究

High Temperature Performance of Warm Mix Crumb Rubber Modified Asphalt Based on Rheological and Viscoelastic Theory

基于流变学与黏弹性理论,对不同温拌剂及温拌剂掺量的温拌胶粉(WCR)改性沥青与胶粉(CR)改性沥青进行高温动态剪切流变试验(DSR)与重复荷载恢复试验(RCRB),并对WCR改性沥青的高温性能进行评价。结果表明:两种温拌剂的加入都可以提高沥青的高温性能,沥青的复数剪切模量G*变大,相位角δ减小,改进的车辙因子G*/(sinδ)9增大;且随每种温拌剂掺量的增加,表面活性剂(SDYK)型WCR改性沥青的高温抗变形能力呈先增大后减小的趋势,降粘剂(EM)型WCR改性沥青的高温抗变形能力呈逐渐减小的趋势。在相同温度和应力水平下,两种温拌剂的加入均会提高沥青的黏性部分Gv值,且SDYK型WCR改性沥青的Gv值在SDYK掺量为0.6%(质量分数,下同)时出现峰值,EM型WCR改性沥青的Gv值在EM掺量为1%时达到峰值;0.6%SDYK掺量与1%EM掺量的WCR改性沥青的高温性能均较好。对比相同温度和应力水平下,0.6%SDYK掺量的WCR改性沥青的残余应变与初始应变比值(ε1/ε2)最小,具有最佳的变形恢复能力。通过层次分析法(AHP)对评价沥青高温性能指标的ε1/ε2、Gv、Z(黏弹指标)进行对比分析发现,Z具有最大的权重,推荐使用黏弹指标Z来评价WCR改性沥青高温性能。

Based on rheological and viscoelastic theory,the high temperature dynamic shear rheological test(DSR)of warm mix rubber modified asphalt(WCR)and rubber powder modified asphalt(CR)with different temperature mixing agents and warming agent dosages and the repeated load recovery test(RCRB)were applied to evaluate the high temperature properties of the WCR modified asphalt.Results showed that the addition of two warming agents can improve the high temperature performance of asphalt.The complex shear modulus G*of asphalt became larger,the phase angleδdecreased,and the improved rutting factor G*/(sinδ)9 increased.The high temperature deformation resistance of SDYK type WCR modified asphalt increased first and then decreased,and the high temperature deformation resistance of EM type WCR modified asphalt decreased gradually.Under the same temperature and stress level,the addition of two warming agents can improve the viscosity of asphalt G v va-lue,the G v value of SDYK type WCR modified asphalt reached a peak when the content of SDYK was 0.6wt%,while that of EM type WCR modified asphalt reached a peak when the content of EM was 1wt%,WCR modified asphalt with 0.6wt%SDYK content and 1wt%EM content had excellent high temperature performance.Compared with the same temperature and stress level,the residual strain to initial strain ratio(ε1/ε2)of 0.6wt%SDYK blended WCR modified asphalt had the smallest deformation recovery capability.Through the analytic hierarchy process(AHP)to evaluate asphalt high temperature performance index epsilonε1/ε2,G v,Z(the viscoelastic index),Z has a maximum weight.Thus,it is recommended to use viscoelastic index Z to evaluate performance of WCR modified asphalt at high temperature.