复合多聚磷酸改性沥青混合料疲劳性能
Fatigue properties of composite polyphosphoric acid modified asphalt mixture

采用四点小梁弯曲疲劳试验方法，考虑不同试验温度和不同应变水平等因素的影响，研究多聚磷酸（PPA）-苯乙烯-丁二烯-苯乙烯嵌段共聚物（SBS）复合改性沥青混合料疲劳性能的变化规律，并与SBS改性沥青混合料进行对比。结果表明：相同条件下，PPA-SBS改性沥青混合料比SBS改性沥青混合料残留劲度模量比大，损伤因子小，稳定阶段耗散能变化率的平均值小，疲劳损伤演变小，抗疲劳性能好；同一温度下，应变水平越大，残留劲度模量比越小，损伤因子越大，耗散能变化率维持稳定阶段的平均值越大，疲劳损伤演变越剧烈，抗疲劳性能越差；同一应变水平下，15℃时沥青混合料试件的抗疲劳性能优于10℃时。 The fatigue behavior of the polyphosphoric acid (PPA)-styrene-butaniene-styrene block copolymer(SBS) composite modified asphalt mixture was studied by considering the influence of different test temperatures and different strain levels. The fatigue behavior of the PPA-SBS modified asphalt mixture was compared with that of the SBS modified asphalt mixture. Results show that under the same conditions, the residual stiffness modulus of PPA-SBS modified asphalt mixture is smaller than that of SBS modified asphalt mixture.The same result is also shown in damage factor, the average change rate of dissipation energy in the stable stage and fatigue damage evolution, meaning the fatigue performance of PPA-SBS modified asphalt mixture is better; At the same temperature, the greater the strain level is, the smaller the residual stiffness modulus ratio is. Similarly, the large strain level brings a larger damage factor and average value of the stable rate of dissipation energy, which means severe fatigue damage evolution and worse fatigue resistance; At the same strain level, the anti-fatigue performance of the asphalt mixture specimen at the temperature of 10℃ is better than that of 15℃. 国家自然科学基金（11462018）；内蒙古自治区自然科学基金（2015MS0539）；内蒙古自治区交通运输厅建设科技项目（NJ201421）