橡胶沥青混合料疲劳性能影响因素研究

Research on Influence Factors of AR Mixture Fatigue Performance

摘要:

参考美国国家公路与运输协会(AASHTO)标准TP8要求,根据中国沥青混合料的成型现状,采用材料试验机(material test system,MTS)控制加载,选择改进的三分点加载小梁弯曲疲劳试验对橡胶沥青混合料疲劳性能影响因素进行了研究.研究表明：橡胶沥青油石质量比在7.5%~9.0%时,橡胶沥青混合料的疲劳寿命随沥青掺量的增加而增大；在正常的空隙率范围内,随着空隙率的减小,橡胶沥青混合料的疲劳寿命逐渐增加,但饱和度太高,对混合料的疲劳性能不利；胶粉掺量在19%时的疲劳性能最好.对各影响因素进行关联

Abstract:

According to AASHTO TP8 in American standard specification,threepointbendingfatigueloading test method was modified to evaluate the fatigue performance of asphalt rubber(AR)gapgraded mixture.Material test system(MTS)and straincontrol mode were used to evaluate influence factors of fatigue performance of AR mixture.According to the research,the fatigue life of AR mixture increases with the asphalt content when the asphalt content is between 7.0%~8.5%.The decrease of air voids will also improve the fatigue performance if VFA is within a reasonable extent.The best fatigue performance comes out when the crape rubber modifier(CRM)content in AR is 19%.Air voids have the greatest influence on fatigue property of AR mixture and VFA(voids filled with asphalt),asphalt content and CRM content also influence the property obviously.When AR mixture based on fatigue performance is designed,lower air voids first be confirmed according to the engineering requirement and then higher asphalt content and higher CRM content is advised.