疲劳荷载对水泥乳化沥青纤维复合材料黏弹行为的影响及机理分析  

Analysis on Influence of Fatigue Load on Viscoelastic Behavior of Cement Emulsified Asphalt Fiber Composite and Mechanism

作　　者：曹睿明[1] 陈小兵[1] 陈先华[1] CAO Rui-ming;CHEN Xiao-bing;CHEN Xian-hua(School of Transportation,Southeast University,Nanjing Jiangsu 210096,China)

机构地区：[1]东南大学交通学院,江苏南京210096

出　　处：《公路交通科技》2020年第8期1-6,共6页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金项目(51778136)。

摘　　要：为了研究疲劳荷载作用下,水泥乳化沥青纤维复合材料的黏弹行为,采用动态剪切流变仪(DSR),以耗散能和累计耗散能为主要评价指标,研究了A/C(沥灰比),玄武岩纤维掺量和应力水平等因素对试件黏弹行为的影响规律,得到黏弹性能最佳时的复合材料配比,并通过扫描电镜测试从微观角度分析了纤维对复合材料黏弹行为的作用机理。结果显示:耗散能随疲劳荷载的变化规律可分为快速增长期、缓慢增长期和急速增长期3个阶段。A/C越大,胶浆中的柔性成分比例越多,复合材料的耗散能和累计耗散能越大;增大应力水平,会使复合材料的耗散能曲线急剧上升,试件的破坏速度加快;玄武岩纤维的掺入能明显改善水泥乳化沥青胶浆的疲劳寿命和黏弹行为,延缓试件的破坏速度,当纤维掺量为2%时,疲劳寿命和累计耗散能达到最大值,复合材料的黏弹性能最佳;微观分析表明,玄武岩纤维能很好地分散在水泥乳化沥青基体中,形成触角状结构,起到了良好的吸附和加筋作用,改变了水泥乳化沥青胶浆的黏弹行为,延长了复合材料的使用寿命。In order to study the viscoelastic behavior of cement emulsified asphalt fiber composite under fatigue loading,taking dissipation energy and cumulative dissipation energy as the main evaluation indicators,the A/C(asphalt-cement ratio),the influences of basalt fiber content and the stress level on the viscoelastic behavior of the sample are studied by using dynamic shear rheometer(DSR).The ratio of composite for the best viscoelastic performance is obtained,the mechanism of the fiber’s effect on the viscoelastic behavior of the composite is analyzed from a microscopic perspective by SEM.The result shows that(1)The change of dissipative energy with fatigue load can be divided into 3 stages:fast growing stage,slow growing stage and very fast growing stage,the larger the A/C,the larger the proportion of flexible component in the mortar,and the larger the dissipation energy and cumulative dissipation energy in the composite.(2)Increasing the stress level will lead to a sharp rise of the dissipation energy curve of the composite and a faster failure rate of the sample.(3)The addition of basalt fiber can obviously improve the fatigue life and the viscoelastic behavior of cement emulsified asphalt mortar and can delay the failure speed of the sample.When the fiber content is 2%,the fatigue life and the cumulative dissipation energy reach the maximum value,and the composite has the best viscoelastic properties.The microcosmic analysis shows that the basalt fiber can be well dispersed in the matrix of cement emulsified asphalt to form the tentacle-like structure structure,which plays a good role of adsorption and reinforcement,thus the viscoelastic behavior of cement emulsified asphalt mortar is changed,and the service life of the composite is prolonged.

关 键 词：道路工程 黏弹行为 疲劳荷载 水泥乳化沥青胶浆 微观机理 

分 类 号：U414[交通运输工程—道路与铁道工程]