摘要
超吸水性树脂(SAP)有着良好的吸水和保水能力,在水泥基材料中得到了广泛的应用,但在沥青材料中的应用却鲜有研究。以SAP在工程材料领域广阔的应用前景为背景,通过温度扫描试验、多重应力蠕变恢复试验、线性振幅扫描试验、浸水拉拔试验以及扫描电镜试验对SAP替代不同掺量的矿粉(10%,20%,30%,40%)后改性沥青胶浆的基本物理力学性能进行研究。试验结果表明:当SAP等体积替代矿粉后,G*和G*/sinδ在矿粉替代量为10%时达到最大,超过10%后下降,并且掺量越多下降幅度越明显;SAP对沥青胶浆的相位角的影响较小;SAP的掺量为10%时,沥青胶浆表现出最佳的蠕变恢复能力;SAP等体积替代不超过10%的矿粉时,疲劳寿命有一定的提升,但超过10%后开始下降,并且掺量越大疲劳性能越差。SAP在干燥状态下对沥青胶浆与集料之间的黏附性影响很小,浸水后拉拔强度随着SAP掺量的增加略微下降,因此水损害指数逐渐下降;沥青胶浆在干燥状态下的破坏主要是黏聚破坏,而浸水之后的破坏状态为黏附破坏与黏聚破坏共存。SAP微观样貌形态与矿粉十分相似,矿粉和SAP均能够均匀地分散在沥青当中,但由于SAP呈弱酸性,沥青对SAP的包裹弱于沥青对矿粉的包裹。基于以上研究,SAP对矿粉的建议替换量为10%。
Superabsorbent Polymer(SAP)has been widely used in cement-based materials for its excellent water absorption and retention capacity,but its application in asphalt materials is rarely studied.In this paper,under the background of the broad application prospect of SAP in the engineering materials,the basic physical and mechanical properties of modified asphalt mortar were studied by conducting the temperature sweep test,multiple stress creep recovery test,linear amplitude sweep test,water immersion pull-out test and SEM test after SAP was replaced by different amounts of mineral powder(10%,20%,30%,40%).The test results show that when the mineral power isreplaced by SAP,G*and G*/sinδreach the maximum values when the content of SAP is 10%,then decreased when the content is larger than 10%.The larger the SAP content,the more obvious the reduction.When the content of SAP is 10%,the modified asphalt mortar presented the optimal creep recovery ability;the fatigue life is improved to a certain extent when SAP replacement is less than 10%mineral powder but decrease after more than 10%;the larger the SAP content,the worse the fatigue performance.SAP shows negligible effect on the adhesion between asphalt mortar and aggregate under dry condition,and the drawing strength value decreases slightly after soaking;therefore,the moisture damage index decreased with the increase of SAP content.The microstructure of SAP is very similar to that of mineral powder.Mineral powder and SAP can be evenly dispersed in asphalt;due to the weak acid nature of SAP,the encapsulation between SAP and asphalt is weaker than mineral powder.According to the results of this study,the recommended dosage of SAP replacing the mineral power is no more than 10%.
作者
孙雨轩
吴昊
宋卫民
SUN Yuxuan;WU Hao;SONG Weimin(School of Civil Engineering,Central South University,Changsha 410075,China;Science and Technology Innovation Center,Shandong Transportation Research Institute,Jinan 250031,China)
出处
《铁道科学与工程学报》
EI
CAS
CSCD
北大核心
2023年第6期2139-2150,共12页
Journal of Railway Science and Engineering
基金
国家自然科学基金资助项目(52008405)
湖南省交通厅科技进步与创新计划项目(202110)
湖南省自然科学基金资助项目(2020JJ5744,2021JJ30845)。
关键词
超吸水性树脂(SAP)
流变性能
微观形貌
拉拔性能
Superabsorbent Polymer(SAP)
rheological property
microstructure
pull-out performance
