| Superabsorbent Polymer(SAP)has been widely used in cementbased materials due to its excellent engineering and functional characteristics,but its application in asphalt materials remains to be further studied.In this thesis,based on the broad application prospect of SAP in the field of engineering materials,the basic physical and mechanical properties and rheological properties of SAP modified asphalt mortar,road performance and functional properties of SAP modified asphalt mixture were studied.The main contents and conclusions include:(1)The influence of SAP on the basic physical and mechanical properties of asphalt mortar was clarified through micro observation test and analysis.Due to the foaming effect of SAP hydrogel in hot asphalt,adding an appropriate amount of SAP into asphalt material has a certain viscosity reduction effect.After replacing part of mineral powder with SAP,the adhesion performance between SAP asphalt mortar and aggregate is good,and SAP can be evenly dispersed in asphalt material in physical blending state.(2)The rheological properties of SAP modified asphalt mortar were discussed.The results show that when the content of SAP(the equivalent volume replacement ratio of mineral powder)is less than 10%,the high temperature stability and medium-temperature fatigue resistance of asphalt mortar are improved to a certain extent,but when the content is more than10%,these properties decrease,while the low temperature crack resistance shows an opposite trend.(3)The preparation and mixing method of asphalt mixture with SAP hydrogel was proposed.The mixing effect of SAP hydrogel was evaluated by the equal porosity method.The results show that SAP hydrogel can effectively reduce the mixing temperature and improve the mixing efficiency of asphalt mixture.(4)The road performance and functional properties of SAP modified asphalt mixture were discussed through laboratory test.The test results show that the high temperature stability of asphalt mixture can be improved when SAP content is less than 10%,but it will weaken its water stability to some extent.Adding SAP hydrogel into asphalt mixture can improve the compaction effect of asphalt mixture,and the compactness reaches the maximum when SAP replaces 30% mineral powder.SAP can inhibit moisture migration in asphalt mixture,and the higher the SAP content is,the more significant the effect is.After comprehensive analysis,in order to play the functional characteristics of SAP and ensure the mechanical properties of asphalt mixture,the proportion of SAP replacing mineral powder should not exceed 10%. |
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