Effect Of Different Coarse Aggregates On Adhesion Performance And Road Performance Of Cement Emulsified Asphalt Mixture

In this thesis,four kinds of coarse aggregates,namely,diabase,basalt,steel slag and recycled aggregate,are selected to study the adhesion of cement emulsified asphalt concrete.Firstly,the surface texture and water absorption of four kinds of coarse aggregates such as diabase,basalt,steel slag and recycled aggregate are analyzed,and the contact angle between four coarse aggregates and emulsified asphalt is tested.Secondly,the reaction between cement,water,mineral powder and emulsified asphalt is explored,and the interface between cement emulsified asphalt and coarse aggregate is analyzed and scored.The low temperature bonding test and shear resistance test are designed to verify the adhesion evaluation of the interface.Finally,the pavement performance tests of four kinds of coarse aggregate mixtures are carried out respectively,including immersion Marshall stability test,freeze-thaw splitting test,rutting test,trabecular bending test,pendulum friction tester test and sand laying test,and the relationship between adhesion and pavement performance is analyzed.The main conclusions of the study are as follows:(1)The total scores of diabase,basalt,steel slag and recycled aggregate are 2.2,2.6,4.0 and 3.0,respectively.The order of surface texture of the four coarse aggregates from good to bad is:steel slag,recycled aggregate,basalt and diabase.(2)The order of adhesion work of four aggregates from good to bad is:steel slag,recycled aggregate,basalt and diabase.(3)It is found that only simple cement hydration and limestone digestion reactions take place between cement,water,mineral powder and emulsified asphalt.(4)The order of interface adhesion between coarse aggregate surface texture and cement emulsified asphalt from strong to weak should be:steel slag,recycled aggregate,basalt and diabase.The shedding rates of diabase,basalt,steel slag and recycled aggregate on cement emulsified asphalt steel sheet are:75%,31%,71%and 68%,respectively.The shear strength of four kinds of coarse aggregate mixtures,diabase,basalt,steel slag and recycled aggregate,is:1.63 MPa,1.97 MPa,2.93 MPa and 2.33 MPa,respectively.In conclusion,the surface texture of coarse aggregate has a good positive correlation with adhesion.(5)The water stability,high temperature stability,low temperature crack resistance and skid resistance of four kinds of coarse aggregate mixtures,such as diabase,basalt,steel slag and recycled aggregate,meet the requirements of relevant standards.(6)The residual stability of four kinds of coarse aggregate mixtures,such as diabase,basalt,steel slag and recycled aggregate,is:89.044%,91.299%,114.344%,115.779%,and their pendulum representative values are:67.8,70.1,73.6 and 71.9,respectively.Considering the influence of cement hydration,there is a strong positive correlation between water stability and adhesion.At the same time,the order of slip resistance and adhesion is exactly the same.Therefore,there is a strong positive correlation between skid resistance and adhesion,but this is mainly due to the influence of rough aggregate surface texture.