| The traditional hot mix asphalt has many problems,such as high construction temperature,large energy consumption and emission of harmful gases.However,the application of warm mix asphalt technology has effectively improved the series of problems.Among them,the use of water foaming technology to prepare the foamed warm mix asphalt has more technical and economic advantages.At present,foamed warm mix asphalt has been widely applied,but many problems have appeared in practical application.In order to make better application of foamed warm mix asphalt,it is very necessary to further study related issues.The study is aimed at base asphalt mortar and foamed asphalt mortar under the conditions of different filler-asphalt ratio.The two kinds of asphalt mortar rheological properties are compared and analyzed by dynamic shear rheometer(DSR)test,beam bending creep(BBR)test,scanning electron microscopy(SEM)test,differential scanning calorimetry(DSC)test and thermogravimetric(TG)test,which clarify the differences two kinds of asphalt mortar related characteristics,and determine the best filler-asphalt ratio of foamed asphalt mortar.The main research work is as follows:(1)Foamed asphalt is prepared by water foaming technology,two preparation parameters of asphalt temperature and foaming water consumption are mainly considered,and three evaluation indexes of expansion rate,half-life and foaming index are comprehensively analyzed,and the best foaming conditions of asphalt are determined.(2)The DSR test of the foam asphalt mortar with different filler-asphalt ratio was carried out under two modes of temperature and frequencies.The influence of filler-asphalt ratio on the complex shear modulus,phase angle,anti rutting factor and fatigue factor of foamed asphalt mortar is emphatically analyzed,thus determining the best filler-asphalt ratio of foamed asphalt mortar.(3)The vGP curve is used to analyze the G*—? curve superposition of foamed asphalt mortar.The validity of the time-temperature equivalence principle is proved.The main curve of the foamed asphalt mortar is determined.The main curve was use to anaiyze the high temperature stability of the foamed asphalt mortar in the full temperature and full frequency.(4)According to the S and m determined by BBR test,the low temperature cracking resistance of foamed asphalt mortar is evaluated,and the low-grade temperature of foamed asphalt mortar is analyzed,the optimum powder binder ratio of foamed asphalt mortar is determined.The two kinds of asphalt slurry were graded by PG.(5)The microstructure of two kinds of asphalt mortar was analyzed by SEM test.The dispersion of mineral powder in foamed asphalt mortar was clarified.The inherent mechanism of high and low temperature performance of foamed asphalt mortar was preliminarily revealed,and the best filler-asphalt ratio of foamed asphalt mortar was verified.(6)The thermal properties of two kinds of asphalt mortar were studied by measuring the heat flux,glass transition temperature and loss residual mass ratio,and the filler-asphalt ratio of foamed asphalt mortar is analyzed from the perspective of thermal effect. |
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