Study On Road Performance And Test On Bentonite Emulsion Asphalt

With the increasing of highway construction and maintenance engineering,the application of emulsified become more and more widely.Emulsified asphalt can not only be used as seal coat,tack coat and prime coat in new building road,but also can be used as the cementing material for maintenance technology among slurry seal,micro-surfacing,cold regeneration and stone chips seal.Our country has a lot of bentonite and distributes widely,which have good adsorption,water plastic,adhesion,thixotropy and cation exchange.Emulsified asphalt using bentonite was prepared which will expand types of emulsified asphalt,and increased optional ranges of emulsified asphalt in road maintenance technology.Suspension stability of soil solution which used natural sodium bentonite and sodium bentonite from industrial calcium modification was bad.Suspension stability of soil solution became better with expansion capacity and colloid price of bentonite increasing within a certain range through analysis of physical properties of bentonite.Calcium bentonite could prepare high performance sodium bentonite when the concentration of soil slurry was 10%,the dosage of Na2CO3 was 5.0%,the reaction time was 1.5h,the reaction temperature was 70? and the PH was 8.0.Higher performance sodium bentonite was prepared after precipitating 2.Oh through adding the(NaPO3)6 whose concentration was 0.25%,the slurry was viscous,uniform,good dispersion through the appearance of the slurry,hierarchical segregation phenomenon did not appear,Suspension dispersion effect was very good.Modified sodium bentonite did not emulsify bitumen well;Modified sodium bentonite and cationic surfactant could produce emulsified bitumen which did not meet requirements;Modified sodium bentonite and anionic surfactants could produce emulsified bitumen which met requirements,but mix had long demulsification time and setting speed slowly;Modified sodium bentonite and nonionic surfactants could produce emulsified bitumen which met requirements,the viscosity of emulsion was good and mix had good mixing and paving,but the consolidation of mixture had a little toughness so that it was easy to break,poor adhesion between asphalt and stone.The emulsified asphalt which included bentonite(1.2%),Sodium dodecyl sulfate(0.3%),NP-10(0.5%),asphalt(58.5%)and water(39.5%)met requirements through bentonite and surfactant compound.The emulsified asphalt using bentonite and surfactant could adapt to basalt well,and the effect of emulsification did not change with the matrix asphalt model changing.The performance of slurry seal mixture which were based on emulsified asphalt using bentonite,domestic emulsified asphalt and imported emulsified asphalt was studied,adhesion and high temperature stability of slurry seal mixture with emulsified asphalt using bentonite were better than other emulsified asphalt,at the same time,wet track abrasion and load wheel met requirements.The road which was repaired through slurry seal mixture with emulsified asphalt using bentonite had good waterproof performance and anti-slip performance,slurry seal mixture filled ruts of the original road's rutting and made pavement flatness reinstate well.