The Viscosity Of Asphalt Filler Mortar And Its Effect On Mixing Performance Of Mixture

Asphalt pavement is widely used in road engineering.In order to improve the road performance of asphalt mixture,domestic and foreign researchers have conducted a lot of research.According to the structure composition of the mixture,asphalt and mineral powder constitute asphalt mastic,and asphalt mastic and fine aggregate constitute asphalt mortar.In order to improve the construction workability of asphalt mixture and the road performance after paving,this paper,from the perspective of the mixture,studies the viscosity characteristics of asphalt mastic,asphalt mortar and asphalt mixture,and reveals the influence of the viscosity of asphalt filler mortar on the mix workability of asphalt mixture.Firstly,the paper defines asphalt mastic and asphalt mortar,and then tests the basic technical indexes of asphalt mastic with different powder-asphalt ratio,and analyzes its flow characteristics at high temperature.Because of asphalt mortar and mixture in the presence of coarse particle,cannot use the traditional method to test its viscosity,in this paper,the variable speed mixing test was carried out on asphalt mortar and asphalt mixture with ratio of powder to asphalt of 1.0,1.2,1.4 and mastic sand ratio of 2:8,2.5:7.5 and 3:7.,and define a new indicators: mixing viscosity,analysis of different asphalt powder ratio and mastic sand ratio on asphalt mortar and the influence of the asphalt mixture viscosity;By defining the mixing workability index of the mixture,the influence of the change of the powder-asphalt ratio and the mastic-sand ratio on the mixing workability of the asphalt mixture was analyzed.in the end,Marshall test was carried out on the mixtures of three powder asphalt ratios and three mastic sand ratios,and the strength composition of the mixtures was analyzed.The research shows that :(1)the maximum nominal particle size of asphalt mastic should be determined by the gradation of mixture,With the increase of powder asphalt ratio,the technical index of the asphalt mastic and brinell viscosity appeared different degree of change,but the ratio of powder to asphalt has no effect on the viscoelastic ratio;(2)the mixing flow characteristics of asphalt mortar and mixture conform to bingham model,the constitutive equation is P=F+?V,and the slope of the straight line in the P-V diagram is defined as mixing viscosity,the intercept is defined as the mixing limit F by imitating bingham model,the mixing viscosity of asphalt mortar and asphalt mixture is affected by the ratio of powder to asphalt,the ratio mastic to sand.Within a certain range,the mixing viscosity ? increases with the increase of the ratio of powder to asphalt or the ratio of mastic to sand,while the mixing plastic limit F of the mixture is basically unaffected,indicating that the main influence of asphalt mastic and asphalt mortar is the binding force of the mixture;(3)the construction temperature of asphalt mortar or asphalt mixture can be determined by its viscosity-temperature curve,and it has good applicability;(4)by defining the workability index,the influence of asphalt mastic and asphalt mortar on the mixing workability of the mixture can be evaluated,and it is found that the greater the ratio of powder to asphalt or the ratio of mastic to sand,the smaller the workability index is,that is,the worse the workability of the mixture is,but its strength is bigger,so when carrying on the mix design,should choose suitable powder to asphalt ratio and mastic to sand ratio.