Study On Rheological Properties Of Asphalt Mortar Based On High-and-Low Temperature And Fatigue Performance

The asphalt pavement is widely used, and the asphalt pavement accounts for nearly 90% in the highway of having been run in our country. The performance and the life of the asphalt pavement depend on the performance of asphalt and asphalt mixtures. So the asphalt and asphalt mixtures have become the focus of the road-building sector. However, the system of the mineral powder-asphalt has great influence on the performance of asphalt mixtures. Now the study of asphalt mortar is not very mature, and the sdudy of the high viscosity asphalt mortar is few. The paper based on taking the existing relevant research results makes research on the rheological property of the matrix asphalt mortar and the high viscosity asphalt mortar, and this purpose is to study the differences between the two kinds of asphalt mortar, the influence of the mineral powders on the asphalt mortar’s performances.Firstly by the laser particle size analyzer and so on, it tested the physical and chemical indexes of the choosed 5kinds of mineral powder, and it got different mineral powders’ density,particle size distribution, fineness modulus,specific surface area and other indexes, and it focused on the mineral powders’ particle size distribution.The result indicated that the mineral powders which have the same passing rate of 0.075 mm have differences of their continuity of detail. Compared with the mineral powder’s specification requirement, the fineness modulus and other particle size indexes can describe the mineral powder’s fineness accurately.Secondly, by studying the two kinds of asphalt mortars’ rheological properties, it indicated that the mineral powder has obvious synergistic action on the modulus of asphalt mortar, and this makes the high temperature of asphalt mortar enhanced ability to resist deformation, the low temperature crack risitance turned bad. At the same time the mineral powder reduces the fatigue life of asphalt morta. And the mineral powder small effects on phase angle, the different mineral powders and filler-asphalt ratios have differences of asphalt mortar’s rheological property.There were differences of performance betwwen the matrix asphalt mortar and the high viscosity asphalt mortar, and the test result indicated that the high temperature, low temperature and fatigue performances of the high viscosity asphalt mortar were better than the matrix asphalt mortar. It also found that the Non-recoverable difference Jnr-diff got by the multiple stress repeated creep recovery(MSCR) test could be used to judge the largest filler-asphalt ratio of the matrix asphalt mortar. Then it determined the reasonable range of filler-asphalt ratio by the influence of filler-asphalt ratio on the asphalt mortar’s rheological property. Then it studied the relevance about the influence of the mineral powder’s different physical and chemical indexes on the the high temperature, low temperature and fatigue performances of the asphalt mortar based on grey correlation analysis, and it got the key indexes from the influence of the mineral powder on the asphalt mortar, such as density, hydrophilic coefficient, P20, D10, specific surface area and fineness modulus.Lastly, it evaluated the water stability of asphalt mixtures by the asphalt mortar’s cohesive test and the asphalt mixtures’ freeze and thaw splitting strength test. The result indicated that the adhesion of the high viscosity asphalt and it’s asphalt mortar were far better than the matrix asphalt, but the adhesion of the high viscosity asphalt and it’s asphalt mortar didn’t fully evaluate the water stability of asphalt mixtures. The high viscosity asphalt had a better filler-asphalt ratio in the use of the asphalt mixtures, and when it was over this filler-asphalt ratio, it would influence the water stability of asphalt mixtures.