Research On Aging Properties Of Asphalt Mortar And The Impact On Road Milling Planer System Using DMA

Today, a large number of highways in our country have entered the pavement repairing period, and now the main way to overhaul is to remove the old pavement and repave the new road, which will lead to the generation of a large number of waste materials. According to the present situation, asphalt pavement recycling technology will be an important direction in the field of highway development, and as an important part of the regeneration technology, the design of machine parameters of pavement milling will be an important research direction.There are often a lot of stone broken cases in road milling process, and it will occur complicated mechanical behavior when the milling machine get in touch with the aged asphalt mixture. Moreover, the asphalt mortar plays a key role in this process. This paper took the mechanical performance of asphalt mortar as a starting point, and simulated the aging condition of the actual pavement asphalt by the way of accelerating the aging of asphalt in laboratory; By using dynamic mechanical analysis(DMA), we researched the visco-elasticity of aged asphalt,the interface effect of asphalt and mineral powder, and the adhesion property of mortar-aggregate. In addition, we verified the deformation ability of the aged asphalt by the low temperature bending test and explored the improvement of milling system parameters. The result shows that the deeper the degree of aging of asphalt mortar, the viscosity decreased elasticity increase. At 30℃, 40℃, 50℃, The complex shear modulus and rutting factor increased first and then decreased with the aging degree, and the asphalt mortar under deformation ability decreased first and then increased; At 60℃, the complex shear modulus and the rutting factor increase with the aging time. Therefore, When milling to the pavement which was used of more than 6 years of age, the temperature should be controlled within 50℃; Meanwhile, the function of the asphalt and mineral powder will increase with aging, and the deformation ability of aged mortar and aggregate adhesion properties decreased with the delay of aging time, and the small cutting displacement could make the mortar fracture. Therefore, when milling the pavement which was used of more than 6 years of age, the number of cutter head can be set more.