Study On Properties Of Aged Asphalt Mixture

In this paper,AC-13 asphalt mixture is selected as the research object,and the asphalt mixture is subjected to short-term heat aging,long-term heat aging and ultraviolet aging.The performance of asphalt pavement with different aging methods is compared with the performance of triaxial strength.The influence of aging on asphalt mixture provides a certain reference for later design and construction.Firstly,according to the standard test method and test precautions,compare the aging test plan,heat aging to select the oven heating method,select the Xenon weatherproof test box for UV aging,and establish the aging time and aging temperature.After extracting and distilling the aged asphalt mixture and separating the asphalt into four components,the content of light components(saturated and aromatic)of the aged asphalt decreases,and the reduction range of ultraviolet aging is larger than that of short-term aging and smaller than that of long-term thermal aging.The content of asphaltene increased,and the content of asphaltene increased greatly after thermal aging.The asphalt resin content of thermal aging decreases while that of ultraviolet aging increases.The thermal aging of asphalt mixture mainly focuses on short-term thermal aging and the higher the aging temperature,the greater the impact.The aging time with the greatest change in the four components of asphalt after thermal aging is 6-9 h,and the aging time with the greatest change in the four components of asphalt after ultraviolet aging is 116-175 H.The high temperature rutting test,the water immersion Marshall test and the low temperature trabecular bending test were carried out on AC-13 asphalt mixture with different aging conditions,and the comparison of different aged asphalt mixture in high temperature anti-rutting,water temperature qualitative and low temperature crack resistance performance was carried out.To analyze the influence of different aging conditions on the road performance of asphalt mixture.A three-axis experiment of planar isostatic/axial compression and planar isobaric/axial stretching conditions was carried out by a self-made triaxial experimental system.Under the triaxial compression load,the axial compressive strength will increase significantly with the increase of confining pressure.The suitable temperature and heat aging in a short time is beneficial to the increase of asphalt mixture strength.Under the condition of ultraviolet aging,the triaxial compressive strength of asphalt mixture increases first and then decreases.Under the condition of plane isobaric/axial stretching,the axial tensile strength of asphalt mixture decreases gradually.Small,airbag confining pressure also has a significant effect on the axial tensile strength of the asphalt mixture.The higher the air pressure,the lower the strength.The effects of aging conditions and confining pressure on the strength of asphalt mixture were analyzed.