Experimental On Pavement Performance Of Anti-stripping Agent For Asphalt Mixture In Seasonal Freezing Area

Our country is now focusing on road infrastructure construction.More and more governments are interesting in asphalt pavement because of the good integrity,simple and rapid construction,high driving comfort and other advantages.However,due to the increasing traffic load,environmental climate,rainfall and other reasons,asphalt pavement has gradually appeared in lots of damages.The destruction of asphalt pavement is the most serious water damage in the northwest frozen area of China.Therefore,it is very important to take effective measures to improve the water damage ability of asphalt pavement and to study the road performance of asphalt pavement in frozen season.The pavement performance of asphalt mixture without adding anti-stripping agent and with adding lime,cement and rubber powder was studied under supported by the Science and Technology Support Project in Gan Su province(No: 1504GKCA031).The study was carried out with continuous graded AC-13 and AC-16 asphalt mixture.The main contents was as follows:(1)Tests of raw material were used to ensure the requirement of specifications.The AC-13 and AC-16 asphalt mixture gradation designs were performed to determine the optimum asphalt content of the asphalt mixture;(2)the optimum mixing contents of AC-13 and AC-16 asphalt mixtures were carried out by using Marshall test,Freeze-thaw Splitting Test and Soaking Marshall Test for asphalt mixture;(3)The pavement performance test was carried out by adding different doses of slaked lime,cement and rubber powder by high temperature stability Test,Freeze-Thaw Splitting Test,Soaking Marshall Test,repeated Freeze-thaw Cycles Test and low temperature Crack Resistance Test.The results indicated that the Optimum dosages of lime were 1%,the optimum content of cement were 2%,and the optimum contents of rubber powder are 20%.To AC-13 asphalt mixture,the optimum asphalt contents to fly ash were 5.2%,and the optimum asphalt contents to cement were 5.3%,and the optimum asphalt contents to rubber powder were 7.1%.To AC-16 asphalt mixture,the optimum asphalt contents to fly ash were 4.6%,and the optimum asphalt contents to cement were 4.8%,and the optimum asphalt contents to rubber powder were 6.4%.After adding three types of anti-stripping agent,with the addition of lime,cement asphalt mixture TSR increased by about 6%,and mixed with rubber powder,the TSR of asphalt mixture was increased by 16% or more.Consumption of lime,cement asphalt mixture DS increased by about 1500 times/mm,mixing with rubber powder asphalt mixture DS increased by about 3400 times/mm.The maximum bending strain of the asphalt mixture mixed with lime,cement and rubber powder increased significantly.After several freeze-thaw cycles,the asphalt mixture mixed with lime,cement and rubber powder meet the requirements.Cement,immersion stability of asphalt mixture with rubber powder increased 7.1%-19.1%.Three types of anti-stripping agent can improve the asphalt pavement road performance,and rubber powder is the best,following on lime,cement.The advantages and disadvantages of the three types of anti-stripping agents were compared with the improvement of water damage ability,economy,applicability and difficulty of promotion.The anti-stripping agent suitable for the northwest frozen area was determined,which provided theoretical research and technical support for practical construction.