Abstract: In order to explore the pavement characteristics of asphalt concrete with different iron tailings addition,the influence of iron tailings addition on the softening point,high temperature stability,freezethaw splitting,rutting resistance and low temperature cracking resistance of asphalt concrete mixture were investigated by using Qidashan iron tailings to partially replace natural sand as fine aggregate.The results showed that:① With the increase of iron tailings addition,the softening point of the sample increases first and then becomes stable,and the dynamic stability increases first and then decreases.When the iron tailings addition is 20%,the softening point and dynamic stability of the asphalt concrete mixture are the highest,reaching 56 ℃ and 5 292 times /mm,respectively.② With the increase of iron tailings addition,the maximum bending strain decreases first and then increases,and the bending strength increases gradually.The maximum bending strain value reaches the lowest when the iron tailings addition is 30%,and the performance of the sample can basically meet the requirements of pavement performance.③ With the increase of iron tailings addition,the rutting resistance factor increases first and then slightly decreases,and reaches the maximum value when the iron tailings content is 20%.④ With the increase of the number of freezethaw cycles,the splitting strength ratio decreases gradually.Under the same number of freezingthawing cycles,the splitting strength ratio of asphalt samples increases first and then decreases with the increase of iron tailings addition.Based on the test results of iron tailings asphalt concrete,the indicators of asphalt concrete can reach the best when the iron tailings content is 20%~30%.

Key words: iron tailings addition, high temperature stability, low temperature crack resistance, freeze-thaw splitting, rutting resistance, split strength ratio