Road Performances of Asphalt Mixture Integrated with Iron Tailings

Iron tailings is one of the main industrial solid wastes, and its stacking leads serious problems, such as land occupation and environmental pollution. Recycling iron tailings in asphalt pavement is an effective way of high⁃quality and large⁃scale utilization. In this work, the asphalt mixtures integrated with iron tailings (IT⁃AC) were prepared, and the indoor experiments were conducted including Marshall test, rutting test, water immersion rutting test, water immersion Marshall test, freeze⁃thaw splitting test, low temperature bending test and dynamic modulus test, in order to comprehensively explore the influence of the iron tailings volumeteric content on the road performances of IT⁃AC. The results show that the iron tailings contains more than 65%(mass fraction) SiO2 and thus is a kind of acidic aggregate, as well as has relatively high crush value and abrasion value. More micro⁃cracks appear in the surface of iron tailings than that in the natural aggregates and partly absorb asphalt, therefore the asphalt content in IT⁃AC increases with the increasing of the iron tailings content. The 60 ℃ Marshall stability, dynamic stability, water immersion dynamic stability, residual stability, freeze⁃thaw splitting strength ratio, low⁃temperature flexural strain and dynamic modulus of IT⁃AC all decrease with the increasing of the iron tailings volumetric content, indicating that the increase of iron tailings content makes the road performance of IT⁃AC worse. It is recommended that the volumetric content of iron tailings integrated in asphalt mixture should not exceed 40%. © 2022 Cailiao Daobaoshe/ Materials Review. All rights reserved.