Research On Pavement Performance Of Iron Tailings Sand Stabilized With Inorganic Binder

There are many iron mines in Chaoyang Liaoning Province,many iron tailings let out every year.Because of no effective way to use,there are many tailings,engaging land, plugging river,polluting environment.But materials in road construction are shortage gradually.If using iron tailings to build road will not only solve the materials problem,but also save land and resource,improve environment and bring good social and economy benefit.According to the grain composition,about 44%(mass percent) is between 0.3～0.6mm.it contains many SiO₂ Fe₂O₃ and Aa₂O₃,they can react with inorganic binders such as lime or cement.Combining the character of the structure and composition of the semi-rigid base material,three series proportioning plans of iron tailings sand as base material were designed: iron tailings sand stabilized with lime,iron tailings sand stabilized with cement,iron tailings sand stabilized with lime and cement,compared with lime-clay,and researched on the material composition,mechanics properties,water stability and drying shrinkage.It was showed that iron tailings sand stabilized with 31%lime or 11%cement or 12%lime and 2%cement all could satisfy the specification required strength of low grade highway basement.The result of compressive strength,splitting strength and modulus of resilience showed that the results of iron tailings sand stabilized with cement is best,iron tailings sand stabilized with lime is worst,and iron tailings sand stabilized with lime and cement is between both of them,but they are all better then clay stabilized with lime.The wetting and drying cycle test result showed that iron tailings sand stabilized with cement is bad,iron tailings sand stabilized with lime and cement is better.The dry shrinkage test result showed that the mass loss of iron tailings sang stabilized with cement is the fewest,but the shrinkage ratio is the greatest.That means more cement will cause shrinkage crack.Based on overall consideration of various factors,iron tailings sand stabilized with lime and cement is the best proportion plan,and it's more economical than other plans.According to the result of indoor test,we designed the proportioning plans of iron tailings sand stabilized with inorganic binder.In order to improve the strength,we mixed coarse iron tailings with the iron tailings sand.And build two sections testing road to observe the long-term pavement performance.One month after testing road final completion,the result of deflection measurement could satisfy the designing required.