Research On Adaptability Of Machine-made Sand In The Asphalt Mixture

Machine-made sand with its excellent physical properties has been widely used in asphalt pavement. Asphalt pavement mainly select limestone machine-made sand as the fine aggregate, but there are some problems in the application, such as limestone machine-made sand is easy to be crushed. To make the better application of the machine-made sand, it is necessary to study adaptability of machine-made sand in the asphalt mixture. For deficiencies of the application of limestone machine-made sand, the research on the adaptability of diabase, amphibolite, diorite machine-made sand in the asphalt mixture is carried out.Firstly, basing on the mechanism of machine-made sand and uniform design method, gradation of machine-made sand have been optimized and the rationality of results was verified.Secondly, a new method evaluating adhesion between fine aggregate and asphalt was invented.According to this method, adhesion between the neutral rocky machine-made sand and asphalt was analyzed, and evaluated the effect of lime, cement and PA-1 anti-stripping agent on improving adhesion between the neutral rocky(diabase, amphibolite, diorite) machine-made sand and asphalt.Then, some researches on the microscopic mechanical properties of asphalt mortar have been done. This paper proposed a new mix design of asphalt mortar based on mechanical properties. The impact of the type of machine-made sand and asphalt on mechanical properties of asphalt mortar was analysed. The results showed that the mechanical properties of the neutral rocky asphalt mortar are better than that of limestone asphalt mortar.Finally, high temperature stability, crack resistance in low temperature and water stability of asphalt mixtures with the same corse aggregate and fine aggregate were studied, especially water stability.The studies have shown that the pavement performance of the same lithology asphalt mixtures is better than that of asphalt mixtures with limestone machine-made sands.So, based on the above achievements, diabase, amphibolites and diorite machine-made sand can be used as the fine aggregate of asphalt pavement.