چكيده به لاتين
Nowadays, the need of finding a practical solution to increase the durability of track components and the intervals of longer maintenance periods has arisen by increasing speed and axial load. Therefore, the use of Neoballast as an alternative to ballast materials is being considered. In this thesis, the effect of mother rock properties using three different types of ballasts from Shahriyar, Anjilavand, and Koohin mines as a soft, medium, and hard rocks has been investigated after achieving an optimal method for producing Neoballast. For this purpose, the dry and wet abrasion of the samples were evaluated by performing Los Angeles and Micro-Deval tests and Finally, settlement, stiffness, and damping of these materials in comparison to the reference ballast is investigated by using the ballast box machine of the Railway Engineering Faculty of Iran University of Science and Technology after 100,000 load cycles and the effect of material type on each of the parameters of abrasion, settlement and damping ratio is evaluated. The results of the experiments show that gluing rubber powder to ballast aggregates by glue containing 15% rubber powder is optimal. In addition, according to the results of performed experiments on Neoballast samples, in all three types of m, Los Angeles and Micro-Deval abrasion is reduced by almost 72% and 92%, respectively. On the other hand, short-term settlement of Neoballast of samples made of Shahriyar 24%, Anjilavand 27%, and Koohin ore 36% is higher than the reference ballast, while the settlement-number of cycle regression relationships indicate that the settlement of Neoballast in long-term is less than traditional ballast. In addition, the stiffness of Neoballast materials made of all three types of ballast decreases by about 52% compared to the reference ballast, and the damping of Neoballast of Shahriyar, Anjilvand, and Koohin mother rocks increases by 60%, 58%, and 32%, respectively.
