Impact of Iron Filling on the Durability of Asphalt Concrete

Abstract

The uncontrolled load repetitions and environmental impacts causes the flexible pavement to suffer distresses throughout its service life. Development of innovative materials and techniques for asphalt pavement repair are going on, many of them are related to implementation of additives. In this investigation, iron filling was implemented as partical replacement of sand. Two sets of Asphalt concrete specimens have been prepared, Marshall size specimens of 102 mm diameter and 63.5 mm height and cylinderical specimens with 102 mm diameter and height with different percentages of iron filling and corresponding required asphalt content. The first set of specimens was subjected to resistance to moisture damage determination. Part of the first set of specimens practices short and long term aging process then were subjected to 1200 repetitions of indirect tensile stresses. Finally, the tensile strength was determined. The second set of specimens was subjected to repeated compressive stresses using three stress levels then the compressive strength was determined. The durability of asphalt concrete specimens was investigated in terms of aging, resistance to moisture damage, and resistance to rutting. It was observed that implementation of iron filling exhibits a significant impact on the durability of asphalt concrete as compared with control mixtures. It was concluded that permanent deformation was reduced by (58 and 80) % after the first and the 1200 load repetitions respectively due to short- and long-term aging process adopted. Mixture with optimum asphalt content of 4.9% and iron filling content of 5% is capable to resist permanent deformation and is the least susceptible to rutting than mixtures with other percentages of binder content.