Executive Summary : | Pioneer studies have very well established that asphalt concrete has self-healing properties. This self-healing phenomenon can be instigated by the addition of inductive materials like steel wool, scrap metal, or any conductive material into the asphalt mixes. When a cracked asphalt concrete is subjected to inductive heating, the added conductive particles locally increase the temperature, leading to melting of bitumen, healing the cracks, and recovering the mechanical property of the asphalt mix. In the proposed laboratory investigation, steel slag is used as aggregates in various asphalt mixes and their role in promoting the self-healing property in the mix is studied. The ultimate aim of this proposed study is to investigate the influence of steel slag when used as aggregates on self-healing capacity of hot mix asphalt, and, to assess the strength and durability performance of respective mixes post healing process. To achieve the aim, the steel slag will be added as coarse aggregates, fine aggregates and in combination, to a variety of hot mix asphalt mixes like bituminous concrete(BC), Dense bituminous macadam (DBM), open grade friction course (OGFC), and stone matric asphalt (SMA). The samples will be subjected to controlled cracking and divided into two study sets (a) samples subjected to minor cracks (less than or equal to 2mm cracking) and (b) Samples subjected to major cracks (crack width greater than 2mm). Each mix will be subjected to healing mechanism by conditioning them to a suitable temperature and period, found during trial studies. After this, retained strength and durability post healing will be studied by finding retained tensile strength, tensile strength ratio, resilient modulus, and performance in fatigue testing. Microstudies like scanning electron microscopy studies will also be conducted to investigate the structural change of HMA and the influence of the self-healing mechanism. |