New Materials, Compounds and Applications

This research presents a systematic study to evaluate the potential for improving the rheological and mechanical properties of Iraqi asphalt by modifying it using locally available sulfur tailings from the Mishraq sulfur mine, obtained during sulfur extraction and purification, along with a specific proportion of polyphosphoric acid. Initially, the optimal proportion of polyphosphoric acid (PPA) to be added to the asphalt binder was determined by conducting various reactions between asphalt and polyphosphoric acid (PPA) at different weight ratios and under specific reaction conditions in terms of time and temperature. Rheological tests were then performed to determine the best polyphosphoric acid ratio for mixing with the asphalt. This ratio was subsequently used with varying weight amounts of sulfur tailings. The modified samples underwent a series of standard tests, including the ductility test, penetration test, softening point test, viscosity test and Marshall stability test. The asphaltene percentage in all modified samples was determined using a suitable solvent to study the structural changes resulting from the modification process. The results showed a marked improvement in the rheological and mechanical properties of the modified asphalt, confirming its increased resistance to thermal deformation and improved overall performance in paving applications.