M.A.KAMALI - Professor
Engr Imran Hafeez - Assistance professor

the performance of Hot Mix Asphalt immediately after construction is influenced by volumetric properties , resulting from hot mixing and compaction. The effects of method of compaction on volumetric properties were studied in the laboratory by Marshall and Gyratory compaction method and the results were compared with volumetric properties of in-service pavement section. The study reveals that for the same mixes, Superpave Gyratory Compaction method provides better volumetric properties due to its static compaction along with shear action, as compaction along with shear action, as compared to that of Marshall compaction method. Specific gravities of compacted paving mixes can be improved in the field if the volumetric design in the loaboratory is obtained using gyratory compacting method and its certain percentage is ensured in the field. Marshall’s method does nor give exact simulation with the field pneumatic compaction ; due to which , volumetric parameter cannot be fully controlled in the field with confidence . It was also observed that apshlatic concrete of coarser grading results in an improved volumetric properties, if compacted Gyratory methods to that of Marshall. Cores were also taken from a newly constructed (N-5) Southbound SangJani section, constructed using polymer Modified Bitumen (PMB) before opening to traffic and after subsequent hot cold weathers for the comparison of volumetric properties of the cores to the lab.designed mixes.

pavement , Gyratory , Marshall , Volumetric , Compaction