The Effect of Different Filler Materials and Gradation on Rutting and Cracking of Bituminous Mixture

Different filler materials and gradation can change the bituminous performance in
pavement. Filler materials act to improve the quality of mastic. Meanwhile, gradation
can change the mechanical behaviour of bituminous mixture. Types of fillers that are
used in this experiment are Ordinary Portland Cement (OPC), Pulverised Fly Ash (PFA),
and Hydrated Lime. Two types of gradation are well-graded and gap-graded. This gave
six different asphaltic concrete combinations where a series of testing are done to
evaluate the characteristics of each bituminous mixture. Various test on the aggregate
gradation, aphalt material and mineral filler are done before the Marshall Test in
determining the best oil content. It was followed by the WESSEX Wheel Tracking Test,
Beam Fatigue Test, Indirect Tensile Fatigue Test and Creep Test where the outcome are
analyzed to determine which combination of filler and gradation relatively give better
performance in reducing the occurrence of rutting and cracking. It shows that the
combination of lime and well graded produced adequate void rate and flexibility, higher
stability, lower rutting deformation rate, higher stiffuess, and longer fatigue life.