Creep Performance ofVarious Bituminous Mixtures

Creep is a failure mode, used to describe the tendency of a material to move or to
deform permanently to relieve stresses. An example of permanent deformations is
rutting, which is caused by repetitive traffic loading that exceeds the ability of the
pavement structure to maintain its original profile. Aggregate's particle size
distribution, or gradation, is one of the most influential characteristics in the creep
performance analysis. Aggregate gradation plays vital role in the rutting behavior;
different gradation yield different strength and durability of pavement structures.
This report presents mix design and creep performance data of four gradations; gap
graded, continuous graded, open graded and dense graded. The aggregates used are
crushed granite (coarse aggregate), river sand (fine aggregate) and ordinary Portland
cement (OPC) as filler, while the bitumen used is 80 penetration bitumen. The
evaluation of creep performance is done using the Dynamic Creep Test, and the
result showsthat dense graded mixture yields the best creep resistance.