TIle purpose of this study is to determine the effect of non-linearity of unbound
granular material as base course on the road pavement. This study focused in the
determination of the effect of density and level of stress on resilient modulus at
granular base material under repeated loading. The granular material was compacted
at optimum moisture content of the 90 %, 95 % and 100 % of maximum dry density.
The stress application assign to the stress situation caused by wheel loading affected at
the base, upper subbase and lower subbase layer pavement. From the test result, the
graph was plotted by regression analysis and the model fitted base on Brown and PeII,
1976, as Mr = kl (9/90)k2. The result obtained was analysed by Analysis of Variant
(ANOVA) using t-test to detennine the effect of resilient modulus on density and level
of stress. The resilient modulus increases as the level of stress and density increase,
which means that the resilient modulus of unbound granular material is stress
dependent and the relationship is non-linear. The effect of non-linear unbound
granular material on the road pavement is determined by MICH-PA VE software. The
flexible pavement was analysed based on Manual of Pavement Design (JKR) which
the standard and construction layer thickness was taken. The analyses consist of the
maximum horizontal tensile and the average compressive strains in asphalt layer and
compressive strain at the top sub grade. These strains are related to the fatigue life and
rut depth of asphalt pavement. TIle resilient modulus increases with the increase in
density. Everything being equal pavement with unbound layer with lower may have a
higher horizontal or radial strain at the bottom of asphalt, and therefore will have
shorter fatigue life. The lower density at the unbound layer tends to increase the
average compressive strain within the asphalt layer and compressive strain at the top
of subgrade, which may cause at the increment rate total plastic defonnation at the
pavement