In this study, full factorial design of experiment was
carried out to evaluate the effect of various factors such as
bitumen content, specimen diameter, test temperature and
load duration on the resilient modulus of bituminous paving
mixes. It was observed that all the four factors have negative
effect on the resilient modulus of bituminous paving mixes.
Temperature was found the most significant factor affecting
the resilient modulus of bituminous paving mixes, followed
by load duration and specimen diameter. Most high order
interactions were negligible which corroborates sparsity of
effect principle. In 2-way interaction, diameter–temperature,
diameter-load duration, and load duration-temperature were
significant. The most significant 3-way interaction was
bitumen content-temperature-load duration. The bitumen
content alone was an insignificant factor but it became
significant in interaction with test temperature and load
duration. A model to predict the resilient modulus was
developed using two-level four-factor full-factorial design.
The effects of four factors studied were within a selected
range of values. Further studies are recommended with wider
range at both high and low levels of the parameters used in
the present study.