Asphalt concrete is a mixture of
binder, aggregates and filler in different relative proportions. Its design
with other engineering materials is mainly dependent on the selection of
appropriate constituent materials. The aggregate serves as reinforcement and
add strength to the overall composite material while the mineral fillers which
play a dual role in the mixtures act as a part of the mineral aggregate by
filling the voids between the coarser particles in the mixtures and matrix that
cements larger binder particles together. Metakaolin, mineral filler is used in
this research being a pozzolanic in nature. This research aimed at examining
the suitability of metakaolin as a partial replacement of filler material
(stone dust) in asphalt concrete with percentage replacement of metakaolin at
5%, 10%, 15%, 20% and 25% used. The
asphalt constituents were subjected to various standard tests in accordance
with American Society for Testing and Materials (ASTM). Optimum bitumen content
of 5.5% was determined when the values of marshal stability (maximum), void in
mix and compacted density (maximum) were 8KN, 4.50% and 2.60 gm/cm3.
