Abstract
The performance of asphalt concrete pavement depends on the
bitumen properties, asphalt concrete mixtures volumetric properties and
external factors such as traffic volume and environment.Overlay is one of
the quickest preventive maintenance techniques that apply to retard
asphalt pavement deterioration and prolonged service lives. This study
focuses on prepare good performance and flexible modified thin hot mix
asphalt used as an overlay. Styrene-butadiene rubber (SBR) at three
contents (3, 6 & 9 % by asphalt weight) were used either alone to modify
local asphalt penetration grade 40/50. Properties of modified and
unmodified asphalt binder (Penetration, Softening point, Flash point and
Ductility) were examined. Performance of modified and unmodified
asphalt mixtures was evaluated through Marshall, Indirect Tensile
Strength and Wheel Tracking Test. Test results showed that all properties
of the base asphalt binder and asphalt mixes were improved by the
addition of the modifier. The best improvements in the modified binders
and modified mixes were obtained at 6% SBR. Stiffness of modified
asphalt mixes were improved at 6% SBR was introduced. Marshall
stability was increased by 26% and flow was decreased by 12.5% at 6%
SBR. Resistant of the modified asphalt mixes to rutting was increased by
61% at the same modifier content.
The three mix types prepared and tested according to Marshall Method.
Marshall Stability and Indirect tensile tests were conducted on Marshall
specimens. Wheel tracking test were conducted on (50×10×5 cm) AC
mix beams.
