Abstract:
The primary purpose of this study is to identify the causes of rutting in
highway pavements in the form of channelization particularly on wheel
tracks resulting from high traffic repetitions and environmental effects. The
rutting reduces the required performance due to poor hot mix asphalt
(HMA) components and construction to mention a few. The study focused
on the impact of fine aggregate angularity (FAA) to increase Asphalt layer
stability.
AASHTO testing method (T 304) was applied at the expense of
uncompacted void content as a measure to determine the fine aggregate
angularity index. Through the selection of samples of fine aggregate
natural and crushed used in the production of hot mixt asphalt in Khartoum
State by adopting Asphalt Institute requirements as described in Superpave
design method, in Relation between Angularity and Traffic volume
(ESAL) .
This study applied Marshall Design method in the evaluation of properties
of asphalt mixture voids, stability and other indicators to assess the results
in producing accepted mixture with good performance. The study also
included data collection on producing crushed aggregate, quarry sources
and suitability for hot mix asphalt within Khartoum state to study the cause
of rutting in the Ring road and Elsteen Street as case study in order to link
the angularity and texture with the both process of crushing aggregate and
various type crushers available.
Data analysis has shown the high FAA value increase the stability. For the
proper matching between all mixes properties, the mix should not be
design to optimize one particular property mixes. Also the finding from
this study indicate that regarding the existing HMA in the Ring road the
fine aggregate angularity with blended natural and crushed aggregate is
suitable for the current ESAL according to Asphalt Institute requirements.
