The Correlation between Compaction Degree and Performance Life of Asphalt Concrete

Inadequate compaction of wearing course of asphalt concrete is a common phenomenon
in road construction. Contractors choose to apply a minimum compaction effort in order
to cut costs and speed up construction process. Even though the requirement set by
relevant aut})orities such as Jabatan Kerja Raya (JKR), most of the end product failed to
achieve this requirement. Inadequate compaction results in pavement with reduced
rutting and fatigue life. This study aims to establish a correlation between compaction
degree and performance life of asphalt concrete. Such correlations will provide awareness
to the practitioner that the void content is a crucial factor in the performance life of
asphalt concrete. Three types of tests were carried out to provide quantitative information
on performance life of asphalt concrete at various degrees of compaction. The tests were
dynamic creep test, fatigue test and wheel tracking test. The mix type is wearing course
and the mix designation is asphalt concrete wearing course or ACW20. The material
includes asphalt cement, aggregate and cement as filler. Based on JKR recommendation,
penetration graded asphalts were used. The sieve analysis was performed according to
JKR specifications. From dynamic creep test, the correlation between compaction degree
and rutting life obtain_ed was'{ A .=.(4 X 10" 145
} XA 77
•
676 (low porosity), y A= 10-232 XA 120
·
7
(medium porosity) and y A = (3 X 10-256
) XA 133 08 (high porosity), where y A as rutting I ife
in msa and XA as compaction degree in percentage. Low porosity specimen is less
susceptibility to rut depth than the high porosity specimen. The correlation between
porosity and rate of wheel tracking obtained in this study was Y 8 = 0.0018 X8 1.
8624 with
R2 =0.7138, where Y8 is rate of wheel tracking in mm/min and X8 is porosity. This
correlation emphasizes that low porosity specimen is more resistant to permanent
deformation than high porosity specimen. For fatigue failure, the same trend can be
concluded.
Keywords
Compaction, asphalt concrete, porosity, performance life, rutting, fatigue failure