EFFECT OF COMPACTION
METHODS ON THE IN-SITU
PROPERTIES OF ASPHALT
CONCRETE
Ziauddin A. Khan , Hamad I. Al-Abdul Wahab and Mirza G. Baig
The 6th Saudi Engineering
Conference, KFUPM, Dhahran, December 2002 Vol. 3.
ABSTRACT
This paper describes the result of a
comparative study that was conducted to evaluate the representability
of different laboratory compaction methods to actual field compaction based on samples
cored from the field. The compaction methods evaluated in this study were: i) Gyratory Shear Compaction (1.25 degree angle of
gyration), ii) Gyratory Shear Compaction (6 degree angle of gyration), iii) Marshall Manual Impact Compaction, iv) Marshall
Automatic Impact Compaction and v) California
Kneading Compaction. The samples for this study were selected from four
projects located at different locations in the Eastern
Province of Saudi Arabia. The comparison of laboratory
and field compaction was based on samples cored from the field following
compaction without traffic densification and after four years of traffic
densification. The ability of five compaction methods to simulate field
compaction was evaluated by assessing the engineering properties, such as
resilient modulus, air voids, indirect tensile strength, bulk density and
static creep of the asphalt samples prepared in the laboratory and the core
samples obtained from the field. Cores taken after traffic densification of 3
to 4 years were tested for resilient modulus and indirect tensile strength
using Lottman method. The test results indicate the change
in mix stiffness and the effect/damage of water with age based on the
laboratory compaction methods. Overall the gyratory shear compactors
demonstrated the ability to produce mixtures with engineering properties
nearest to those determined from the field cores.
Keywords: Asphalt Mix, Compaction Methods, Pavement,
Engineering Properties, In-situ and Field Cores