DIGEST 2006 - Sabita

Bitumen stabilised materials:
A performance classification
system for SA ... Quo Vadis?
Kim Jenkins
Professor
SANRAL Chair
University of Stellenbosch
As part of its undertaking
to develop a performance
classification system for
South African bitumen, the
specific working group of the
Road Pavements Forum (RPF)
task group on binder
specifications, has arranged
for bitumen from all four local
refineries to be tested for
compliance with the SHRP
SuperPave grading system.
This testing was arranged by
Professor Kim Jenkins, convenor of
the working group, to be
conducted at the University
Wisconsin, Madison by members
of the research group headed by
Professor Hussain Bahia.
In Nov 2003 the RPF Resolved that
” the Bitumen Specifications
Working Group be reconvened
with the objective of reviewing the
South African binder specifications
relative to international trends of
Performance Grading (PG). A
precursor of the above review
process was the fingerprinting of
various South African crude source
binders using the American PG
System. Professor Bahia played a
key role in the development and
implementation of the SHRP
binder grading system and, having
had several years of involvement
in South African binders, kindly
agreed to assist in both the testing
and the interpretation of the PG
results.
Fingerprinting
In general, the test results
confirmed that the bitumen,
sampled from all four South
African refineries for the
fingerprinting, complies with
specific grades of the SuperPave
classification system. This is
encouraging, and will lay a sound
platform for developing
performance related specifications
in SA. The full range of low
temperature tests were not
conducted on the binders (e.g. the
Direct Tension Test (DTT) was
omitted) as these are not directly
applicable to the in-service
conditions encountered in the SA
climate. However, some additional
138