Abstract:
One of the main problems with roads and highways in China is the reflection cracking
caused by the cement stabilized subbase layers passing through the overlying asphaltic
layers. The cracks permit the ingress of moisture which softens the layers below the
subbase resulting in loss of support and accelerated breakdown of the subbase layer and
reduction in the riding quality. The aim of this paper is to present the use of South African
pavement design approach of deep structure and thin surfacing to overcome the existing
problems. The deep pavement structure provides good long-term support and avoids the
influence of moisture ingress, which means that only surfacing damage needs to be
repaired. An unbound crushed stone base layer which is an integral component of the
pavement structure limits reflection cracking.
The paper first deals with the South African pavement design procedure and contrast
this with the Chinese pavement design method. The inherent weaknesses of these
methods are discussed and flowing from this discussion proposals for adapting the South
African approach to China is presented. The resultant proposals have a high likelihood of
success and will counteract the influences of extreme climate and rampant overloading
that occurs on the Chinese roads.
