South Africa is a country fortunate in possessing a well developed
network of paved roads that provides a basic and often overlooked
facility for the social and economic welfare of the country. However,
an accute shortage of funds available for pavement rehabilitation is
endangering the integrity of this network, making continuous research
for improved and more economical rehabilitation procedures necessary.
I believe that this thesis, provides in a need for improved techniques,
as a uniform approach is advocated, incorporating the best available
procedures applicable throughout the country.
In compiling the document, specific attention was given to current South
African practice, ensuring that the recommended procedures are based on
the use of readily available equipment and techniques familiar to
engineers in this country. Guidelines to all the main stages of rehabilitation
investigations are contained in a logical and systematic procedure
of investigation, evaluation, analysis, rehabilitation design and
finally. economic appraisal of applicable options. In the process full
use is made of past pavement behaviour and pavement condition, thereby
making possible an early assessment of additional information needed.
Although evaluation and analysis procedures are suggested for use, no
formal method in this regard is excluded, provided the method is relevant
to the case and information obtainable will benefit the analysis in
terms of the probable influence on the best rehabilitation strategy to
follow. By assessment of the value of information obtainable, much
emphasis is placed on the optimum utilization of available resources in
designing the best applicable remedy to an existing problem.
This procedure is demonstrated by the inclusion of a study that I
undertook in co-ordination with the Transvaal Roads Department for the
NITRR. This case study demonstrates the applicability of the various
evaluation, analyses and rehabilitation design methods, and the use of
decision trees in an economic analysis to select the best applicable
rehabilitation option. In conclusion the consequences of implementation to date are investigated.
Recommendations for further research and possible improvements for
future revisions of the recommended procedure are finally looked at.