EVALUATION OF
EMULSIFIED ASPHALT MIXTURES FOR USE IN SAUDI ARABIA
H. I. AI-Abdul
Wahhab and M. Arora
ABSTRACT
Road
construction industry in Saudi
Arabia has been so far confined to the use
of dense graded hot asphalt mix. Asphalt concrete is used for the construction
of wearing coarse, base course and full depth asphalt pavements. The use of
cold mixes is limited to cut back asphalts in some maintenance and construction
work, while emulsified asphalt is not used. Emulsified asphalt has a number of
unique properties that make it more suitable than asphalt cement for road bases
and low volume roads construction. It can treat most materials ranging from
coarse aggregates to fine sands and clays without heating or pollution. It has
better resistance to stripping than asphalt cement especially when marginal
aggregates are used.
This
study explores the feasibility of using locally available asphalt cement (60/70
pen) to produce suitable emulsified asphalt under laboratory controlled
conditions. Produced emulsified asphalt was compared to that produced in United States
and was used to treat locally available marginal aggregates and sands. Optimum
mixes, which were designed by modified Marshall
method, were subjected to static and dynamic testing
to evaluate their behavior under field simulated conditions.
Results
indicated that emulsified asphalt produced from locally available asphalt
cement is comparable to that produced in the United States (complying with ASTM
specs). Emulsified asphalt mixes (sand, marl and aggregate) were found to
perform satisfactorily especially when low percentages of cement were added. Sufficient
stability and modulus values were obtained. Results of this study indicate the
potential advantages of the use of emulsified asphalt locally.