H. I. AI-Abdul Wahhab and M. Arora




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.