A benchmarking study of anionic bitumen emulsion properties for slurry seals

Abstract

Bitumen emulsions are the most commonly used bituminous products for roads in Southern Africa because they are relatively inexpensive to apply, in comparison with hot bituminous binders. Although there have been great strides taken in the improvement of bituminous emulsions for slurry seals through the years, current specifications and testing procedures are empirical and not related to common service failures. The quality of a bituminous emulsion is affected by the rheological properties of the base binder, particle size and formulation ingredients, which in turn affects its in-service performance. Several potential performance related test methods for emulsions have been developed over the years. This paper evaluates the properties of South African anionic emulsions with these performance-related tests and the current empirical tests. This paper aims to show the possible limitations of empirical tests in analysing bituminous emulsion properties and the need for better characterisation methods to overcome current performance challenges.