In April 1994 a comparative trial of the performance of bitumen emulsion and cutback bitumen as chipsealing binders was constructed. The trial contained bitumen emulsions with a 60% and 68% binder content using a grade 5 chip, and 68% binder content with a grade 4 chip. The binder application was varied from -0.3 to +0.31/m2 from the design value. With both chip sizes, a control section using cutback bitumen at the design application was also constructed.
After three years of monitoring texture depth, it has been found that there is no obvious difference in performance of the two types of binder. It has been concluded that the Transit New Zealand sealing design methodology is appropriate.
Keywords: bitumous emulsion, chipsealing