Bitumen Spray Sealing: Problems and Practical Solutions

Abstract

In recent times Wambo Shire Council has experienced trouble with the performance of sprayed seals on both its Council and Declared roads. These problems seem to have arisen for a number of reasons that collectively have caused the failure of the seal layer. Such things as increased traffic volumes, Environmental and safety standards have caused the Department of Main Roads to set sealing timeframes for our district that in themselves are contributing to seal failures. At the same time, Bitumen Refineries seem to be producing a Class 170 product that is still within Departmental specification but on site seems a vastly differing product than that supplied in the previous years despite testing to dispute this fact. Also, the arrival of proprietary products such Multigrade Bitumen and Polymer Modified Bitumen has given a vast range of products available to the Road Engineers. The days have gone where the same seal treatment could be used on each new road construction. This paper will investigate various products available to try to come up with an understanding of how these products behave and where they are best suited. This information can then be used to come up with the best value options for each projects particular needs