Paper presented at the 26th Annual Southern African Transport Conference 9 - 12 July 2007 "The challenges of implementing policy?", CSIR International Convention Centre, Pretoria, South Africa. ABSTRACT: The existing bitumen extraction methods, including solvent extraction, the ignition method, the nuclear asphalt content device and biological resolving were analysed and examined for their applicability in determining the asphalt and SEAM contents of asphalt mixtures modified with sulphur-extended asphalt modifier. In SEAM-modified mixtures, sulphur separates out scatters in the mixture and dissolves in asphalt at a temperature lower than 115 °C. Sulphur can dissolve in sodium hydroxide and react chemically with new materials. In this study, the NaOH solvent extraction method was chosen to determine the SEAM content. The conventional solvent extraction method was used to determine the total amount of asphalt and SEAM. Detailed procedures and the testing precision of the NaOH solvent extraction method are given. The test method proposed in this study can be used in highway construction to control the SEAM content.
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