Surface Tension of Various Asphalts and Correlation with their Components

To compare the difference of surface tension of asphalt in various penetration grades, the surface tension for 18 kinds of asphalt with penetration grades 60-80, 80-100 and 150-200 were measured. Furthermore, these asphalts are individually segregated into four components, and the relation between total surface energy (Hs) and asphalt components are investigated using a statistical analysis. Penetra-tion grade 60-80 asphalt is found to have the largest value of standard deviation, and 80-100 and150-200 show almost the same value. The relation between each of the four components of 18 kinds of asphalt and Hs are analyzed by use of a single regression analysis. It is found that asphaltenes have the largest correlationcoefficient value for Hs. Also, the relation between four components and Hs are analyzed by use of amultiple regression analysis. From these data, it is clarified that asphaltenes had an influence onthis relationship. Furthermore, in order to investigate the influence of asphaltenes concentration in asphalt, 6 kinds of asphalt were selected and the surface tension for their malthenes components measured. Low surface tension for each asphalt is observed. It is indicated that the asphalt is influenced by asphaltenes concentration of more than 13-14%.