Optimization of asphalt foaming characteristics

In order to optimize asphalt foaming characteristics, asphalt foaming tests using five surfactants and two ways of surfactant addition, six use levels of foaming water and two foaming water temperatures were conducted. Then, the performance tests of foamed asphalt mixtures made by foamed asphalts with different foaming characteristics were conducted. The results show that the surfactants can significantly improve the half-life of foamed asphalt, however, it can't effectively improve the expansion rate of foamed asphalt. The expansion rate and the half-life of foamed asphalt can be improved by adding a cationic surfactant, increasing use level of foaming water and foaming water temperature. The foaming characteristics of foamed asphalt has no significant effect on the indirect tensile strength(ITS), dry-wet tensile strength ratio, freeze-thaw tensile strength ratio and flexural strain of asphalt mixtures, but has significant effect on the fatigue life. The foamed asphalt mixture made by foamed asphalt with good foaming characteristics has a better long-term performance.