The Application Research Of Native Hard Bitumen In Gussasphalt

Hard bitumen has a low penenration and has better high temperature performance than soft bitumen. It is wildly used in Gussasphalt in Germany and in Japan. The research did a lot of indoor tests on the Gussasphalt used hard bitumen as the binder, which can satisfy the special climate and traffic character in China,referring to the overseas useful experience.According to the specification on the binder in our country, a lot of binder tests were done.Based on the results and the binder specification in Germany and Japan, the research chosed three kinds of hard bitumen, straight hard bitumen produced in our country, PmB45 bitumen made in our lab and PmB25 imported from Germany, as the binder of the Gussasphalt.Based on the analysis of the gussasphalt mixture design in and abroad, the paper presents more reasonable mixture design methods and test indexes. The pavement performance of gussasphalt with three kinds of hard bitmen was evaluated by workability test, indentation test, rutting test, bending test and fatigue test.The results showed that the mixtures have excellent pavement performance except their high temperature performance.In order to improve the high temperature performance of gussasphalt with straight hard bitmen made in our country, the paper presents a composite-modified method with two kinds of modifier. The results are excited, especially the high temperature performance of the gusssasphalt.