The Performance Improvement of Hot Mix Asphalt and Enhanced Applicability to Pavement Structure Thickness Design Using DAMA (Drain Asphalt Modified Additive) Jung-hoon, Jin* * University of Incheon ITS. R.C. Researcher 3. Laboratory Test Methods and Results The composition of the hot mix asphalt was designed optimum asphalt content determination by the drain HMA design method and Marshall mixture design methods. The asphalt mixtures of five kinds of type (dense graded 19mm, drain graded 13mm, drain graded 19mm, superpave graded 19mm, SMA graded 19mm) were then subject to Marshall stability test (KS F 2337), indirect tensile strength test (KS F 2376), compaction test, resilient modulus test (KS F 2336), and wheel tracking test (KS F 2374). The weight of DAMA varied 0%, 0.5%, and 1% of the asphalt mixture. Table 5 shows VTM(voids in total mix) and asphalt binder content of each HMA, and table 6 exhibits permeability index and abrasion loss ratio of drain graded 13mm and 19mm. ¢Æ Table 5 Voids in total mix(VTM) and Asphalt binder content ¢Æ Table 6 Permeability index and abrasion loss ratio of the drain graded 13mm and 19mm * abrasion loss ratio criterion : 20% and below