MODIFIERS FOR ASPHALT CONCRETE

ONE OF THE MAJOR PROBLEMS AFFECTING THE PERFORMANCE OF AIR FORCE ASPHALT CONCRETE PAVEMENTS IS PERMANENT DEFORMATION (RUTTING) ASSOCIATED WITH HIGH TEMPERATURE SERVICE. BECAUSE MANY CURRENT AND FUTURE GENERATIONS OF AIRCRAFT REQUIRE HIGH-PRESSURE TIRES AND THRUST VECTORING, IT IS EXPECTED THAT RUTTING PROBLEMS WILL INCREASE IN THE FUTURE. A HOST OF PRODUCTS ARE AVAILABLE, HOWEVER, WHICH CAN BE USED TO MODIFY THE NATURAL PROPERTIES OF AN ASPHALT CONCRETE. THE OBJECTIVES OF THIS RESEARCH ARE TO IDENTIFY THE MOST PROMISING TYPES OF ADDITIVES FOR REDUCING PERMANENT DEFORMATION IN AIRFIELD PAVEMENT. SELECTION WILL BE BASED ON (1) A LITERATURE REVIEW, (2) LABORATORY TESTING OF SELECTED BINDER AND BINDER-AGGREGATE MIXTURES, (3) FIELD PERFORMANCE ESTIMATES, AND (4) AN ANALYSIS OF ECONOMIC FEASIBILITY. BINDER TESTS WILL INCLUDE PENETRATION AND VISCOSITY AT TWO TEMPERATURES AND DUCTILITY. THESE TESTS WILL BE PERFORMED BEFORE AND AFTER AGING IN A ROLLING THIN-FILM OVEN. MIXTURE TESTS WILL INCLUDE MARSHALL STABILITY AND FLOW, RESILIENT MODULUS AT TWO TEMPERATURES, CREEP AT TWO TEMPERATURES, AND SPLITTING TENSILE STRENGTH. THE MIXTURE TESTRESULTS WILL BE USED WITH STATE-OF-THE-ART ANALYTICAL TECHNIQUES TO ESTIMATE THE ADDITIVES EFFECTS ON FIELD PERFORMANCE.