The Low Temperature Performance of Rubberized Bituminous Mixture Using the Dry Process

Abstract

AbstractThe paper evaluated the low temperature performance of the bituminous mixtures, which were produced in the plant using the dry process and compacted in the laboratory. ElastikoR crumb rubber was chosen to modify the bituminous mixture. Four types of bituminous mixtures, including leveling layer and surface layer gradation with and without crumb rubber, were produced in a plant in Iron Mountain, MI. The volumetric design of the mixture followed the Superpave mixture design. The leveling layer and surface layer mixture used 25 and 17% recycled asphalt pavement (RAP) (by weight of bituminous mixture). To improve the moisture resistance, dosages of 0.125 and 0.08% anti-stripping agent (by weight of bitumen) were selected for the leveling layer and surface layer. The low temperature cracking properties of four types of bituminous mixtures were evaluated using the Disk-shaped Compact Tension (DCT) test. The RAP content, bitumen content, and nominal maximum aggregate size (NMAS) influenced the low temperature cracking performance of the bituminous mixture. The fracture energy of the surface layer bituminous mixture was higher than that of the leveling layer bituminous mixture. The cracking resistance of the leveling layer and surface layer bituminous mixture were improved after the addition of rubber. The maximum CMOD was linearly correlated with the fracture energy of different types of bituminous mixtures.KeywordsRubberDCTDry processLow temperature crackingBituminous materials