Abstract:
Roads of various kinds have existed since prehistoric Egyptian times. Roads pavements can be broadly categorized as Flexible Pavements and Rigid Pavements. Asphalt Pavements fall in the category of Flexible Pavement. Asphalt has also been used for pavement construction by prehistoric Babylonians. Modern Asphalt pavements came into existence in the last quarter of 19th century. Asphalt pavements consist of stone gravel, stone dust and bituminous binder. The durability and properties of asphalt mix can be altered by altering the proportion of various constituents. Choosing a different criterion or a different mix design will also alter the properties of the mix. Mixture in laboratory is prepared using Marshall Mix Design method or Super Pave Gyratory Compactor. Criteria for selection can be percent air voids or Percent Theoretical Maximum Density (%Gmm). In this Study the criterion of Binder Film Thicknesses (BFT), found both analytically and experimentally have been used to observe its comparative effects with respect to percent air voids and percent theoretical max density. Samples from both Marshall and Superpave Gyratory mixes have been tested. Scanning Electron Microscope (SEM) has also been used to ascertain Binder Film Thickness. The samples are tested under Universal Texting Machine (UTM) and Double Wheel Tracker (DWT). The sample designed on the basis of BFT proved the most appropriate in Rutting under DWT. Marshall Sample had the highest Resilient Modulus (Mr) and the best resilience to moisture damage. Superpave sample endured the most cycles until failure in case of Indirect Tensile Fatigue Test (ITFT). The subject holds promises for further findings in future researches.
