Assessing the Durability of Stone Matrix Asphalt Concrete

Abstract

Stone Mastic Asphalt (SMA) is widely used throughout the world as one of the preferred asphalt surfacings. The local specifications define asphalt concrete durability based on maximum loads at failure. Therefore, it is required to assess the durability of the road surface materials of SMA and their ability to resist operational effects in terms of environmental impact. In this investigation, the durability of stone matrix asphalt concrete was assessed in terms of temperature susceptibility, resistance to moisture damage, and sensitivity to the variation in asphalt content. Specimens of 102 mm diameter and 63.5 mm height were compacted using Marshal method at 150 °C. The optimum asphalt content was determined. The stabilizing additives were not implemented. Additional specimens were prepared with 0.5 % asphalt above and below the optimum requirement. Specimens were subjected to indirect tensile strength ITS determination at (25 and 40) °C, and double punch shear strength determination. Another group of specimens were subjected Marshal preoerties determination and to moisture damage. It was observed that stone matrix asphalt exhibit lower sensitivity to the change in asphalt content from the resistance to moisture damage and temperature susceptibility points of view. However, the tensile and shear properties exhibit significant sensitivity to the variation in asphalt content.