Use of the parallel gradation technique to assess the shear Strength of reclaimed asphalt pavement in direct shear

Abstract

The demand for pavement construction aggregate is growing significantly. With a rise in aggregate consumption, the use of recycled materials has become an attractive solution in pavement construction from both economical and environmental perspectives. Use of recycled materials in the base course demands understanding of their properties including its shear strength and recognition of potential problems that may arise. The parallel gradation technique involves evaluating the parameters of a coarse material using a gradation that is finer but parallel to the prototype. It has been successfully used for estimating the shear strength parameters under certain conditions. The main objectives of this study are to: assess the applicability of the parallel gradation technique to estimate the shear strength of Reclaimed Asphalt Pavement (RAP) and determine the shear strength parameters of RAP in direct shear at two relative compactions.