Dependency of Cyclic Plastic Deformation Characteristics of Unsaturated Recycled Base Course Material on Principal Stress Axis Rotation

Abstract

Nowadays, in order to economize the cost of pavements, recycled crusher-run (recycled concrete) that is recycled material is employed as base course material instead of natural crusher-run (andesite). Therefore, mechanical response of recycled crusher-run is required to evaluate in order to construct quality roads with minimum cost. In this research paper, an attempt is made to determine strength-deformation characteristics of unsaturated recycled crusher-run material, under various loading conditions and saturation degrees. In addition, cyclic plastic deformation behaviour of two types of materials that are natural crusher-run (andesite) and recycled crusher-run (recycled concrete) is compared and analysed. A series of laboratory element test were carried out by using multi-ring shear apparatus, which can take in to account the rotation of principal stress axis. The experimental results show that, cyclic plastic deformation considerably enhances due to the rotation of principal stress axis under repeated axial and shear loading tests. Moreover, cyclic plastic deformation of recycled crusher-run material increases to some extent when compared with natural crusher-run material under same experimental condition.