Effects of recycled aggregate composition on the mechanical characteristics and material design of cement stabilized cold recycling mixtures using road milling materials

Road milling materials, including the reclaimed asphalt pavement (RAP) and the reclaimed cement stabilized base-course (RAI), have been widely used as the recycled aggregates (RA) to prepare cement stabilized cold recycling mixtures (CSCRM) used in highway rehabilitation. However, there are few studies on the effect of RA composition (RAP and RAI proportion in RA) on the pavement performance of CSCRM. In this study, therefore, a total of forty-two groups of CSCRM are prepared in the case of different RA contents, RA compositions and cement contents. The investigation of mechanical characteristics (unconfined compressive strength, splitting strength and uniaxial compression modulus) of CSCRM reveals the effect of RA content, RA composition and cement content. The RA content, RA composition and cement content play an important role in the mechanical properties of CSCRM. The strength mechanisms of CSCRM are revealed via the micro-interface characteristics for based on SEM-image. Finally, the recommended material compositions of CSCRM are put forward and verified via durability tests (fatigue tests, dry-shrinkage tests and water-erosion tests). Results show that the recommended CSCRMs present a better overall performance. (C) 2020 Elsevier Ltd. All rights reserved.