Evaluation of the rheological behavior of fresh self-compacting rubberized concrete by using the Herschel–Bulkley and modified Bingham models

The study herein presents the use of the Herschel–Bulkley and modified Bingham models to monitor the rheological behavior related to workability of the fresh self-compacting concrete containing waste rubber. Therefore, the self-compacting rubberized concretes were produced at a constant water-to-binder ratio of 0.35 and binder content of 520 kg/m3. Class F fly ash was incorporated as 30% of total binder content by weight. Two types of waste scrap tire rubber, crumb rubber and tire chips, were utilized instead of natural fine and coarse aggregate at various level, respectively. The tire chips and three different graded crumb rubbers (No.18, No.5, and mixed crumb rubber) and five designated rubber contents of 5%, 10%, 15%, 20%, and 25% were considered as experimental parameters. The rheological behavior related to workability of the fresh concretes was investigated by using the ICAR rheometer. The torque–speed relationship obtained from rheometer was used to characterize the rheological behavior of fresh self-compacting rubberized concrete by applying the Herschel–Bulkley and modified Bingham models to experimental data. The results revealed that the self-compacting concretes produced in this study exhibited shear thickening behavior and increasing the rubber content resulted in higher exponent ‘n’ values for the Herschel–Bulkley and c/μ coefficients for the modified Bingham models.