Sensitivity analysis of gyratory compactor variables to mimic roller compacted concrete pavement performance

The compaction parameters suggested for Superpave gyratory compactor by ASTM C1800 are primarily derived from the asphalt mix (ASTM D6925). Since the rheological behaviour of Roller Compacted Concrete Pavement (RCCP) is significantly different from asphalt mixes, conventional Superpave compaction parameters cannot be directly adopted for RCCP. Hence, the current study focuses on formulating compaction parameters for the design of RCCP to resemble the field behaviour. For this task, response surface methodology was employed to investigate the effect of gyratory compactor parameters such as internal angle (0.82-3 degrees), compaction pressure (600-1000 kPa), and gyration levels (60-120) on the performance of RCCP specimens. The accuracy of the response prediction model was verified with ANOVA analysis. Further, multiobjective optimization was performed and validated with experimental findings. For validation of laboratory findings, a field test section was constructed using a duplex roller (dual drum vibratory roller). The results showed that the ASTM C1800 suggested gyratory parameters resulted in lower fresh density and strength properties of 4% and 7-45%, respectively, than the field specimens. However, the specimens fabricated at 1.92 degrees internal angle, 120 gyrations, 1000 kPa, and 1 aspect ratio in the gyratory compactor could provide comparable field properties.