Full-scale and laboratory investigations on the performance of asphalt mixture containing recycled aggregate with low viscosity binder

•Absolute viscosity of extracted binder from recycled aggregate has strong impact on RAP mixture.•Absolute viscosity of recycled aggregate should be controlled at lower than 40,000 Poise.•The excessive use of rejuvenators in high-viscosity RAP results in the critical strength drop.•Low-viscosity asphalt binder is a prominent solution to restore the aged binder.•Accelerated pavement test confirms the potential use of RAP mixture with low viscosity binder. The proposed research aims to evaluate the practical application of the reclaimed asphalt pavement (RAP) mixture fabricated from recycled aggregate with the low-viscosity extracted binder. To cope with this objective, the combined effects of extracted binder’s absolute viscosity and nominal maximum aggregate size (NMAS) of recycled aggregate on the performance of the RAP mixture were investigated in the research. Various mix designs and laboratory experiments were then developed to examine the characteristics of RAP specimens including Indirect Tensile Strength, Direct Tensile Cyclic, Dynamic Modulus, and Hamburg Wheel Tracking tests. Afterward, the full-scale testbed accompanied by Heavy Vehicle Simulator was performed in the field to verify the practical application of the best RAP mixture. Regards to the improvement method, the low-viscosity binder (700 Poise) techniques were added to the mixture to enhance the performance of the RAP. In general, the test results reveal that the absolute viscosity of extracted binder of recycled aggregate should be controlled at lower than 40,000 Poise to ensure proper durability. Meanwhile, the application of 80,000 Poise recycled aggregate may result in a critical drop in cracking and permanent deformation resistance. Further, the NMAS of 13 mm of recycled aggregate is suggested to be applied in the RAP mixture instead of the 10 mm type to enhance the bearing capacity of the recycled mix. The results also suggest the slight contribution of the proposed measure to partly restore the capacity of the RAP mixture while the field test result confirmed equivalent rutting results between the controlled and RAP section.