Evaluation of water loss and stiffness increase in cold recycled mixes during curing

Abstract

Implementing cold solutions is one of the primary efforts in the road sector to counteract CO2 emissions and climate change. Using cold recycled mixtures (CRM) permits the reuse of up to 100% of reclaimed asphalt pavement (RAP). This research examines how CRM develop their resilient response during the curing process. Using cyclic loading dynamic triaxial (DTx) testing, resilient moduli of CRM made with various proportions of bitumen emulsion were determined. Curing times from 0 days to 18 months were assessed. Binder content and water loss speed proved to be fundamental factors in the evolution of the resilient moduli of the CRM studied. CRM with a binder content of 2.50% exhibited the best short-term response, while those with a binder content of 3.00% showed greater stiffness values over more extended curing. Once water losses stopped, the CRM continued showing changes in stiffness, proving their evolutionary response.

Keywords

• Cold recycled mixtures (CRM)
• Reclaimed asphalt pavement (RAP)
• Bitumen emulsion
• Triaxial testing
• Nonlinear elastic behavior
• Curing