Cold Central Plant Asphalt Mixture Stockpiling: Laboratory Evaluation

Stockpiling a cold central plant recycled (CCPR) asphalt mixture may be beneficial to a producer as it allows them to optimize paving and material production. However, no previous studies have been found in the literature, and it is unclear if stockpiling a CCPR mixture has any positive or negative effect on the strength properties of the CCPR mixture. This study investigated the effect of laboratory simulated stockpiling on the strength properties of a CCPR mixture that used foamed asphalt as a recycling agent. To simulate the stockpile, the mixture was stored in buckets to ensure minimal moisture loss, and test specimens were fabricated from the laboratory stockpile at varying time intervals. Moisture content, compaction effort, indirect tensile strength, and dynamic modulus were measured, and AASHTOWare Pavement ME Design was used to determine any change in performance prediction for the laboratory stockpiled mixture. The tensile strength and dynamic modulus decrease significantly within the first three days of stockpiling, after which they remain constant, but the pavement performance prediction showed little effect, highlighting the need for further model development.