# Influence of Aging on Hot Mix Asphalt with the Incorporation of Recycled Concrete Aggregates

## TL;DR

This study examines how aging affects hot mix asphalt with recycled concrete aggregates, finding that moderate aggregate levels improve durability and reduce aging susceptibility.

## Contribution

The study is the first to evaluate the effects of aging on hot mix asphalt with recycled concrete aggregates.

## Key findings

- HMA with 12% recycled concrete aggregates showed the best balance of stiffness, deformability, and aging resistance.
- High recycled concrete aggregate contents may reduce resistance to rutting and moisture damage.
- Optimal performance is achieved by balancing binder content and aggregate absorption to minimize aging susceptibility.

## Abstract

The aging of asphalt mixture is one of the primary factors influencing the durability and performance of pavements. This study analyzed the influence of short-term (STOA) and long-term (LTOA) aging on hot mix asphalt (HMA) with the incorporation of recycled concrete aggregates (RCAs). The effect of aging on these types of mixtures has not been previously evaluated. HMAs were produced with 0%, 12%, and 21% RCAs (by mass), referred to as HMA Control, HMA RCA12, and HMA RCA21. These replacement percentages correspond to particles ranging between 19 and 12.5 mm (12%) and 19 and 9.5 mm (21%). The Marshall test was employed to determine the optimal asphalt content, followed by indirect tensile strength, resilient modulus, and permanent deformation resistance tests on samples subjected to STOA and LTOA. Overall, the results demonstrate that the incorporation of RCAs could improve the durability of asphalt mixtures by reducing their susceptibility to aging. Specifically, HMA RCA12 exhibited the best balance between stiffness, deformability, and resistance to aging, suggesting a favorable technical potential for its application in sustainable pavements, although additional testing is required to validate its long-term performance. Despite this, high RCA contents may reduce resistance to rutting and moisture damage. The results suggest that the optimal performance is achieved by balancing binder content and aggregate absorption to minimize susceptibility to aging.