# Investigation into the Adhesion Performance of the Recycled Asphalt Mastic–Limestone Filler Interface Using the Pull-Off Test and Surface Free Energy Theory

## TL;DR

This paper investigates how well recycled asphalt mastic sticks to limestone filler using tests and energy theory.

## Contribution

The study introduces a new method to calculate the contribution ratio of mineral filler to adhesion performance.

## Key findings

- Bonding strength is highest at 20% aged asphalt binder dosage.
- Adhesion performance decreases with higher rejuvenator dosage.
- Optimal filler–asphalt binder ratio is 1.4 for maximum adhesion contribution.

## Abstract

This study aims to evaluate the adhesion performance of the recycled asphalt mastic (RAM)–limestone filler interface and the contribution ratio (CR) of mineral filler to the adhesion performance of the RAM–limestone filler interface. Using the pull-off test and surface free energy theory, the impacts of aged asphalt binder dosage, resurfacing dosage, and filler–asphalt binder ratio (F/A) on the grip capacity of the RAM–limestone filler contact were examined. The CR of mineral filler to the adhesion performance of the RAM–limestone filler interface under different influencing factors was calculated. Results show that the bonding strength and adhesion work of the RAM–limestone filler interface reach their best when the aged asphalt binder dosage is 20%. As the rejuvenator dosage increases, the RAM–limestone filler interface’s adhesion performance declines. As the amount of mineral filler increases, the bonding strength of the RAM–limestone filler interface first rises and subsequently falls. When the dosage of aged asphalt binder is 20%, the mineral filler’s CR to the RAM–limestone filler interface’s adhesion performance is at its highest. The impact of mineral filler on the RAM–limestone filler interface’s adhesion performance can be lessened by increasing the amount of rejuvenator. The greatest CR of mineral filler to the adhesion performance of the RAM–limestone filler interface occurs when the F/A is 1.4.