*Article* **Quantitative Assessment of Road Performance of Recycled Asphalt Mixtures Incorporated with Steel Slag**

**Zipeng Wang <sup>1</sup> , Shaopeng Wu 2,\*, Chao Yang 2,\* , Jun Xie <sup>2</sup> , Yongli Xiao <sup>3</sup> , Zenggang Zhao <sup>2</sup> , Fusong Wang <sup>4</sup> and Lei Zhang <sup>5</sup>**


**Abstract:** Circular utilization of reclaimed asphalt pavement (RAP) has received extensive attention for its economic and environmental benefits. The application of recycled asphalt mixtures (RAM) in the upper layer of asphalt pavement faces the issue of inferior anti-slip performance and durability. This study aims to recycle steel slag as virgin aggregates in RAM and quantitatively evaluate the service performance of RAM with steel slag. Steel slag and basalt RAM were firstly fabricated and the five different RAP contents were involved. Then tests of Marshall stability, indirect tensile strength and Cantabro spatter loss were conducted to investigate the moisture susceptibility of RAM. Moreover, their high temperature stability, crack resistance and skid resistance were characterized. Indirect tensile fatigue test combined with Hamburg wheel tracking test were carried out to discuss the durability of RAM. The comprehensive performance of RAM with steel slag were quantitatively assessed based on an improved radar chart evaluation method. The results show that involving steel slag reveals a remarkable enhancement function on water stability, high and low temperature performance, skid resistance and fatigue resistance of RAM. Steel slag RAM with 50% RAP content demonstrates a rutting depth of 7.60 mm and a creep slope of 2.54 <sup>×</sup> <sup>10</sup>−<sup>4</sup> , indicating its superior durability in high temperature and water environment. Compared with the comprehensive evaluation function of 0.5336 for basalt RAM with 30% RAP dosage, steel slag RAM reaches 0.7801, which represents its preferable road performance.

**Keywords:** steel slag; RAP; recycled asphalt mixtures; road performance; radar chart evaluation
