Experimental evaluation of Mode I fracture toughness and fracture energy of hot mix asphalt modified with steel slag powder using the ENDB specimen at low and intermediate temperatures

Salehi, Seyed Miad; Aliha, M.R.M

doi:10.22075/jtie.2026.40908.1758

Experimental evaluation of Mode I fracture toughness and fracture energy of hot mix asphalt modified with steel slag powder using the ENDB specimen at low and intermediate temperatures

Document Type : Research Paper

Authors

Seyed Miad Salehi ¹

M.R.M Aliha ²

¹ Assisstant Professor, School of Management, Economics and Progress Engineering, Iran University of Science and Technology (IUST), Narmak, 16846-13114, Tehran, Iran

² Associate Professor, school of Industrial Engineering, Iran University of Science and Technology (IUST), Narmak, 16846-13114, Tehran, Iran

10.22075/jtie.2026.40908.1758

Abstract

Steel slag, as one of the most favorable recycled industrial by-products, is widely used in green asphalt mixtures as a sustainable alternative to a portion of natural mineral aggregates. In this study, the effect of adding steel slag powder as a filler on Mode I fracture toughness of Hot Mix Asphalt (HMA) was investigated. circular bending specimens with a straight-through notch (ENDB) were utilized to perform the fracture tests. Different HMA mixtures containing 0%, 3%, and 5% steel slag powder by weight of total filler were prepared using the Superpave Gyratory Compactor at a target air void content of 7%. Mode I fracture experiments were conducted under symmetric loading at an intermediate temperature of +25°C and a low temperature of −12°C. Two key fracture parameters, fracture energy and fracture toughness, were calculated and analyzed to evaluate the cracking resistance of the asphalt mixtures. The results indicated that the addition of steel slag powder and the increase in its percentage significantly improved both fracture toughness and fracture energy at both test temperatures. The highest values of fracture energy and fracture toughness were observed in the mixture containing 5% steel slag powder. Furthermore, increasing the test temperature resulted in a decrease in fracture toughness and an increase in fracture energy.

Keywords

Hot mix asphalt

Steel slag powder

Low and Intermediate temperature fracture toughness

Fracture Energy

Edge notch disc bend(ENDB)

Subjects