Design and Production of Steel Slag Warm Mix Asphalt (SSWMA) Using an Amino-Based Resin

Abstract

In traditional method of hot mix asphalt (HMA) production, large energy consumption and increased environmental awareness have resulted in the innovation of a production technology named warm mix asphalt (WMA). In this technology, various methods are used to reduce the temperature of production and paving. On the other hand, steel slag is the by-product of iron and steel factories, and many researches have been done around the world to use these materials in several fields, such as HMA industry. Various studies show steel slag to be considerably effective in improving the performance of asphalt concrete. One of the properties of steel slag is having high heat capacity value which leads to higher energy consumption during the production of HMA compared to conventional aggregates. The main aim of this study is therefore using WMA technology to reduce the energy consumption and to produce steel slag warm mix asphalt (SSWMA). In order to fabricate SSWMA in lab, an amino-based resin was used as an additive to decrease the viscosity of the bitumen. The amount of resin was ranged from 5 to 15 % by the weight of bitumen. The performance of SSWMA samples was evaluated by several tests, including dynamic shear rheometer, bending beam rheometer, Marshall test, moisture sensitivity, indirect tensile strength, and resilient modulus. Experimental results revealed that amino-based resin additive can decrease the viscosity of the bitumen by producing foam particles. This reduction of viscosity leads to reduction of asphalt production temperature as much as 25 °C in application of 10 % resin by the total weight of the bitumen. It can be also concluded that SSWMA proposed acceptable moisture resistance, and modified bitumen showed a superior performance rather than the neat bitumen in the case of rutting resistance. © 2016, Springer Science+Business Media New York.