Warm Mix Asphalt Using Sasobit in Cold Region

Abstract

The potential of using Warm Mix Asphalt (WMA) in reducing the energy consumption of hot mix asphalt (HMA) is becoming more and more attractive nowadays. The goals for the WMA are to lower mixing and compacting temperatures and use the same Hot Mix Asphalt (HMA) plants to produce mixes that still meet specifications. The benefits of WMA include reduced emissions and binder aging, lower mixing and compacting temperatures, decreased energy (fuel) consumption and early traffic opening. The advantage of WMA is significant for cold-weather paving because of the slower cooling rate due to a smaller difference between production and ambient temperatures. This study presents an overview of WMA in terms of environmental aspect through a field project. Observations from the field project indicated that emissions produced during WMA construction were significantly reduced compared to HMA. Samples of HMA and WMA (with 1.5% Sasobit) were collected from the job site and tested for Dynamic Modulus and Tensile Strength Ratio to evaluate WMA's moisture susceptibility, fatigue and rutting potential. The results indicated that the moisture susceptibility of WMA was comparable to HMA. The fatigue potential of WMA was slightly higher than HMA; and the specific WMA used in this study has a lower rutting potential than HMA.