Study on Estimation of Optimum Dosage of Warm Mix Additives for Production of Asphalt Mixtures

Abstract

Use of warm mix asphalt (WMA) technologies is among the sustainable construction techniques that allow the production of asphalt mixtures at reduced heating temperatures, relative to conventional hot mix asphalt (HMA). The primary focus of the present study was to optimize the dosage of five different WMA additives. One base asphalt binder and two aggregate sources were used for the preparation of HMA and WMA mixtures. The mixing and compaction temperatures of WMA mixtures were determined using a novel workability-based approach. Further, coating and compaction ability checks were applied to verify the obtained mixing and compaction temperatures, respectively. Results revealed that the incorporation of WMA additives in asphalt mixtures lowered the production temperatures, irrespective of the WMA technology, dosage, and aggregate source. Validation checks indicated that all the WMA mixtures attained similar to better aggregate coating and consistent packing density as compared to conventional HMA mixtures, despite being produced at reduced production temperatures. It was found that the optimum dosage of WMA additives is a function of aggregate source and WMA technology. It is expected that WMA mixtures prepared at the optimum dosage, determined through the proposed approach, may provide equivalent properties as HMA. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.