Moisture Susceptibility, Adhesion and Rutting Behaviour of Warm Mix Asphalt Using Industrial Wastes as Mineral Filler

Warm mix asphalt mixtures became attractive paving mixes by reducing the production temperature to around 25-40 degrees C as compared to that of conventional hot mix asphalt (HMA). This study aims to evaluate the warm mix asphalt (WMA) using wax-based additives by incorporating two types of industrial wastes. The potential application of low calcium fly ash (FA), i.e. class F type and marble dust (MD), has been evaluated by varying different percentage. The cylindrical samples were prepared and assessed for moisture susceptibility by being subjected to Marshall stability, retained Marshall stability (RMS), indirect tensile strength (ITS) and tensile strength ratio (TSR) tests. Furthermore, the samples were also evaluated for finding the refusal density, Cantabro loss and the rutting performance. A scanning electron microscope (SEM) was also used to evaluate the size and microstructure of the filler particles. The results revealed that the inclusion of fillers into mixes had significant improvement in the mechanical properties and lowered the rutting value with FA and MD addition. The warm mix additive and fillers used were also useful in reducing the binder content of the mixes. The mixing temperature was found to be in the range of 120-130 degrees C using the warm mix additive. The optimum usage of FA and MD can be up to 5% based on the evaluation. The statistical results reported that there was a significant difference between FA-based and MD-based WMA.