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Warm mix asphalt mixtures became attractive paving mixes by reducing the production temperature to around 25–40 °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 °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. [ABSTRACT FROM AUTHOR]

Warm-mix asphalt (WMA) is produced at lower temperatures—about 30°C–40°C lower—than hot-mix asphalt (HMA). Huge amounts of brick dust (BD) and fly ash (FA) are generated every year throughout the world, causing an environmental hazard, and their disposal is a serious problem. In addition, the high mixing temperature of HMA production increases environmental load. This study evaluated warm mixes made using organic wax and chemical-based technologies. Two types of filler material, i.e., FA and BD, were used as binary blended fillers (BBF). Cylindrical Marshall specimens were prepared and subjected to moisture susceptibility tests for both aged and unaged conditions. The durability of these samples was tested by evaluating the tensile strength ratio using the modified Lottman test method. The cohesion resistance of the mixtures was evaluated by Cantabro loss. Furthermore, a wheel tracker test (WTT) setup was used for rutting evaluation. Results revealed that the use of BBF in mixes led to a marked increase in mechanical properties. Microstructural behavior was studied using scanning electron microscopy (SEM) images for particle-size distribution. The statistical test indicated a significant difference in stability values and rut depths. [ABSTRACT FROM AUTHOR]

Warm mix asphalt (WMA) has the advantage of lower production temperature as compared to conventional hot mix asphalt (HMA). It is prepared by using various types of technologies which change the properties of bitumen binder attributes to ease in workability of the mixes. In the present study, bitumen emulsion was used for preparing WMA mixes by pre-coating the aggregates. Moreover, the conventional filler used in such mixes was replaced with industrial wastes to further reap environmental benefits. Marble dust (MD) and ground granulated blast-furnace slag (GGBS) are generated abundantly and disposal is a big issue. These were used in varying contents (i.e. from 2% to 8% by the weight of mix) and WMA properties were evaluated for strength and durability. Marshall properties and indirect tensile strength test (ITS) were carried out for strength evaluation. The tensile strength ratio (TSR) was conducted as per AASHTO T 283 for durability analysis. The wheel tracker test was performed for rutting analysis. Cantabro loss was determined to assess the cohesion resistance of the asphalt mixtures. Scanning electron microscopy (SEM) images were used to assess the microscopic characteristics of WMA and its constituents. The results revealed that the inclusion of both MD and GGBS as fillers into WMA had significantly improved the stability, tensile strength, TSR, rutting and Cantabro loss results as compared to the control mix. However, the addition of GGBS filler in emulsified warm mixes showed better resistance to moisture too. Lower rut depth was observed using GGBS as compared to marble dust filler. The statistical analysis reported that there was a significant difference between stability and TSR values whereas for adhesion loss it showed insignificant difference between the GGBS and MD based mixes. [ABSTRACT FROM AUTHOR]