Determination of the moisture susceptibility characteristics of warm mix asphalt

Researches are done to decrease greenhouse gases and energy consumption in Europe andUSA. The bitumen mixture industry is getting more aware of the warm mix asphalt (WMA)technology. The viscosity of the bitumen which contain WMA additive is lower than normalbitumen at high temperatures. Therefore the mixing and compaction temperatures of theWMA mixtures may be lower, reduced mixing temperature leads to a reduction in emissionand energy consumption.In this study, 50/70 penetration bitumen was modified with three different waxes additive.Warm mix asphalt mixtures were prepared with the modified bitumen and determinedMarshall stability with different blows (50 and 75blows). Moreover AASHTO T-283 andNicholson stripping tests were conducted to determine of moisture susceptibility of themixtures.The test results indicated that Marshall stability of wax modified bitumen mixtures nochanged significantly with diffirent blows. However, stability of unmodified bitumenincreased with higher blows. Nicholson stripping test showed that the mixtures resistance tostripping. The moisture susceptibility of mixtures increased by the additive of wax additives.