Examination of the resistance of warm mix asphalts against chemical de-icers

During winter maintenance operations, anti–icing and de-icing materials are used on roads. Contrarily to their beneficial effects, the used chemicals have also negative influences on asphalt pavement and environment. The most widespreadly used de-icing chemical material in Turkey is sodium chloride (NaCl). It is frequently preferred since it is easy to provide and store, economical, and have high reserves. The mixing – compaction tempratures of Warm Mix Asphalts (WMA) are lower about 20 –40 ˚C than the mixing - compaction tempratures of Hot Mix Asphalts (HMA). This situation reduces energy consumption, allows releasing less greenhouse gas emulsions and decreases viscosity of the mixture. Viscosity reduction improves workability of the mixture, hence provides more easily mixability and compactibility and allows asphalt mixtures to be hauled longer distances. Also, decreased greenhouse gas emulsions constitute less danger to workers' health. In order to determine resistance of Warm Mix Apshalts (WMA) against de-icing chemical NaCl, Marshall samples were prepared in two types of HMA and WMA. Sheltering referance samples in both types, remaining samples were exposed to corrosive environmental conditions. Distilled water and NaCl were used as corrosive environmental conditions. The concentration of NaCl solutions were selected as 0.8%, 1.6%, 2.1%, 6.5% and 10.4%. After the experiment, Marshall Stability test were performed to samples, Marshall Stability and flow values of samples were measured. Also, ultrasonic velocity tests were applied to samples. According to Marshall Stability test results, it was detected that resistance of WMAs against de-icing material NaCl were higher than HMAs' values.