Integrated Approach to Investigation of Effect of Salt on Bitumen Properties and Stability of Flexible Pavement in Coastal Areas
Demand for modifications is increasing throughout the world parallel to develop the existing highway materials to fulfill the increasing demand of vehicles. Some materials produce good effect and enhance the strength as well as qualities of bitumen. On the other hand, some materials are responsible for adverse effect on the bitumen. In saline areas like coastal regions, the salt plays a significant role on the bituminous pavement. In this area, the most of the highways come to contact with salts content materials. In present study, the focus was given to find the various effects of salts on bitumen and bituminous mixers. A number of samples were prepared with addition of sodium chloride with respect to 2%, 4%, 6%, 8%, and 10% weight of bitumen. To determine its behavior and suitability, a variety of tests such as penetration test, softening point test, flash point and fire point test, ductility test, specific gravity test, solubility test etc. were conducted by standard ASTM method. It was observed from laboratory test that the penetration and specific gravity value are gradually increased and ductility, flash point, fire point, and softening point was gradually decreased due to the increase of salts content in a bituminous mix. To observe the effect of salt on stability of flexible pavement Marshall Mix design method was used with varying percentage of salt content. The stability value of bituminous mixes was decreased with increase the salt content in bitumen. From the consideration of stability, maximum 2% salt in bitumen can be allowed for road construction.
