Advanced thermal and rheological characterization of a sustainable anti-icing hydrogel for winter road maintenance operations

As a part of the advancements in the winter road maintenance, a sustainable anti-icing hydrogel has been recently developed for the treatment of the open-graded asphalt pavements. It is obtained by mixing water, a chemical agent and a phyto-based additive (seaweed fiber powder) having thickening and gelling properties. The product has the ability to form a gel-like structure when hot-sprayed on a cold pavement surface. The influence of the interaction between the solutes, i.e. sodium chloride (marine salt) and seaweed fiber, on the gel behavior was evaluated through a laboratory scale study, based on thermal (differential scanning calorimetry) and rheological (rotational and oscillatory tests) analyses. The research findings offer a substantial support for the definition of most suitable recipe and the configuration of the spray application system. The results revealed that the formulation of the anti-icing hydrogel is predominantly governed by the salt concentration, which establishes the freezing point depression capacity. Once the salt dosage is defined on the basis of the climatic condition and the accepted level of service, the gellant content, which controls the gelation mechanism, can be optimized to obtain a sprayable gel with a sufficient stiffness and strength.