Laboratory analysis on the effectiveness of Winterpave anti-icing additives in wearing course asphalt mixtures.

Since there are no standard tests for the characterization of anti-icing additives mixed in wearing course asphalt mixtures (the Winterpave additive is considered in this paper), the purpose of this thesis was that, after a carful analysis and review of the tests existing to date, to propose a laboratory procedure to evaluate the effectiveness of this type of additive. In the first part of the thesis, the effects of winter climatic conditions on road infrastructures have been analysed, evaluating the characteristics and the different types of distresses due to low temperatures and the resulting social and winter road maintenance costs. To reduce this kind of costs, a lot of additives have been studied. The Winterpave additive, produced by Iterchimica, was then analysed: it aims to lower the freezing point of water to avoid the formation of ice on the road surface due to low temperatures in different climatic conditions (rain, snow and icy). From a functional point of view, the anti-freezing action of the pavement is guaranteed over time by the gradual “migration” of the salt particles inside the asphalt. Subsequently, a review of the tests, for the evaluation of the characteristics and effectiveness of the non-mixed additives, existing to date was made: the tests with standardized procedures refer to the effectiveness of the de-icing additives (liquid or solid) that are sprayed on the road surface during and after the winter storm event and to the effectiveness of the anti-icing additives that are sprayed before winter storm event. The thesis ends with a proposal procedure for the characterization of Winterpave additive in order to be able to prove what was declared by the manufacturer on the effectiveness of the product. The suggested procedure uses a special apparatus (climatic chamber), in which the samples are inserted and tested under freezing-thaw cycles, that has been modified to simulate the different winter climatic conditions