Quantifying Expansion Effects Induced by Freeze-Thaw Cycles in Partially Water Saturated Bituminous Mix

ABSTRACT Contraction/expansion effects induced by freeze-thaw cycles are thought to be at the origin of important and sudden deteriorations of pavement surface course, observed on some road sections in North-East of France. Therefore following these events and observations, it was decided to investigate in laboratory the phenomenon of freeze-thaw on partially water saturated bituminous materials specimen. This article presents some aspects of this beginning research work. We report an experimental investigation on the effect of the freezing-thaw cycles of bituminous materials. Some specimens are subjected to laboratory freeze-thaw cycles under a freezing rate without moisture change with the environment. In addition to basic mechanical properties and pore distribution, the measurement is also performed for freezing expansion of material of the specimen in each cycle. From these results, it is observed that the freezing expansion can be measured for high degree of saturation of the material. The results indicate also that the specimens experiment significant swelling at the beginning of the freezing periods. It is believed that the phenomenon could be detrimental to pavements, especially in the case of differential horizontal strains appearing within the structure layers, due to different swelling conditions depending on the materials and their moisture content.