| This research deals with the effects caused by the thawing of highway pavement structures. The pavements used for experimental study are those of the Minnesota Road Research Project (Mn/ROAD) built in the spring of 1994.; The impact of thawing on pavement is studied by comparing the mechanical response of three different pavement structures under the action of a moving truck. The experiments were all conducted on the same spring day, March 23, 1994. As part of the Mn/ROAD project, these pavements have been instrumented for the measurement of pore water pressure across the subsoils of the pavement structures. Other parameters which have been measured in-situ for the purpose of this work were: temperature, moisture and depth of freezing of the soils. These measurements were taken to estimate the state of freezing and thawing of the pavement subsoils.; The ultimate goal of this research is to better predict load restriction requirements to flexible pavements during spring thaw in terms of the magnitude of the maximum permitted load and the timing of the restrictions. This work is focused on the mechanics of dynamic pore water pressure response in the unbound layers of pavement structures. Ultimately variations in the pore water pressure affect the strength of the soils characterized by their resilient moduli and subsequently affect the pavement response, i.e. the strains at the bottom of the asphalt pavement layer, on top of the subgrade and the surface deflections of the pavement. |
