The second generation of Minnesota accelerated loading facility - Minne-ALF-2

This paper presents the second generation of Minnesota Accelerated Loading Facility (Minne-ALF-2), a laboratory-based loading pavement test stand that simulates the passage of heavy wheel loads moving over a small full-scale pavement test strip. It is shown that Minne-ALF-2 can provide important information related to long-term performance of dowel joints of concrete pavements, as well as useful information which may lead to a better understanding of the mechanics of joints in concrete pavements. The first results of the ongoing test program are also presented in the paper. This initial study of joint behavior during loading and unloading of a joint with hollow dowels reveals an interesting pattern: deflections in the unloading path are different from the deflections at the loading path. It was also found that the residual differential deflections remain after the first loading and unloading cycle. Available finite element models for rigid pavements do not explain these effects. Hence, advanced models of PCC joints explaining the observed above phenomenon are needed for a better understanding of the joint behavior and joint design optimization.