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The introduction of fiber reinforced plastic (FRP) dowels as possible alternatives to the epoxy-coated and stainless-steel dowels, was contemporaneous with a paucity of knowledge of their long-term performance. Although various isolated efforts had examined them on a short-term basis and produced some qualitative results or long-term predictive models, actual long-term performance in service was still unknown and unanalyzed. An experiment at the MnROAD Research facility placed FRP dowels in 2000 in some of the jointed plain concrete pavement (JPCP) panels of test Cell 52 and used epoxy-coated dowels in the remaining panels of this cell. The contiguity of this test cell with Cell 53, a JPCP high-performance concrete cell built in 2008 with stainless steel dowels, and Cell 54, a taconite JPCP cell with epoxy-coated dowels in built in 2004, facilitated a comparative analysis of performance of the 3 dowel types particularly in load transfer efficiency (LTE) and ride quality. The difference in the inception of the cells constrained a performance over time and encouraged a time-series autoregressive integrated moving average (ARIMA) analysis. Projections to 30 years showed that LTE and ride quality of FRP dowels were no different from those of the epoxy-coated dowels and the stainless-steel dowels although Cell 53 was designed and built with thicker concrete (12-in. thick) compared to 7.5-in in cells 52 and 54.

Sound absorption is an important characteristic of pavement. In particular, sound absorption is a proxy for overall pavement condition in pervious pavements. In this research, sound absorption tests were done using an impedance tube, white noise source, two microphones, and an analyzer on MnROAD low-volume sections 32 and 39 (two non-contiguous cells of non-pervious concrete) and 5 contiguous arrangements of Cells 85, 86, 87, 88, and 89 at the Low-Volume Road of MnROAD (pervious concrete on granular subgrade, pervious asphalt on granular subgrade, non-pervious asphalt, pervious asphalt on cohesive subgrade, and pervious concrete on cohesive subgrade, respectively). These were constructed in 2008 and measurements taken in 2009, 2010, 2011, and 2014 were analyzed. Data analysis using two-sample t-tests at the natural frequency of 1000 Hz and the construction of probability density functions for each test section showed that the non-pervious pavements had significantly lower sound absorption when compared to the pervious pavements. The concrete pavements had significantly lower sound absorptions in comparison to the asphalt counterparts all things being equal. The largest sound absorption occurred in the pervious asphalt on granular subgrade, and the smallest sound absorption occurred in the non-pervious concrete test section.