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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.

In June and July 2013, MnDOT constructed three new concrete pavement test sections or cells at the MnROAD facility. On MnROAD's Interstate 94 mainline, a 7.5 inch thick sustainable concrete pavement was constructed using a 75% recycled concrete aggregate (RCA) mix, to study the performance of recycled aggregates in new concrete. Geocomposite transverse joint drains and preformed neoprene joint seals were also incorporated into this test section. Also on the MnROAD mainline, new bonded concrete overlays of distressed asphalt pavement (BCOA) test sections were built. These BCOA or whitetopping test cells were built with 4 and 5 inch thick fiber reinforced concrete slabs. On MnROAD's Low Volume Road loop, a 3 inch thick ultra-thin unbonded concrete overlay was constructed over two different thicknesses of geotextile fabric interlayer. The concrete overlay also contained structural fibers in the mix. This report documents the design, construction, field testing, sampling and testing, and sensor instrumentation associated with these new test sections. Additionally, a thin 5 inch concrete pavement (cell 32) on the low volume road was repaired and retrofitted with unique load transfer devices; post-repair diamond grinding was performed. The pervious concrete overlay test cell (Cell 39) was ground to ascertain 1) whether slurry from grinding operations significantly impair the permeability. Details about the cells: Mainline sustainable concrete pavement and whitetopping: Cells 613, 140 & 240, and 160-163 (SP 8680-169); Low-volume thin unbonded concrete overlay with geosynthetic interlayer and pervious pavement rehab: Cells 32, 39 (SP 8680-170).

This research project performed statistical pass-by (SPB) measurements of tire/pavement noise influence on overall traffic noise levels. The pavement specimens included in the project were a conventional grind surface, an innovative grind surface, a transverse tine surface, and a burlap drag surface, all located on I-94 to the northwest of Minneapolis. Due to the high volume of traffic on the interstate highway, field measurements were not feasible. An alternative method was adopted of recording video and high-quality audio of all the traffic over several hours, along with a calibration reference level, and analyzing the recorded traffic in the office. This allowed selection of several hundred pass-by events meeting data quality requirements out of the several thousand vehicles present in the recordings. The results showed the innovative grind was clearly the quietest pavement with four-wheeled passenger cars. The results also showed the innovative grind was quieter than most other pavement surfaces, but was inconclusive against the conventional grind with dual-axle and multi-axle heavy vehicles due to insufficient data. On-board sound intensity measurements showed a dBA difference of 4.7 to 5 between the innovative grind and the pre-existing surface texture.

Geofoam, an XPS polystyrene with a unit weight of 1 to 3 lb/ft.3, was used as embankment fill for Minnesota Trunk Highway (TH) 100 segment 3 (SP 2735-159) in 2000. It was also used at Technology Drive in 2002 to correct a slope failure that had occurred in a large embankment near a ramp. The TH 100 segment consisted of a 10 in. dowelled jointed plain concrete pavement (JPCP) and the Technology Drive section was a 7 in. bituminous pavement. Concerns about the vibration issues during and immediately after paving led to a retrofit of the sites with multi-depth deflectometers (MDD) and a two-year study of pavement response. The authors seasonally investigated flexible and rigid pavement response to Falling Weight Deflectometer (FWD) loads, loaded and calibrated snow and ice trucks through the MDDs, and a seismograph. This study compared seasonal deflection basins, elastic moduli, and dominant frequencies of flexible and rigid pavements built with Geofoam fill to their corresponding contiguous control sections built without Geofoam fill. The 3-ft. of granular fill above the 4 in. concrete cap covering the Geofoam compounded the process of layer moduli computations. The report concludes with interesting findings, particularly that the response of Geofoam pavements may exhibit higher deflections and vibration amplitudes and they are in a time series. However, these are not resonant vibrations that would require design changes from the current practice.

In September 2011 MnDOT constructed two cells in the MnROAD Mainline in continuation of the study of unbonded overlay (Cell 5) and to facilitate studies on a drainable base (Cell 6) with a longitudinal tined texture. Additionally, roller-compacted concrete shoulders were constructed in these cells to replace the preexisting asphalt shoulders. Finally, repairs were done to a thin concrete overlay of existing asphalt pavement installed in 2004 (Cell 63). This report discusses the construction procedure, instrumentation and the initial monitoring from these test cells.

This report presents results of the research that examined various asphalt pavement surfaces in the MnROAD facility. It covers the fundamentals of surface profilometry, describes the construction of the textures and elucidates the performance trends of the various surface parameters. The variables examined include friction, measured with the lock wheel skid truck, smoothness, measured with the light weight profiler, mean profile depth measured by the circular track meter, sound absorption measured by the acoustic impedance tube and Tire- Pavement-Interaction-Noise measured by the on board sound intensity device. Traffic difference was found to be a significant variable in the friction trend of the asphalt surfaces when the low-volume road inside lane of the cells were compared to the corresponding outside lane and when the mainline driving and passing lanes were compared. Based on the Wilcoxon Rank sum, Wilcoxon Sign Rank, and the T-test, traffic levels affected skid resistance. Additionally, the frictional-time series appeared to follow the half-life equation typical of disintegrating materials. A similar test on tire-pavement-noise difference found traffic to be insignificant within the five years of monitored performance of the same test tracks. This study found that certain surface characteristics change with time regardless of traffic while others change with time and traffic. As the study found friction to be related to traffic, periodic measurements of friction can be performed when practicable, otherwise the half-life model developed in this study may be a rough predictor. In the deduced model, friction degradation appeared to be a function of the initial friction number and traffic-induced decay factor. In the low-volume road, there was hardly any evidence of effect of traffic on friction from a comparison of the traffic and environmental lanes. However, at higher traffic levels, (mainline driving versus passing lanes) traffic appeared to affect noise and friction. The study also proposes a temperature-based correction algorithm for Tire-Pavement-Interaction-Noise. From distress mapping, IRI, and permeability measurements, there were no noticeable trends within the five years of study. Additionally, this research performed advanced data analysis, identified significant variables and accentuated intrinsic relationships between them. Additionally, the "on board sound intensity" (OBSI)-Temperature correlation exhibited a negative polynomial relationship indicating the higher importance of temperature to OBSI relationship in asphalt than published characteristics of concrete pavements. It ascertained that texture mean profile depth was not as significant as texture skewness in predicting surface properties. Smoothness measurements indicated that most asphalt surfaces are not associated with laser-induced anomalous IRI reading errors. The major properties affecting ride in most asphalt surfaces were evidently extraneous to the surface texture features..

This report summarizes the construction and early performance assessment of three composite (new, multi-layer, construction) test cells at the MnROAD: HMA over a recycled aggregate concrete; diamond grind concrete over recycled aggregate concrete; and exposed aggregate concrete over a low cost concrete. The compilation of this report is strictly a MnDOT activity that documents construction and instrumentation of concrete cells at our MnROAD facility and should not be misconstrued for a SHRP 2 activity. Strength, on board sound intensity, sound absorption, friction, texture and international roughness index were tested to better understand the performance of these, pavement types. Results suggest that the exposed aggregate concrete surface does not provide significant noise reduction. Exposed aggregate surfacing can provide more than adequate friction for skid resistance and safety. Overall, however, these two lift concrete pavements proved to address issues such as high cost of virgin aggregates and high trucking costs for areas that don't have quality aggregates to use. Continued monitoring of these test cells will help develop the extensive understanding of composite pavements needed for effective design and accurate service life models.

This report describes the 7-year performance of the 60-year concrete design test cell (Cell 53) built in 2008 in the MnROAD Low Volume Road). Many characteristics of this 115-foot cell, two 12-feet wide lanes, 12 inch thick dowelled concrete test have exhibited insignificant change in performance criteria over the 5-year period. . The test cell maintained adequate skid resistance since it was constructed in 2008. Transverse joint monitoring and fault measurements also indicated insignificant faulting over the period of review. In many cases, measured properties in the inside lane of Cell 53 were significantly different from outside lane. The International Roughness Index (IRI) was not initially low but has remained relatively constant. Additionally, a slight disparity of IRI between the inside (traffic) lane and the outside (environmental) lane was evident. The IRI in the inside lane was consistently higher than the outside lane. Seasonal deflection basins created for both summer and spring dates soon after construction in 2009 and similar summer and spring dates in 2013 showed deflections below 100 microns, which also suggests good performance. The test cell displayed excellent load transfer at all of the transverse joints tested in this research. The average load transfer was approximately 0.85, which was in some cases over four times as high as another MnROAD concrete pavement test cell which was undoweled and in poor condition. The load transfer in the 60-year design cell had not shown significant decrease over time. Researchers used the Evaluation of Layer Moduli and Overlay Design (ELMOD) to determine the layer properties of the pavement test cell. Again, similar dates in both spring and summer seasons were compared for the year 2009 and 2013. Summer results exhibited a slight decrease in calculated Moduli values for the base, subbase and subgrade layers, for both the inside and outside lane. This slight decrease over the period was not interpreted as failure in the base layers. Seven years of monitoring reveal that 60-year design concrete pavement test cell has not shown any performance issues apart from those inherent in the construction process. Most Importantly, evidence of lesser strain in the concrete when compared to thinner pavements designed for a shorter service life at the research facility.

In pavement infrastructure, functional characteristics are mainly preponderant over structural characteristics as the former typically govern pavement rehabilitation, maintenance and reconstruction decisions. Evidently, agencies invest in provision or restoration of friction (skid resistance) and make policies to minimize traffic noise. Most agencies accept (or reject) construction projects based mainly on initial ride quality. Consequently, this study examined various concrete textures imparted on new pavements in the 2007, 2010 and 2011 MnROAD test cell construction and monitored their ride quality, friction, tire pavement noise, visual conditions and acoustic impedance over time. The study successfully developed an in-situ impedance tube evaluation method for pervious concrete for a proxy to material and hydraulic conductivity condition. It also created tenable time-series equations for the progression of the various texture characteristics and developed a friction degradation model based on traffic and texture type. Advanced data analysis showed that longitudinal texturing and negative textures were strongly associated with pavement quietness. Investment analysis revealed that certain surfaces produced noise reduction of 6 decibels over the transverse time. Those textures including pervious concrete and diamond grinding were found to be cost-beneficial for noise abatement consideration. This research also associated rectangular texturing with anomalous laser-induced ride-quality measurements. Further analysis also accentuated a correlation of pavement condition to surface acoustics thus recommending the development of impedance tube for pavement joint condition monitoring. Additionally, This research recommended drag pre-textured longitudinal-tining as the optimal texture for durability, quietness and skid resistance based on the overall research results.

Practitioners have often wondered whether; during ride measurement with inertial devices; the motion of the laser through pavement texture introduces non representative values of international roughness index (IRI); particularly in certain textures. In response to this problem; a special texture study created a non-textured strip by a recession of the middle 4 ft of a texturing broom dragged longitudinally behind the paver. The study measured IRI and other surface properties in adjacent textured and non-textured strips by using a lightweight profiler outfitted with a line laser and a triple laser arranged in tandem. IRI measurements were performed after sufficient concrete strength gain and repeated as soon as the joints were sawn. The same measurements were repeated after the joints were deployed. Results showed a significant difference between the IRI of a textured strip and that of a non-textured strip. Further analysis indicated that; although texture appears to affect IRI; this effect was amplified by the type of laser used; as the triple laser appeared to indicate higher IRIs in comparison with the RoLine laser. Although the RoLine is not a reference profiler for IRI values unaffected by texture; the prevalence of the RoLine and the triple laser in construction acceptance testing is sufficient reason to be concerned about the difference inherent in the obtained results. Chi-square and t-test statistical analysis showed that laser type induced comparable and even higher IRI anomalies than did the experimental drag texture. In addition; the texture-induced IRI anomaly can be minimized by measuring smoothness for acceptance at least 2 weeks after paving. There was no significant difference in pavement noise in terms of on board sound intensity (OBSI) between textured and non-textured strips. The friction numbers derived from the Dynamic Friction Tester indicated a correlation between the nontextured and textured strip friction numbers in each of the 6 sections. This indicated that the finishing process before texturing continued to influence the microtexture even after the broom drag. This finding is limited to the texture types investigated. Therefore; extrapolation of these results to other textures should be done with caution due to anomalous laser -induced IRI on certain textures.