Composite Pavement Systems, Volume 2: PCC/PCC Composite Pavements (2013) / Chapter Skim
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21 Introduction The field composite pavement sections used in the structural modeling included a combination of special research sections in the United States and Canada and regularly constructed projects in Europe.
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22 test Sections at MnrOaD Introduction In May 2010, two full-scale PCC/PCC test sections were constructed on I-94 at MnROAD to emulate best practices of constructing PCC/PCC composite pavements. Before the construction of the mainline test sections, a 200-ft two-lane test strip was constructed at the MnROAD facilities.
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23 term "low-cost" signifies that the PCC design was such that the lowest possible amount of cement and most inexpensive coarse aggregates were used by the contractor. In addition, various textures were considered for the surface PCC layer.
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24 Construction of the Test Sections The construction project was awarded to C
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25 Subgrade Soil Grading and Compaction A string line was set for trimming of the subgrade and the base. The subgrade was cut with a trimming machine (Figure 2.9)
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26 available natural fine aggregates, and a coarse RCA as a lowcost alternative coarse aggregate. All basic components of the lower-layer PCC were selected in light of a desire to reduce costs, investigate methods of sustainability, and investigate the reuse of materials into structural components.
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27 cementitious materials including, but not limited to, fly ash. Fly ash replacement of 60% was approved and used in the final mix design for the low-cost PCC mix.
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28Table 2.4. Aggregate Gradation for PCC Mixes Designation 37.5 mm (1½ in.)
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29 of the slab. Temperature sensors were located in each of the different pavement structures so that the seasonal, daily, and construction temperature profiles that developed could be documented.
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30 .5" 1.5" 2.5" 3.25" 4" 6" 8" 9" 13" 17" 20" 26" 6" PCC Special 2 8" Class 5 Existing Clay Subgrade Wheelpath Legend Static Strain Gauge Thermocouple Sensor Fence Centerline Riser BD Pedestal Conduit Dynamic Strain Gauge Moisture Gauge Thermocouple TreeHand hole 12' 10' Bit Shoulder 15' 15' 15' 15' 15' Static PanelsDynamic Panels Spacing PanelNo Sensors ~45' P1P2P3P4P5 3" 2" 3" 2" 4" 4" New Cab 2-4" Passing Lane Driving Lane N 3" PCC Special 1 Figure 2.12. Elevation and plan view of instrumentation layout for PCC/PCC test sections at MnROAD.
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31 Figure 2.13. Instrumentation installed prior to placement of the PCC to measure pavement responses to temperature and traffic loads (static strain gauge, top left; dynamic strain gauges, bottom left; humidity sensors, top right; temperature sensors [thermocouple tree]
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32 Figure 2.15. Paving train constructing R21 test sections along I-94 at MnROAD (from left to right: the mixer truck, first paver, belt placer, and second paver)
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33 Another concern about delays included the integrity of the bond at the interface of the two lifts. An ultrasonic tomography testing device was used to assess the bond at the transverse joints and at midslab locations on the demonstration slab.
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34 Paving the mainline sections progressed at a rate of between 1 and 4 ft per minute, and the project contractor was confident that this rate would be greatly increased with a larger project and a consistent supply of PCC for paving. While joint cuts sawed to a depth of 3 in.
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35 to achieve a coarse aggregate of a desired size. Early estimates missed the amount of recycled concrete required, which led to only 275 ft of PCC/PCC using the RCA mix being paved, instead of the originally planned 475 ft.
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36 of the surface treatment were delayed because of mechanical problems on the finishing platform, which provided insufficient pressure to the spray nozzles. The treatment (Figure 2.23)
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37 of brushing was determined using a combination of a sand patch test and an aggregate peak counting test (Figure 2.25)
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38 have good air void distribution for protection against freeze– thaw damage. Noise Measurements Construction of the EAC finish was attempted because of its durability and because it channels water away from the wheel path in multiple directions.
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39 Figure 2.27. OBSI device.
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40 Source: Akkari and Izevbekhai 2011.
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41 Table 2.6. PCC/PCC Composite Pavement Field Sections Composite Pavement Type Location Construction Year and Traffic Comments 3-in.
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42 Table 2.6. PCC/PCC Composite Pavement Field Sections Composite Pavement Type Location Construction Year and Traffic Comments 3-in.
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43 Table 2.6. PCC/PCC Composite Pavement Field Sections Composite Pavement Type Location Construction Year and Traffic Comments 3-in.
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44 Table 2.6. PCC/PCC Composite Pavement Field Sections Composite Pavement Type Location Construction Year and Traffic Comments 1.5-in.
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45 Table 2.6. PCC/PCC Composite Pavement Field Sections Composite Pavement Type Location Construction Year and Traffic Comments 3-in.
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46 Table 2.6. PCC/PCC Composite Pavement Field Sections Composite Pavement Type Location Construction Year and Traffic Comments 3-in.
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