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Publication Number: FHWA-HRT-05-068
Date: October 2005

Achieving A High Level of Smoothness in Concrete Pavements Without Sacrificing Long-Term Performance

CHAPTER 6. SHORT-TERM CHANGES IN INITIAL SMOOTHNESS OF CONCRETE PAVEMENTS

INTRODUCTION

All SHAs that construct PCC pavements have a smoothness specification. Some smoothness specifications will give a timeframe after construction within which smoothness measurements must be performed while others do not. An issue with PCC pavements is the effect of curling and warping of PCC slabs on smoothness. Some contractors perform smoothness measurements as soon as possible after construction because they perceive that curling and warping effects on the pavement will be negligible immediately after construction. However, if curling and warping occurs in the pavement during its early life, causing a significant reduction in smoothness, the validity of bonuses paid based on smoothness measurements obtained immediately after construction becomes questionable.

A study was performed to investigate how the smoothness of a PCC pavement changes during the first 3 months of its life. Test sections were established at the following paving projects for this study:

All of these pavements were doweled JPC pavements. The smoothness measurements were generally performed at the following time periods using an inertial profiler:

Smoothness measurements were performed in each wheel path, and three repeat measurements were performed for each data set. At several test sections, measurements were obtained in the morning and the afternoon during the 1-week and 3-month testing. At one test section, measurements were also obtained approximately 1 year after construction.

The following analyses were performed on the collected profile data:

  1. Obtain average IRI and RN: Compute IRI and RN for all profile runs. Then compute an average IRI and RN for each data set using the values obtained for the three repeat runs.
  2. Investigate the repeatability of the profiler: The IRI values obtained for the entire test section from the repeat runs for each data set were evaluated to determine the repeatability of the profiler.
  3. Investigate the short-interval IRI repeatability: This investigation was performed by comparing IRI values at 15-m (49-ft) intervals for the repeat runs in each data set. This investigation indicates whether the distribution of the roughness within the section for the three repeat runs was repeatable. In some cases, IRI from the repeat runs for a pavement section can be very close to each other; however, the distribution of roughness within the section for the repeat runs can be variable. When the overall roughness for the section is computed, the roughness variability within the section can cancel out, and give close IRI values for repeat runs even though they may have very different roughness distributions within a section.
  4. Evaluate changes in IRI and RN: Compare IRI and RN obtained the first time the section was profiled with values obtained from subsequent profiling. This analysis provides information on how the smoothness of PCC pavements changes during the first few months of their life relative to the smoothness obtained immediately after paving.
  5. Evaluate the effect of joints on profile data and smoothness indices: In the two projects in Iowa, a sawcut that is 6 mm (0.25 inches) wide and 25 mm (1 inch) deep is made on the pavement. Thereafter, the joint is sealed. Profile data collected for these two conditions of the joint were available for the two Iowa projects. In the Michigan and the Pennsylvania projects, a 3-mm (0.12-inch)-wide initial sawcut is made on the pavement. Thereafter, the joint is widened to form a reservoir and then sealed. Profile data collected for all three conditions of the joint were available. These profile data were analyzed to see how the joint appeared in the profile data and to investigate the impact of these different joint conditions on IRI and RN.
  6. Use roughness profiles to investigate the distribution of roughness: For this analysis, IRI roughness profiles based on an 8-m (26-ft) base length were used. Roughness profiles for the left wheel path, right wheel path, and an overlaid plot that showed profiles for both wheel paths were used in this analysis.
  7. Evaluate profile characteristics: Profile data collected at different time periods were analyzed using profile plots and PSD plots to investigate changes in profile, and to see whether a dominant wavelength or a dominant waveband that is affecting IRI is present in the profile. The CI values of the profiles also were computed to investigate slab curvature.
  8. CTE values and microscopical examination: Cores obtained from the pavement or cylinders cast from concrete used in the project were used to determine the CTE of the concrete and to perform a microscopical examination to identify the coarse and the fine aggregate in the concrete. The CTE test was carried out using the test procedure CRD-C 39-81 that is described in the U.S. Army Corps of Engineers Materials Testing Handbook(36). The microscopical examination of the concrete cylinder or core was performed in accordance with portions of ASTM C 856-02, Standard Practice for Petrographic Examination of Hardened Concrete(37).

The results obtained at each project are explained separately below.

STATE ROUTE 6220 PROJECT - PENNSYLVANIA

Project Description

This project involved new construction and was located in Centre County, PA. This roadway is a four-lane divided highway with two lanes in each direction. A 168-m (550-ft)-long test section was established for testing on the two southbound lanes. The test section was established between stations 588+00 and 582+50. (Stations are in U.S. customary units).

Pavement Details

Table 21 shows pavement details. The subgrade consisted of blasted rock mixed with fines. Table 22 provides information about the joints in the pavement.

Table 21. Pavement details - S.R. 6220.
ItemDescriptionValue
Pavement thicknessConcrete thickness280 mm (10.9 inches)
Base thickness100 mm (3.9 inches) asphalt-treated permeable base over 150 mm (5.9 inches) of aggregate base
Pavement widthTotal pavement width7.30 m (24 ft)
Width of inside lane3.65 m (12 ft)
Width of outside lane3.65 m (12 ft)
ShoulderShoulder typeConcrete, 280 mm (10.9 inches) thick
Width of shoulderInside 1.2 m (3.9 ft), outside 3 m (9.8 ft)
Joint spacingJoint spacing4.6 m (15.1 ft)
Joints skewed?No
DowelsDowel typeEpoxy coated
Dowel diameter38 mm (1.5 inches)
Dowel length457 mm (17.8 inches)
TiningTining typeTransverse tining
Tining spacingRandom spacing
Tining depth3.2 to 4.8 mm (0.1 to 0.2 inches)
Table 22. Joint details - S.R. 6220.
DescriptionValue
Joint formationInitial sawcut then reservoir widened
Initial sawcut3 mm (0.12 inch) wide and 93 mm (3.63 inches) deep
Joint reservoir width9.5 mm (0.37 inch)
Joint reservoir depth38 mm (1.5 inches)
Sealant typeHot-pour asphalt
Depth to top of sealant5 mm (0.2 inches)

Concrete Mix Design

Table 23 presents the mix proportions used for the concrete mix. An entrained air admixture and a water-reducing admixture were added to the concrete mix. Table 24 shows the gradation of the aggregates used in the concrete mix.

Table 23. Mix proportions - S.R. 6220.
ComponentWeight Kilograms per cubic meters (kg/m3 (lb/yd3))
Cement Type 1297 (500)
Fly ash;52 (88)
Coarse aggregate1,097 (1,849)
Sand653 (1,100)
Table 24. Gradation of aggregates - S.R. 6220.
SievePercentage Passing
Coarse AggregateSand
37.5 mm (1.5 inches)100-
25.0 mm (1 inch)100-
12.5 mm (0.5 inch)45-
9.5 mm (0.4 inch)-100
No. 4899
No. 8380
No. 16-68
No. 30-48
No. 50-21
No. 100-6

Paving Details

Table 25 shows the date and time of test section paving and other details related to the paving process. The concrete was placed using a slipform paver.

Table 25. Paving Information - S.R. 6220.
ItemDescriptionComment
Date and timeDate of paving9/17/03
Time of paving9 a.m.
Paving processHaul routeAdjacent to inside lane
Stringline7.6-m (25-ft) spacing, both sides
DowelsFixed to base
Tie barsInserted by paver
Concrete deposit methodBelt placers
Spreader used?Yes, one
Paver typeGOMACO™ GHP - 2800
ConcreteTemperature21 oC (69.8 oF)
Curing methodCuring compoundWater-based curing compound sprayed on pavement

Profiling of Section

Eight sets of profile data were collected over a 3.5-month period. The pavement was first profiled 1 day after paving; the second set of profiles were collected 3 days after paving. The third and fourth sets of data were collected 1 week after paving in the morning and afternoon, respectively. The fifth and sixth sets of data were collected 1 month after paving in the morning and afternoon, respectively. The seventh and eighth sets of data were collected about 3.5 months after paving in the morning and afternoon, respectively. The profile data were collected using an ICC lightweight laser profiler. This profiler recorded data at 31-mm (1.2-inch) intervals.

Table 26 shows the dates and times when profile data collection was performed, the approximate age of the pavement at each instance, and the low, high, and mean air temperatures for each profiling day.

The 3-mm (0.12-inch)-wide initial sawcut had been made on the pavement when the profile data were collected 1 day after paving. The joint reservoirs had been formed, but the joints were not sealed when the profile data were collected in the morning of the 1-month data collection. The joints were sealed when the 1-month afternoon runs were performed. During the 3.5-month data collection, it was noted that the first 5.5 m (18 ft) of the inside lane had been diamond ground.

Table 26. Profile data collection - S.R. 6220.
Date of ProfilingApproximate Age of PavementTime of ProfilingAir Temperature oC (oF )
Inside LaneOutside Lane
Left Wheel PathRight Wheel PathLeft Wheel PathRight Wheel PathLowHighMean
9/18/031 day2:32 p.m.2:34 p.m.2:37 p.m.N/A12 (54)21(70)17 (63)
9/20/033 days1:02 p.m.1:14 p.m.1:35 p.m.N/A11(52)21(70)16 (61)
9/24/037 days9:44 a.m.9:53 a.m.10:04 a.m.N/A7 (45)22 (72)15 (55)
5:09 p.m.5:21 p.m.5:33 p.m.N/A
10/15/031 month8:38 a.m.8:48 a.m.8:59 a.m.9:05 a.m.7 (45)13 (55)11 (52)
2:32 p.m.2:40 p.m.2:48 p.m.2:56 p.m.
12/29/033.5 months9:53 a.m.10:46 a.m.11:21 a.m.11:45 p.m.1 (34)16 (61)8 (46)
3:51 p.m.4:02 p.m.4:23 p.m.4:41 p.m.

N/A: Profile data not collected

Roughness Indices

IRI Values

The average IRI values computed from the three repeat runs are presented in table 27 and shown graphically in figure 71. The IRI for the right wheel path in the outside lane is not shown in this figure, because data were collected along this path only during the 1-month and 3.5-month data collection. Table 28 shows the percentage change in IRI values for different test sequences with respect to the IRI obtained at 1 day. Values for right wheel of outside lane are not presented in this table because profiling was performed along this path only during the 1-month and 3.5-month data collection.

Table 27. IRI values for different test sequences - S.R. 6220.
Date of ProfilingApproximate Age of PavementTime of ProfilingIRI (m/km)
Inside LaneOutside Lane
Left Wheel PathRight Wheel PathLeft Wheel PathRight Wheel Path
9/18/031 day2:30 to 2:40 p.m.1.321.21.0.96N/A
9/20/033 days1 to 1:40 p.m.1.271.241.01N/A
9/24/037 days9:45 to 10 a.m..1.271.180.96N/A
5:05 to 5:35 p.m.1.271.200.98N/A
10/15/031 month8:40 to 9 a.m.1.301.220.970.90
2:30 to 3 p.m.1.311.180.940.93
12/29/033.5 months10 to 11:30 p.m.1.211.130.940.91
3:50 to 4:40 p.m.1.211.100.940.86

N/A: Profile data not collected

1 m/km = 63.4 inches/mi

Figure 71. IRI values for different test sequences - S.R. 6220.

Chart. IRI values for different test sequences - S.R. 6220. This chart shows three sets of bar charts. Each set of bar charts shows the IRI values along the inside lane left wheel path, inside lane right wheel path, and outside lane right wheel path for eight test sequences. The test sequences are: 1-day PM, 3-day AM, 7-day AM, 7-day PM, 1-month AM, 1-month PM, 3.5-month AM, and 3.5-month PM. The IRI values obtained along the inside lane left wheel path for the eight test sequences starting with the first are: 1.32, 1.27, 1.27,1.27, 1.30, 1.31, 1.21, and 1.21 meters per kilometer (84, 81, 81, 81, 82, 83, 77, and 77 inches per mile). The IRI values obtained along the inside lane right wheel path for the eight test sequences starting with the first are: 1.21, 1.24, 1.18, 1.20, 1.22, 1.18, 1.13, and 1.10 meters per kilometer (77, 79, 75, 76, 77, 75, 72, and 70 inches per mile). The IRI values obtained along the outside lane left wheel path for the eight test sequences starting with the first are: 0.96, 1.10, 0.96, 0.98, 0.97, 0.94, 0.94, and 0.94 meters per kilometer (61, 70, 61, 62, 61, 60, 60, and 60 inches per mile).

Table 28. Percentage change in IRI with respect to 1-day IRI - S.R. 6220.
Date of ProfilingApproximate Age of PavementTime of ProfilingPercentage Change in IRI with Respect to 1-Day IRI
Inside LaneOutside Lane
Left Wheel PathRight Wheel PathLeft Wheel Path
9/20/033 days1 to 1:40 p.m.-325
9/24/037 days9:45 to 10 a.m.-4-20
5:05 to 5:35 p.m.-3-12
10/15/031 month8:40 to 9 a.m.-111
2:30 to 3 p.m.-1-3-2
12/29/033.5 months10 to 11:30 p.m.-8-7-2
3:50 to 4:40 p.m.-8-9-3

Note: 1-day profile data not collected along right wheel path of outside lane

The following observations were noted when evaluating the IRI values:

RN Values

The average RN values obtained from the three runs are presented in table 29 and shown in figure 72. Table 30 shows the percentage change in RN values for different test dates with respect to the RN obtained at 1 day. The RN for the right wheel path in the outside lane is not shown in figure 72 and table 30 because data were collected along this path only during the 1-month and 3.5-month data collection.

Table 29. RN values for different test sequences - S.R. 6220.
Date of ProfilingApproximate Age of PavementTime of ProfilingRide Number
Inside LaneOutside Lane
Left Wheel PathRight Wheel PathLeft Wheel PathRight Wheel Path
9/18/031 day2:30 to 2:40 p.m.3.593.713.84N/A
9/20/033 days1 to 1:40 p.m.3.593.663.80N/A
9/24/037 days9:45 to 10 a.m..3.453.513.62N/A
5:05 to 5:35 p.m.3.443.553.62N/A
10/15/031 month8:40 to 9 a.m.3.373.263.403.40
2:30 to 3 p.m.3.683.813.953.88
12/29/033.5 months10 to 11:30 p.m.3.693.783.953.87
3:50 to 4:40 p.m.3.673.803.973.93

Figure 72. RN values for different test sequences - S.R. 6220.

Chart. RN values for different test sequences - S.R. 6220. This chart shows three sets of bar charts. Each set of bar charts shows the RN values along the inside lane left wheel path, inside lane right wheel path, and outside lane right wheel path for eight test sequences. The test sequences are: 1-day PM, 3-day AM, 7-day AM, 7-day PM, 1-month AM, 1-month PM, 3.5-month AM, and 3.5-month PM. The RN values obtained along the inside lane left wheel path for the eight test sequences starting with the first are: 3.59, 3.59, 3.45, 3.44, 3.37, 3.68, 3.69, and 3.67. The RN values obtained along the inside lane right wheel path for the eight test sequences starting with the first are: 3.71, 3.66, 3.51, 3.55, 3.26, 3.81, 3.78, and 3.80. The RN values obtained along the outside lane left wheel path for the eight test sequences starting with the first are: 3.84, 3.80, 3.62, 3.62, 3.40, 3.95, 3.95 and 3.97.

Table 30. Percentage change in RN with respect to 1-day RN - S.R. 6220.
Date of ProfilingApproximate Age of PavementTime of ProfilingIRI (m/km)
Inside LaneOutside Lane
Left Wheel PathRight Wheel PathLeft Wheel Path
9/20/033 days1 to 1:40 p.m.0-1-1
9/24/037 days9:45 to 10 a.m..-4-5-6
5:05 to 5:35 p.m.-4-4-6
10/15/031 month8:40 to 9 a.m.-6-12-11
2:30 to 3 p.m.233
12/29/033.5 months10 to 11:30 p.m.323
3:50 to 4:40 p.m.223

N/A: Profile data not collected

The following observations were noted when the RN values were evaluated:

Repeatability of IRI Values

An evaluation of the IRI values obtained from repeat runs for each data set indicated good repeatability. Usually when the IRI from three runs were compared, the difference between the maximum and the minimum IRI was between 0.02 to 0.03 m/km (1.27 to 1.90 inches/mi).

The three repeat runs obtained along the left wheel path of the outside lane for the 1-month afternoon runs were used to evaluate the short interval repeatability of IRI within the section. The IRI of each run was computed at 15-m (49-ft) intervals to perform this evaluation. The 165-m (541-ft)-long section has 11 segments that are 15 m (49 ft) long (the last 3 m (10 ft) of the section was ignored). Figure 73 shows the IRI values obtained at 15-m (49-ft) intervals for each run. Overall, reasonable repeatability in IRI values was obtained for the majority of segments. The difference between the maximum and minimum IRI for a segment obtained from the repeat runs ranged from a low of 0.03 m/km (1.9 inches/mi) at segment 2 to a high of 0.21 m/km (13.3 inches/mi) at segment 8. The average of the difference between maximum and minimum IRI for a segment was 0.09 m/km (5.7 inches/mi).

Figure 73. IRI values for repeat runs - S.R. 6220.

Chart. IRI values for repeat runs - S.R. 6220. This figure presents a bar chart that shows IRI values that were obtained for 11 segments, each 15 meters (49 feet) long, for three repeat runs of the profiler. The three repeat runs shown in this figure were obtained along the left wheel path of the outside lane during the 1-month afternoon profiling. The following IRI values that are presented in ascending order of runs were obtained for each segment: segment 1: 1.30, 1.29, and 1.34 meters per kilometer (82, 82, and 85 inches per mile); segment 2: 0.75, 0.72, and 0.74 meters per kilometer (48, 46, and 47 inches per mile); segment 3: 0.84, 0.75, and 0.78 meters per kilometer (53, 48, and 50 inches per mile); segment 4: 1.06, 1.05, and 0.92 meters per kilometer (67, 67, and 58 inches per mile); segment 5: 0.94, 1.05, and 1.09 meters per kilometer (60, 67, and 69 inches per mile); segment 6: 1.08, 1.16, and 1.13 meters per kilometer (69, 74, and 72 inches per mile); segment 7: 1.05, 1.12, and 1.11 meters per kilometer (67, 71, and 70 inches per mile); segment 8: 0.92, 0.78, and 0.71 meters per kilometer (58, 50, and 45 inches per mile); segment 9: 0.75, 0.64, and 0.68 meters per kilometer (48, 41, and 43 inches per mile); segment 10: 0.86, 0.82, and 0.83 meters per kilometer (55, 52, and 53 inches per mile); and segment 11: 0.91, 0.86, and 0.93 meters per kilometer (58, 55, and 59 inches per mile).

Effect of Condition of Joint on Profile Data

During this study, profile data were collected when the joints were in the following conditions:

Profile data collected when the joint was at each of the three conditions described previously were evaluated to investigate how the joints showed up on the profile. Data collected along the left wheel path of the outside lane at the following profiling times were evaluated: 1 day (initial sawcut), 1-month morning (joint reservoir sawed), and 1-month afternoon (joint sealed). Figures 74 - 76 show how a typical joint appeared on the profile for each of these conditions. The joint appears between 30.4 and 30.6 m (99.7 and 100.3 ft) in the plots. The following observations are noted for each case shown in figures 74 - 76.

For all three cases, the joint appears in the profile as a small depression spread over a distance of about 220 mm (8.7 inches), when the actual width of the joint is 9.5 mm (0.4 inch). Also, the depth of the joint that appears in the profile for each case is much less than the actual depth. This phenomenon is caused by the averaging performed on the height sensor data and the low-pass filtering that is applied on the profile data to prevent aliasing.

Figure 74. Measurements at a joint, initial sawcut, 1-day - S.R. 6220.

Chart. Measurements at a joint, initial sawcut, 1-day - S.R. 6220. This figure consists of profile data collected over a joint 1-day after paving with the initial sawcut present on the pavement. The X-axis shows distance, while the Y-axis shows elevation. Data collected between 30 and 31 meters (98.4 and 101.7 feet) are shown. The plot shows data collected when the initial sawcut was present on the pavement. In this plot, the joint appears in the profile as a small depression that is spread over a distance of about 220 millimeters (8.7 inches) with a maximum depth about of 1.5 millimeters (0.06 inches).

1 m = 3.28 ft
1 mm = 0.039 inch

Figure 75. Measurements at a joint, reservoir widened, 1-month morning - S.R. 6220.

Chart. Measurements at a joint, reservoir widened, 1-month morning - S.R. 6220. This figure consists of profile data collected during 1-month morning profiling when the joint reservoir had been sawed. The X-axis shows distance, while the Y-axis shows elevation. Data collected between 30 and 31 meters (98.4 and 101.7 feet) are shown. This plot shows profile data collected when the joint reservoir was widened. In this plot, the joint appears as a small depression that is spread over a distance of about 220 millimeters (8.7 inches), with a maximum depth of about 3.5 millimeters (0.14 inches).

1 m = 3.28 ft
1 mm = 0.039 inch

Figure 76. Measurements at a joint, joint sealed, 1-month afternoon - S.R. 6220.

Chart. Measurements at a joint, joint sealed, 1-month afternoon - S.R. 6220. This figure consists of profile data collected during 1-month afternoon profiling after the joint had been sealed. The X-axis shows distance, while the Y-axis shows elevation. Data collected between 30 and 31 meters (98.4 and 101.7 feet) are shown. This plot shows data collected after the joint was sealed. In this plot, the joint appears as a small depression that is spread over a distance of about 220 millimeters (8.7 inches), with a maximum depth of about 1.5 millimeters (0.06 inches).

1 m = 3.28 ft
1 mm = 0.039 inch

The lightweight profiler used for data collection recorded profile data at 31-mm (1.2-inch) intervals. However, the height sensor in the profiler obtains data at much closer intervals, and an averaged height sensor value is used to compute profile data points at 31-mm (1.2-inch) intervals. In addition, a low-pass filter appears to have been applied on the data further attenuating the depth of the joint, and causing the joint to appear as a much wider feature. Although the profiles obtained when the joint reservoirs had been sawed do show a downward feature at the joint that has a higher depth compared to the other two cases, the depth of the features is not large enough to have an effect on the IRI. Hence, the IRI values computed from profiles collected under the three different scenarios were very close to each other. However, the downward spikes of the magnitude seen for 1-month morning profiling where the joint reservoirs had been sawn do have a significant impact on RN. The 1-month afternoon RN values obtained after the joints were sealed were higher than the morning values by 9 to 16 percent for the different wheel paths.

Roughness Profiles

Figures 77 - 79 and figures 80 - 82 show the roughness profiles for a 6-m (20-ft) base length for the outside lane and inside lane, respectively. The roughness profile for the outside lane was computed from data obtained for the 3-month afternoon testing, whereas the roughness profile for the inside lane was computed using data obtained from 3-day testing. The joint spacing of the pavement is 4.6 m (15 ft) and each vertical line in the plots corresponds to a joint. The peaks in the plots indicate areas of high roughness. Many peaks are coinciding with the joint locations or are very close to joint locations. This situation indicates that the dowel baskets may be affecting roughness.

Figure 83 shows a high roughness area along the left wheel path of the inside lane at the start of the section. This area was subsequently diamond ground. Several localized areas of high roughness are noted along the left wheel path of the inside lane, and the roughness of these areas contributed to making this wheel path have the highest roughness of all tested wheel paths.

Evaluation of Profile Data

Apart from the differences in joint conditions, no significant differences between the profiles obtained during the different test sequences could be observed. The profiles obtained along the inside lane during 3.5 months of testing showed the effect of diamond grinding at the start of the section. Also, no distinct profile feature or a dominant waveband could be identified in the profile data.

As described previously, the IRI varied transversely across the section. The difference in IRI between the left wheel path of the inside lane and the right wheel path of the outside lane based on 1-month afternoon testing was 0.38 m/km (24 inches/mi). Evaluation of the profile data did not show a distinct profile feature that was responsible for this difference in IRI.

The CI value was computed for one profile run from each data set, and the computed values are shown in table 31. This table does not show values for the right wheel path of the outside lane because profile data were only collected along this path during the 1-month and 3.5-month data collection. The CI values for all data sets were extremely small, which indicates the slabs are more or less flat with virtually no curvature. No noticeable changes in curvature were observed between the data sets.

Figure 77. Roughness profiles for outside lane, left wheel path - S.R. 6220.

Chart. Roughness profiles for outside lane, left wheel path - S.R. 6220. This figure contains a plot that shows the roughness profile of the outside lane along the left wheel path. The X-axis shows the distance, while the Y-axis shows the IRI. The roughness profile from 3 to 163 meters (10 to 534 feet) is shown in each plot. The left wheel path roughness profile varies between 0.45 and 1.30 meters per kilometer (29 and 82 inches per mile) for most of the section. Values outside these limits are noted between the following limits: (1) between 6 and 9 meters (20 and 30 feet) where the IRI is 1.50 meters per kilometer (95 inches per mile), (2) between 152.4 and 155.5 meters (500 and 520 feet) where the IRI has a maximum value of 1.60 meters per kilometer (101 inches per mile), and (3) at 27 meters (89 feet) where the IRI has a minimum value of 0.40 meters per kilometer (25 inches per mile).

1 m = 3.28 ft
1 m/km =63.4 inches/mi

Figure 78. Roughness profiles for outside lane, right wheel path - S.R. 6220

Chart. Roughness profiles for outside lane, right wheel path - S.R. 6220. This figure contains a plot that shows the roughness profile of the outside lane along the right wheel path. The X-axis shows the distance, while the Y-axis shows the IRI. The roughness profile from 3 to 163 meters (10 to 534 feet) is shown. The right wheel path roughness profile varies between 0.45 and 1.30 meters per kilometer (29 and 82 inches per mile) for most of the section. Values outside these limits are seen between the following limits: (1) 6 and 9 meters (20 and 30 feet) where the IRI has a maximum value of 1.7 meters per kilometer (108 inches per mile), and (2) at 55 meters (180 feet) where the IRI has a value of 1.4 meters per kilometer (89 inches per mile).

1 m = 3.28 ft
1 m/km =63.4 inches/mi

Figure 79. Roughness profiles for outside lane, left and right wheel path - S.R. 6220.

Chart. Roughness profiles for outside lane, left and right wheel path - S.R. 6220. This figure contains a plot that shows the roughness profile of both the left and the right wheel path of the outside lane, with different line patterns used for the two wheel paths. The X-axis shows the distance, while the Y-axis shows the IRI. The roughness profile from 3 to 163 meters (10 to 534 feet) is shown. This plot shows that the left wheel path has higher IRI than the right wheel path between 55 and 100 meters (180 and 328 feet), while the right wheel path has higher IRI than the left between 120 and 145 meters (394 and 476 feet).

1 m = 3.28 ft
1 m/km =63.4 inches/mi

Figure 80. Roughness profiles for inside lane, left wheel path - S.R. 6220.

Chart. Roughness profiles for inside lane, left wheel path - S.R. 6220. This figure contains a plot that shows the roughness profile of the inside lane along the left wheel path. The X-axis shows the distance, while the Y-axis shows the IRI. The roughness profile from 3 to 163 meters (10 to 535 feet) also is shown. The left wheel path roughness profile varies between 0.5 and 2.0 meters per kilometer (32 and 127 inches per mile), except between 3 and 14 meters (10 and 46 feet) where the IRI has a peak value of 2.9 meters per kilometer (184 inches per mile).

1 m = 3.28 ft
1 m/km =63.4 inches/mi

Figure 81. Roughness profiles for inside lane, right wheel path - S.R. 6220.

Chart. Roughness profiles for inside lane, right wheel path - S.R. 6220. This figure contains a plot that shows the roughness profile of the inside lane along the right wheel path. The X-axis shows the distance, while the Y-axis shows the IRI. The roughness profile from 3 to 163 meters (10 to 535 feet) also is shown. The right wheel path roughness profile varies between approximately 0.75 and 1.75 meters per kilometer (48 and 111 inches per mile), except between 3 and 14 meters (10 and 46 feet), where the IRI has a peak value of 2.20 meters per kilometer (139 inches per mile).

1 m = 3.28 ft
1 m/km =63.4 inches/mi

Figure 82. Roughness profiles for inside lane, left and right wheel path - S.R. 6220.

Chart. Roughness profiles for inside lane, left and right wheel path - S.R. 6220. This figure contains a plot that shows the roughness profiles of both the left and the right wheel path of the inside lane, with different line patterns used for the two wheel paths. The X-axis shows the distance, while the Y-axis shows the IRI. The roughness profile from 3 to 163 meters (10 to 535 feet) also is shown. This plot shows that the two roughness profiles exhibit reasonable agreement with each other, except between 3 and 14 meters (10 and 46 feet). Within these limits, the left wheel path has a higher IRI

1 m = 3.28 ft
1 m/km =63.4 inches/mi

Table 31. CI values - S.R. 6220.
Date of ProfilingApproximate Age of PavementTime of ProfilingCurvature Index x 1,000 (1/m)
Inside LaneOutside Lane
Left Wheel PathRight Wheel PathLeft Wheel Path
9/18/031 day2:30 to 2:40 p.m.0.10-0.100.08
9/20/033 days1 to 1:40 p.m.-0.13-0.09-0.05
9/24/037 days9:45 to 10 a.m..0.070.050.08
5:05 to 5:35 p.m.0.030.08-0.02
10/15/031 month8:40 to 9 a.m.0.180.050.13
2:30 to 3 p.m.0.16-0.020.02
12/29/033.5 months10 to 11:30 p.m.0.05-0.09-0.03
3:50 to 4:40 p.m.0.07-0.10-0.02

1/m = 1/3.28 ft

Coefficient of Thermal Expansion and Microscopical Examination

A CTE test and a microscopical examination were performed on a 150-by-300 mm (5.9-by-11.8 inch) cylinder that was cast from the concrete used in the project. The CTE value for the specimen was 9.60 x 10-6 per oC (5.33 x 10-6 per oF). The microscopical examination identified the coarse aggregate to be primarily dolomite/dolomitic limestone (carbonate) with traces of granite (silicious). The fine aggregate was classified as silicious.

Summary

U.S. 20 PROJECT IN IOWA

Project Description

This was a reconstruction project located in Hardin County, IA. This roadway is a four-lane divided highway with two lanes in each direction. A 183-m (600-ft)-long test section was established for testing on the westbound inside lane. The test section was established between stations 1269+00 and 1275+00. (Stations are in U.S. customary units.)

Pavement Details

Table 32 presents pavement details. Table 33 presents information about the joints in the pavement.

Table 32. Pavement details - U.S. 20.
ItemDescriptionValue
Pavement thicknessConcrete thickness260 mm (10.1 inches)
Base thickness278-mm (10.8-inch) semidrainable Unbound granular base
Pavement widthTotal pavement width7.8 m (25.6 ft)
Width of inside lane3.6 m (11.8 ft)
Width of outside lane4.2 m (13.8 ft)
ShoulderShoulder type150-mm (5.9-inch)-thick granular shoulder
Width of shoulderInside 1.8 m (5.9 ft), outside 2.4 m (7.9 ft)
Joint spacingJoint spacing6 m (19.7 ft)
Joints skewed?Yes, 6:1
DowelsDowel typeEpoxy coated
Dowel diameter35 mm (1.4 inch)
Dowel length457 mm (18 inches)
Tining informationTining typeLongitudinal tining
Tining spacing20 mm (0.8 inch)
Tining width3 mm (0.12 inch)
Tining depth3 mm (0.12 inch)
Table 33. Joint details - U.S. 20.
DescriptionValue
Joint formationSingle sawcut using soft cut saw
Width of cut6 mm (0.24 inch)
Depth of cut25 ±6 mm (1 ±0.24 inch)
Sealant typeHot-pour bituminous
Depth to top of sealant6 ±3 mm (0.24 ±0.12 inch) from top of pavement

Concrete Mix Design

Table 34 presents the mix proportions used in the concrete mix. An entrained air admixture and a water-reducing admixture were added to the concrete mix. Table 35 presents the gradation of the aggregates used in the concrete mix.

Paving Details

Table 36 presents the date and time when the test section was paved as well as other details about the paving process. The concrete was placed using a slipform paver. Figure 83 is a photograph of the paving operation. The paver had a super-smoother finishing attachment at the back of the paver for finishing the concrete. More than 25 mm (1 inch) of rain occurred after 8 p.m. on the day paving took place.

Table 34. Mix proportions - U.S. 20.
ComponentWeight Kilograms per cubic meters (kg/m3 (lb/yd3))
Cement Type 1273 (460)
Fly ash;48 (81)
Coarse aggregate844 (1,423)
Intermediate aggregate281 (474)
Sand716 (1,207)
Table 35. Gradation of aggregates - U.S. 20.
SievePercentage Passing
Coarse AggregateIntermediate Alden LimestoneFine Becker-Brandt Sand
37.5 mm (1.5 inches)100100100
25.0 mm (1 inch)83100100
19.0 mm (0.75 inch)60100100
12.5 mm (0.5 inch)2899100
9.5 mm (0.4 inch)1684100
No. 421599
No. 81286
No. 160.91.858
No. 30-1.528
No. 50-1.37.5
No. 100-10.9

Profiling of Section

Six sets of profile data were collected over a 3-month period. The pavement was first profiled 1 day after paving, and then the second set of profiles was collected 3 days after paving. The third and fourth sets of data were collected approximately 1 week after paving in the morning and afternoon, respectively. The fifth and sixth sets of data were collected 3 months after paving in the morning and afternoon, respectively, of the same day. The profile data collection was performed using an Ames lightweight profiler that recorded data at 30-mm (1.2-inch) intervals. Table 37 shows the dates and times when profile data collection was performed, the approximate age of the pavement at each of these instances, and the low, high, and mean air temperatures for each profiling day.

A 6-mm (0.25-inch)-wide and 25-mm (1-inch)-deep sawcut had been made on the pavement when the profile data were collected for the first time. The joints were sealed after the 3-day data collection was performed.

Table 36. Paving information - U.S. 20.
ItemDescriptionComment
Date and timeDate of paving5/13/03
Time of paving9 a.m. to noon
Paving processHaul routeAdjacent to inside lane
Stringline10-m (33-ft) spacing, both sides
DowelsFixed to base
Tie barsInserted by paver
Concrete deposit methodBelt placers
Spreader used?Yes, one
PaverCMI 450B
ConcreteTemperature14 oC (57.2 oF)
Curing methodCuring compoundWhite pigmented Conspec white wax - IA

Figure 83. Paver in operation.

Photo. Paver in operation. This figure shows a photograph of the front view of slipform paver that is paving a PCC pavement. The photograph shows dowel baskets that are placed on the base in front of the paver

Table 37. Profile data collection - U.S. 20.
Date of ProfilingApproximate Age of PavementTime of ProfilingAir Temperature oC (oF )
LowHighMean
5/14/031 day3 to 4 p.m.11 (52)21 (70)19 (66)
5/16/033 days10 to 10:30 a.m.6 (43)20 (68)13 (55)
5/21/038 days2 to 3 p.m.6 (43)18 (64)12 (54)
5/22/039 days7 to 8 a.m.5 (41)19 (66)12 (54)
8/13/033 months8:30 a.m.14 (57)28 (82)22 (72)
8/13/033 months2 p.m.

Roughness Indices

IRI Values

The average IRI values computed from the three repeat runs are presented in table 38 and shown in figure 84. Table 39 shows the percentage change in IRI values for different test sequences with respect to the IRI obtained at 1 day.

Table 38. IRI values for different test sequences - U.S. 20.
Date of ProfilingApproximate Age of PavementTime of ProfilingIRI (m/km)
Left Wheel PathRight Wheel Path
5/14/031 day3 to 4 p.m.1.181.65
5/16/033 days10 to 10:30 a.m.1.241.64
5/21/038 days2 to 3 p.m.1.201.60
5/22/039 days7 to 8 a.m.1.171.62
8/13/033 months8:30 a.m.1.201.48
8/13/033 months2 p.m.1.201.50

Note: Joints were sealed after the 3-day data collection
1 m/km = 63.4 inches/mi

Figure 84. IRI values for different test sequences - U.S. 20.

Chart. IRI values for different test sequences - U.S. 20. This figure includes two sets of bar charts that show the IRI values along the left and the right wheel paths. Each set of bar charts show IRI values for the following six test sequences: 1-day PM, 3-day AM, 8-day PM, 9-day AM, 3-month AM, and 3-month PM. The IRI values obtained along the left wheel path for these six test sequences starting with the first are: 1.18, 1.24, 1.20, 1.17, 1.20, and 1.20 meters per kilometer (75, 79, 76, 74, 76, and 76 inches per mile). The IRI values obtained along the right wheel path for the six test sequences starting with the first are: 1.65, 1.64, 1.60, 1.62, 1.48, and 1.50 meters per kilometer (105, 104, 101, 103, 94, and 95 inches per mile).

Table 39. Percentage change in IRI with respect to 1-day IRI - U.S. 20.
Date of ProfilingApproximate Age of PavementTime of ProfilingPercentage Change in IRI
Left Wheel PathRight Wheel Path
5/16/033 days10 to 10:30 a.m.5-1
5/21/038 days2 to 3 p.m.2-3
5/22/039 days7 to 8 a.m.-1-2
8/13/033 months8:30 a.m.1-10
8/13/033 months2 p.m.2-9

The following observations were noted when evaluating the IRI values:

RN Values

The average RN obtained from the three repeat runs are presented in table 40 and shown in figure 85. Table 41 shows the percentage change in RN values for different test sequences with respect to RN obtained at 1 day. The following observations were noted when evaluating the RN values:

Table 40. RN values for different test sequences - U.S. 20.
Date of ProfilingApproximate Age of PavementTime of ProfilingRN
Left Wheel PathRight Wheel Path
5/14/031 day3 to 4 p.m.3.633.28
5/16/033 days10 to 10:30 a.m.3.593.27
5/21/038 days2 to 3 p.m.3.693.36
5/22/039 days7 to 8 a.m.3.723.34
8/13/033 months8:30 a.m.3.713.44
8/13/033 months2 p.m.3.743.45

Note: Joints were sealed after the 3-day data collection

Figure 85. RN values for different test sequences to U.S. 20.

Chart. RN values for different test sequences to U.S. 20. This figure includes two sets of bar charts that show the RN values along the left and the right wheel paths. Each set of bar charts show the RN values for the following six test sequences: 1-day PM, 3-day AM, 8-day PM, 9-day AM, 3-month AM, and 3-month PM. The RN values obtained along the left wheel path for the six test sequences starting with the first are: 3.63, 3.59, 3.69, 3.72, 3.71, and 3.74. The RN values obtained along the right wheel path for the six test sequences starting with the first are: 3.28, 3.27, 3.36, 3.34, 3.44, and 3.45.

Table 41. Percentage change in RN with respect to 1-day RN - U.S. 20.
Date of ProfilingApproximate Age of PavementTime of ProfilingIRI (m/km)
Left Wheel PathRight Wheel Path
5/16/033 days10 to 10:30 a.m.-10
5/21/038 days2 to 3 p.m.23
5/22/039 days7 to 8 a.m.32
8/13/033 months8:30 a.m.25
8/13/033 months2 p.m.35

Repeatability of IRI Values

On average, when all data sets were considered, the difference between the maximum and minimum IRI values obtained from the three repeat runs was 0.06 m/km (3.8 inches/mi).

The three repeat runs collected along the left wheel path for day-1 testing were used to evaluate the short interval IRI repeatability by comparing IRI values obtained at 15-m (49-ft) intervals. For the 183-m (600-ft)-long section, there are twelve 15-m (49-ft) long segments (the last 3 m (10 ft) of the section was ignored). Figure 86 shows the IRI values obtained at 15-m (49-ft) intervals for the three runs.

An evaluation of the IRI values shown in figure 86 indicates that the IRI values from the different runs were variable for many segments. The difference between the maximum and minimum IRI for each segment obtained from the three repeat runs ranged from a low of 0.02 m/km (2.5 inches/mi) that occurred at segment 6, to a high of 0.60 m/km (38 inches/mi) that occurred at segment 8. The average of the difference between maximum and minimum IRI from the three runs when all segments were considered was 0.25 m/km (16 inches/mi).

The IRI for the entire section obtained from the three repeat runs were very close to each other; the IRI values were 1.66, 1.64, and 1.66 m/km (105, 104, and 105 inches/mi). Although the IRI values for the whole section from the three repeat runs were very close to each other, the distribution of the IRI within the section was very different for the three runs. When the overall IRI for the section is computed, the variations of the IRI within the section for a run are averaged out.

Figure 86. IRI values for repeat runs - U.S. 20.

Chart. IRI values for repeat runs - U.S. 20. This figure presents a bar chart that shows IRI values that were obtained for 12 segments, each 15 meters (49 feet) long, for three repeat runs of the profiler. The three repeat runs were performed along the left wheel path during the 1-day testing. The following IRI values that are presented in ascending order of runs were obtained for each segment: segment 1: 1.82, 1.45, and 1.49 meters per kilometer (115, 92, and 94 inches per mile); segment 2: 1.75, 1.43, and 1.38 meters per kilometer (111, 91, and 87 inches per mile); segment 3: 2.03, 1.89, and 2.05 meters per kilometer (129, 120, and 130 inches per mile); segment 4: 1.91, 2.08, and 1.95 meters per kilometer (121, 132, and 124 inches per mile); segment 5: 1.50, 1.38, and 1.65 meters per kilometer (95, 87, and 105 inches per mile); segment 6: 2.30, 2.28, and 2.33 meters per kilometer (146, 145, and 148 inches per mile); segment 7: 1.42, 1.43, and 1.42 meters per kilometer (90, 91, and 90 inches per mile); segment 8: 2.19, 1.71, and 1.59 meters per kilometer (139, 108, and 101 inches per mile); segment 9: 1.15, 1.46, and 1.56 meters per kilometer (73, 93, and 99 inches per mile); segment 10: 1.45, 1.68, and 1.59 meters per kilometer (92, 107, and 101 inches per mile); segment 11: 1.28, 1.62, and 1.77 meters per kilometer (81, 103, and 112 inches per mile); and segment 12: 1.08, 1.12, and 1.17 meters per kilometer (68, 71, and 74 inches per mile).

This pavement section has longitudinal tining. When profile data are collected at this type of section, because of lateral variations in the profile path, the laser dot of the height sensor in the profiler can sometimes traverse along the top of the tining and sometimes dip into the tining and collect data at the bottom of the tining. This phenomenon can result in very different data being collected for repeat runs. The high variability in IRI values between the runs when IRI of 15-m (49-ft) segments were considered is attributed to this phenomenon.

Effect of Joint Condition on Profile Data

The joints were not sealed when the 1-day and 3-day profile data collection was performed. The joints were sealed immediately after the 3-day data collection. Profiles obtained before and after joint sealing were evaluated to investigate how the joints appear on the profile. The left wheel path data collected at 1-day and 1-month afternoon were used in this evaluation.

Figures 87 - 88 show how a typical unsealed and a sealed joint appeared in the profile data. The joint is approximately at a distance of 48 m (157 ft) in the plots. The joint reservoir is 6 mm (0.25 inch) wide. In the unsealed condition, the joint depth was 25 mm (1 inch). When the joint was sealed, the depth to the top of the sealant from the pavement surface was approximately 6 mm (0.25 inch). Although the joint is 6 mm (0.25 inch) wide, the joint appears in the profile as a feature spread over a distance of approximately 300 mm (11.8 inches). The profile plots indicated a depth at a joint of about 2 mm (0.08 inches) and 1 mm (0.04 inches) for the unsealed and sealed condition, respectively.

Figure 87. Measurements at a joint, unsealed - U.S. 20.

Chart. Measurements at a joint, unsealed - U.S. 20. This figure is a companion figure to figure 88 and contains a plot of profile data that was collected over a joint when the joint was unsealed. The X-axis shows distance, while the Y-axis shows elevation. Data collected between 47.5 and 49 meters (156 and 161 ft) are shown, and the joint is approximately at a distance of 48 meters (157 feet). In this figure, the joint appears in the profile as a feature that is spread over a distance of approximately 300 millimeters (11.8 inches). The profile plot shows the depth of the joint to be about 2 millimeters (0.08 inch) for the unsealed condition.

Figure 88. Measurements at a joint, sealed - U.S. 20.

Chart. Measurements at a joint, sealed - U.S. 20. This figure is a companion figure to figure 87 and contains a plot of profile data that was collected over a joint when the joint was sealed. The X-axis shows distance, while the Y-axis shows elevation. Data collected between 47.5 and 49 meters (156 and 161 ft) are shown, and the joint is approximately at a distance of 48 meters (157 feet). In this figure, the joint appears in the profile as a feature that is spread over a distance of approximately 300 millimeters (11.8 inches). The profile plot shows the depth of the joint to be about 1 millimeter (0.04 inch) for the sealed condition.

As described previously when discussing joint conditions for the S.R. 6220 project, averaging effects of the height sensor and the anti-alias filter applied on the profile data causes the joint depth to be attenuated as well as the joint to appear as a feature spread over a distance much wider than the actual width of the joint. There is a small difference (approximately 1 mm (0.04 inch)) in the magnitude of the depth of the dip between the unsealed and sealed conditions. However, this difference in magnitude has no effect on IRI; hence, no difference in IRI between the sealed and the unsealed conditions was observed. However, this feature does appear to have a small impact on RN; the RN value increased by 0.1 after the joints were sealed.

Roughness Profiles

The IRI roughness profiles for a 6-m (20-ft) base length for the left wheel path, right wheel path, and an overlaid plot of the two wheel paths obtained from data collected during day-1 testing is shown in figures 89 - 91. The vertical lines in the plots correspond to joint locations.

The roughness profiles show that the roughness of the right wheel path is much higher than that for the left wheel path up to a distance of 128 m (420 ft), but after that the roughness levels of the two wheel paths are close to each other. Some peaks in the roughness profiles, particularly after a distance of 128 m (420 ft) correspond to or are very close to a joint. This phenomenon may indicate a possible effect of dowel baskets on roughness level.

Figure 89. Roughness profiles for U.S. 20, left wheel path.

Chart. Roughness profiles for U.S. 20, left wheel path. This figure contains a plot that shows the roughness profile of the left wheel path. The X-axis shows the distance, while the Y-axis shows the IRI. The roughness profile from 6 to 176 meters (20 to 577 feet) also is shown. The IRI of the left wheel path roughness profile varies between 0.7 and 1.8 meters per kilometer (44 and 114 inches per mile).

1 m = 3.28 ft
1 m/km = 63.4 inches/mi

Figure 90. Roughness profiles for U.S. 20, right wheel path.

Chart. Roughness profiles for U.S. 20, right wheel path. This figure contains a plot that shows the roughness profile of the right wheel path. The X-axis shows the distance, while the Y-axis shows the IRI. The roughness profile from 6 to 176 meters (20 to 577 feet) also is shown. The IRI of the right wheel path roughness profile varies between 0.85 and 2.65 meters per kilometer (54 and 168 inches per mile)

1 m = 3.28 ft
1 m/km = 63.4 inches/mi

Figure 91. Roughness profiles for U.S. 20, left and right wheel path.

Chart. Roughness profiles for U.S. 20, left and right wheel path. This figure contains a plot that shows the roughness profile of both the left and the right wheel paths, with different line patterns used for the two wheel paths. The X-axis shows the distance, while the Y-axis shows the IRI. The roughness profile from 6 to 176 meters (20 to 577 feet) also is shown. The roughness profile shows that the right wheel path has a higher IRI than the left wheel path, up to a distance of 128 meters (420 feet). After that, the roughness profiles for the two wheel paths show better agreement with each other.

1 m = 3.28 ft
1 m/km = 63.4 inches/mi

Evaluation of Profile Data

An evaluation of the profile data indicated the presence of a repetitive wave in the right wheel path that had an approximate wavelength of 1.6 m (5.2 ft). This wave was not observed in the left wheel path profile. Figure 92 shows a band-pass filtered profile plot of the data collected along the left and the right wheel paths, with the profiles offset for clarity. The right wheel path shows more waviness, which is caused by the repetitive wave.

Figure 92. Band-pass filtered elevation profile.

Chart. Band-pass filtered elevation profile. This figure shows plots of band-pass filtered elevation profiles along the left and the right wheel paths. The X-axis of the plot shows distance, while the Y-axis shows the elevation. The two profiles are offset for clarity. The right wheel path plot shows more waviness than the left wheel path plot.

1 m = 3.28 ft
1 mm = 0.039 inch

Figure 93 shows the PSD plot of the left and right wheel path data. The right wheel path profile shows higher roughness between wavenumbers of 0.29 and 2.05 m/cycle (0.95 and 6.7 ft/cycle) compared to the left wheel path. These wavenumbers correspond to wavelengths between 0.5 and 3.5 m (11.5 ft). The cause for the high IRI of the right wheel path compared to the left wheel path is attributed to the higher roughness contribution between these wavelengths. The right wheel path PSD plots shows a peak at wavenumber of 0.65 cycles/m (2.1 cycle/ft), which corresponds to a wavelength of 1.6 m (5.2 ft). This is the dominant repetitive wavelength seen in the right wheel path profile.

The CI value was computed for one profile run from each data set. The computed values are shown in table 42. The CI values obtained for this project were somewhat higher than CI values obtained for the other projects. Some changes in CI were also noted between the data sets. The CI is influenced not only by slab curling that affects the slab over the 6-m (20-ft) slab length, but also other curvature within the slab. For example, for this pavement, the repetitive wave that has a wavelength of 1.6 m (5.2 ft) has a significant effect on CI. Evaluation of the profile data did not indicate much movement in the slabs at the joints for the different data sets. However, changes in slab shapes occurring in other areas between the different data sets contributed to changes in CI between the data sets. Generally, CI for data collected in the afternoon had higher CI values; these values were negative, which indicate downward curvature.

Figure 93. PSD plots of profiles.

Chart. PSD plots of profiles. This figure shows PSD plots of the left and right wheel path data. The X-axis of the plot shows wavenumber, while the Y-axis shows the PSD of profile slope. The plot for the right wheel path shows higher spectral content between wave numbers of 0.29 and 2.05 cycles per meter (0.088 to 0.625 cycles per foot) when compared to the left wheel path. The right wheel path PSD plot shows a peak at a wavenumber of 0.65 cycles per meter (0.2 cycles per foot).

1 m = 3.28 ft

Table 42. CI values - U.S. 20.
Date of ProfilingApproximate Age of PavementTime of ProfilingCurvature Index x 1,000 (1/m)
Left Wheel PathRight Wheel Path
5/14/031 day3 to 4 p.m.-0.33-0.20
5/16/033 days10 to 10:30 a.m.0.02-0.39
5/21/038 days2 to 3 p.m.-0.04-0.02
5/22/039 days7 to 8 a.m.0.06-0.40
8/13/033 months8:30 a.m.-0.250.11
8/13/033 months2 p.m.-0.34-0.41

1/m = 1/3.28 ft

Coefficient of Thermal Expansion and Microscopical Examination

A CTE test conducted on a 100-by-275-mm (4-by-10.8-inch) core indicated a value of 9.83 x 10-6 per oC (5.46 x 10-6 per oF.) A microscopical examination indicated that the coarse aggregate was limestone (carbonate) and the fine aggregate was silicious.

Summary

I-80 PROJECT IN IOWA

Project Description

This project was a reconstruction project and is located in Pottawattamie County, IA. This roadway is a four-lane divided highway with two lanes in each direction. A 305-m (1,000-ft)- long test section was established on the eastbound outside lane.

Pavement Details

Table 43 presents details of the pavement section. The joint details of this section are similar to those for the U.S. 20 project (see table 33).

Concrete Mix Design

Table 44 presents the mix proportions used in the concrete mix. An entrained air admixture and a water-reducing admixture were added to the concrete mix. Table 45 presents the gradation of the aggregates used in the concrete mix.

Paving Details

Table 46 presents the date and time the test section was paved and other details regarding the paving process. The concrete was placed using a slipform paver. Two photographs of the paving process are shown in figures 94 and 95.

Profiling of Section

Five sets of profile data were collected over a 1-month period. The pavement was first profiled 2 days after paving, and the second set of profiles was collected 3 days after paving. The third and fourth sets of data were collected 1 week after paving in the morning and afternoon, respectively. The fifth set of data was collected 1 month after paving in the afternoon. The profile data collection was performed using an Ames lightweight profiler.

Table 43. Pavement details - I-80.
ItemDescriptionValue
Pavement thicknessConcrete thickness300 mm (14.8 inches)
Base thickness260 mm (10.2 inches), semidrainable unbound granular base (crushed concrete)
Pavement widthTotal pavement width7.8 m (25.6 ft)
Width of inside lane3.6 m (11.8 ft)
Width of outside lane4.2 m (13.8 ft)
ShoulderShoulder type200 mm (7.8 inches) asphalt
Width of shoulderInside 1.8 m (5.9 ft), outside 2.4 m (7.9 ft)
Joint spacingJoint spacing6 m (19.7 ft)
Joints skewed?Yes, 6:1
DowelsDowel typeEpoxy coated
Dowel diameter38 mm (1.5 inches)
Dowel length457 mm (17.8 inches)
TiningTining typeLongitudinal
Tining spacing20 mm (0.8 inch)
Tining width3 mm (0.1 inch)
Tining depth3 mm (0.1 inch)
Table 44. Mix proportions - I-80.
ComponentWeight Kilograms per cubic meters (kg/m3 (lb/yd3))
Cement Type IP272 (458)
Fly ash-Council Bluffs Class C48 (81)
Coarse aggregate870 (1,466)
Intermediate/fine938 (1,581)
Table 45. Gradation of aggregates - I-80.
SievePercentage Passing
Coarse AggregateSand
37.5 mm (1.5 inches)100100
25.0 mm (1 inch)100100
19 mm (0.75 inch)94-
12.5 mm (0.5 inch)5898
9.5 mm (0.4 inch)2697
No. 44.382
No. 81.467
No. 16-53
No. 30-35
No. 50-12
No. 100-0.8
No. 2000.30
Table 46. Paving information - I-80.
ItemDescriptionComment
Date and timeDate of paving10/7/03
Time of pavingMost of the day
Paving processHaul routeAdjacent to inside lane
Stringline8-m (26-ft) spacing, both sides
DowelsFixed to base
Tie barsInserted by paver
Concrete deposit methodBelt placer
Spreader used?Yes, one
PaverGuntert & Zimmerman S850
ConcreteTemperature24 oC (75 oF)
Curing methodCuring compoundWhite pigmented Curing compound

Figure 94. Overall view of the paving train.

Photo. Overall view of the paving train. This figure shows a photograph of a spreader, which is followed by a slipform paver.

Figure 95. Slipform paver used for paving..

Photo. Slipform paver used for paving. This figure shows a photograph of the front view of the slipform paver, which is paving a PCC pavement.

Table 47 shows the dates and times when profile data collection was performed, the approximate age of the pavement at each of these instances, and the low, high, and mean air temperatures for each profiling day.

Table 47. Profile data collection - I-80.
Date of ProfilingApproximate Age of PavementTime of ProfilingAir Temperature oC (oF )
LowHighMean
10/9/032 daysMorning12 (53.6)21 (70)19 (66)
10/10/033 daysMorning12 (53.6)20 (68)13 (55)
10/14/037 daysMorning4 (29.2)18 (64.4)11 (51.8)
7 daysAfternoon.
11/5/033 monthsAfternoon14 (57)28 (82)22 (72)

The joints had been sealed except for the first 76 m (249 ft) of the test section when the 2-day testing was performed.

Roughness Indices

IRI Values

The IRI was computed for the entire 304.8-m (1,000-ft)-long test section as well as for each of the two 152.4-m (500-ft)-long sections contained within the section. The average IRI values (computed using values obtained from three runs) are shown in table 48. The IRI values for the 304.8-m (1,000-ft)-long section for the different test sequences are shown in figure 96. Table 49 shows the percentage change in IRI values for different test sequences with respect to IRI obtained from 2-day testing.

Table 48. IRI values for different test sequences - I-80.
Date of ProfilingApproximate Age of PavementTime of ProfilingRide Number
Left Wheel PathRight Wheel Path
Entire SectionFirst 152.4m (500 ft)Second 152.4 m (500 ft)Entire SectionFirst 152.4 m (500 ft)Second 152.4 m (500 ft)
9/18/032 daysMorning.1.041.090.980.880.970.79
9/20/033 daysMorning1.031.070.970.880.950.82
9/24/037 daysMorning.1.141.171.110.941.030.86
7 daysAfternoon1.121.111.120.941.000.88
10/15/031 monthAfternoon1.111.231.010.930.990.87

Note: Joints were not sealed in the first 76 m (249 ft) of the section during 2-day profiling. Joints were sealed for all other profiling days.

1 m/km = 63.4 inches/mi

Figure 96. IRI values for different test sequences for entire test section - I-80.

Chart. IRI values for different test sequences for entire test section - I-80. This figure shows two sets of bar charts that show the IRI values along the left and the right wheel path. Each set of bar charts show the IRI values for the following five test sequences: 2-day AM, 3-day AM 7-day AM, 7-day PM, and 1 month PM. The IRI values for the left wheel path for these five test sequences starting with the first are: 1.04, 1.03, 1.14, 1.12, and 1.11 meters per kilometer (66, 65, 72, 71, and 70 inches per mile). The IRI values along the right wheel path for the five test sequences starting with the first are: 0.88, 0.88, 0.94, 0.94, and 0.93 meters per kilometer (56, 56, 60, 60, and 59 inches per mile).

Table 49. Percentage change in IRI with respect to 2-day IRI - I-80.
Approximate Age of PavementTime of ProfilingPercentage Change in IRI
Left Wheel PathRight Wheel Path
Entire SectionFirst 152.4m (500 ft)Second 152.4 m (500 ft)Entire SectionFirst 152.4 m (500 ft)Second 152.4 m (500 ft)
3 daysMorning-1-1-10-23
7 daysMorning.10714769
7 daysAfternoon82147312
1 monthAfternoon71336210

The following observations were noted when evaluating the IRI values:

RN Values

RN was computed for the entire 304.8-m (1,000-ft)-long section, as well as for the two 152.4-m (500-ft)-long sections contained within it. The average RN values are tabulated in table 50. The RN values for the 304.8-m (1,000-ft)-long section for the different test dates and times are shown in figure 97. Table 51 shows the percentage change in RN for different test sequences with respect to RN obtained from 2-day testing.

Table 50. RN values for different test sequences - I-80.
Date of ProfilingApproximate Age of PavementTime of ProfilingRN
Left Wheel PathRight Wheel Path
Entire SectionFirst 152.4m (500 ft)Second 152.4 m (500 ft)Entire SectionFirst 152.4 m (500 ft)Second 152.4 m (500 ft)
9/18/032 daysMorning.3.793.703.903.943.854.04
9/20/033 daysMorning3.883.813.954.023.974.08
9/24/037 daysMorning.3.743.693.793.963.924.01
7 daysAfternoon3.783.753.823.953.943.97
10/15/031 monthAfternoon3.783.653.903.963.944.00

Note: Joints were not sealed in the first 76 m (249 ft) of the section during 2-day profiling. Joints were sealed for all other profiling days.

Figure 97. RN values for different test sequences for entire test section - I-80.

Chart. RN values for different test sequences for entire test section - I-80. This figure shows two sets of bar charts that show the RN values along the left and the right wheel path. Each set of bar charts show the RN values for the following five test sequences: 2-day AM, 3-day AM, 7-day AM, 7-day PM, and 1 month PM. The RN values for the left wheel path for the five test sequences starting with the first are: 3.79, 3.88, 3.74, 3.78, and 3.78. The RN values for the right wheel path for the five test sequences starting with the first are: 3.94, 4.02, 3.96, 3.95, and 3.96.

Table 51. Percentage change in RN with respect to 2-day RN - I-80.
Date of ProfilingApproximate Age of PavementTime of ProfilingPercentage Change in RN
Left Wheel PathRight Wheel Path
Entire SectionFirst 152.4m (500 ft)Second 152.4 m (500 ft)Entire SectionFirst 152.4 m (500 ft)Second 152.4 m (500 ft)
9/20/033 daysMorning231231
9/24/037 daysMorning.-10-312-1
7 daysAfternoon01-202-2
10/15/031 monthAfternoon0-1012-1

The following observations were noted when evaluating the RN values:

Repeatability of IRI Values

When all profile data sets were considered, the average difference between the maximum and minimum IRI values from the three repeat runs was 0.09 m/km (5.7 inches/mi) when the entire section was considered. When the two 152.4-m (500-ft) sections within the test section were considered individually, this value was 0.11 and 0.12 m/km (7.0 and 7.6 inches/mi) for the first and the second sections, respectively.

The short-interval IRI repeatability was evaluated using the data collected for 2-day testing along the right wheel path. For each run, the IRI values were computed at 15-m (49-ft) intervals to perform this evaluation. For the 304.8-m (1,000-ft)-long section, there are 20 15-m (49-ft)-long segments (the last 4.8 m (16 ft) was omitted). Figure 98 shows the IRI values that were obtained at each 15-m (49-ft)-long segment for the three runs. The IRI values for the segments obtained from the different runs showed high variability for several segments. The difference between the maximum and minimum IRI of the segments obtained from the three repeat runs ranged from a low of 0.07 m/km (4.4 inches/mi) that occurred at segment 16, to a high of 0.27 m/km (17 inches/mi) that occurred at segment 10, with an average value of 0.14 m/km (8.8 inches/mi).

Figure 98. IRI values from repeat runs - I-80.

View alternate text

As in the U.S. 20 project, the IRI for the entire section for the three repeat runs used in this analysis were very close to each other, with the IRI values being 0.91, 0.87, and 0.87 m/km (58, 55, and 55 inches/mi). However, the distribution of the IRI within the section was different for the three runs. The IRI variations tend to compensate for each other when data are averaged over the entire section, and this is the reason why the overall IRI for the three repeat runs were very close to each other, even though the IRI distribution within the section for the three runs showed variability.

This pavement has longitudinal tining similar to the U.S. 20 project. As described for the U.S. 20 project, the variability between runs for short interval IRI in this project is also attributed to the longitudinal tining.

Effect of Condition of Joint on Profile Data

The method used to form joints in this section was similar to that used for the test section in U.S. 20, where joints were formed using a soft cut saw that sawed a joint reservoir 6 mm (0.25 inch) wide and 25.4 mm (1 inch) deep. Profile data collection for this section was performed using the same profiler that collected data at the U.S. 20 test section. The effect of the condition of the joint (sealed versus unsealed) that was seen in the profile data at this test section was similar to the observations noted at the test section located on U.S. 20.

Roughness Profiles

Figures 99 - 101 show IRI roughness profiles based on a 6-m (20-ft) base length for day-3 testing for the left wheel path, right wheel path, and an overlaid plot of the two wheel paths.

Figure 99. Roughness profiles for I-80, left wheel path.

Chart. Roughness profiles for I-80, left wheel path. This figure contains a plot that shows the roughness profile along the left wheel path. The X-axis shows the distance, while the Y-axis shows the IRI. The roughness profile from 9 to 305 meters (30 to 1000 feet) also is shown. The IRI of the left wheel path roughness profile varies between 0.37 and 1.70 meters per kilometer (23 to 108 inches per mile).

1 m = 3.28 ft 1 m/km = 63.4 inches/mi

Figure 100. Roughness profiles for I-80, right wheel path.

Chart. Roughness profiles for I-80, right wheel path. This figure contains a plot that shows the roughness profile along the right wheel path. The X-axis shows the distance, while the Y-axis shows the IRI. The roughness profile from 9 to 305 meters (30 to 1000 feet) also is shown. The IRI of the right wheel path roughness profile varies between 0.35 and 1.50 meters per kilometer (22 to 95 inches per mile).

1 m = 3.28 ft 1 m/km = 63.4 inches/mi

Figure 101. Roughness profiles for I-80, left and right wheel path.

Chart. Roughness profiles for I-80, left and right wheel path. This figure contains a plot that shows the roughness profile of both the left and the right wheel paths, with different line patterns used for the two wheel paths. The X-axis shows the distance, while the Y-axis shows the IRI. The roughness profile from 9 to 305 meters (30 to 1000 feet) also is shown. This plot shows there is generally good agreement between the roughness profiles along the two wheel paths, except for some localized locations. The left wheel path shows higher IRI than the right between 63 and 94 meters (207 and 308 feet), and 179 and 197 meters (587 and 646 feet). The right wheel path shows higher IRI than the left between 39 and 51 meters (128 and 167 feet), and 234 and 252 meters (768 and 827 feet).

1 m = 3.28 ft 1 m/km = 63.4 inches/mi

The vertical lines in the plots correspond to joint locations. The left wheel path shows a higher roughness level than the right wheel path, particularly for the first 155 m (508 ft) of the section. Except for some localized areas, the 6-m (20-ft) base length IRI along the right wheel path was less than 1 m/km (63 inches/mi). Some peaks in the roughness profiles are coinciding with the joint or are very close to the joint, which may indicate a possible effect of dowel baskets on the roughness.

Evaluation of Profile Data

No differences could be observed in profile data for the different test sequences. In addition, no distinct profile feature or dominant waveband that had a significant influence on the roughness could be identified in the profile data.

The CI value was computed for one profile run from each data set, and the computed values are presented in table 52. These CI values are very small, which indicates that the pavement is essentially in a flat condition. No noticeable changes in curvature have occurred over the monitored period.

Table 52. CI values - I-80.
Date of ProfilingApproximate Age of PavementTime of ProfilingCurvature Index x 1,000 (1/m)
First 152.4m (500 ft)Second 152.4 m (500 ft)
9/18/032 daysMorning.-0.100.11
9/20/033 daysMorning-0.070.00
9/24/037 daysMorning.-0.10-0.05
7 daysAfternoon-0.17-0.04
10/15/031 monthAfternoon0.02-0.11

1/m = 1/3.28 ft

Coefficient of Thermal Expansion and Microscopical Examination

A CTE test was conducted on a 100-by-200-mm (4-by-8-inch) cylinder made from the concrete used in this project. The CTE value for the specimen was 13.2 x 10-6 per oC (7.33 x 10-6 per oF). A microscopical examination indicated that the coarse aggregate was quartzite (silicious) and the fine aggregate was silicious.

Summary

U.S. 23 PROJECT IN MICHIGAN

Project Description

This project was a reconstruction project located in Monroe County, MI. This roadway is a four-lane divided highway with two lanes in each direction. A 157-m (515-ft)-long test section was established for testing on the two southbound lanes. The test section was established between stations 739+85 and 745+00. (Stations are in U.S. customary units.)

Pavement Details

Table 53 provides pavement details. Table 54 presents information about the joints in the pavement.

Table 53. Pavement details.
ItemDescriptionValue
Pavement thicknessConcrete thickness280 mm (10.9 inches)
Base thickness100 mm (4 inches) open-graded aggregate drainage course on 100 mm (4 inches) of dense-graded aggregate base
Pavement widthTotal pavement width7.9 m (25.9 ft)
Width of inside lane3.6 m (11.8 ft)
Width of outside lane4.3 m (14.1 ft)
ShoulderShoulder typeAsphalt
Width of shoulderInside 1.2 m (3.9 ft), outside 3 m (9.8 ft)
Joint spacingJoint spacing4.6 m (15.1 ft)
Joints skewed?No
DowelsDowel typeEpoxy coated
Dowel diameter32 mm (1.25 inches)
Dowel length457 mm (17.8 inches)
TiningTining typeTransverse tining
Tining spacing12.5 mm (0.5 inch)
Tining width3 mm (0.12 inch)
Tining depth3 to 6 mm (0.12 to 0.23 inch)
Table 54. Joint details - U.S. 23.
DescriptionValue
Joint formationInitial sawcut then reservoir widened
Initial sawcut3 mm (0.12 inch) wide and 89 mm (3.5 inches) deep
Width of cut9.5 mm (0.4 inch)
Depth of cut38 mm (1.5 inches)
Sealant typeNeoprene
Depth to top of sealant6 mm ±1.5 mm (0.25 ±0.06 inch)

Concrete Mix Design

Table 55 presents the mix proportions used in the concrete mix. An air-entraining admixture and a water-reducing admixture were added to the concrete mix. Table 56 presents the gradation of the aggregates used in the concrete mix. The coarse aggregate consisted of a mix of Michigan DOT (MDOT) 4AA and 6AAA limestone aggregate.

Table 55. Mix proportions - U.S. 23.
ComponentWeight Kilograms per cubic meters (kg/m3 (lb/yd3))
Cement Type 1279 (470)
Coarse aggregate-4AA Limestone377 (635)
Coarse aggregate-6AAA Limestone688 (1,160)
Sand866 (1,460)
Table 56. Gradation of aggregates - U.S. 23.
SievePercentage Passing
Coarse AggregateSand
75 mm (3 inches)100-
37.5 mm (1.5 inches)100-
50 mm (2 inches)94-
37.5 mm (1.5 inches)80-
25.0 mm (1 inch)67-
19 mm (0.75 inch)49-
12.5 mm (0.5 inch)17-
9.5 mm (0.4 inch)8100
No. 43100
No. 8385
No. 16366
No. 30344
No. 50318
No. 10034
No. 200-1.2

Paving Details

Table 57 presents the date and time of paving of the test section as well as other details about the paving process. The paving commenced at 6:30 a.m. and stopped at 11:30 a.m. because rain was predicted later for that day. It started to rain in the afternoon.

Figure 102 shows the view of the base course ahead of the paver and shows the tie bars and dowel baskets placed on the base. Figure 103 shows a view of the paving train used in the project, which consisted of a spreader, slipform paver, and the curing/texturing unit.

Table 57. Paving information - U.S. 23.
ItemDescriptionComment
Date and timeDate of paving8/3/03
Time of paving6:30 to 11:30 a.m.
Paving processHaul routeAdjacent to inside shoulder
Stringline7.6-m (25-ft) spacing, both sides
DowelsFixed to base
Tie barsFixed to base
Concrete deposit methodBelt placers
Spreader used?Yes, one
Curing methodCuring compoundChemMasters' Safe-Cure 1000TM

Figure 102. Tie bars and dowel basket placed on base.

Photo. Tie bars and dowel basket placed on base. This photograph shows tie bars and dowel baskets that have been placed on the base before paving.

Profiling of Section

Five sets of profile data were collected at the test section in 2003 within a 10-day period. The profile data were collected using a lightweight profiler that was owned by MDOT, which was using software developed by Transology Association. Figure 104 shows a photograph of the lightweight profiler. This profiler is equipped with a laser height sensor and recorded profile data at 76-mm (3-inch) intervals.

The pavement was first profiled 1 day after paving. Initial sawcuts over joints had been completed a short time before profiling, and dry slurry from the saw-cutting operation was present adjacent to the joints. The second set of data was collected 5 days after paving. The third set of data was collected 9 days after paving in the morning. The joint reservoirs were sawed and unsealed when the profile data were collected. The contractor sealed the joints in the afternoon. The fourth and fifth sets of data were collected on the 10thday after paving in the morning and the afternoon, respectively.

Figure 103. View of the paving train.

Photo. View of the paving train. This photograph shows the paving train used in this project. The paving train consists of a spreader, a slip form paver, and the texture/curing unit.

Figure 104. Profile data collection using a lightweight inertial profiler.

Photo. Profile data collection using a lightweight inertial profiler. A photograph of a lightweight profiler that is collecting data on a new PCC pavement is shown.

Approximately 1 year after paving, profile data were collected at the test section using a Dynatest high-speed profiler. This profiler is equipped with laser height sensors and recorded profile data at 25-mm (1-inch) intervals. Figure 105 shows a photograph of the Dynatest high-speed profiler.

Figure 105. High-speed inertial profiler.

Photo. High-speed inertial profiler. A photograph of a high-speed inertial profiler is shown.

Table 58 presents the dates and times when profile data collection was performed, the approximate age of the pavement at each instance, and the low, high, and mean air temperatures for each data collection date.

Table 58. Profile data collection - U.S. 23.
Date of ProfilingApproximate Age of PavementTime of ProfilingAir Temperature oC (oF )
Inside LaneOutside Lane
Left Wheel PathRight Wheel PathLeft Wheel PathRight Wheel PathLowHighMean
8/4/032 days10:33 a.m.10:57 a.m.10:38 a.m.10:48 a.m.16 (60)27 (80)22 (71)
8/8/035 days2:39 p.m.12:25 p.m.1:03 p.m.11:49 a.m.19 (66)28 (82)23 (73)
8/12/039 days10:34 a.m.11:11 a.m.10:44 a.m.10:58 a.m.19 (66)28 (82)24 (75)
8/13/0310 days10:47 a.m.10:21 a.m.10:42 a.m.10:05:.am.18 (64)29 (84)24 (75)
3:04 a.m.3:34 p.m.2:55 p.m.4:35 pm. .
8/5/041 year6:30 p.m.6:30 p.m.6:02 p.m.6:02 p.m.13 (55)23 (73)18 (64)

Roughness Indices

IRI Values

The average IRI values (computed from the three repeat runs) are presented in table 59 and shown in figure 106. Table 60 shows the percentage change in IRI values for the different test sequences with respect to the IRI obtained at 1 day.

Table 59. IRI values for different test sequences - U.S. 23.
Date of ProfilingApproximate Age of PavementTime of ProfilingRide Number
Inside LaneOutside Lane
Left Wheel PathRight Wheel PathLeft Wheel PathRight Wheel Path
8/4/031 day10:30 a.m. to 10:50 a.m.1.110.991.070.85
8/8/035 days11:50 a.m. to 2:40 p.m.1.010.830.810.79
8/12/039 days10:35 to 11:15 a.m1.030.991.100.84
8/13/0310 days10:05 to 10:50 a.m.0.890.790.840.70
2:55 to 3:55 p.m.0.900.810.850.72
8/4/041 year6 to 6:30 p.m.0.740.740.700.73

Notes:

  1. Initial sawcut 3-mm (0.12-inch)-wide present when data were collected at 1 and 5 days.
  2. Joint reservoir had been sawed but unsealed when data were collected at 9 days.
  3. Joints were sealed when data were collected at 10 days.

1 m/km = 63.4 inches/mi

Figure 106. IRI values for different test sequences - U.S. 23.

Chart. IRI values for different test sequences - U.S. 23. This figure shows four sets of bar charts that show the IRI values along the following paths: left wheel path of inside lane, right wheel path of inside lane, left wheel path of outside lane, and right wheel path of outside lane. Each set of bar charts shows IRI values for the following six test sequences: 1-day AM, 5-day AM, 9-day AM, 10-day AM, 10-day PM, and 1-year PM. The IRI values along the left wheel path of the inside lane for the six test sequences starting with the first are: 1.11, 1.01, 1.03, 0.89, 0.90, and 0.74 meters per kilometer (70, 64, 65, 56, 57, and 47 inches per mile). The IRI values of the right wheel path of the inside lane for the six test sequences starting with the first are: 0.99, 0.83, 0.99, 0.79, 0.81, and 0.74 meters per kilometer (63, 53, 63, 50, 51, and 47 inches per mile). The IRI values of the left wheel path of the outside lane for the six test sequences starting with the first are: 1.07, 0.81, 1.10, 0.84, 0.85, and 0.70 meters per kilometer (68, 51, 70, 53, 54, and 44 inches per mile). The IRI values for he right wheel path of the outside lane for the six test sequences starting with the first are: 0.85, 0.79, 0.84, 0.70, 0.72, and 0.73 meters per kilometer (54, 50, 53, 44, 46, and 46 inches per mile).

Table 60. Percentage change in IRI with respect to 1-day IRI - U.S. 23.
Date of ProfilingApproximate Age of PavementTime of ProfilingPercentage Change in IRI
Inside LaneOutside Lane
Left Wheel PathRight Wheel PathLeft Wheel PathRight Wheel Path
8/8/035 days11:50 a.m. to 2:40 p.m.-9-16-24-7
8/12/039 days10:35 to 11:15 a.m-703-2
8/13/0310 days10:05 to 10:50 a.m.-19-20-21-18
2:55 to 3:55 p.m.-18-17-21-15
8/4/041 year6 to 6:30 p.m.-33-25-35-14

Notes:

  1. Joint reservoir had been sawed but unsealed when data were collected at 9 days.
  2. Joints were sealed when data were collected at 10 days.

The following observations were noted when evaluating the IRI values:

RN Values

The average RN values are presented in table 61 and shown in figure 107. Table 62 shows the percentage change in RN values for the different test sequences with respect to the RN obtained at 1 day.

The following observations were noted when evaluating the RN values:

Table 61. RN values for different test sequences.
Date of ProfilingApproximate Age of PavementTime of ProfilingRide Number
Inside LaneOutside Lane
Left Wheel PathRight Wheel PathLeft Wheel PathRight Wheel Path
8/4/031 day10:30 a.m. to 10:50 a.m.3.813.843.833.72
8/8/035 days11:50 a.m. to 2:40 p.m.3.863.934.063.87
8/12/039 days10:35 to 11:15 a.m3.002.862.883.10
8/13/0310 days10:05 to 10:50 a.m.3.753.703.793.87
2:55 to 3:55 p.m.3.813.693.773.84
8/4/041 year6 to 6:30 p.m.3.903.913.943.99

Notes:

  1. Initial sawcut 3 mm (0.12 inch) wide present when data were collected at 1 and 5 days.
  2. Joint reservoir had been sawed but unsealed when data were collected at 9 days.
  3. Joints were sealed when data were collected at 10 days.

Figure 107. RN values for different test sequences - U.S. 23..

Chart. RN values for different test sequences - U.S. 23. This figure shows four sets of bar charts that show the RN values along the following paths: left wheel path of inside lane, right wheel path of inside lane, left wheel path of outside lane, and right wheel path of outside lane. Each set of bar charts shows RN values for the following six test sequences: 1-day AM, 5-day PM, 9-day AM, 10-day AM, 10-day PM, and 1-year PM. The RN values for the left wheel path of the inside lane for the six test sequences starting with the first are: 3.81, 3.86, 3.00, 3.75, 3.81, and 3.90. The RN values for the right wheel path of the inside lane for the six test sequences starting with the first are: 3.84, 3.93, 2.86, 3.70, 3.69, and 3.91. The RN values for the left wheel path of the outside lane for the six test sequences starting with the first are: 3.83, 4.06, 2.88, 3.79, 3.77, and 3.94. The RN values for the right wheel path of the outside lane for the six test sequences starting with the first are: 3.72, 3.87, 3.10, 3.87, 3.84, and 3.99.

Table 62. Percentage change in RN with respect to 1-day RN-U.S. 23.
Date of ProfilingApproximate Age of PavementTime of ProfilingPercentage Change in RN with Respect to 1-Day RN (%)
Inside LaneOutside Lane
Left Wheel PathRight Wheel PathLeft Wheel PathRight Wheel Path
8/8/035 days11:50 a.m. to 2:40 p.m.1264
8/12/039 days10:35 to 11:15 a.m-21-25-25-17
8/13/0310 days10:05 to 10:50 a.m.-2-3-14
2:55 to 3:55 p.m.0-4-23
8/4/041 year6 to 6:30 p.m.2237

Notes:

  1. Initial sawcut 3 mm (0.12 inch) wide present when data were collected at 1 and 5 days.
  2. Joint reservoir had been sawed but unsealed when data were collected at 9 days.
  3. Joints were sealed when data were collected at 10 days.

Repeatability of IRI Values

When the IRI from three runs for all test sequences were evaluated, the difference between the maximum and the minimum IRI was between 0.01 to 0.11 m/km (0.6 to 7.0 inch/mi), with the average difference being 0.06 m/km (3.8 inches/mi).

An evaluation of the repeatability of short-interval IRI was performed by computing IRI at 15-m (49-ft) intervals for the three repeat runs collected along the left wheel path of the inside lane for the day-10 morning runs. For the 156-m (512-ft)-long section, there are 10 15-m (49-ft) long segments (the last 6 m (20 ft) of the section were not considered). Figure 108 shows the IRI values that were obtained at 15-m (49-ft) intervals for each run for each segment.

Figure 108. Repeatability of IRI values - U.S. 23.

Chart. Repeatability of IRI values - U.S. 23. This figure contains bar charts that show IRI values obtained for 10 segments, each 15 meters (49 feet) long, for three repeat runs of the profiler. These repeat runs were obtained along the left wheel path during the day-10 morning profiling. The following IRI values, which are presented in ascending order of runs, were obtained for each segment: segment 1: 0.81, 0.94, and 1.06 meters per kilometer (51, 60, and 67 inches per mile); segment 2: 0.82, 0.75, and 0.73 meters per kilometer (52, 48, and 46 inches per mile); segment 3: 0.92, 0.87, and 0.87 meters per kilometer (58, 55, and 55 inches per mile); segment 4: 0.93, 0.89, and 0.89 meters per kilometer (59, 56, and 56 inches per mile); segment 5: 0.59, 0.70, and 0.63 meters per kilometer (37, 44, and 40 inches per mile); segment 6: 0.82, 0.78, and 0.83 meters per kilometer (52, 49, and 53 inches per mile); segment 7: 0.64, 0.79, and 0.65 meters per kilometer (41, 50, and 41 inches per mile); segment 8: 0.80, 0.70, and 0.69 meters per kilometer (51, 44, and 44 inches per mile); segment 9: 0.74, 0.68, and 0.71 meters per kilometer (47, 43, and 45 inches per mile); and segment 10: 0.78, 0.81, and 0.83 meters per kilometer (49, 51, and 53 inches per mile).

A few sections had significant differences in IRI values between runs. The difference between the maximum and minimum IRI for each segment obtained from the three repeat runs ranged from a low of 0.04 m/km (2.5 inches/mi) that occurred at segment 4, to a high of 0.25 m/km (15.6 inches/mi) that occurred at segment 1, with an average 0.10 m/km (6.3 inches/mi). The IRI values obtained from the three runs for the entire section were 0.79, 0.80, and 0.79 m/km (50, 51, and 50 inches/mi). Significant differences in IRI were shown for repeat runs at a few 15-m (49-ft) segments. However, when IRI of the entire section from the three runs was compared, the three values were almost identical. As described previously for the other projects, this result is caused by compensating effects.

Effect of Joint Condition on Profile Data

During this study, the lightweight profiler collected profile data when the joints were in the following conditions:

The data collected under these three conditions were evaluated to investigate how the joints showed up on the profile. Data collected along the left wheel path of the outside lane were used in this investigation. Figures 109 - 111 show how a typical joint appeared on the profile for each of these conditions. The joint is located between 35 and 35.5 m (114.8 and 116.4 ft). Note the following observations for each case shown in figures 109 - 111:

Figure 109. Measurement at a joint, initial sawcut - U.S. 23.

Chart. Measurement at a joint, initial sawcut - U.S. 23. This figure contains a plot that presents profile data collected over a joint when the initial sawcut was present on the pavement. The X-axis shows distance, while the Y-axis shows elevation. Data collected between 34.5 and 36 meters (113 and 118 feet) are shown. The plot shows data collected when initial sawcut was present on the pavement. The joint location cannot be detected in this profile data plot.

1 m = 3.28 ft
1 mm = 0.039 inch

Figure 110. Measurement at a joint, joint reservoir widened - U.S. 23.

Chart. Measurement at a joint, joint reservoir widened - U.S. 23. This figure contains a plot that presents profile data collected over a joint when the joint reservoir had been sawed, but not sealed. The X-axis shows distance, while the Y-axis shows elevation. Data collected between 34.5 and 36 meters (113 and 118 feet) are shown. In this plot, the joint appears as a feature that is spread over a distance of about 450 millimeters (17.7 inches), with a depth of about 4 millimeters (0.16 inches).

1 m = 3.28 ft
1 mm = 0.039 inch

Figure 111. Measurement at a joint, joint sealed - U.S. 23.

Chart. Measurement at a joint, joint sealed - U.S. 23. This figure contains a plot that presents profile data collected over a joint after the joint had been sealed. The X-axis shows distance, while the Y-axis shows elevation. Data collected between 34.5 and 36 meters (113 and 118 feet) are shown. In this plot, the joint appears as a feature that is spread over about 450 millimeters (17.7 inches), with a depth of 1.25 millimeters (0.05 inches).

1 m = 3.28 ft
1 mm = 0.039 inch

An evaluation of IRI values shown in table 59 shows that IRI obtained after the joints were sealed was lower than that obtained when the joint reservoir was sawed but the joint not sealed. IRI decreased after the joint was sealed because the lower depth of the joint is recorded in the profile.

As described previously for the other projects, the averaging performed on the height sensor data and the anti-alias filter applied on the profile data cause the depth of the joint to be attenuated. In addition, these factors cause the joint to appear in the profile data as a feature spread over a much wider distance than the actual width of the joint. The actual width of the joint in this case is 9.5 mm (0.4 inch), but the joint appears in the profile as a dip that is spread over a distance of 450 mm (17.7 inches). The depth of the joint reservoir is 38 mm (1.5 inches) and when sealed the depth to the top of the sealant from the pavement surface according to the specification should be 6 mm (0.25 inch). The depths noted for these two cases in the profile were approximately 4 and 1.5 mm (0.16 and 0.06 inch), respectively.

The 1-year data at this section were collected using a Dynatest high-speed profiler. The locations of the joints were clearly visible in the data collected by this profiler. Figure 112 shows the data that were typically collected by this profiler at a joint. The joint is located between 3.5 and 3.6 m (11.5 and 11.8 ft).

Figure 112. Data collected over a joint by the high-speed profiler.

Chart. Data collected over a joint by the high-speed profiler. This figure shows a plot of the data collected by the high-speed profiler over a joint. The X-axis of the plot shows distance, while the Y-axis shows the elevation. Data collected between 3.3 and 3.8 meters (10.8 and 12.5 feet) are shown in the plot. The joint is located between 3.5 and 3.6 meters (11.5 and 11.8 feet). The joint appears in the plot as a feature that is 75 millimeters (3 inches) wide and about 3.75 millimeters (0.15 inch) deep.

1 m = 3.28 ft
1 mm = 0.039 inch

Roughness Profiles

The 6-m (20-ft) base length IRI roughness profiles for the day-10 morning data for the inside and outside lanes are shown in figures 113 - 118, respectively. In each roughness profile, the vertical lines correspond to a joint location.

As seen in figures 113 - 115, several localized rough spots were along both wheel paths of the inside lane. The roughness at these localized locations was not excessive, except in the left wheel path of the inside lane, where there was a noticeable rough spot at about 35 m (115 ft). Figures 116 - 118 shows that in the outside lane, the first 16 m (49 ft) of the left wheel path has a higher roughness compared to the rest of the left wheel path and the right wheel path. In the outside lane apart from the first 16 m (49 ft) of the left wheel path, the left and right wheel paths show a close roughness distribution along the section.

Evaluation of Profile Data

An evaluation of profile data collected at different time sequences indicated that the profiles obtained at day 1 were different from the other profiles because they showed a small hump around each joint. Figure 119 shows how the humps appeared in the profile. The profile data collection at day 1 was performed immediately after the joints were sawed, and residue from the sawing operation was present adjacent to the joint. Figure 120 shows a photograph of the pavement that was obtained at the time profiling was performed at day 1. The humps seen in the profile appear to have been caused by the residue from the sawing operation. These humps were not noticeable for data collected after day-1 profiling because the residue would have been washed from the rain experienced after profiling. The decrease in IRI after day-1 profiling is attributed to elimination of these humps from the profile.

Figure 113. Roughness profiles for inside lane, left wheel path - U.S. 23.

Chart. Roughness profiles for inside lane, left wheel path - U.S. 23. This figure contains a plot that shows the roughness profile of the inside lane along the left wheel path. The X-axis shows the distance, while the Y-axis shows the IRI. The roughness profile from 3 to 152 meters (10 to 500 feet) is shown. The IRI of the left wheel path roughness profile varies between 0.46 and 1.51 meters per kilometer (21 and 96 inches per mile).

1 m = 3.28 ft 1 m/km = 63.4 inches/mi

Figure 114. Roughness profiles for inside lane, right wheel path - U.S. 23.

Chart. Roughness profiles for inside lane, right wheel path - U.S. 23. This figure contains a plot that shows the roughness profile of the inside lane along the right wheel path. The X-axis shows the distance, while the Y-axis shows the IRI. The roughness profile from 3 to 152 meters (10 to 500 feet) is shown. The IRI of the right wheel path roughness profile varies between 0.46 and 1.34 meters per kilometer (29 and 85 inches per mile).

1 m = 3.28 ft 1 m/km = 63.4 inches/mi

Figure 115. Roughness profiles for inside lane, left and right wheel path - U.S. 23..

Chart. Roughness profiles for inside lane, left and right wheel path - U.S. 23. This figure contains a plot that shows the roughness profiles of both the left and the right wheel path of the inside lane, with different line patterns used for the two wheel paths. The X-axis shows the distance, while the Y-axis shows the IRI. The roughness profile from 3 to 152 meters (10 to 500 feet) is shown. The plot that contains roughness profiles for both the left and the right wheel path shows the left wheel path has a higher IRI than the right for most of the section.

1 m = 3.28 ft 1 m/km = 63.4 inches/mi

Figure 116. Roughness profiles for outside lane, left wheel path - U.S. 23.

Chart. Roughness profiles for outside lane, left wheel path - U.S. 23. This figure contains a plot that shows the roughness profile of the outside lane along the left wheel path. The X-axis shows the distance, while the Y-axis shows the IRI. The roughness profile from 3 to 152 meters (10 to 500 feet) is shown. The IRI of the left wheel path roughness profile varies between 0.43 and 1.20 meters per kilometer (27 and 76 inches per mile), except from 3 to 16 meters (10 to 52 feet). Within these limits, the IRI has a peak value of 1.90 meters per kilometer (120 inches per mile).

1 m = 3.28 ft 1 m/km = 63.4 inches/mi

Figure 117. Roughness profiles for outside lane, right wheel path - U.S. 23.

Chart. Roughness profiles for outside lane, right wheel path - U.S. 23. This figure contains a plot that shows the roughness profile of the outside lane along the right wheel path. The X-axis shows the distance, while the Y-axis shows the IRI. The roughness profile from 3 to 152 meters (10 to 500 feet) is shown. The IRI of the right wheel path roughness profile varies between 0.43 and 1.01 meters per kilometer (27 and 64 inches per mile)

1 m = 3.28 ft 1 m/km = 63.4 inches/mi

Figure 118. Roughness profiles for outside lane, left and right wheel path - U.S. 23.

Chart. Roughness profiles for outside lane, left and right wheel path - U.S. 23. This figure contains a plot that shows the roughness profiles of both the left and the right wheel path of the outside lane, with different line patterns used for the two wheel paths. The X-axis shows the distance, while the Y-axis shows the IRI. The roughness profile from 3 to 152 meters (10 to 500 feet) is shown. This plot shows there is a major difference in the roughness profiles between 3 and 16 meters (10 and 52 feet). Within these limits, the left wheel path has significantly higher IRI than the right. For the rest of the section, the two roughness profiles show a similar patter, although differences in IRI are noted between the two wheel paths at localized locations

1 m = 3.28 ft 1 m/km = 63.4 inches/mi

Figure 119. Humps in profile for 1-day profile data.

Chart. Humps in profile for 1-day profile data. This figure shows a plot of the profile data obtained from the 1-day profiling. The X-axis of the plot shows distance, while the Y-axis shows elevation. Profile data between 85 and 113 meters (279 and 371 feet) are shown in the plot. The plots show slight humps appearing in the profile at 4.6-meter (15-foot) intervals.

1 m = 3.28 ft 1 m/km = 63.4 inches/mi

Figure 120. Residue from joint sawing operation adjacent to a joint.

Photo. Residue from joint sawing operation adjacent to a joint. A photograph of the area adjacent to a transverse joint in a PCC slab is shown. The area adjacent to the transverse joint contains residue from the joint sawing operation.

IRI obtained from 1-year profiling (data collected by high-speed profiler) was lower than IRI obtained from day-10 profiling (data collected by lightweight profiler). There were some differences in these two profile data sets, but no distinct profile feature that caused the differences in IRI to occur could be identified. Analysis of the data collected over the joints indicated these two profilers have different averaging and/or low-pass filtering methods. It is not clear whether the reduction in IRI was related to changes in the pavement profile or to differences between the profiling equipment.

CI was computed for one profile run from each data set, and the computed values are shown in table 63. These CI values are very small indicating the pavement is essentially in a flat condition. No noticeable changes in curvature have occurred over the monitored period.

Table 63. CI values - U.S. 23.
Date of ProfilingApproximate Age of PavementTime of ProfilingPercentage Change in RN with Respect to 1-Day RN (%)
Inside LaneOutside Lane
Right Wheel PathLeft Wheel PathRight Wheel Path
8/4/031 day10:30 .to 10:50 a.m.0.070.130.07
8/8/035 days11:50 a.m. to 2:40 p.m.0.00-0..070.01
8/12/039 days10:35 to 11:15 a.m0.12-0.16-0.17
8/13/0310 days10:05 to 10:50 a.m.-0.02-0.16-0.10
2:55 to 3:55 p.m.-0.08-0.16-0.11
8/4/041 year6 to 6:30 p.m.-0.01-0.260.18

1/m = 1/3.28 ft

Coefficient of Thermal Expansion and Microscopical Examination

The core obtained from this pavement was lost in the mail when it was shipped to the laboratory to perform the CTE test. Hence, a CTE value is not available for the concrete used in this project.

Summary

I-69 PROJECT IN MICHIGAN

Project Description

This project was a reconstruction project located in Calhoun County, MI. This roadway is a four-lane divided highway with two lanes in each direction. A 148-m (485-ft)-long test section was established for testing on the inside lane in the southbound direction. The test section was established between stations 1450+84 and 1445+97. (Stations are in U.S. customary units.)

Pavement Details

Table 64 presents details regarding the pavement. The joint details in this project were similar to those used in the U.S. 23 project (see table 54).

Table 64. Pavement details - I-69.
ItemDescriptionValue
Pavement thicknessConcrete thickness280 mm (10.9 inches)
Pavement widthTotal pavement width7.9 m (25.9 ft)
Width of inside lane3.6 m (11.8 ft)
Width of outside lane4.3 m (14.1 ft)
ShoulderShoulder typeAsphalt
Joint spacingJoint spacing4.6 m (15.1 ft)
Joints skewed?No
DowelsDowel typeEpoxy coated
Dowel diameter32 mm (1.25 inches)
Dowel length457 mm (17.8 inches)
TiningTining typeTransverse tining
Tining spacing12.5 mm (0.5 inch)
Tining width3 mm (0.12 inch)
Tining depth3 to 6 mm (0.12 to 0.23 inch)

Concrete Mix Design

Table 65 presents the mix proportions that were used in the concrete mix. Table 66 presents the gradation of the aggregates used in the concrete mix.

Table 65. Mix proportions - I-69.
ComponentWeight Kilograms per cubic meters (kg/m3 (lb/yd3))
Cement237 (400)
Fly ash42 (71)
Coarse aggregate1071 (1,805)
Sand838 (1,412)
Table 66. Aggregate gradation - I-69.
SievePercentage Passing
Coarse AggregateSand
62.5 mm (2.4 inches)100100
50 mm (2 inches)97.7100
37.5 mm (1.5 inches)77.5100
25.0 mm (1 inch)62.3100
19 mm (0.75 inch)52.6100
12.5 mm (0.5 inch)28.3100
9.5 mm (0.4 inch)16.4100
No. 42.899.4
No. 81.389.2
No. 16167.8
No. 30139.5

Paving Details

Table 67 presents the date and time the test sections were paved and other details about the paving process. The paving for that day began at 6 a.m. and stopped at noon because rain was predicted later for that day. It started to rain in the afternoon. The test section was observed to have had less than ideal (probably less than specified) tining depth, which was probably the result of the rain that occurred in the afternoon. Figure 121 shows a photograph of the front view of the paver and figure 122 shows a photograph of the finishing process behind the paver.

Table 67. Paving information.
ItemDescriptionComment
Date and timeDate of paving7/8/03
Time of paving6 a.m. to noon
Paving processHaul routeAdjacent to inside shoulder
Stringline7.6-m (25-ft) spacing, both sides
DowelsInserted by paver
Tie barsInserted by paver
Concrete deposit methodDeposited by trucks in front of paver
Spreader used?No
Curing methodCuring compoundWhite curing compound

Figure 121. View from the front of the paver.

Photo. View from the front of the paver. This photograph shows a front view of the slipform paver that is paving a PCC pavement

Profiling of Section

Four sets of profile data were collected within a 10-day period with a lightweight profiler that is owned by MDOT. This profiler uses software provided by Transology Association. The data recording interval in the profiler is 76 mm (3 inches). The pavement was first profiled 1 day after paving. Initial sawcuts over joints had just been completed before the runs were made. Wet slurry from the saw-cutting operation was present on the pavement adjacent to the joints when

the pavement was profiled. The second set of profiles was collected 6 days after paving. The third and fourth sets of data were collected on the 10th day; separate data sets were collected in the morning and in the afternoon. After the morning runs were made, and before performing the afternoon runs, the contractor widened the initial sawcut to create the reservoir for placing the joint sealant. Day-10 afternoon profiles were obtained when the joints were in this condition.

Figure 122. Finishing process behind the paver..

Photo. Finishing process behind the paver. This photograph shows finishing operations being performed on the PCC pavement with straightedges after the pavement was placed by the slipform paver.

About 4.5 months after paving, this section was profiled again with the high-speed profiler owned by MDOT. Table 68 presents the dates and times when data collection was performed, the approximate age of the pavement at each of these instances, and the low, high, and mean air temperature for each data collection date.

Table 68. Profile data collection - I-69.
Date of ProfilingApproximate Age of PavementTime of ProfilingAir Temperature oC (oF )
Left Wheel PathRight Wheel PathLowHighMean
7/9/031 day11:41 a.m.11:53 a.m.17 (62)26 (78)16 (60)
7/14/06 days11:27 a.m.11:53 a.m.12 (53)28 (82)21 (69)
7/18/0310 days9:18 a.m.9:34 a.m.13 (55)26 (78)19 (66)
3:54 p.m.3:47 p.m.
11/26/034.5 months12:10 p.m.12:10 p.m.-2 (28)8 (46)3 (37)

Roughness Indices

IRI Values

The average IRI values (computed by averaging data obtained from repeat runs) are tabulated in table 69 and shown in figure 123. Table 70 shows the percentage change in IRI values for the different test sequences with respect to the IRI obtained at 1 day.

Table 69. IRI values for different test sequences - I-69.
Date of ProfilingApproximate Age of PavementTime of ProfilingIRI (m/km)
Left Wheel PathRight Wheel Path
7/9/031 day11:40 to 11:55 a.m.1.151.17
7/14/036 days11:25 to 11:55 a.m.1.051.12
7/18/0310 days9:15 to 9:35 a.m.1.091.04
10 days3:45 to 3:55 p.m.1.291.48
7/9/034.5 months12:10 p.m.1.251.43

Notes:

  1. Initial sawcut 3 mm (0.12 inch) wide present when data were collected at 1-day, 6-day, and 10-day morning.
  2. Joint reservoir was formed and joint not sealed when data were collected on the afternoon of day 10.

Figure 123. IRI values for different test sequences - I-69.

Chart. IRI values for different test sequences - I-69. This figure shows two sets of bar charts that show the IRI values along the left and the right wheel paths for five test sequences. Each set of bar charts show the IRI values for the following five test sequences: 1-day AM, 5-day AM, 10-day AM, 10-day PM, and 4.5 months. PM The IRI values for the left wheel path for the five test sequences starting with the first are: 1.15, 1.05, 1.09, 1.29, and 1.25 meters per kilometer (73, 67, 69, 82, and 79 inches per mile). The IRI values for the right wheel path for the five test sequences starting with the first are: 1.17, 1.12, 1.04, 1.48, and 1.43 meters per kilometer (74, 71, 66, 94, and 91 inches per mile).

Table 70. Percentage change in IRI with respect to 1-day IRI - I-69.
Date of ProfilingApproximate Age of PavementTime of ProfilingPercentage Change in IRI
Left Wheel PathRight Wheel Path
7/14/036 days11:25 to 11:55 a.m.22
7/18/0310 days9:15 to 9:35 a.m.47
10 days3:45 to 3:55 p.m.-21-30
7/9/034.5 months12:10 p.m.-4-6

Notes:

  1. Initial sawcut 3 mm (0.12 inch) wide present when data were collected at 6-day and 10-day morning.
  2. Joint reservoir was formed and joint not sealed when data were collected on the afternoon of day 10.
  3. Joints sealed during 4.5-month data collection.

The following observations were noted when evaluating the IRI values:

RN Values

The average RN values (computed by averaging values of the three repeat runs) are presented in table 71 and shown in figure 124. Table 72 shows the percentage change in RN values for the different test sequences with respect to the RN obtained at 1 day.

Table 71. RN values for different test sequences.
Date of ProfilingApproximate Age of PavementTime of ProfilingRide Number
Left Wheel PathRight Wheel Path
7/9/031 day11:40 to 11:55 a.m.3.663.66
7/14/036 days11:25 to 11:55 a.m.3.733.74
7/18/0310 days9:15 to 9:35 a.m.3.813.91
10 days3:45 to 3:55 p.m.2.872.58
7/9/034.5 months12:10 p.m.3.503.45

Notes:

  1. Initial sawcut 3 mm (0.12 inch) wide present when data were collected at 1-day, 6-day, and 10-day morning.
  2. Joint reservoir formed when data were collected on afternoon of day 10.
  3. Joints sealed during 4.5-month data collection.

Figure 124. RN values for different test sequences - I-69.

Chart. RN values for different test sequences - I-69. This figure shows two sets of bar charts that show the RN values along the left and the right wheel paths for five test sequences. Each bar chart shows RN values for the following five test sequences: 1-day AM, 5-day AM, 10-day AM, 10-day PM, and 4.5 months PM. The RN values of the left wheel path for the five test sequences starting with the first are: 3.66, 3.73, 3.81, 2.87, and 3.50. The RN values of the right wheel path for the five test sequences starting with the first are: 3.66, 3.74, 3.91, 2.58, and 3.45.

Table 72. Percentage change in RN with respect to 1-day RN - I-69.
Date of ProfilingApproximate Age of PavementTime of ProfilingPercentage Change in RN
Left Wheel PathRight Wheel Path
7/14/036 days11:25 to 11:55 a.m.-8-4
7/18/0310 days9:15 to 9:35 a.m.-5-11
10 days3:45 to 3:55 p.m.1327
7/9/034.5 months12:10 p.m.922

Notes:

  1. Initial sawcut 3 mm (0.12 inch) wide present when data were collected at 1-day, 6-day, and 10-day morning.
  2. Joint reservoir was formed and joint not sealed when data were collected on the afternoon of day 10.
  3. Joints sealed during 4.5-month data collection.

The following observations were noted when evaluating the RN values:

Repeatability of IRI Values

When the IRI values obtained for the entire section from all profile sequences for the lightweight profiler were compared, the difference between the maximum and minimum IRI for the three runs ranged between 0.01 to 0.10 m/km (6.3 inches/mi), with the average difference of 0.04 m/km (2.5 inches/mi).

An evaluation of the short-interval IRI repeatability of the lightweight profiler was performed by computing IRI values at 15-m (49-ft) intervals for day-9 morning right wheel path data. For the 148-m (485-ft)-long test section, there are nine 15-m (49-ft)-long segments. Figure 125 shows the IRI values that were obtained at 15-m (49-ft) intervals for each run for each segment. Overall, the repeatability appeared to be satisfactory for most segments, but a few segments had significant differences in IRI values between runs. The difference between the maximum and minimum IRI for each segment obtained form the three repeat runs ranged from a low of 0.06 m/km (3.8 inches/mi) at segment 3, to a high of 0.24 m/km (15.2 inches/mi) at segment 1. The average of the difference between maximum and minimum IRI from the three runs for the segments was 0.11 m/km (7 inches/mi). The IRI values obtained from the three runs for the entire section were 1.04, 1.03, and 1.06 m/km (66, 65, and 67 inches/mi). Although there were differences in individual 15-m (49-ft) segments between runs, when the overall IRI of the entire section from the three runs were compared, the three values were almost identical. As described previously for the other projects, this closeness occurs because of compensating effects of IRI over the section.

Figure 125. Repeatability of IRI values - I-69.

Chart. Repeatability of IRI values - I-69. This figure contains bar charts that show the IRI values obtained for nine segments, each 15 meters (49 feet) long, for three repeat runs of the profiler. These repeat runs were obtained along the right wheel path during the day-9 morning profiling. The following IRI values, which are presented in ascending order of runs, were obtained for each segment: segment 1: 1.09, 1.33, and 1.30 meters per kilometer (69, 84, and 82 inches per mile); segment 2: 1.08, 0.96, and 1.09 meters per kilometer (68, 61, and 69 inches per mile); segment 3: 0.97, 0.91, and 0.93 meters per kilometer (61, 58, and 59 inches per mile); segment 4: 1.03, 1.01, and 0.95 meters per kilometer (65, 64, and 60 inches per mile); segment 5: 0.96, 0.99, and 0.90 meters per kilometer (61, 63, and 57 inches per mile); segment 6: 0.82, 0.88, and 0.82 meters per kilometer (52, 56, and 52 inches per mile); segment 7: 1.22, 1.19, and 1.27 meters per kilometer (77, 75, and 81 inches per mile); segment 8: 1.29, 1.27, and 1.45 meters per kilometer (82, 81, and 92 inches per mile); and segment 9: 0.95, 0.90, and 1.01 meters per kilometer (60, 57, and 64 inches per mile).

Effect of Joint Condition on Profile

The method used to form joints in this section was similar to that used for the test section on U.S. 23. Profile data collection for this section was performed using the same profiler that collected data at the U.S. 23 test section. The effect of joints seen in the profile data at this test section was similar to the observations noted at the test section located on U.S. 23.

Roughness Profiles

Figures 126 - 128 show the 6-m (20-ft) base length roughness profile for the section. The vertical lines in the plots correspond to joint locations. These roughness profiles are for data that were collected at 9 days after paving in the morning. The IRI values of the entire section for the two wheel paths for that test date were extremely close to each other: IRI of the left and the right wheel paths were 1.09 and 1.04 m/km (67 and 66 inches/mi), respectively. Although the overall roughness values for the two wheel paths are close to each other, the roughness profiles shown in figures 126 - 128 show that the variability of roughness within the section is greater for the left wheel path. Along the left wheel path, the roughness profile exceeded 1.5 m/km (95 inches/mi) at five locations compared to one location for the right wheel path.

Evaluation of Profile Data

Five profile data sets were obtained at this test section. The first four data sets were obtained with a lightweight profiler; the last data set was obtained with a high-speed profiler. There were significant differences in the spatial distribution of roughness within the section obtained by the two profilers. Hence, it is unclear whether the differences in IRI noted between the 4.5-month profiling and 1-day profiling were caused by a difference in the pavement profile, or whether they were related to differences between the two profilers' data collection capabilities. As was indicated previously, when profile data collection was performed with the high-speed profiler, a median barrier was present between the lanes. Hence, the high-speed profiler may not have been able to follow the exact path that was profiled by the lightweight profiler. This is another factor that could have contributed to differences in IRI obtained by the high-speed profiler and the lightweight profiler.

An evaluation of the profile data did not indicate a distinct profile feature or a waveband that had a dominant contribution to IRI.

CI was computed for one profile run from each data set, and the computed values are presented in table 73. All CI values are small, which indicates that the PCC slabs are essentially in a flat condition with negligible curvature. No noticeable changes in curvature were noted between the different data sets.

Figure 126. Roughness profiles for I-69, left wheel path.

Chart. Roughness profiles for I-69, left wheel path. This figure contains a plot that shows the roughness profile along the left wheel path. The X-axis shows the distance, while the Y-axis shows the IRI. The roughness profile from 7 to 146 meters (23 to 479 feet) is shown. The IRI of the left wheel path roughness profile varies between 0.42 and 1.90 meters per kilometer (27 to 120 inches per mile).

1 m = 3.28 ft 1 m/km = 63.4 inches/mi

Figure 127. Roughness profiles for I-69, right wheel path.

Chart. Roughness profiles for I-69, right wheel path. This figure contains a plot that shows the roughness profile along the right wheel path. The X-axis shows the distance, while the Y-axis shows the IRI. The roughness profile from 7 to 146 meters (23 to 479 feet) is shown. The IRI of the right wheel path roughness profile varies between 0.52 and 1.68 meters per kilometer (33 to 107 inches per mile).

1 m = 3.28 ft 1 m/km = 63.4 inches/mi

Figure 128. Roughness profiles for I-69, left and right wheel path.

Chart. Roughness profiles for I-69, left and right wheel path. This figure contains a plot that shows the roughness profiles of both the left and the right wheel paths, with different line patterns used for the two wheel paths. The X-axis shows the distance, while the Y-axis shows the IRI. The roughness profile from 7 to 146 meters (23 to 479 feet) is shown. The plot shows differences between the roughness profiles of the left and right wheel paths along the section. The difference in IRI between the two roughness profiles varies from 0.02 to 0.82 meters per kilometer (1 to 52 inches per mile).

1 m = 3.28 ft 1 m/km = 63.4 inches/mi

Table 73. CI values-I-69.
Date of ProfilingApproximate Age of PavementTime of ProfilingCurvature Index x 1,000 (1/m)
Left Wheel PathRight Wheel Path
7/9/031 day11:40 to 11:55 a.m.0.0490.184
7/14/036 days11:25 to 11:55 a.m.0.1870.194
7/18/0310 days9:15 to 9:35 a.m.0.0820.062
10 days3:45 to 3:55 p.m.0.0950.125
7/9/034.5 months12:10 p.m.0.0000.127

Coefficient of Thermal Expansion and Microscopical Examination

A CTE test was conducted on a 150-by-300-mm (5.9-by-11.8-inch) core from the pavement. The CTE value for the specimen was 8.25 x 10-6 per oC (4.58 x 10-6 per oF). A microscopical examination of the core indicated that the coarse aggregate was dolomite/dolomitic limestone (carbonate) and the fine aggregate was silicious.

Summary

 


The Federal Highway Administration (FHWA) is a part of the U.S. Department of Transportation and is headquartered in Washington, D.C., with field offices across the United States. is a major agency of the U.S. Department of Transportation (DOT).
The Federal Highway Administration (FHWA) is a part of the U.S. Department of Transportation and is headquartered in Washington, D.C., with field offices across the United States. is a major agency of the U.S. Department of Transportation (DOT). Provide leadership and technology for the delivery of long life pavements that meet our customers needs and are safe, cost effective, and can be effectively maintained. Federal Highway Administration's (FHWA) R&T Web site portal, which provides access to or information about the Agency’s R&T program, projects, partnerships, publications, and results.
FHWA
United States Department of Transportation - Federal Highway Administration