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Publication Number: FHWA-HRT-01-167
Date: April 2005

Structural Factors of Jointed Plain Concrete Pavements: SPS-2—Initial Evaluation and Analysis

Chapter 5. SPS-2 Project Status Summaries

This chapter summarizes key site information, pavement design factors, and monitoring data availability for each of the SPS-2 projects. For each SPS-2 project, the following are presented:

  • General description of the pavement construction site and equipment installed.
  • Key observations and deviations.
  • Summary table of the key information and monitoring data availability.
  • Project status summary.

The SPS-2 projects are presented in the following alphabetical order:

  • Arizona (State code: 04).
  • Arkansas (05).
  • Colorado (08).
  • Delaware (10).
  • Iowa (19).
  • Kansas (20).
  • Michigan (26).
  • Nevada (32).
  • North Carolina (37).
  • North Dakota (38).
  • Ohio (39).
  • Washington (53).
  • Wisconsin (55).

Arizona SPS-2

The Arizona SPS-2 project site is located in the eastbound lanes of Interstate 10 (I-10) in southwestern Arizona, approximately 56 km west of Phoenix. I-10 is a rural interstate; in 1992 the AADT was 15,900. The initial annual ESALs was estimated at 1,052,626. The SPS-2 project was constructed as part of the rehabilitation of I-10. The typical pavement design consists of two 3.66-m-wide lanes, an outside shoulder width of 3.05 m, and an inside shoulder width of 1.22 m. The SPS-2 test sections were constructed on a portion of I-10 that is relatively straight and flat.

Bending plate WIM equipment was installed in the fall of 1993. Calibration was completed on January 24, 1994.

Construction of the SPS-2 site started in June 1993 with the removal of the existing pavement. Construction of individual test sections was completed and the area was opened to traffic on October 1, 1993.

All required core sections were constructed. Nine supplemental State test sections were constructed. Table 39 summarizes key project information and data available for all the sections.

Project level information and data availability Construction date: 10/01/1993

Table 39. Arizona SPS-2 project summary.
Climate - DNF Data Availability Average Values As planned?
CLM: 17 years

AWS: 6 years
FI: 0°C days, Precip. 232 mm

FI: 0°C days, Precip. 199mm
Yes
Traffic WIM: 6 years 1,052,625 ESALs/year (>200,00) Yes
Subgrade type Coarse-grained soil for all. As designed? Yes
Flexural strength
14-day MPa
Design value Actual Averages Within 10%?
3.8
6.2
3.94
5.77
Yes
Yes
PCC tests available On average 99% completed for core sections

Section level key design factors and monitoring data availability

Key pavement design factors Monitoring data availability, No. of tests
ID Slab Thick. mm Base type With Drain Lane Width m As Design ? IRI FWD Distress Meet Min. Req'd?
  Actual Design Manual Photo. Faulting
0213 201 203 AGG No   Yes 4 6 3 1 3 No
0214 211   AGG No   Yes 5 7 3 1 3 No
0215* 287 279 AGG No   Yes 12 28 12 1 12 No
0216 284   AGG No   Yes 5 6 2 1 2 No
0217 206 203 LCB No   Yes 5 6 2 1 2 No
0218 211   LCB No   Yes 5 6 2 1 2 No
0219 274 279 LCB No   Yes 5 7 2 1 2 No
0220 287   LCB No   Yes 5 6 3 1 3 No
0221 208 203 PATB Yes   Yes 5 6 3 1 3 No
0222 218   PATB Yes   Yes 5 6 3 1 3 No
0223 282 279 PATB Yes   Yes 5 5 3 1 3 No
0224 272   PATB Yes   Yes 5 6 3 1 3 No
Overall- Good, except for 0222 Overall- Fair, late initial surveys.
Supplemental Sections - Total 9 sections, 7 PCC and 2 AC
0260 216 mm AC on 102 mm DGAB 5 3 0 1 NA
0261 216 mm AC on 102 mm DGAB 5 5 0 1 NA
0262 203 mm undoweled JPC (3.8 MPa) on DGAB, 4.27 m 5 4 3 1 3
0263 203 mm undoweled JPC (3.8 MPa) on DGAB, 4.27 m 5 1 3 1 3
0264 279 mm undoweled JPC (3.8 MPa) on DGAB, 3.66 m 5 2 3 1 3
0265 279 mm undoweled JPC (3.8 MPa) on DGAB, 3.66 m lane 5 3 3 1 3
0266 318 mm doweled JPC (3.8 MPa) on BTB, 4.27 m lane 5 1 3 1 3
0267 279 mm doweled JPC (3.8 MPa) on BTB, 4.27 m lane 5 1 3 1 3
0268 203 mm doweled JPC (3.8 MPa) on BTB, 4.27 m lane 5 1 3 1 3
  Overall - Good, except for 0260, 0261.

Note: * Indicates seasonal monitoring section(s)
Min. Req'd - Initial survey age less than 1 year and all long-term monitoring intervals less than 3 years for all monitoring types
Bolded and italic letters represent constructed values that are either not as designed or outside the design range. For slab thickness, the design range is set at (design value +/- 12.7 mm)

Key Observations and Deviations

The following key observations were noted in the project construction report:

  • American Association of State Highway and Transportation Officials (AASHTO) No. 57 coarse aggregate was utilized as the backfill material in the pavement base drain.
  • A tapered transition of the PATB into the DGAB could not be achieved. This resulted in the PATB being placed against the DGAB at the end of section 040263.
  • The class B geotextile supplied was not large enough to be wrapped around the PATB edge as per SHRP specifications. This unwrapped area could facilitate soil intrusion from the adjacent DGAB.
  • Transverse drains were installed perpendicular to the roadway centerline instead of in a herringbone fashion.
  • A 0.9-m-wide roll of filter fabric was placed with a 0.305-m-wide section under the median edge of the PATB. The remaining width was wrapped around the median edge of the PATB to prevent soil infiltration.
  • Transverse cracking occurred in the LCB of sections 040217 through 040220 prior to placement of the PCC slab.
  • Longitudinal joint tie bars were uncoated and were only 508 mm in length. SHRP specifications require epoxy-coated rebar at 762 mm in length. However, this is a dry no-freeze area.
  • Paving was intermittently stopped in several of the test sections due to concrete unavailability, mix adjustments, and equipment failure.
  • PCC segregation and/or slump variations occurred in several of the sections.
  • The concrete temperature throughout construction generally ranged from 28 °C to 31 °C.

Project Status Summary

Overall, this project site is in excellent shape. The appendices to this report also contain a significant amount of monitoring data. The following summarizes the status of this project:

  • Designed versus constructed-Most key sections of this project were built adequately for the key experimental design variables. One exception is section 040222, which has excessively high slab thickness compared to the design value.
  • Construction difficulties and deviations-Only relatively minor construction problems were noted in the construction report.

Data availability-Excellent overall.

  • Site condition data-Very good.
  • Key PCC materials testing data availability for core sections-Excellent, with 99 percent completed.
  • Monitoring data availability-Excellent for all key monitoring data types for the core sections.

The Arizona SPS-2 site does not appear to exhibit significant problems that will cause difficulty in performance analysis.

Arkansas SPS-2

The Arkansas SPS-2 project site is located in the westbound lanes of I-30 in west central Arkansas, just to the west of the I-70/I-30 interchange. I-30 is classified as a rural interstate; in 1993 the AADT was 18,000, with 45 percent heavy trucks. The estimated initial annual ESALs is 2,069,550. The SPS-2 project was included in the reconstruction of I-30. Of the 12 test sections required for the SPS-2 project, 3 were located in original construction fill areas, 6 were located in original construction cut areas, and 3 sections were at grade. The typical roadway for this project consists of two 3.66-m-wide lanes, an outside asphalt shoulder width of 3.05 m, and an inside shoulder width of 1.22 m.

Construction of the SPS-2 site began in November 1993 with the removal of the existing pavement. Construction of individual test sections was completed on October 1, 1995, and the project site was opened to traffic on November 1, 1995.

All required core sections were constructed, and no supplemental State test sections were constructed at this site. Table 40 summarizes key project information and data available for all the sections.

Project level information and data availability Construction date: 10/01/1995

Table 40. Arkansas SPS-2 project summary.
Climate - DNF Data Availability Average Values As planned?
CLM: 17 years

AWS: 0 year
FI: 0°C days, Precip. 232 mm

NA
Yes
Traffic WIM: NA NA -
Subgrade type Fine-grained soil for all. As designed? Varies
Flexural strength
14-day MPa
Design value Actual Averages Within 10%?
3.8
6.2
3.94
5.77
Yes
No
PCC tests available On average 99% completed for core sections

Section level key design factors and monitoring data availability

Key pavement design factors Monitoring data availability, No. of tests
ID Slab Thick. mm Base type With Drain Lane Width m As Design ? IRI FWD Distress Meet Min. Req'd?
  Actual Design Manual Photo. Faulting
0213 188 203 AGG No 4.27 No 1 2 1 0 1 No
0214 211   AGG No 3.66 Yes 1 1 1 0 1 No
0215* 284 279 AGG No 3.66 Yes 1 2 1 0 1 No
0216 277   AGG No 4.27 Yes 1 2 1 0 1 No
0217 191 203 LCB No 4.27 Yes 1 2 1 0 1 No
0218 188   LCB No 3.66 No 1 2 1 0 1 No
0219 282 279 LCB No 3.66 Yes 1 1 1 0 1 No
0220 272   LCB No 4.27 Yes 1 2 1 0 1 No
0221 208 203 PATB Yes 4.27 Yes 1 1 1 0 1 No
0222 213   PATB Yes 3.66 Yes 1 1 1 0 1 No
0223 277 279 PATB Yes 3.66 Yes 1 1 1 0 1 No
0224 277   PATB Yes 4.27 Yes 1 1 1 0 1 No
Overall- Good, except for 0213 and 0218. Overall- Fair, late initial surveys.

Note: * Indicates seasonal monitoring section(s)
Bolded and Italic letters represent constructed values that are either not as designed or outside the design range. For slab thickness, the design range is set at (design value +/- 12.7 mm)

Key Observations and Deviations

The following key observations and deviations were noted in the project construction and deviation report:

  • On section 050208, the vibrators of the slip-form paver became entangled with the dowel basket assembly at station 2+50. This caused the augers of the paver to stop operating. The contractor removed and replaced the affected concrete and dowel basket assembly.
  • Longitudinal joints were not sealed until early 1997. By this time, pumping was evident through these joints.

Project Status Summary

This project site was well constructed overall, but is in fair-to-poor shape mainly due to very limited performance monitoring data, traffic data, PCC materials testing data, and

AWS data. There are no supplemental sections at this site. The following summarizes the status of this project:

  • Designed versus constructed-Good, except that the mean 14-day flexural strength value (4.6 MPa) for the 6.2 MPa design cell was significantly below the design value.
  • Construction difficulties and deviations-Minor.
  • Data availability-Poor overall.
    • Site condition data-Poor. Traffic data and AWS data not available at the time of analysis.
    • Key PCC materials testing data availability for core sections-Fair, with 68 percent completed.
    • Monitoring data availability-Poor, with only one survey for many key monitoring data types.

The Arkansas SPS-2 site does not appear to have significant problems that will cause difficulty in performance analysis if construction, traffic, AWS, and monitoring data become available.

Colorado SPS-2

The Colorado SPS-2 project site is located in the eastbound lanes of I-76 in central Colorado, approximately 32 km northeast of Denver. I-76 is a rural interstate; in 1988 the AADT was 8,400, with 16 percent heavy trucks. The initial annual ESALs are estimated at 347,646. Six SPS-2 test sections were included in the phase 1 section of I-76, which was constructed on a new alignment (sections 080217, 080220, 080221, 080222, 080223, and 080224). The remaining six sections (sections 080213, 080214, 080215, 080216, 080218, and 080219) were located within the phase 2 section of I-76, which was being reconstructed. The 136th Street interchange bisects this SPS-2 site. However, no appreciable difference in traffic loading is expected due to the presence of this interchange.

All sections are on a tangent. The vertical grade averages +1.4 percent in the direction of traffic. Six sections were located in a cut (sections 080217, 080218, 080219, 080220, 080223, and 080224), while all other sections were located on fills. The typical roadway for this project consists of two 3.66-m-wide lanes, an outside shoulder width of 3.05 m, and an inside shoulder width of 1.22 m.

Construction of the SPS-2 site began on July 1, 1993, and was completed on November 1, 1993. The phase 1 work (new alignment) was opened to traffic on October 7, 1993. The phase 2 work (I-76 reconstruction) began after phase 1 was opened to traffic. Phase 2 sections were opened to traffic on January 5, 1994.

All required core sections were constructed. One supplemental State test section was also constructed. Table 41 summarizes key project information and data availability for all the sections.

Project level information and data availability Construction date: 10/01/1993

Table 41. Colorado SPS-2 project summary.
Climate - DNF Data Availability Average Values As planned?
CLM: 17 years
AWS: 5 years
FI: 327 0°C days, Precip. 370 mm
FI: 394 0°C days, Precip. 232 mm
Yes
Traffic WIM: 3 years 347,646 ESALs/year (>200,000) Yes
Subgrade type Fine-grained soil for all. As designed? Varies
Flexural strength
14-day MPa
Design value Actual Averages Within 10%?
3.8
6.2
3.94
5.77
Yes
Yes
PCC tests available On average 94% completed for core sections

Section level key design factors and monitoring data availability

Key pavement design factors Monitoring data availability, No. of tests
ID Slab Thick. mm Base type With Drain Lane Width m As Design ? IRI FWD Distress Meet Min. Req'd?
  Actual Design Manual Photo. Faulting
0213 221 203 AGG No 4.27 No 3 5 2 2 3 Not quite
0214 213   AGG No 3.66 Yes 3 5 2 2 3 Not quite
0215 290 279 AGG No 3.66 Yes 3 5 2 2 3 Not quite
0216 300   AGG No 4.27 No 3 5 2 2 3 Not quite
0217 218 203 LCB No 4.27 No 3 3 2 2 3 Not quite
0218 196   LCB No 3.66 Yes 3 4 2 2 3 Not quite
0219 282 279 LCB No 3.66 Yes 3 4 2 2 3 Not quite
0220 282   LCB No 4.27 Yes 3 3 2 2 3 Not quite
0221 211 203 PATB Yes 4.27 Yes 3 4 2 2 3 Not quite
0222 221   PATB Yes 3.66 No 3 4 2 2 3 Not quite
0223 300 279 PATB Yes 3.66 No 3 4 2 2 3 Not quite
0224 297   PATB Yes 4.27 No 3 4 2 2 3 Not quite
Overall- Fair. Six sections outside design range. Good, except for late initial faulting surveys.
Supplemental Sections - 1 PCC section.
0259 279 mm JPC (4.5 MPa) on subgrade and 3.66 m lanes. 3 3 2 2 3 Not quite
    Overall - Good

Note: * Indicates seasonal monitoring section(s)
Bolded and Italic letters represent constructed values that are either not as designed or outside the design range. For slab thickness, the design range is set at (design value +/- 12.7 mm)

Key Observations and Deviations

The following key observations were noted in the project construction report:

  • Subgrade pumping occurred on several phase 1 sections due to rainy weather and a locally high water table. Pumping did not occur on the phase 2 sections. The embankment in these test sections consisted of stable fill material including pulverized concrete and asphalt capped by a fine sand layer.
  • Several of the PATB sections contained too many fines in the mix. This resulted in removal and replacement of the mat in section 080221.
  • Due to its high plasticity, the 6.2 MPa concrete mix was harder to work with than the 3.8 MPa mix.
  • While paving section 080218, equipment and concrete delivery problems (muddy haul roads) caused several work stoppages. The dowel bars and basket assembly were torn up at station 141+50 but not replaced.
  • No major problems occurred during construction of the DGAB and LCB layers.

Project Status Summary

Overall, this project site is in excellent shape. The appendices to this report contain a significant amount of monitoring data. The following summarizes the status of this project:

  • Designed versus constructed-Good except for the following:
    • Subgrade type varies, with four sections having a fine-grained subgrade soil rather than a coarse-grained soil, as designed.
    • Mean slab thickness values for six sections are more than 12.7 mm higher than the design value.
  • Construction difficulties and deviations-Minor. Several PATB sections contained too many fines in the mix.
  • Data availability-Very good overall.
    • Site condition data-Meets experimental conditions.
    • Key PCC materials testing data availability for core sections-Excellent, with 94 percent completed.
    • Monitoring data availability-Very good, except that the initial survey for faulting data was very late, 2.5 years after the construction.

The Colorado SPS-2 site does not appear to exhibit significant problems that will cause difficulty in performance analysis.

Delaware SPS-2

The Delaware SPS-2 project site is located in the southbound lanes of U.S. 113 in central Delaware, between Milford and Georgetown. U.S. 113 is a rural principal arterial; in 1989 the AADT was 10,708, with 10 percent heavy trucks. The initial annual ESALs are estimated at 234,000. The SPS-2 project was included in the addition of two southbound lanes to an initial two-lane roadway. The two new southbound lanes were separated from the existing northbound lanes by a 7.92- to 12.8-m-wide median. Route S-625 and another access road bisect this SPS-2 site. The traffic from these routes is expected to have little impact on the SPS-2 site. There is no record of WIM installation at this site.

The roadway typically consists of two 3.66-m-wide lanes, an outside shoulder width of 3.05 m, and an inside shoulder width of 1.22 m. The subgrade consists of sand and silty sand. Test sections were constructed on shallow cuts or fills. The cut sections ranged up to 1.52 m in depth. Several wetland areas exist adjacent to the mainline pavement, where the water table is at or near the surface for an extended time period.

This project was completed and opened to traffic on May 1, 1996. All required core sections were constructed, and two supplemental State test sections were constructed. Table 42 summarizes key project information and data available for all the sections.

Project level information and data availability Construction date: 05/01/1996

Table 42. Delaware SPS-2 project summary.
Climate - WF Data Availability Average Values As planned?
CLM: 17 years

AWS: 0 year
FI: 103°C days, Precip. 1,144 mm

NA
Yes
Traffic WIM: 0 year N/A N/A
Subgrade type Fine-grained soil for all. As designed? Varies
Flexural strength
14-day MPa
Design value Actual Averages Within 10%?
3.8
6.2
4.53
5.22
No
No
PCC tests available On average 94% completed for core sections

Section level key design factors and monitoring data availability

Key pavement design factors Monitoring data availability, No. of tests
ID Slab Thick. mm Base type With Drain Lane Width m As Design ? IRI FWD Distress Meet Min. Req'd?
  Actual Design Manual Photo. Faulting
0213 211 203 AGG No 3.66 Yes 6 3 3 0 4 Yes
0214 224   AGG No 4.27 No 6 2 2 0 3 Yes
0215 297 279 AGG No 4.27 No 6 2 2 0 3 Yes
0216 279   AGG No 3.66 Yes 6 2 2 0 3 Yes
0217 234 203 LCB No 3.66 No 6 2 2 0 3 Yes
0218 226   LCB No 4.27 No 6 2 2 0 3 Yes
0219 287 279 LCB No 4.27 Yes 6 2 2 0 3 Yes
0220 307   LCB No 3.66 No 6 2 2 0 3 Yes
0221 208 203 PATB Yes 3.66 Yes 6 2 2 0 4 Yes
0222 211   PATB Yes 4.27 Yes 6 2 2 0 3 Yes
0223 300 279 PATB Yes 4.27 No 6 2 2 0 3 Yes
0224 315   PATB Yes 3.66 No 6 2 2 0 3 Yes
Overall- Fair. Seven sections outside design range. Good, except for late initial faulting surveys.
Supplemental Sections - 1 PCC section.
0259 279 mm JPC (20.7 MPa f'c) on 203 mm DGAB; 3.66 m lane; steel dowels 6 2 2 0 3 Yes
0260 254 mm JPC (20.7 MPa f'c) on 203 mm DGAB; 3.66 m lane; steel dowels 6 2 2 0 3 Yes
    Overall - Excellent

Note: * Indicates seasonal monitoring section(s)
Bolded and Italic letters represent constructed values that are either not as designed or outside the design range. For slab thickness, the design range is set at (design value +/- 12.7 mm)

Key Observations and Deviations

The following key observations were noted in the project construction report:

  • During paving of the LCB layer, depressions in the subgrade occurred during stoppage of the paver. Transverse shrinkage cracks developed in the LCB layer prior to PCC paving, and some of these shrinkage cracks developed in the depression areas.
  • During removal of the cracked PCC (Delaware Department of Transportation (DelDOT) mix) in section 100205, construction personnel noticed that some of the shrinkage cracks in the LCB had reflected through the PCC. Some areas of the LCB had bonded to the PCC; however, the underside areas of most of the slabs was smooth and clean, which is representative of an unbonded condition. The second application of a curing compound immediately before PCC paving appears to have been effective in debonding the PCC, except where surface depressions and irregularities existed in the underlying LCB.
  • A longitudinal crack had developed by October 13, 1995, in section 100207 at 457 mm from the centerline and parallel to the centerline. This crack was near the underlying construction joint in the LCB. This crack was cored on October 26, 1995, and was not found to extend the full depth of the concrete pavement. This crack may be attributable to late sawing of the longitudinal joint, since this section was paved on June 28 but longitudinal joint sawing was not performed until July 3.
  • Before removing the concrete in sections 100205, 100206, and 100207, coring of transverse and longitudinal shrinkage cracks was performed. These cracks were found to extend either entirely or partially through the PCC but not into the underlying LCB. No bond was found to occur between the PCC and the underlying LCB.
  • Removal of some of the DGAB occurred in sections 100201 and 100202 with removal of the cracked JPC. Additional DGAB was added before JPC repaving in the test sections to create a uniform mat. The DGAB was then reshaped and recompacted.
  • After full-depth repair was completed, several additional cracks developed during the winter of 1995-1996 in section 100205 (LCB). Two additional cracks developed in section 100201 (DGAB), but no additional cracking developed in section 100209 (PATB).
  • Full-depth repair of these cracks was performed from April 18 to 19, 1996. At this time, 17 fine transverse cracks were noticed in various test sections. These cracks occurred at the edge of the pavement and only extended a few meters into the slab panel.
  • No. 57 Stone was used as the edge drain backfill instead of PATB.
  • Transverse joint sealant reservoirs were sawn to 19 mm width and 38.1 mm depth, while the longitudinal joints were sawn to a width of 6.4 mm and a depth of 13 mm. The transverse joints in all test sections except sections 100206, 100202, and 100210 were sealed with neoprene seals. The transverse joints in the remaining sections and all longitudinal joints were sealed with hot poured rubberized asphalt material.

The following deviations from SPS-2 guidelines were noted in the project deviation report:

  • Eight of the 12 test sections contained partial shallow cuts, but the cut subgrades had to meet Type A borrow specifications. Those cut subgrades that did not meet the Type A specifications were excavated to receive 305 mm of Type A borrow (with prior approval) (sections 100201, 100203, 100204, 100205, 100207, 100208, 100209, and 100211).
  • A transverse construction joint was placed within section 100212.
  • The longitudinal joint was sawn five days after the concrete placement (sections 100211, 100203, and 100207).
  • Bases did not extend the full width of the shoulder (with prior approval).
  • Neoprene was used in the transverse joints (hot poured in three sections where the joints were rough), and hot-poured rubberized asphalt was used in the longitudinal joint.
  • No joint sealant was used between the mainline concrete pavement and the asphalt shoulder.
  • Joints were sealed in 1996 and in the second construction season.
  • The road was opened to construction traffic before joint sealing.
  • Tensile strength testing equipment was not obtained until after July 25, 1995, so cylinders and cores requiring this test prior to this time were missed.
  • 365-day cores will not be obtained until the northbound lanes have been rehabilitated and opened to traffic.
  • Samples have been sent to the laboratories, but the materials testing data available to date is not complete.
  • For sections 100212, 100210, 100211, and 100209:
    • Edge drains were not located at the outside edges of the shoulder.
    • Edge drain outlets were spaced at distances greater than 76 m.
  • Construction guideline deviations:
    • 3.8-MPa flexural strength concrete was not used on sections 100207, 100203, and 100211; 20.7 MPa compression strength tested concrete was used instead.
    • 3.8 MPa flexural strength concrete used on sections 100201, 100205, and 100209 was removed and replaced with 4.5 MPa flexural strength.
    • Sections 100202 and 100206 were placed with 6.2 MPa flexural strength 6.5-bag mix. Concrete was later removed and replaced with 6.2 MPa flexural 7.5-bag mix.
    • Profile index was greater than 158 mm/km for section 100205. This section is scheduled for diamond grinding.

Project Status Summary

Overall, this project site is in fair shape. The supplemental sections also contain a significant amount of monitoring data. The following summarizes the status of this project:

  • Designed versus constructed-Fair, with the following problems:
    • Subgrade type varies, with four sections having a fine-grained subgrade soil type and not as designed.
    • Mean slab thickness values for six sections are more than 12.7 mm higher than the design value.
    • PCC strength was not within design guidelines.
  • Construction difficulties and deviations-Moderate.
  • Data availability-Very good overall except for traffic WIM.
    • Site condition data-Very good except for change in subgrade.
    • Key PCC materials testing data availability for core sections-Excellent, with 91 percent completed.
    • Monitoring data availability-Very good, except that initial survey for faulting data was very late, 2.5 years after the construction.
    • Traffic data-No WIM data are available for this SPS site.

Data from the Delaware SPS-2 site will require special analysis techniques to adjust for various design factors that were not constructed as planned.

Iowa SPS-2

The Iowa SPS-2 project site is located in the northbound lanes of U.S. 65 in central Iowa, northeast of Des Moines. U.S. 65 is an urban/principal arterial; in 1994 the AADT was 17,400, with 16 percent trucks. The estimated initial ESALs for the section is approximately 600,000. The SPS-2 project was included in the relocation of U.S. 65 in both the northbound and southbound lanes.

The typical roadway consists of two 3.66-m-wide lanes, an outside asphalt shoulder width of 3.05 m, and an inside shoulder width of 1.22 m. The SPS-2 sections were constructed on a portion of U.S. 65 that included both tangent and superelevated sections. All sections were constructed on a tangent except sections 190215 and 190216. These sections were constructed on the high side of a horizontal curve with a superelevation rate of 2.5 percent. Vertical grades throughout the project area range from -2.6 percent to +2.2 percent. Sections 1902215 through 190220 were constructed on fill sections ranging from near 0 to 11.58 m in height. Sections 190221 through 190224 were constructed on cut sections ranging from 0.91 to 7.01 m.

WIM and AVC equipment were installed in June 1995 on U.S. 65, approximately 1.61 km north of the junction with IA-163 (state highway). Reconstruction was completed in 1994 during a period of relatively wet weather conditions. The project site was opened to traffic on December 1, 1994.

All required core sections were constructed. An additional supplemental State test section was also constructed. Table 43 summarizes key project information and data available for all the sections.

Project level information and data availability Construction date: 08/01/1994

Table 43. Iowa SPS-2 project summary.
Climate - WF Data Availability Average Values As planned?
CLM: 17 years

AWS: 3 years
FI: 580 °C days, Precip. 900 mm

NA
Yes
Traffic WIM: 1 year 56,400 ESALs/year (<200,000) No
Subgrade type Fine-grained soil for all. As designed? Varies
Flexural strength
14-day MPa
Design value Actual Averages Within 10%?
3.8
6.2
3.22
5.19
No
No
PCC tests available On average 98% completed for core sections

Section level key design factors and monitoring data availability

Key pavement design factors Monitoring data availability, No. of tests
ID Slab Thick. mm Base type With Drain Lane Width m As Design ? IRI FWD Distress Meet Min. Req'd?
  Actual Design Manual Photo. Faulting
0213 216 203 AGG No 4.27 Yes 5 2 2 1 3 Yes
0214 213   AGG No 3.66 Yes 5 1 1 1 2 Yes
0215 300 279 AGG No 3.66 No 5 1 2 1 3 Yes
0216 295   AGG No 4.27 No 5 1 2 1 3 Yes
0217 196 203 LCB No 4.27 Yes 5 2 2 1 3 Yes
0218 208   LCB No 3.66 Yes 5 2 2 1 3 Yes
0219 284 279 LCB No 3.66 Yes 5 1 2 1 3 Yes
0220 290   LCB No 4.27 Yes 5 2 2 1 3 Yes
0221 239 203 PATB Yes 4.27 No 5 2 2 1 3 Yes
0222 211   PATB Yes 3.66 Yes 4 1 1 1 3 Yes
0223 297 279 PATB Yes 3.66 No 5 1 1 1 3 Yes
0224 295   PATB Yes 4.27 No 5 1 1 1 2 Yes
Overall- Fair. Seven sections outside design range. Good, but late initial faulting survey for 0219
Supplemental Sections - 1 PCC section.
0259 279 mm JPC; 4.27 m wide lane 5 1 1 1 2 Yes
    Overall - Good.

Note: * Indicates seasonal monitoring section(s)
Bolded and Italic letters represent constructed values that are either not as designed or outside the design range. For slab thickness, the design range is set at (design value +/- 12.7 mm)

Key Observations and Deviations

The following key observations were noted in the project construction report:

  • Underground structures were located in 6 of the 13 sections (sections 190213, 190214, 190215, 190217, 190219, and 190221). These ranged from a 0.61-m diameter concrete pipe at 2.44 m below profile grade to a 2.44-m by 3.05-m concrete pipe at 12.19 m below profile grade.
  • The contractor removed at least 0.3 m of geotextile from the longitudinal edge drains due to the low permeability of the geotextile.
  • The boundaries of section 190222 were relocated after construction because dowel bars with the wrong diameter were placed in the initial boundaries of this section.
  • Four sections (190215, 190216, 190212, and 190223) had concrete thicknesses in excess of SPS-2 tolerances. These thicknesses ranged from 8 to 23 mm above the desired thickness.
  • During placement of the PCC pavement for test section 190222, incorrect dowel baskets were placed. This area was removed, and the section location was shifted to avoid the replaced pavement area. Because of misinterpretation of guidelines, the section numbers were revised. The correct numbers should be from 13 through 24. This revision was done after most of the sampling and testing and data collection had been completed.

Project Status Summary

Overall, this project site is in fair shape. The appendices to this report contain a significant amount of monitoring data. The following summarizes the status of this project:

  • Designed versus constructed-Poor. The key deviations are listed below:
    • Mean slab thickness values for five sections are more than 12.7 mm higher than the design value.
    • Mean 14-day flexural strength values are more than 10 percent below the design values.
    • Lane width values of the two sections are wrong. This might be a data entry error. A feedback report was submitted.
  • Construction difficulties and deviations-Moderate.
  • Data availability-Excellent overall.
    • Site condition data-Good, except for deficient traffic data and missing AWS data.
    • Key PCC materials testing data availability for core sections-Excellent, with 98 percent completed.
    • Monitoring data availability-Very good, except that the initial survey for faulting data for section 190219 was very late.

Data from the Iowa SPS-2 site will require special analysis techniques to adjust for various design factors that were not constructed as planned.

Kansas SPS-2

The Kansas SPS-2 project site is located in the westbound lanes of I-70 in central Kansas, east of Abilene. I-70 is a rural interstate; the estimated AADT is 13,750, with 21.4 percent trucks. The initial annual ESALs in the design lane are estimated at 639,131. The roadway typically consists of two 3.66-m-wide lanes, an outside shoulder width of 3.05 m, and an inside shoulder width of 1.22 m. The SPS-2 project was included in the reconstruction of I-70. The existing pavement was concrete. The SPS-2 test sections were constructed on a tangent section of I-70 with vertical grades ranging from -2.48 percent to +2.11 percent. All test sections were constructed on fills.

An onsite weather monitoring station had not been installed before completion of the project. However, installation was scheduled to occur by 1994. A Toledo Model 9430TM high-speed WIM system was installed onsite.

Construction of this SPS-2 project was completed on July 1, 1992. The project site was opened to traffic on August 1, 1992. All required core sections were constructed. A supplemental State test section was also constructed. Table 44 summarizes key project information and data available for all the sections.

Project level information and data availability Construction date: 07/01/1992

Table 44. Kansas SPS-2 project summary.
Climate - DF Data Availability Average Values As planned?
CLM: 17 years

AWS: 4 years
FI: 259°C days, Precip. 819 mm

FI: 254°C days, Precip. 698 mm
No
Traffic WIM: 1 year 639,131 ESALs/year (<200,000) Yes
Subgrade type Fine-grained soil for all. As designed? Varies
Flexural strength
14-day MPa
Design value Actual Averages Within 10%?
3.8
6.2
4.23
5.81
No
Yes
PCC tests available On average 98% completed for core sections

Section level key design factors and monitoring data availability

Key pavement design factors Monitoring data availability, No. of tests
ID Slab Thick. mm Base type With Drain Lane Width m As Design ? IRI FWD Distress Meet Min. Req'd?
  Actual Design Manual Photo. Faulting
0213 196 203 AGG No 3.66 Yes 7 5 2 2 2 No
0214 188   AGG No 4.27 No 8 6 2 2 2 No
0215 282 279 AGG No 4.27 Yes 8 7 2 2 2 No
0216 287   AGG No 3.66 Yes 8 5 2 2 2 No
0217 198 203 LCB No 3.66 Yes 8 5 2 2 2 No
0218 201   LCB No 4.27 Yes 8 6 2 2 2 No
0219 287 279 LCB No 4.27 Yes 8 5 2 2 2 No
0220 279   LCB No 3.66 Yes 8 5 2 2 2 No
0221 216 203 PATB Yes 3.66 Yes 8 5 2 2 1 No
0222 211   PATB Yes 4.27 Yes 8 5 2 2 2 No
0223 282 279 PATB Yes 4.27 Yes 8 5 2 2 2 No
0224 277   PATB Yes 3.66 Yes 8 5 2 2 2 No
Overall- Excellent, except for 0202. Good, except for deficient faulting data.
Supplemental Sections - 1 PCC section.
0259 305 mm doweled JPC (4.1 MPa mix) on 152 mm stabilized base and 152 mm modified Flyash subgrade, 3.66 m lane. 7 2 2 2 1 No
  Overall, Excellent, except for 0202. Overall - Good, except for deficient faulting data.

Note: * Indicates seasonal monitoring section(s)
Bolded and Italic letters represent constructed values that are either not as designed or outside the design range. For slab thickness, the design range is set at (design value +/- 12.7 mm)

Key Observations and Deviations

The following key observations were noted in the project construction report:

  • The LTPP SPS Project Construction Report indicates that the PATB was difficult to place. The contractor placed this material too thick in several of the test sections. The excess was removed with a trimmer. During initial construction operations, the PATB deformed when compacted. This problem was resolved as the contractor gained experience with this material.
  • Underground structures were present in sections 200204, 200208, 200209, 200210, 200211, and 200212. Median drains were present in several test sections. However, these drains were at least 1.52 m below the pavement surface.
  • Weather station was not installed until 1996 (4 years after construction was complete).
  • The DOT staff experienced many problems with the sampling and testing requirements.
  • An insufficient number of cores was specified in the sampling and testing plan.
  • Field cores of the PATB could not be collected. Therefore, it was impossible to conduct tests on samples CA 01, 02, 03, 05, 47, 48, 51, and 54.
  • Traffic monitoring data was only submitted for 1993 (78-day period).
  • The first distress survey was not performed until April 1993.
  • Vertical curves (-2.48 to +2.11 percent grade) exist within the limits of the test sections.
  • Several underground structures exist within the limits of the test sections.
  • Many of the sections contain 457-mm median drains. These drains are located >1.5 m below the surface of the pavement.
  • Sections 200204, 200208, 200209, and 200211 have box culverts located within their limits.
  • Section 200210 contains a transverse drain for the PATB.
  • Section 200211 contains a median drain ±1.2 m below the surface of the pavement.
  • Several sections have concrete pavement thicknesses that exceed the allowable tolerance of ±6.4 mm (200209 = +13 mm; 200210 = 7.6 mm; 200211 = -25.4 mm; 200212 = -48 mm; and 200204 = +10 mm).
  • Construction was delayed due to an extremely wet and rainy season.
  • The contractor experienced many problems while trying to place the PATB. Trimming was often required to obtain the desired thickness.
  • Type C fly ash was used to help dry up and stabilize the subgrade.
  • Section 200201 required one full-depth repair and two partial-depth patches in 1995.
  • Section 200204 required two partial-depth patches in 1995.

Project Status Summary

Overall, this project site is in good shape. The appendices to this report contain a significant amount of monitoring data (except for faulting surveys). The following summarizes the status of this project:

  • Designed versus constructed-Good. The key deviations are listed below:
    • Annual precipitation value is higher than the planned dry climatic zone.
    • Mean slab thickness values for five sections are more than 12.7 mm higher than the design value.
    • Mean 14-day flexural strength values for the lower strength concrete are more than 10 percent above the design values.
    • Construction difficulties and deviations-Relatively minor.
  • Data availability-Excellent overall.
    • Site condition data-Good, except for deficient traffic data and missing AWS data.
    • Key PCC materials testing data availability for core sections-Poor, with only 66 percent completed.
    • Monitoring data availability-Good, except for deficient faulting data.

The Kansas SPS-2 site exhibits some significant problems (data unavailable and construction deviations) that will cause difficulty in performance analysis.

Michigan SPS-2

The Michigan SPS-2 project site is located in the northbound and southbound lanes of U.S. 23 in southeastern Michigan, approximately 16 km west of Toledo. U.S. 23 is a rural principal arterial; in 1989 the AADT was 35,000, with 22 percent heavy trucks. The initial year ESALs was estimated at 1,346,045. The SPS-2 project was included in the reconstruction of 9.7 km of U.S. 23 in both the northbound and southbound lanes. Consear Road, a low-volume county road, bisects this SPS-2 site. Traffic counts taken in the northbound lanes reveal that traffic south of this interchange is 7 percent higher than traffic north of this interchange (AVC data only).

The roadway typically consists of two 3.66-m-wide lanes, an outside asphalt shoulder width of 3.05 m, and an inside shoulder width of 1.22 m. The SPS-2 sections were constructed on a portion of U.S. 23 that is relatively straight and flat. Vertical grades throughout the project area range from 0.00 percent to +0.55 percent. Most of the sections were constructed on shallow fills. However, sections 260214, 260218, and 260219 were constructed on deeper fills. All sections except 260214, 260218, and 260219 were constructed in tangent sections. Section 260214 was constructed in a superelevation transition area, while sections 260218 and 260219 were constructed on a full superelevation of 0.037 m/m.

WIM and AVC equipment were installed on U.S. 23 south of Consear Road. Only AVC equipment was installed north of Consear Road.

Reconstruction of U.S. 23 began in April 1993 with removal of the existing pavement layers. Construction of the subgrade progressed from mid-May through mid-June, and placement and compaction of the embankment was completed by mid-June. Undercuts were completed in Sections 260216, 260022, and 260223 due to unstable soil conditions revealed during proofrolling. These undercuts were 11 m wide and 0.3 m deep, but only extended for a partial length of each section. The undercuts were backfilled with embankment borrow clay. Base and subbase layer construction began by mid-June and was completed by mid-September 1993. Concrete paving commenced on September 13, 1993 (excluding control section) and was completed on September 21, 1993. The project site was opened to traffic in November 1993.

All required core sections were constructed, and one supplemental State test section was constructed. Table 45 summarizes key project information and data available for all the sections.

Project level information and data availability Construction date: 11/01/1993

Table 45. Michigan SPS-2 project summary.
Climate - DF Data Availability Average Values As planned?
CLM: 17 years

AWS: 3 years
FI: 259°C days, Precip. 819 mm

FI: 254°C days, Precip. 698 mm
Yes
Traffic WIM: 5 years 1.346.0451 ESALs/year (>200,000) Yes
Subgrade type Fine-grained soil for all. As designed? Varies
Flexural strength
14-day MPa
Design value Actual Averages Within 10%?
3.8
6.2
4.27
6.71
No
Yes
PCC tests available On average 82% completed for core sections

Section level key design factors and monitoring data availability

Key pavement design factors Monitoring data availability, No. of tests
ID Slab Thick. mm Base type With Drain Lane Width m As Design ? IRI FWD Distress Meet Min. Req'd?
  Actual Design Manual Photo. Faulting
0213 218 203 AGG No 4.27 No 9 5 5 1 5 Yes
0214 226   AGG No 3.66 No 9 4 4 1 5 Yes
0215 284 279 AGG No 3.66 Yes 9 4 4 1 5 Yes
0216 290   AGG No 4.27 Yes 9 5 5 1 5 Yes
0217 216 203 LCB No 4.27 Yes 7 4 4 1 4 Yes
0218 180   LCB No 3.66 No 8 3 3 1 3 Yes
0219 277 279 LCB No 3.66 Yes 9 4 4 1 5 Yes
0220 282   LCB No 4.27 Yes 8 4 4 1 5 Yes
0221 208 203 PATB Yes 4.27 Yes 8 5 5 1 6 Yes
0222 213   PATB Yes 3.66 Yes 9 4 4 1 5 Yes
0223 279 279 PATB Yes 3.66 Yes 9 4 4 1 5 Yes
0224 284   PATB Yes 4.27 Yes 9 4 4 1 5 Yes
Overall- Excellent, except for 0202. Good, except for deficient faulting data.
Supplemental Sections - 1 PCC section.
0259 267 mm JRC on 102 mm OGDB on 76 mm aggregate base. 9 4 4 1 4 Yes
    Overall - Excellent

Note: * Indicates seasonal monitoring section(s)
Bolded and Italic letters represent constructed values that are either not as designed or outside the design range. For slab thickness, the design range is set at (design value +/- 12.7 mm)

Key Observations and Deviations

For sections 260213 through 260220, the moisture content of the subgrade was not maintained within the range of 85 to 120 percent of the optimum moisture content. Moderate-to-severe desiccation cracks (up to 50.8 mm width and 254 mm depth) developed in the subgrade, which was compacted dry of optimum since the completed embankment was exposed to hot and dry weather conditions before construction of the overlying base or subbase layers. This occurred on all sections except those constructed with PATB. Cracking did not occur on PATB sections because the DGAB was placed soon after completion of the embankment.

Michigan DOT required the contractor to scarify the desiccated subgrade sections and recompact severely desiccated subgrade to SPS-2 requirements.

  • The following are some specific observations:
    • The DGAB in section 260221 segregated but was reworked in the worst areas to minimize segregation.
    • The DGAB was not kept uniformly wet prior to paving in sections 260213 through 260216.
    • Rutting of the PATB in the outside shoulder area occurred due to construction traffic. This also caused deformation of the edge drains.
    • Cracking of the LCB occurred in the outside shoulder area of sections 260217 and 260220 due to construction traffic.
    • Bonding of the LCB to the PCC was noticed in two of the sampling cores. This was not evident in other LCB/PCC cores.
    • The LCB in sections 260218 through 260220 had a slump less than 25.4 mm.
    • The LCB was milled between inside and outside lane placements in section 260218. The surface grooves were filled with grout and the spray cure was reapplied.
    • The PCC in sections 260214, 260219, and 260220 had an air content less than 5 percent.
    • The PCC did not meet SHRP requirements for 3.8 MPa and 6.2 MPa flexural strengths at 14 days. The flexural testing indicated that the 3.8 MPa mix and the 6.2 MPa mix had similar flexural strengths at 365 days after placement. The flexural strengths at 1 year respectively averaged 6.1 MPa for the 3.8 MPa design mix and 6.6 MPa for the 6.2 MPa design mixes.
    • Several pavement layers were out of specifications with respect to thickness tolerances.
    • Elevation measurements were not taken on all embankment layers.
    • Longitudinal joint seal damage at the lane/shoulder joint occurred in several test sections by 1994. The entire length of this joint in all test sections (except control section) failed by 1995. No damage was evident in the control section, which was constructed with tied concrete shoulders.
    • Pumping was observed at the longitudinal joint and transverse joints in most of the sections constructed with a DGAB and all of the sections constructed with an LCB (undrained). No pumping was observed in PATB (drained) sections.
    • Low-severity transverse joint sealant damage occurred in several test sections by 1995.
    • Structural distresses including pumping, transverse joint faulting, transverse cracking, longitudinal cracking, and corner breaks occurred in section 260218.
    • The following data collection deviations were noted:
      1. Early in the project, elevation measurements were not taken at the required embankment layer locations.
      2. Elevation measurements have only a fair-to-poor correlation with the measured pavement thickness.
      3. Fresh concrete samples of section 260259 were not obtained within the limits of that test section.
      4. The AWS was not installed until 1996. Until then, climatic data was obtained from the Toledo, OH, airport, which is about 16 km from the project site.
      5. Splitspoon samples were used in place of shelby tubes, due to the hardness of the subgrade and the presence of gravel and cobblestone.

      The following site location guideline deviations were noted:

      1. Section 260259 (control section) has tied concrete shoulders, neoprene transverse joint seals, and hot-poured rubberized asphalt longitudinal joint seals.
      2. A low-volume road intersects the test sections near the middle of the project site, which causes a minor difference in traffic volumes and loading across the test sections. To help monitor this difference, the WIM was located to the south of the interchange and an AVC was placed on each side of the interchange.
      3. Sections 260214, 260218, and 260219 are located on deep fills and on a superelevated horizontal curve (1E).
      4. Vertical curves, with grades ranging from -0.81 to +0.55 percent, exist within the test section limits.
      5. A 762-mm concrete culvert exists ±267 m below the top of the pavement surface in section 260224.
    • The following construction guideline deviations were noted:
      1. The moisture content of the compacted subgrade was not within the range of 85 to 120 percent of optimum for sections 260213, 260214, 260215, 260216, 260217, 260218, 260219, and 260221. This resulted in severe desiccation cracking of the subgrade that the contractor had to rework.
      2. The DGAB layer in section 2602121 segregated. The contractor reworked and improved the area, but some segregation still existed.
      3. The surface of the DGAB was not kept uniformly moist in sections 260213, 260214, 260215, and 260216.
      4. The underdrain filter fabric did not extend the minimum of 0.305 m under the pavement.
      5. Traffic was allowed on the outside shoulder of the PATB, which resulted in rutting of 13 to 44.5 mm.
      6. A transverse construction joint in the LCB was located within the test section limits.
      7. The paving equipment was allowed to operate on the outside shoulder area of the LCB, which resulted in longitudinal cracking in sections 260217 and 260220.
      8. Fresh LCB samples revealed a slump lower than the 25.4 mm limit for sections 260218, 260219, and 260220.
      9. Cores of the LCB in section 260218 did not satisfy the thickness tolerance of design ±13 mm.
      10. Fresh concrete samples revealed a slump lower than the 25.4 mm limit in sections 260215 and 260219, and air contents lower than the 5.0 percent limit in sections 260214, 260219, and 260220.
      11. The 14-day flexural strength requirements were not satisfied.
      12. Cores of the concrete in sections 260213, 260214, 260217, 260218, 260222, and 260259 did not satisfy the tolerance of design ±6.4 mm.
      13. Test sections 260216, 260222, and 260223 had to be undercut because of unstable subgrade material.
      14. Test sections 260221 and 260224 had areas of unstable subgrade but were not undercut.
      15. The contractor had problems maintaining the proper elevation for the PATB because the paver was not using a stringline.
      16. Test section 260213 was diamond ground to remove a "must-grind" bump.

Project Status Summary

Overall, this project site is in good shape except for the concrete strength (the high and low strengths are practically the same after 1 year). The appendices to this report contain a significant amount of monitoring data. The following summarizes the status of this project:

  • Designed versus constructed-Good. The key deviations are listed below:
    • Mean 14-day flexural strength value for 3.8 MPa cell is more than 10 percent below the design value.
  • Construction difficulties and deviations-Moderate.
  • Data availability-Excellent overall.
    • Site condition data-Very good.
    • Key PCC materials testing data availability for core sections-Good, with 82 percent completed.
    • Monitoring data availability-Excellent.

Data from the Michigan SPS-2 site will require special analysis techniques to adjust for various design factors that were not constructed as planned.

Nevada SPS-2

The Nevada SPS-2 project site is located in north central Nevada, approximately 8 km west of Battle Mountain, in the outer eastbound lane of I-80. The SPS-2 sections extend from station 1596+65 to station 64+50 (milepost 223.7). The initial annual ESALs were estimated to be 812,944.

The construction work on this segment of I-80 consisted of removing the existing AC surfacing, cement-treated base (CTB), DGAB, and embankment. The original subgrade was stabilized with lime, and the embankment was replaced. The SHRP structural sections were then placed on top of the embankment. The terrain surrounding the test sections is generally flat with minimal ground cover.

All required core sections were constructed. One supplemental State section was also constructed. Table 46 summarizes key project information and data available for all the sections.

Project level information and data availability Construction date: 11/01/1993

Table 46. Nevada SPS-2 project summary.
Climate - DF Data Availability Average Values As planned?
CLM: 17 years

AWS: 5 years
FI: 276°C days, Precip. 819 mm

FI: 181°C days, Precip. 698 mm
Yes
Traffic WIM: 1 year 1.346.0451 ESALs/year (>200,000) Yes
Subgrade type Fine-grained soil for all. As designed? Varies
Flexural strength
14-day MPa
Design value Actual Averages Within 10%?
3.8
6.2
3.60
5.41
Yes
No
PCC tests available On average 82% completed for core sections

Section level key design factors and monitoring data availability

Key pavement design factors Monitoring data availability, No. of tests
ID Slab Thick. mm Base type With Drain Lane Width m As Design ? IRI FWD Distress Meet Min. Req'd?
  Actual Design Manual Photo. Faulting
0213 234 203 AGG No 3.66 No 4 6 2 1 2 Yes
0214 208   AGG No 4.27 No 2 4 2 1 2 Yes
0215 302 279 AGG No 4.27 Yes 4 3 2 1 2 Yes
0216 300   AGG No 3.66 Yes 8 15 8 1 8 Yes
0217 216 203 LCB No 3.66 Yes 4 5 2 1 2 Yes
0218 198   LCB No 4.27 No 2 3 2 1 2 Yes
0219 277 279 LCB No 4.27 Yes 4 2 2 1 2 Yes
0220 279   LCB No 3.66 Yes 4 2 2 1 2 Yes
0221 226 203 PATB No 3.66 Yes 4 6 2 1 3 Yes
0222 257   PATB Yes 4.27 Yes 4 5 3 1 3 Yes
0223 287 279 PATB Yes 4.27 Yes 4 4 3 1 2 Yes
0224 NA - Section taken out of the SPS-2 study from the beginning.
Overall- Excellent, except for 0202. Good, except for deficient faulting data.
Supplemental Sections - 1 PCC section.
0259 267 mm JRC on 38 mm leveling course, 27.6 MPa ± 20% 14-day compressive strength. 4 2 2 1 2 Yes
    Overall - Excellent.

Note: * Indicates seasonal monitoring section(s)
Bolded and Italic letters represent constructed values that are either not as designed or outside the design range. For slab thickness, the design range is set at (design value +/- 12.7 mm)

Key Observations and Deviations

The following key observations were noted in the project construction report:

  • This project site was constructed over an existing section of highway, and the removal of the existing pavement structure was required. When this was performed, it was discovered that the subgrade, which was sandy silt, was out of specifications for NDOT subgrade material. This required the lime stabilization of the top 0.3 m of subgrade material.
  • After this stabilization, embankment material was placed and compacted. FWD testing on the embankment showed that sections 320201, 320205, 320207, and 320209 had significantly higher deflections than the other sections.
  • The DGAB was placed on 8 of the 12 sections. The material was placed in either one or two lifts, depending on the design thickness. Sections 320201 and 320209 were found to have high variations in deflections during FWD testing, and section 320203 had deflections in the first 38.1 m, while the other five sections were more consistent.
  • As per the SPS-2 experiment design, four sections received a 102-mm PATB. Edge drains were constructed on these sections utilizing a geotextile and open-graded rock placed in trenches.
  • As per the SPS-2 experiment design, four sections had a 152-mm LCB placed directly on the embankment. The LCB was placed in one 12.19-m-wide pass and no joints were sawed. All sections except 320206 exhibited extensive cracking within 2 weeks of paving.

    The PCC consisted of three different mixes. Section 320259 was the State standard mix, six sections were constructed using a 3.3 MPa mix, and six were constructed using a 5.2 MPa mix. The typical SPS-2 project has six 3.8 MPa and six 6.2 MPa mixes, but it wasn't possible to reach the 6.2 MPa target using local materials, so the target strengths were revised. A number of other problems that occurred during PCC paving are detailed in appendix B.

  • The majority of the problems with the PCC paving came as a result of the mixes being significantly different than those typically used by the paving crew. This was especially true for the 5.2 MPa mix. Proof of this fact is that section 320259, which was the State standard mix, had none of the problems with shrinkage cracks and tearing that were so common for the majority of the project. The primary conclusion that can be made on the basis of this project is that trying to perform nonstandard construction can cause significant problems. It is highly unlikely that the majority of the test sections will last anywhere close to their design lives.

Project Status Summary

Overall, this project site is in poor shape. The appendices to this report contain a significant amount of monitoring data. The following summarizes the status of this project:

  • Designed versus constructed-Good. The key deviations are listed below:
    • Subgrade type varies, and nine sections have a different subgrade type than was designed.
    • Mean 14-day flexural strength value for the 6.2 MPa cell is 5.41 MPa, or more than 10 percent below the design value.
  • Construction difficulties and deviations-Major problems that led to extensive early cracking.
  • Data availability-Excellent overall.
    • Site condition data-Very good.
    • Additional traffic data are needed.
    • Key PCC materials testing data availability for core sections-Excellent, with 97 percent completed.
    • Monitoring data availability-Excellent.

Data from the Nevada SPS-2 site will require special analysis techniques to adjust for various design factors that were not constructed as planned. In particular, slab cracking will not be able to be evaluated in comparison with other sites; this may cause other problems that will complicate performance analysis.

North Carolina SPS-2

The North Carolina SPS-2 project site is located in the southbound lanes of U.S. 23, near Lexington, NC. U.S. 52 is a rural principal arterial with an AADT of 23,500 to 26,100 (1994) and 13 percent heavy trucks. The annual ESALs was estimated at 750,902. The SPS-2 project was included in the construction of 7.8 km of U.S. 52 in both the northbound and southbound lanes. U.S. 64 bisects this SPS-2 site. All test sections except section 370204 are located north of the U.S. 64 interchange. This section will be monitored with AVC equipment to determine if the traffic south of U.S. 64 is different from traffic to the north of U.S. 64.

The roadway typically consists of two 3.66-m-wide lanes, an outside shoulder width of 3.05 m, and an inside width of 1.22 m. The shoulders were constructed with econocrete instead of the SPS-2 required flexible bituminous design. The majority of SPS-2 test sections were constructed on tangent sections with slight grades. Sections that include a 203-mm PCC slab were constructed as add-on lanes adjacent to the mainline travel lane. This parallel roadway section was constructed through some deep cuts and high embankments.

Seasonal monitoring sensors, strain gauges, and linear variable differential transducers were installed on several test sections. Reconstruction began in 1992 with earthwork grading.

All required core sections were constructed. Two supplemental State test sections were also constructed. Table 47 summarizes key project information and data available for all the sections.

Project level information and data availability Construction date: 11/01/1993

Table 47. North Carolina SPS-2 project summary.
Climate - WNF Data Availability Average Values As planned?
CLM: 17 years

AWS: 5 years
FI: 47°C days, Precip. 1,151 mm

FI: 67°C days, Precip. 1,199 mm
Yes
Traffic WIM: 5 years 750,902 ESALs/year (>200,000) Yes
Subgrade type Fine-grained soil for all. As designed? Varies
Flexural strength
14-day MPa
Design value Actual Averages Within 10%?
3.8
6.2
N/A
N/A
N/A
N/A
PCC tests available On average 82% completed for core sections Fair

Section level key design factors and monitoring data availability

Key pavement design factors Monitoring data availability, No. of tests
ID Slab Thick. mm Base type With Drain Lane Width m As Design ? IRI FWD Distress Meet Min. Req'd?
  Actual Design Manual Photo. Faulting
0201* 229 203 AGG No 3.66 No 10 25 9 1 10 Not quite
0202 259   AGG No 4.27 No 8 2 1 1 2 Not quite
0203 284 279 AGG No 4.27 Yes 8 2 1 1 2 Not quite
0204 284   AGG No 3.66 Yes 7 2 1 1 1 Not quite
0205 203 203 LCB No 3.66 Yes 8 3 1 1 2 Not quite
0206 213   LCB No 4.27 No 8 2 1 1 2 Not quite
0207 295 279 LCB No 4.27 Yes 8 2 1 1 2 Not quite
0208 284   LCB No 3.66 Yes 7 3 1 1 1 Not quite
0209 218 203 PATB No 3.66 Yes 8 5 5 1 6 Not quite
0210 213   PATB Yes 4.27 Yes 8 2 1 1 2 Not quite
0211 290 279 PATB Yes 4.27 Yes 8 2 1 1 2 Not quite
0212* 277   PATB Yes 3.66 Yes 8 3 1 1 1 Not quite
Overall- Fair, four sections outside design range. Overall - Good, except for late initial surveys.
Supplemental Sections - 2 PCC sections.
0259 254 mm JRC on 102 mm PATB on 25.4 mm AC on 203 mm lime-stabilized subgrade. 7 2 1 1 2 Yes
0260 279 mm JRC on 2.54 cm AC on 127 mm BTB on 203 mm cement-treated subgraded. 8 2 1 1 2 Yes
    Overall - Excellent.

Note: * Indicates seasonal monitoring section(s)
Bolded and Italic letters represent constructed values that are either not as designed or outside the design range. For slab thickness, the design range is set at (design value +/- 12.7 mm)

Key Observations and Deviations

The following key observations were noted in the project construction report:

  • Edge drains were located at a 0.61-m offset from the pavement edge, rather than the SPS-2 required 2.4-m offset. Stone was used instead of PATB as trench backfill.
  • Econocrete shoulders were approved for use instead of asphalt shoulders.
  • The DGAB extended only 0.61 m into the shoulder from the pavement edge.
  • Dowel bars (25.4 mm diameter) were utilized on sections, which included a 203-mm PCC. The LCB was constructed to extend only 0.61 m into the shoulder from the pavement edge.
  • Cracks developed in the LCB layer in several sections before construction of the PCC. These cracks were covered with tar paper prior to PCC paving. Several of these cracks reflected through the PCC. Consequently, some of these slabs were repaired.

Project Status Summary

Overall, this project site is in fair shape. The appendices to this report contain a significant amount of monitoring data. The following summarizes the status of this project:

  • Designed versus constructed-Good. The key deviations are listed below:
    • Mean PCC slab thickness for the 203-mm cell is more than 12.7 mm above the design value.
    • No data are available to evaluate the mean 14-day flexural strength adequacy.
  • Construction difficulties and deviations-Minor data availability-Fair overall.
    • Site condition data-Very good.
    • Key PCC materials testing data availability for core sections-Poor, with only 37 percent completed.
    • Monitoring data availability-Very good. Some sections have late initial surveys.

North Dakota SPS-2

The North Dakota SPS-2 project is located in the eastbound lanes of I-94 in eastern North Dakota, west of Fargo. I-94 is a rural interstate; in 1996 the AADT was 8,310, with 12 percent trucks. The initial annual ESALs in the design lane are estimated at 246,000.

The roadway typically consists of two 3.66-m-wide lanes, an outside shoulder width of 3.05 m, and an inside shoulder width of 1.22 m. The SPS-2 project was included in the reconstruction of a concrete pavement that included 229-mm concrete on 76-mm aggregate base on 152- to 229-mm aggregate subbase. The SPS-2 test sections were constructed on a portion of I-94 that is very flat and relatively straight. All sections except North Dakota supplemental sections 380260 and 360261 were constructed on tangent sections.

Several delays were encountered during subgrade preparation, due to the presence of extremely wet clayey soils. Construction of individual test sections was completed on October 1, 1994, and the pavements were opened to traffic on November 1, 1994.

All required core sections were constructed. Six supplemental State test sections were constructed. Table 48 summarizes key project information and data available for all the sections.

Project level information and data availability Construction date: 11/01/1994

Table 48. North Dakota SPS-2 project summary.
Climate - DF Data Availability Average Values As planned?
CLM: 17 years

AWS: 5 years
FI: 1,313°C days, Precip. 545 mm

FI: 1,162°C days, Precip. 534 mm
Yes
Traffic WIM: 0 year N/A N/A
Subgrade type Fine-grained soil for all. As designed? Varies
Flexural strength
14-day MPa
Design value Actual Averages Within 10%?
3.8
6.2
N/A
N/A
N/A
N/A
PCC tests available On average 82% completed for core sections Fair

Section level key design factors and monitoring data availability

Key pavement design factors Monitoring data availability, No. of tests
ID Slab Thick. mm Base type With Drain Lane Width m As Design ? IRI FWD Distress Meet Min. Req'd?
  Actual Design Manual Photo. Faulting
0213 208 203 AGG No 4.27 No 2 2 2 1 3 Not quite
0214 201   AGG No 3.66 No 2 2 1 1 2 Not quite
0215 279 279 AGG No 3.66 Yes 2 2 1 1 1 Not quite
0216 284   AGG No 4.27 Yes 2 2 1 1 1 Not quite
0217 201 203 LCB No 4.27 Yes 2 1 2 1 3 Not quite
0218 201   LCB No 3.66 No 2 1 1 1 2 Not quite
0219 277 279 LCB No 3.66 Yes 2 1 1 1 2 Not quite
0220 277   LCB No 4.27 Yes 2 1 1 1 2 Not quite
0221 206 203 PATB No 4.27 Yes 2 1 2 1 3 Not quite
0222 208   PATB Yes 3.66 Yes 2 1 1 1 2 Not quite
0223 282 279 PATB Yes 3.66 Yes 2 1 1 1 2 Not quite
0224 274   PATB Yes 4.27 Yes 2 1 1 1 2 Not quite
Overall- Fair, four sections outside design range. Overall - Good, except for late initial surveys.
Supplemental Sections - 6 PCC sections.
0259 254 mm doweled JPC (ND mix) on 203 mm salve with skewered joints and 3.66 m lanes. 2 1 1 1 2 Yes
0260 279 mm doweled JPC (ND mix) on DGAB with skewed joints and 4.27 m lanes. 2 2 1 1 1 Yes
0261 279 mm doweled JPC (3.8 MPa MR) on DGAB with skewed joints and 3.66 m lanes. 2 2 1 1 1 Yes
0262 279 mm doweled JPC on LCB with skewed joints (various lengths) and 4.27 m lanes. 2 1 1 1 2 Yes
0263 279 mm doweled JPC on PATB with random skewed joints and 3.66 m lanes. 2 1 1 1 2 Yes
0264 279 mm doweled JPC on PATB with skewed joints and 4.27 m lanes. 2 1 1 1 2 Yes
    Overall - Good.

Note: * Indicates seasonal monitoring section(s)
Bolded and Italic letters represent constructed values that are either not as designed or outside the design range. For slab thickness, the design range is set at (design value +/- 12.7 mm)

Key Observations and Deviations

The following key observations were noted in the project construction report:

  • The LCB was difficult to place until the mix design was changed to increase the strength of this layer. The thickness tolerances on four core SPS-2 sections were not met (sections 380217, 380218, 380219, and 380220).
  • Transverse cracks developed in section 380217. These cracks reflected through the 203-mm PCC within 5 days after construction of the PCC.
  • The PATB deformed when compacted.
  • The subgrade in section 380218 was unstable and should have been undercut. This caused some initial frost heave, but the condition has corrected itself.
  • The layer thickness for the following sections contained deviations:
    • 380217-LCB not within the 0.012 m design tolerance, based only on rod and level.
    • 380218 and 380220-LCB not within the 0.012 m design tolerance, based on both rod and level, and core results.
  • 380219-LCB not within the 0.012 m design tolerance, based on core results.
  • LCB was difficult to place, so the mix was made stronger than the guidelines.
  • PATB was difficult to roll due to its fluid-like characteristics and its short length requirements.
  • On section 380217, the transverse cracks in the LCB reflected through to the 203 mm of PCC pavement.
  • Sections 380260 and 380261 were built on slight superelevations just after the on-ramp from Casselton.

Project Status Summary

Overall, this project site is in good shape. The appendices to this report contain a significant amount of monitoring data. The following summarizes the status of this project:

  • Designed versus constructed-Good (however, PCC strength is unknown). The key deviations are listed below:
    • Annual precipitation value is higher than the planned dry climatic zone. Mean slab thickness values for five sections are more than 12.7 mm higher than the design value.
    • No data are available to evaluate the mean 14-day flexural strength adequacy.
  • Construction difficulties and deviations-Relatively minor.
  • Data availability-Good overall.
    • Site condition data-Fair. Traffic data not available at the time of analysis.
    • Key PCC materials testing data availability for core sections-Good, with 81 percent completed.
    • Monitoring data availability-Very good, except for the initial surveys of the longitudinal profile.

The North Dakota SPS-2 site does not appear to exhibit significant problems that will cause difficulty in performance analysis.

Ohio SPS-2

The Ohio SPS-2 project site is located in the northbound lanes of U.S. 23 in central Ohio, approximately 48 km north of Columbus. U.S. 23 is a rural principal arterial; in 1994 the AADT was 20,210, with 12 percent trucks. The initial annual ESALs are estimated at 600,000. The roadway typically consists of two 3.66-m-wide lanes, an outside asphalt shoulder width of 3.05 m, and an inside asphalt shoulder width of 1.22 m. The SPS-2 test sections were constructed on a portion of U.S. 23 that is relatively straight and flat.

Permanent WIM equipment consisting of weigh plates was mounted in each lane of U.S. 23. Additional instrumentation was installed in the SPS-2 project area to collect environmental data, including temperatures of individual pavement layers and moisture freeze/thaw conditions of the subbase and subgrade layers. The load-response monitoring instrumentation that was installed included strain, deflection, and pressure gauges.

Construction started in the fall of 1994 with the subgrade preparation. Individual test sections were completed by October 1995, and the project was open to traffic on October 1, 1996. All required core sections were constructed. Seven supplemental State test sections were also constructed. Table 49 summarizes key project information and data available for all the sections.

Project level information and data availability Construction date: 09/01/1996

Table 49. Ohio SPS-2 project summary.
Climate - WF Data Availability Average Values As planned?
CLM: 17 years

AWS: 6 years
FI: 375°C days, Precip. 972 mm

FI: 121°C days, Precip. 730 mm
Yes
Traffic WIM: 0 year N/A N/A
Subgrade type Fine-grained soil for all. As designed? Varies
Flexural strength
14-day MPa
Design value Actual Averages Within 10%?
3.8
6.2
4.72
4.23
No
No
PCC tests available On average 96% completed for core sections

Section level key design factors and monitoring data availability

Key pavement design factors Monitoring data availability, No. of tests
ID Slab Thick. mm Base type With Drain Lane Width m As Design? IRI FWD Distress Meet Min. Req'd?
  Actual Design Manual Photo. Faulting
0201 201 203 AGG No 4.27 No 4 5 1 1 2 Yes
0202 211   AGG No 3.66 No 4 4 1 1 2 Yes
0203 277 279 AGG No 3.66 Yes 4 3 1 1 2 Yes
0204* 282   AGG No 4.27 Yes 8 15 1 1 3 Yes
0205 203 203 LCB No 4.27 Yes 4 4 1 1 2 Yes
0206 201   LCB No 3.66 No 4 3 1 1 2 Yes
0207 282 279 LCB No 3.66 Yes 4 3 1 1 2 Yes
0208 279   LCB No 4.27 Yes 4 3 1 1 2 Yes
0209 206 203 PATB No 4.27 Yes 4 5 1 1 2 Yes
0210 203   PATB Yes 3.66 Yes 4 5 1 1 2 Yes
0211 290 279 PATB Yes 3.66 Yes 4 4 1 1 2 Yes
0212 269   PATB Yes 4.27 Yes 4 4 1 1 2 Yes
Overall- Fair, four sections outside design range. Overall - Excellent.
Supplemental Sections - 7 PCC sections.
0259 279 mm JPC (3.8 MPa MR) on 152 mm DGAB 3 4 1 0 2 Yes
0260 279 mm JPC (3.8 MPa MR) on 102 mm PATB on 1022 mm DGAB 4 4 1 1 2 Yes
0261 279 mm JPC (3.8 MPa MR) on 102 mm CTPB on 1022 mm DGAB 4 3 1 1 2 Yes
0262 279 mm JPC on 102 mm CTPB on 102 mm DGAB 3 3 1 1 2 Yes
0263 279 mm JPC on 152 mm DGAB 3 3 1 0 2 Yes
0264 279 mm JPC on 152 mm DGAB 4 2 1 0 2 Yes
0265 279 mm JPC (3.8 MPa MR) on 102 mm PATB on 102 mm DGAB 4 4 1 1 2 Yes
    Overall - Excellent

Note: * Indicates seasonal monitoring section(s)
Bolded and Italic letters represent constructed values that are either not as designed or outside the design range. For slab thickness, the design range is set at (design value +/- 12.7 mm)

Key Observations and Deviations

The following key observations were noted in the project construction report:

  • The LTPP SPS Project Deviation Report indicates that some of the DGAB cracked during compaction (sections 390259 and 390204). Contaminated PATB was removed and replaced due to an oil spill in section 390260.
  • Monolithic construction of base layers would have ensured that a layer of uniform thickness and material quality would have been constructed transversely across the typical pavement section. Monolithic construction would also have created the highest support conditions at the pavement edge, which is often the most critical stress area (edge stresses and positive curling stresses) for a doweled JPCP. Only the CTPB width can be considered monolithic.
  • Individual pavement layer thicknesses are often in excess of LTPP tolerances. Variability of a single layer depth occurs both within an individual test section and from section to section for those test sections that have common layer depth requirements.
  • 390259 and 390204-Some surface aggregate cracked due to compaction.
  • 390260-Oil spilled on PATB. Contaminated sections removed and replaced.

Project Status Summary

Overall, this project site is in very good shape. The appendices to this report contain a significant amount of monitoring data. The following summarizes the status of this project:

  • Designed versus constructed-Good. The key deviations are listed below:
    • Mean 14-day flexural strength values deviated by more than 10 percent from the design values.
  • Construction difficulties and deviations-Relatively minor.
  • Data availability-Excellent overall.
    • Site condition data-Good, traffic data not available.
    • Key PCC materials testing data availability for core sections-Excellent, with 96 percent completed.
    • Monitoring data availability-Excellent.

The Ohio SPS-2 site does not appear to exhibit significant problems that will cause difficulty in performance analysis.

Washington SPS-2

The Washington SPS-2 project site is located in the northbound lanes of S.R. 395 in eastern Washington, 4.8 km south of Ritzville. S.R. 395 is an urban principal arterial; in 1993 the AADT was 18,000. The initial annual ESALs are estimated at 461,759. The SPS-2 project includes construction of two new northbound lanes and the upgrade of S.R. 395 to a four-lane divided highway. The new lanes were constructed uphill from the existing lanes. Two sections were located in a cut (section 530203 and 530259), while all other sections were located on fills. The roadway design for this project consists of two 3.66-m-wide lanes, an outside shoulder width of 3.05 m, and an inside shoulder width of 1.22 m.

The initial SPS-2 sections were constructed on a horizontal curve to the left from the beginning of the SPS-2 project to Station 2050+00. Section 530201 is partially located within a horizontal curve and partially located within a superelevation runout area. Sections 530205, 530206, 530207, and 530208 are on tangent, while the remaining sections were constructed on a curve to the left. The maximum superelevation rate for this curve is 3 percent. Vertical grades range from 0.14 percent to 3 percent.

Construction of the SPS-2 site started in June 1993 with the removal of the existing pavement. Construction of individual test sections was completed by November 1, 1995.

All required core sections were constructed, as was one supplemental State test section. Table 50 summarizes key project information and data available for all the sections.

Project level information and data availability Construction date: 11/01/1995

Table 50. Washington SPS-2 project summary.
Climate - DF Data Availability Average Values As planned?
CLM: 17 years

AWS: 5 years
FI: 265°C days, Precip. 308 mm

FI: 138°C days, Precip. 355 mm
Yes
Traffic WIM: 2 years N/A Yes
Subgrade type Fine-grained soil for all. As designed? Varies
Flexural strength
14-day MPa
Design value Actual Averages Within 10%?
3.8
6.2
3.34
5.7 23
No
Yeso
PCC tests available On average 96% completed for core sections

Section level key design factors and monitoring data availability

Key pavement design factors Monitoring data availability, No. of tests
ID Slab Thick. mm Base type With Drain Lane Width m As Design ? IRI FWD Distress Meet Min. Req'd?
  Actual Design Manual Photo. Faulting
0201 221 203 AGG No 3.66 No 4 5 3 0 3 Yes
0202 211   AGG No 4.27 Yes 4 5 3 0 3 Yes
0203 282 279 AGG No 4.27 Yes 4 5 3 0 3 Yes
0204* 284   AGG No 3.66 Yes 4 5 3 0 3 Yes
0205 216 203 LCB No 3.66 Yes 4 4 3 0 3 Yes
0206 218   LCB No 4.27 No 4 4 3 0 3 Yes
0207 282 279 LCB No 4.27 Yes 4 4 3 0 3 Yes
0208 284   LCB No 3.66 Yes 4 4 3 0 3 Yes
0209 229 203 PATB No 3.66 No 4 5 3 0 3 Yes
0210 211   PATB Yes 4.27 Yes 4 5 3 0 3 Yes
0211 300 279 PATB Yes 4.27 No 4 5 3 0 3 Yes
0212 287   PATB Yes 3.66 Yes 4 5 3 0 3 Yes
Overall- Fair, four sections outside design range. Overall - Excellent.
Supplemental Sections - 1PCC section.
0259 Undoweled 254 mm JPC (4.5 MPa MR) on 76 mm ATB on 51 mm crushed surfacing base courses; 4.27 m lane. 4 4 3 0 3 Yes
    Overall - Excellent

Note: * Indicates seasonal monitoring section(s)
Bolded and Italic letters represent constructed values that are either not as designed or outside the design range. For slab thickness, the design range is set at (design value +/- 12.7 mm)

Key Observations and Deviations

The following key observations were noted in the project construction report:

  • Construction traffic helped to further consolidate the DGAB as evidenced by an average density of 2,106 kg/m3 for those DGAB sections receiving construction traffic and an average density of 1,867 kg/m3 for the control section (section 530259) that did not receive construction traffic.
  • Six of the eight test sections constructed with DGAB had average thicknesses between 10 and 23 mm greater than SPS-2 specifications.
  • The average PATB thickness was 66 mm with 10 mm standard deviation. The SPS-2 specified thickness was 76 mm ±6.4 mm.
  • The average LCB thickness was either 155 or 157 mm for each test section paved with LCB. The SPS-2 specified thickness was 152 mm ±6.4 mm.
  • The 203-mm PCC test sections had average thicknesses ranging from 211 to 206 mm. Sections 530201, 530206, and 530209 had thicknesses of 221, 218, and 216 mm, respectively.
  • All 279-mm PCC test sections had PCC thicknesses within 7.6 mm of the specified depth.
  • The 14-day core compressive strengths for three of the four LCB test sections were within SHRP tolerances of 3.4 to 5.2 MPa. Section 530207 had compressive strengths up to 2.5 times as high as other LCB test sections. This was attributed to a water-cement ratio lower than the mix design.
  • All but one PATB section had an average thickness of either 97 or 99 mm. Section 530212 had an average PATB thickness of 89 mm.
  • The 3.8 MPa mix had hairline cracks below the sawn transverse joint and 6.4 mm joint widths several days after paving for the DGAB and LCB sections. The 203-mm PCC on LCB (section 530205) had not cracked at the transverse joints by October 2, 1995.
  • The 6.2 MPa mix had larger cracked joint widths than the 3.8 MPa mix for corresponding sections.
  • The 3.8 MPa mix had cracked joints up to 7.9 mm in the PATB sections, while the 6.2 MPa mix had transverse and average joint crack width of 13 mm on PATB sections.
  • Section 530206 developed shrinkage cracks from 1.6 to 3.2 mm in width. All but 1 slab was cracked, and 19 of the 32 slabs had more than 5 cracks per slab.
  • Transverse and longitudinal joints were sealed with a hot pour material.
  • FWD testing revealed that those sections constructed in cut areas had the most variability in support (0.4 to 1.4 mm), while those test sections constructed on embankments had more uniform support.

Project Status Summary

Overall, this project site is in good shape. The appendices to this report contain a significant amount of monitoring data. The following summarizes the status of this project:

  • Designed versus constructed-Good. The key deviations are listed below:
    • Mean 14-day lower flexural strength values deviated by more than 10 percent from the design values.
    • Mean slab thickness value for the 279 mm cell deviated by more than 12.7 mm from the design value.
  • Construction difficulties and deviations-Relatively minor.
  • Data availability-Excellent overall.
    • Site condition data-Good; need more traffic data.
    • Key PCC materials testing data availability for core sections-Excellent, with 100 percent completed.
    • Monitoring data availability-Excellent.

The Washington SPS-2 site does not appear to exhibit significant problems that will cause difficulty in performance analysis.

Wisconsin SPS-2

The Wisconsin SPS-2 project site is located on the westbound and eastbound lanes of Wisconsin State Highway 29 (STH-29), a rural arterial road, in Marathon County, WI. This site is roughly 5.6 km east of Hatley, WI. In 1995, the ADT was 6,650 vehicles with a truck distribution of 29.5 percent. The initial annual ESALs were estimated at 500,000. The site is located on a 0.3 percent downgrade with four curves in between. The maximum curve does not exceed 2 degrees with a superelevation equal to 0.055 l/l. The lanes are 3.66 m and 4.27 m wide, with an outside shoulder of 3.05 m and an inside shoulder of 1.83 m.

A WIM system was installed on August 29, 1997. The WIM equipment used was a DAW-1000 bending plate unit manufactured by PAT Equipment.

The subgrade preparation for this project began in early June 1997, and paving operations were completed by mid-October 1997.

All required core sections were constructed. Eight supplemental State test sections were also constructed. Table 51 summarizes key project information and data available for all the sections.

Project level information and data availability Construction date: 10/01/1997

Table 51. Wisconsin SPS-2 project summary.
Climate - DF Data Availability Average Values As planned?
CLM: 0 year

AWS: 0 year
N/A

N/A
N/A
Traffic WIM: 0 year N/A N/A
Subgrade type Fine-grained soil for all. As designed? Varies
Flexural strength
14-day MPa
Design value Actual Averages Within 10%?
3.8
6.2
4.37
6.09
No
Yes
PCC tests available On average 71% completed for core sections

Section level key design factors and monitoring data availability

Key pavement design factors Monitoring data availability, No. of tests
ID Slab Thick. mm Base type With Drain Lane Width m As Design ? IRI FWD Distress Meet Min. Req'd?
  Actual Design Manual Photo. Faulting
0213 NA 203 AGG No 4.27 NA 3 1 1 0 1 Yes
0214   AGG No 3.66 3 1 1 0 2 Yes
0215 279 AGG No 3.66 3 1 1 0 1 Yes
0216   AGG No 4.27 3 1 1 0 1 Yes
0217 203 LCB No 4.27 3 1 1 0 1 Yes
0218   LCB No 3.66 3 1 1 0 1 Yes
0219 279 LCB No 3.66 3 1 1 0 1 Yes
0220   LCB No 4.27 3 1 1 0 1 Yes
0221 203 PATB No 4.27 3 1 1 0 1 Yes
0222   PATB Yes 3.66 3 1 1 0 1 Yes
0223 279 PATB Yes 3.66 3 1 1 0 1 Yes
0224   PATB Yes 4.27 3 1 1 0 1 Yes
Overall- Not enough data. Overall - Excellent.
Supplemental Sections - 8 PCC sections.
0259 279 mm JPC (3.8 MPa MR) on 152 mm DGAB 3 1 1 0 1 Yes
0260 279 mm JPC (3.8 MPa MR) on 152 mm DGAB, with alternative dowel bar placement 3 1 1 0 1 Yes
0261 203 mm JPC (3.8 MPa MR) on 102 mm OGDB on 102 mm DGAB 3 1 1 0 1 Yes
0262 203 mm JPC (6.3 MPa MR) on 152 mm DGAB, with tied concrete shoulder 3 1 1 0 1 Yes
0263 203-279 mm JPC (3.8 MPa MR) on 152 mm DGAB, variable pavement thickness 3 1 1 0 1 Yes
0264 279 mm JPC (3.8 MPa MR) on 152 mm DGAB, with composite dowels 3 1 1 0 1 Yes
0265 279 mm JPC (3.8 MPa MR) on 152 mm DGAB, with stainless steel dowels. 3 1 1 0 1 Yes
0266   3 0 0 0 0 Yes
    Overall - Excellent

Note: * Indicates seasonal monitoring section(s)
Bolded and Italic letters represent constructed values that are either not as designed or outside the design range. For slab thickness, the design range is set at (design value +/- 12.7 mm)

Key Observations and Deviations

The following key observations were noted in the project construction report:

  • During the splitspoon testing, a number of areas had existing concrete slabs located beneath the old pavement structure. These areas of concrete were removed and fill was placed in these areas.
  • Because of the process used to remove the existing pavement, it was not possible to obtain undisturbed samples of the existing base or subbase material.
  • Soil boring records were provided that made it unnecessary to perform shoulder probes. The depth to rigid layer exceeded 6.1 m.

Project Status Summary

Overall, this project site is in good shape, given the available data. The appendices to this report contain a significant amount of monitoring data as well as significant materials testing data. However, site condition data, pavement structure data, and other key pavement design feature data are deficient at this time. Not enough data exist in the database to assess the designed versus constructed status of the project.

The following summarizes the status of this project:

  • Designed versus constructed-Good. The key deviations are listed below:
    • Mean 14-day lower flexural strength values deviated by more than 10 percent from the design values.
  • Construction difficulties and deviations-Relatively minor.
    • Data availability-Some missing data, probably in the pipeline.
    • Site condition data not available at the time of analysis.
    • Key PCC materials testing data availability for core sections-Fair, with 71 percent completed.
    • Monitoring data availability-Excellent.

 

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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.
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