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Publication Number: FHWA-RD-01-169
Date: October 2005

Rehabilitation of Jointed Portland Cement Concrete Pavements: SPS-6, Initial Evaluation and Analysis

Chapter 5. DESIGN VERSUS ACTUAL CONSTRUCTION

One of the main objectives of this report is to identify factors introduced into the SPS-6 experiment by virtue of construction deviation or other factors not accounted for in the original experimental design. It is important to evaluate the design variables that are considered key design factors in the SPS-6 experiment and to determine if the as-constructed sections meet the design parameters established in the design factorial. Therefore, this section of the report evaluates the design construction versus the actual construction of key variables as defined by the guidelines for the experiment. The major guidelines established in these documents are described below:

The first report, Guidelines for Nomination and Evaluation of Candidate Projects for Experiment SPS-6 Rehabilitation of Jointed Portland Cement Concrete Pavements, was used to nominate potential candidates for the SPS-6 experiment.(17) According to this report, several key guidelines were listed as follows:

  • Entire project must have the same structural design and construction date.
  • Type, extent, and severity of distress should be relatively uniform over the entire project.
  • Fine-grained soils, such as silty clay materials (A-4, A-5, A-6, and A-7), are preferred; however, coarse-grained soils will also be considered.
  • Pavement must have at least 76 mm (3 inches) of a stabilized or unstabilized base or subbase.
  • Original PCC pavement must have been constructed between 1965 and 1979.
  • PCC pavement must be 203 to 254 mm (8 to 10 inches) thick.

The second report, Specific Pavement Studies Construction Guidelines for Experiment SPS-6, Rehabilitation of Jointed Portland Cement Concrete Pavements, establishes the rehabilitation guidelines for each of the SPS-6 sections.(18) This includes the following guidelines:

  • Thickness tolerances for the AC overlays are ± 6 mm (0.2 inches) for a 102- (4-inch) AC overlay and ± 12 mm (0.5 inches) for a 203-mm (8-inch) AC overlay.
  • Finished AC overlay surfaces should have a prorated profile index (PI) of less than 0.16 m per kilometer (km) (10 inches per mile (mi)) as measured by a California-type profilograph.
  • If a friction course is added to the pavement surface, it shall be limited to 19 mm (0.7 inches) and should not be included in the structural thickness of the AC overlay.

This report also defines the rehabilitation treatments to be applied for each experiment section type. This includes all mandatory and optional rehabilitation treatments, and specific rehabilitation treatments that should not be performed.

This chapter evaluates the design construction versus the actual construction of key variables identified from the experimental design factorial and the experiment guidelines mentioned above. This includes:

  • Site climatic condition.
  • Site traffic.
  • Construction age of original PCC and rehabilitated pavement.
  • Pavement structure.
  • Initial AC smoothness.
  • Rehabilitation treatments.

SITE CLIMATIC CONDITION

All sections in the LTPP program are classified by climatic region based on annual precipitation and the annual freezing index. It was determined that pavements that receive less than 508 mm (20 inches) of precipitation are located in a "dry" region, while precipitation greater than this amount indicates a "wet" region. Pavements located in areas where the annual freezing index is less than 83.3 degree-days (degrees Celsius (°C)) are classified as "no freeze" regions, while a value greater than this indicates a "freeze" region. These climatic zones were used to develop the original SPS-6 design matrix.

Based on this classification system, each of the SPS-6 sites was selected to fill part of the original design matrix. The designated precipitation and freezing index zones are listed in tables 30 and 31, respectively. The actual annual precipitation and freezing index values for each site were obtained from the IMS tables CLM_VWS_PRECIP_ANNUAL and CLM_VWS_TEMP_ANNUAL, respectively, with the exception of the California site. The climatic information was not included in the database received from IMS. Therefore, the climatic information for California was obtained from the DataPave, version 2.0, software program. The average annual precipitation and freezing index values were then compared to those of the designated zone for each SPS-6 site.

Tables 30 and 31 summarize the design versus constructed climatic results. As shown in these tables, most of the sections were constructed in the anticipated climatic zones. However, a few sections did not quite meet the criteria. According to the limits established by the LTPP program, the Arizona, California, and South Dakota sites should be classified as "wet" climatic zones. In addition, the Oklahoma and Tennessee sites should be classified as "freeze" climatic zones and the California sites should be classified as "no freeze" climatic zones.

These changes in the designated climatic zones will alter the original experimental design matrix. This will result in more sites located in the wet-freeze zone and, consequently, fewer sites located in the wet-no freeze and dry-freeze zones.

 

Table 30. Summary of SPS-6 design versus constructed average annual precipitation.
State Weather Station Designated From General Climatic Information Same as Designated?
Zone Precipitation, mm Actual Precipitation, mm
AL N/A Wet > 508 N/A -
AZ VWS Dry < 508 548 No
AR VWS Wet > 508 1326 Yes
CA N/A Dry < 508 910* No
IL VWS Wet > 508 1040 Yes
IN VWS Wet > 508 980 Yes
IA VWS Wet > 508 860 Yes
MI VWS Wet > 508 782 Yes
MO VWS Wet > 508 983 Yes
MO(A) N/A Wet > 508 N/A -
OK VWS Wet > 508 855 Yes
PA VWS Wet > 508 1031 Yes
SD VWS Dry < 508 529 No
TN VWS Wet > 508 1363 Yes

1 mm= .039 inch
N/A= not available
VWS= Contains link between test site and associated virtual weather station.

*Information obtained from DataPave.

 

Table 31. Summary of design versus constructed average annual freezing index.
State Weather Station Designated From General Climatic Information Same as Designated?
Zone Freezing Index, degree-days (°C) (Designed) Freezing Index, degree-days(°C) (Actual)
AL N/A No Freeze < 83.3 N/A -
AZ VWS Freeze > 83.3 275 Yes
AR VWS No Freeze < 83.3 46 Yes
CA N/A Freeze > 83.3 59* No
IL VWS Freeze > 83.3 343 Yes
IN VWS Freeze > 83.3 472 Yes
IA VWS Freeze > 83.3 656 Yes
MI VWS Freeze > 83.3 550 Yes
MO VWS Freeze > 83.3 427 Yes
MO(A) N/A Freeze > 83.3 N/A -
OK VWS No Freeze < 83.3 142 No
PA VWS Freeze > 83.3 405 Yes
SD VWS Freeze > 83.3 1068 Yes
TN VWS No Freeze < 83.3 94 No

°F=1.8*°C+32
N/A= not available
VWS= Contains link between test site and associated virtual weather station.

*Information obtained from DataPave.

SITE TRAFFIC

Table 32 lists the average annual ESALs for each SPS-6 site. Alabama, Arkansas, Missouri (A), and Tennessee do not have any ESAL information in the IMS database. Arizona and California have negative ESAL values in the IMS database. These values are in error and should be corrected before further analysis is conducted. Of the remaining sites, only South Dakota does not meet the ESAL requirement of more than 200,000 rigid ESALs per year. However, based on the location of the site in South Dakota, the ESAL values appear to be correct even though they are lower than that required for the SPS-6 experiment.

 

Table 32. Average annual ESALs for each SPS-6 site.
State Designated Design ESALs Actual Average ESALs Same as Designed?
AL > 200,000 N/A -
AZ > 200,000 Negative value -
AR > 200,000 N/A -
CA > 200,000 Negative value -
IL > 200,000 619,495 Yes
IN > 200,000 443,417 Yes
IA > 200,000 369,056 Yes
MI > 200,000 345,230 Yes
MO > 200,000 499,948 Yes
MO(A) > 200,000 N/A -
OK > 200,000 373,309 Yes
PA > 200,000 2,136,964 Yes
SD > 200,000 58,630 No
TN > 200,000 N/A -

N/A= not available

Because of the existing condition of the calculated ESAL values, a brief review of the single- and tandem-axle distributions and the vehicle classification trends was conducted. In general, the traffic trends appear to be reasonable from year to year. Occasionally, it appears that 1 or 2 years of traffic data were not consistent with the rest of the years. These data should be reviewed and adjusted or corrected as required.

CONSTRUCTION AGE OF ORIGINAL PCC AND REHABILITATED PAVEMENT SECTIONS

According to the design guidelines, the original PCC pavement must have been constructed between 1965 and 1979. Most of the data obtained for this comparison were extracted from the INV_AGE table of the IMS database. Additional dates were obtained from the SPS construction forms/construction reports as noted. The ages of the original PCC pavements (constructed and opened to traffic) for each site are listed in table 33.

Based on these results, most of the sites meet the design guidelines. It should be noted that, of the sites that do not meet the age criteria, Alabama, Illinois, Michigan, and Oklahoma are older than the construction age desired for the project. This should pose no significant problem in the analysis.

 

Table 33. Designed versus selected age of original PCC.
State Constructed Open to Traffic Design Age Criteria Meets Design Criteria?
AL N/A 1/01/64* 1965-1979 No
AZ 9/01/66 1/01/67 Yes
AR 12/01/78 1/01/79 Yes
CA 11/01/73 8/01/74 Yes
IL 6/01/64 4/01/65 No
IN 1/01/72 1/01/74 Yes
IA 11/01/65 11/01/65 Yes
MI 6/01/58 6/01/58 No
MO 7/01/75 10/01/75 Yes
MO(A) N/A 1/01/69* Yes
OK 11/01/62 1/01/63 No
PA 9/01/68 9/01/68 Yes
SD 4/01/73 10/01/73 Yes
TN N/A 1/01/66* Yes

N/A= not available

*Dates obtained from the SPS construction report or LTPP coordinating offices.

PAVEMENT STRUCTURE

Several key parameters were developed for the pavement structure, including the subgrade, base, PCC, and AC overlay layers. Within each of these layers, there are key design components that will affect the overall quality of the SPS-6 experiment. Each key design component was evaluated and discussed as follows for each section within the experiment. This information was extracted from the TST_L05B table (levels A through E) unless specified otherwise.

Subgrade

The initial guidelines established for this experiment identify the subgrade material type as a key design variable.

Material Type

The factorial design for this experiment identifies the fine-grained subgrade soils, such as silty clay materials (A-4, A-5, A-6, and A-7), as influencing factors; however, sections with coarse- grained subgrade soils will also be considered. Table 34 lists the subgrade material codes that were used in the SPS-6 experiment. Most of these codes refer to fine-grained subgrade materials. A few sections have subgrade materials classified as coarse-grained. Even though coarse-grained materials are not recommended for inclusion in this experiment, they are tolerated and, therefore, are included in the study.

Table 35 shows the subgrade material codes for each core and supplemental section included in the experiment. As shown in the table, each section within the experiment has uniform subgrade materials. In addition, most of the sites generally have similar subgrade materials within the entire site. Only Arizona and California were constructed on coarse-grained subgrades. In addition, a couple of sections in Tennessee were also built on coarse-grained subgrade materials.

 

Table 34. IMS material codes and description.
Material Code Material Code Description
102 Fine-grained soils: Lean inorganic clay
104 Fine-grained soils: Clay with gravel
113 Fine-grained soils: Sandy clay
114 Fine-grained soils: Sandy lean clay
119 Fine-grained soils: Sandy clay with gravel
131 Fine-grained soils: Silty clay
141 Fine-grained soils: Silt
148 Fine-grained soils: Clayey silt
203 Coarse-grained soils: Poorly graded sand with gravel
204 Coarse-grained soils: Poorly graded sand with silt
215 Coarse-grained soils: Silty sand with gravel
253 Coarse-grained soils: Poorly graded gravel with sand
287 Sandstone

Base Layer

The initial guidelines established for this experiment identify the thickness of the existing base layer as a key variable in this experiment.

Thickness

As part of the selection criteria for the SPS-6 factorial design, all of the core sections should have a base thickness of at least 76 mm (3 inches). This thickness includes all stabilized or unstabilized base and subbase materials. Table 36 shows the average base thickness for each core and supplemental section included in the experiment. All of the core and State supplemental sections have thicknesses of at least 76 mm (3 inches) and, therefore, meet this criterion.

 

Table 35. As-constructed subgrade material type.
Section State
AL AZ AR CA IL IN IA MI MO MO(A) OK PA SD TN
***601 113 287 - - 113 - 113 131 113 - 141 141 131 204
***602 113 287 - 253 113 113 113 131 113 - 141 141 131 204
***603 113 287 - 253 113 113 113 131 113 - 141 141 148 102
***604 113 287 - 253 113 113 113 131 113 - 141 141 148 114 / 119
***605 113 215 - 253 113 113 113 131 113 - 141 141 148 102
***606 113 215 - 253 113 113 113 131 113 - 141 141 148 102
***607 113 287 - 253 113 113 113 104 113 - 141 141 148 114
***608 113 215 - 203 113 113 113 104 113 - 141 141 148 114
***659   215   253 113 113 113 104 113          
***660   215   253 113 113     113     141 148  
***661 113 287   253 113 113     113     141 148 114
***662 113 215   203 113 113     113     141 148 114
***663 113 215   203 113 113     113          
***664   287   253 113 113     113          
***665   287       113     113          
***666   287       113     113          
***667   287       113                
***668   287       113                
***669   287       113                
***670           113                
***671           113                
***672           113                
Materials in Each State 113 215 / 287   203 / 253 113 113   104 / 131 113   141 141 131 / 148 102 / 114 / 119 / 204

 

Table 36. Designed versus constructed base thickness.
Section Design Base Thickness, mm State
AL AZ AR CA IL IN* IA* MI MO MO(A) OK PA SD TN
***601 At least 76 N/A 325 N/A N/A 178 76 102 1321 107 N/A 419 254 102 152
***602 At least 76 N/A 853 N/A 104 178 76 102 1321 86 N/A 419 305 112 152
***603 At least 76 N/A 307 N/A 102 178 76 102 1016 122 N/A 386 254 112 191
***604 At least 76 N/A 274 N/A 130 178 76 102 1016 114 N/A 386 254 91 168
***605 At least 76 N/A 851 N/A 114 178 76 102 1321 97 N/A 376 279 102 191
***606 At least 76 N/A 292 N/A 114 178 76 102 1016 89 N/A 376 229 112 191
***607 At least 76 N/A 452 N/A 117 178 76 102 1778 107 N/A 386 264 142 168
***608 At least 76 N/A 462 N/A 112 183 76 102 1321 135 N/A 376 241 135 168
***659 At least 76   137   124 178 76 102 864 152          
***660 At least 76   284   211 178 76     107     254 140  
***661 At least 76 N/A 279   130 178 76     107     279 140 168
***662 At least 76 N/A 762   130 178 76     140     254 140 168
***663 At least 76 N/A 274   137 178 76     114          
***664 At least 76   315   135 178 76     130          
***665 At least 76   315       76     117          
***666 At least 76   315       76     117          
***667 At least 76   315       76                
***668 At least 76   315       76                
***669 At least 76   315       76                
***670 At least 76           76                
***671 At least 76           76                
***672 At least 76           76                

1 mm= 039 inch
N/A= not available

*Values listed are the "as-designed" values.

PCC Pavement

The initial guidelines established for this experiment identify the thickness of the existing PCC pavement to be rehabilitated as a key variable in this experiment. In addition, it was specified that the type, extent, and severity of distress should be relatively uniform over the entire project. It is nearly impossible to determine the uniformity of these distresses without the distress maps, which are not currently available. Therefore, at this time, this parameter could not be evaluated.

Thickness

As part of the selection criteria for the SPS-6 factorial design, all of the core sections should have a PCC thickness between 203 and 254 mm (8 and 10 inches). Table 37 shows the average PCC thicknesses for all core and supplemental sections included in the experiment. Because the State supplemental sections are not part of the design factorial established by the experiment, no PCC thickness limits were established for the supplemental sections.

Figure 12 visually illustrates the ranges of constructed PCC thicknesses for the core experiment sections. This figure shows that 9 percent (8 sections) were less than, 89 percent (77 sections) were within, and 2 percent (2 sections) exceeded the proposed design thickness range of 203 to 254 mm (8 to 10 inches).

Figure 12. Frequency of PCC thickness.

Frequency of PCC thickness. Graph. Thickness range is graphed on the horizontal axis from less than 160 to greater than 260 millimeters (6.3 to greater than 10.2 inches) . Frequency is graphed on the vertical axis from 0 to 40 percent. The figure is a histogram with the design range between 200 to 260 millimeters (7.9 to 10.2 inches). There are three histograms between the design range. The highest is 240 to 260 millimeters (9.4 to 10.2 inches) at 37 percent frequency. The other two histograms in the design range are 220 to 240 millimeters (8.7 to 9.4 inches)at 34 percent frequency and 200 to 220 millimeters (7.9 to 8.7 inches) at 17 percent frequency. The remaining thicknesses tested below 20 percent.

 

Table 37. Designed versus constructed PCC thickness.
Section Design Base Thickness, mm State
AL AZ AR CA IL IN* IA* MI MO MO(A) OK PA SD TN
***601 203 to 254 N/A 201 N/A N/A 259 254 254 229 231 N/A 224 262 178 229
***602 203 to 254 N/A 203 N/A 218 257 254 257 229 234 N/A 224 259 178 226
***603 203 to 254 N/A 211 N/A 203 254 254 254 229 231 N/A 229 257 180 229
***604 203 to 254 N/A 208 N/A 211 259 254 246 234 231 N/A 229 262 180 229
***605 203 to 254 N/A 211 N/A 226 259 254 254 229 231 N/A 229 257 178 229
***606 203 to 254 N/A 216 N/A 208 257 254 254 241 226 N/A 231 257 183 241
***607 203 to 254 N/A 213 N/A 208 257 254 254 229 236 N/A 229 257 185 224
***608 203 to 254 N/A 208 N/A 216 257 254 254 236 239 N/A 234 257 196 218
***659 203 to 254   213   216 259 254 244 241 236          
***660 203 to 254   211   114 259 254     246     269 185  
***661 203 to 254 N/A 213   216 267 254     239     254 185 229
***662 203 to 254 N/A 203   208 259 254     239     259 185 226
***663 203 to 254 N/A 254   25 254 254     241          
***664 203 to 254   201   211 254 254     246          
***665 203 to 254   201       254     229          
***666 203 to 254   201       254     231          
***667 203 to 254   201       254                
***668 203 to 254   201       254                
***669 203 to 254   201       254                
***670 203 to 254           254                
***671 203 to 254           254                
***672 203 to 254           254                

1 mm= 039 inch
N/A= not available

*Values listed are the "as-designed" values.

AC Overlay Thickness

Based on the data stored in IMS for the SPS-6 experimental design plan, sections ***603, ***604, ***606, and ***607 were designed to have 102-mm (4-inch) AC overlays and section ***608 was designed with a 203-mm (8-inch) AC overlay. The allowable construction design thickness ranges from 95 to 108 mm (3.7 inches to 4.3 inches) for the 102-mm (4-inch) overlays and 190 to 216 mm (7.5 inches to 8.5 inches) for the 203-mm (8-inch) overlays.

Table 38 shows the average AC overlay thicknesses as constructed for all core and supplemental sections included in the SPS-6 experiment. Because the State supplemental sections are not part of the design factorial established by the experiment, no AC overlay thickness limits were established. This information is visually illustrated in figures 13 and 14 for the core experiment sections with 102-mm (4-inch) and 203-mm (8-inch) AC overlays, respectively. Figure 13 shows that 16 percent (7 sections) were less than, 48 percent (21 sections) were within, and 36 percent (16 sections) exceeded the design thickness of 102 mm (4 inches). Likewise, figure 14 shows that 27 percent (three sections) were less than, 55 percent (six sections) were within, and 18 percent (two sections) exceeded the proposed design thickness of 203 mm (8 inches).

INITIAL AC OVERLAY SMOOTHNESS

The initial smoothness of the AC overlays has also been identified as a key issue. It is important that the surface of an AC overlay be constructed to a sufficient smoothness. A high degree of variability in the pavement smoothness will result in a very rough riding surface. This constructed roughness may lead to early deterioration of the pavement because of vehicular response and dynamic loading. The smoothness of each AC overlay will be evaluated using the initial PI.

Initial Profile Index

The construction guidelines have noted the importance of AC surface smoothness on the finished surface of the overlay immediately after construction.(18) It is desirable that each AC overlay is smooth and provides an excellent level of ride; each overlay shall be evaluated using the prorated PI. A PI of less than 0.16 m/km (10 inches/mi) (5-mm (0.2-inch) blanking band) as measured by a California-type profilograph will achieve this goal.

 

Table 38. Designed versus constructed AC overlay thickness.
Section Design Base Thickness, mm State
AL AZ AR CA IL IN* IA* MI MO MO(A) OK PA SD TN
***601                              
***602                              
***603 95 to 108 N/A 102 N/A 97 94 102 102 130 97 N/A 102 102 112 112
***604 95 to 108 N/A 102 N/A 114 94 102 117 137 97 N/A 97 109 112 107
***605                              
***606 95 to 108 N/A 119 N/A 79 79 102 104 127 91 N/A 109 114 109 104
***607 95 to 108 N/A 117 N/A 94 94 102 104 117 109 N/A 117 112 122 112
***608 190 to 216 N/A 224 N/A 206 173 203 203 173 201 N/A 198 213 168 221
***659 Variable   114   107 84 140 102 102 109          
***660 Variable   216   107   140     198     241 147  
***661 Variable N/A 114   107   102     290     665 117 211
***662 Variable N/A 114     89 254     185     196 104 218
***663 Variable N/A 51     203 140     272          
***664 Variable   152   107 152 140     175          
***665 Variable   152       140     117          
***666 Variable   152       140                
***667 Variable   152       140                
***668 Variable   152       140                
***669 Variable   152       102                
***670 Variable           102                
***671 Variable           102                
***672 Variable           140                

1 mm= 039 inch
N/A= not available

*Values listed are the "as-designed" values.

Figure 13. Frequency of 102-mm (4-inch) AC overlays.

Frequency of 102-millimeter (4-inch) AC overlays. Graph. Thickness range is graphed on the horizontal axis from less than 95 to greater than 125 millimeters (3.7 to greater than 4.9 inches). Frequency is graphed on the vertical axis from 0 to 30 percent. The design range falls between 95 to 110 millimeters (3.7 to 4.3 inches). The three histograms between the design ranges are 95 to 100 millimeters (3.7 to 3.9 inches) at 8 percent, 100 to 105 millimeters (3.9 to 4.1 inches) at 27 percent, and 105 to 110 millimeters (4.1 to 4.3 inches) at 12 percent.

Figure 14. Frequency of 203-mm (8 inch) AC overlays.

Frequency of 203-millimeter (8-inch) AC overlays. Graph. Thickness range is graphed on the horizontal axis from less than 190 to greater than 220 millimeters (7.4 to greater than 8.7 inches). Frequency is graphed on the vertical axis from 0 to 30 percent. The design range is between 190 and 215 millimeters (7.4 to 8.5 inches). The center of the design range is 200 to 205 millimeters (7.9 to 8.1 inches) at 27 percent frequency. Thicknesses between 195 to 200 millimeters (7.8 to 7.9 inches), 205 to 210 millimeters (8.1 to 8.2 inches), and 210 to 215 millimeters (8.2 to 8.5 inches) are all at 8 percent.

The PI values immediately after construction are listed in IMS table SPS6_QC_MEASUREMENTS. These results are listed in table 39. Unfortunately, this table only contains PI values for three States, and only a small percentage of these PI values meet the design criteria. In addition, the PI values for Missouri are significantly different than the Indiana and Iowa sites, indicating that Missouri data may, in fact, be another measure of roughness and should not be included in this IMS table. Therefore, it is not possible to accurately assess the PI value directly for each of the SPS-6 sites. However, a correlation exists between the PI and the International Roughness Index (IRI). Therefore, it can be determined whether these sections were approximately below the specified PI values immediately after construction based on the corresponding IRI values. This correlation is based on a study by Kalevela, Kombe, and Scofield(19) and is shown as follows (in English units of inches/mi):

(1)

AVG IRI= 52.9 + 6.1 * PI

Based on a PI value of 0.16 m/km (10 inches/mi), the estimated average IRI is approximately 1.82 m/km (114 inches/mi). Table 40 lists the average IRI values for each section using the first average IRI rating available immediately after the AC overlay was placed. All average IRI data for these sections were collected between 2 and 13 months after placement of the AC overlay. All of the pavement sections listed meet this criterion.

REHABILITATION TREATMENTS

The appropriate rehabilitation treatments for each section of the SPS-6 experiment are listed in table 41. A comparison of the designed rehabilitation treatments and the treatments applied to each section is summarized in tables 42 through 49. These tables provide an overview of the rehabilitation treatments applied at each section. More detailed information about the rehabilitation conducted is available in appendix A or in the construction reports.

In general, the sections in poor condition received more treatments than the pavement sections in fair condition. From these tables, it can be noted that most of the SHAs completed the required rehabilitation treatments as designated for each section. In addition, most of the SHAs conducted some optional rehabilitation alternatives based on their pavement experience and the initial pavement condition prior to rehabilitation. A few of the SHAs also performed rehabilitation treatments that were specifically identified as treatments not to be performed. The required and optional treatments, and the treatments that were not to be performed, will have some effect on the performance of each pavement section and should be monitored closely.

 

Table 39. PI values (5-mm (0.2-inch) blanking band) immediately after rehabilitation.
Section Design Base Thickness, mm State
AL AZ AR CA IL IN* IA* MI MO MO(A) OK PA SD TN
***601                              
***602                              
***603 <10           27 12   2          
***604 <10           15 12   1.5          
***605                              
***606 <10           5 12   1.8          
***607 <10           25 12   1.8          
***608 <10           15 12   1.8          
***659 <10           35 12   1.8          
***660 <10           13     1.8          
***661 <10           5     1.8          
***662 <10           10     1.8          
***663 <10           38     1.8          
***664 <10           15     1.8          
***665 <10           8     1.8          
***666 <10           10                
***667 <10                            
***668 <10           40                
***669 <10           23                
***670 <10           30                
***671 <10           8                
***672 <10           55                

1 inch/mi= 15.8 mm/km

 

Table 40. Average IRI values after AC overlay construction.
Section Design Base Thickness, mm State
AL AZ AR CA IL IN* IA* MI MO MO(A) OK PA SD TN
***601                              
***602                              
***603 <1.82   0.88 0.91 0.85 1.02 0.88 0.90 1.29 1.09   0.74 1.07 1.09 0.71
***604 <1.82   0.86 0.99 0.81 1.13 0.92 1.06 1.15 1.08   0.86 1.14 1.26 0.66
***605                              
***606 <1.82   1.00 0.98 0.95 1.07 0.94 0.92 0.90 1.10   0.92 1.09 1.04 0.83
***607 <1.82   0.80 1.05 1.01 1.22 0.99 1.02 1.07 131   1.08 1.04 1.02 0.68
***608 <1.82   0.90 0.87 0.89 1.16 0.93 1.21 0.87 1.28   1.27 1.00 0.84 0.75
***659 <1.82   1.06   0.70 1.37 1.10 1.00 1.14 1.26          
***660 <1.82   1.01   0.81   1.10     1.18     0.96 0.88  
***661 <1.82   0.72   0.83   0.95     1.22     0.84 1.02 0.76
***662 <1.82   0.77     1.10 0.85     1.24     0.91 1.05 0.75
***663 <1.82   1.44     0.92 1.17     1.37          
***664 <1.82   0.69   0.91 1.08 1.15     1.18          
***665 <1.82   0.69       0.93     1.15          
***666 <1.82   0.63       0.88                
***667 <1.82   1.05       0.95                
***668 <1.82   0.61       1.07                
***669 <1.82   0.77       1.04                
***670 <1.82           1.00                
***671 <1.82           1.08                
***672 <1.82           1.10                

1 m/km= 63.36 inches

 

Table 41. Rehabilitation treatments for SPS-6 test sections.
Section Rehabilitation Treatments
***601 Routine maintenance only (as per agency practice):
3 to 5 years of service desired.
***602 Minimal surface preparation, no AC overlay:
  • Perform joint and crack sealing, if warranted.
  • Perform partial and full-depth patching, if warranted.
  • Perform full-surface diamond grinding, if warranted.
***603 Minimal surface preparation with 102-mm (4-inch) AC overlay:
  • Perform partial- and full-depth patching, if warranted.
  • Place 102-mm- (4-inch-) thick AC overlay.
***604 Minimal surface preparation with saw and seal of 102-mm (4-inch) AC overlay:
  • Perform partial- and full-depth patching, if warranted.
  • Place 102-mm- (4-inch-) thick AC overlay.
  • Saw and seal overlay over existing PCC pavement joints and working cracks.
***605 Intensive surface preparation, no AC overlay:
  • Remove and replace existing joint and crack sealing.
  • Perform additional joint and crack sealing, if warranted.
  • Remove and replace existing partial- and full-depth patches.
  • Perform additional partial- and full-depth patching, if warranted.
  • Correct poor load transfer at joints and/or working cracks by full-depth patching or retrofitting dowels.
  • Perform full-surface diamond grinding.
  • Retrofit subsurface edge drainage system.
  • Perform undersealing, if warranted.
***606 Intensive surface preparation with 102-mm (4-inch) AC overlay:
  • Remove and replace existing partial- and full-depth patches.
  • Perform additional partial- and full-depth patching, if warranted.
  • Correct poor load transfer at joints and/or working cracks by full-depth patching or retrofitting dowels.
  • Retrofit subsurface edge drainage system.
  • Perform undersealing, if warranted.
  • Place 102-mm- (4-inch-) thick AC overlay.
***607 Crack/break and seat section with 102-mm (4-inch) AC overlay:
  • Crack/break and seat.
  • Retrofit subsurface edge drainage system.
  • Total section length, including transition, should be at least 457.5 m (1500 ft) (152.5-m (500-ft) transitions at each end).
  • Place 102-mm- (4-inch-) thick AC overlay.
***608 Crack and seat section with 203-mm (8-inch) AC overlay:
  • Crack/break and seat.
  • Retrofit subsurface edge drainage system.
  • Place 203-mm- (8-inch-) thick AC overlay.

 

Table 42. Control section with routine maintenance, no restoration or rehabilitation (***601).
Preparation Technique State
AL AZ AR CA IL IN IA MI MO MO(A) OK PA SD TN
Joint sealing1     v             v v     v
Crack sealing1     v             v        
Partial-depth patch2     v                      
Full-depth patch/joint repair2     v               v      
Slab replacement2                           v
Initial Pavement Condition Fair Poor Poor Poor Poor Poor Fair Fair Poor Fair Fair Fair Fair Fair

1Optional treatment
2"Do not perform" treatment

 

Table 43. Minimum restoration for bare PCC sections (***602).
Preparation Technique State
AL AZ AR CA IL IN IA MI MO MO(A) OK PA SD TN
Joint sealing1 v v v v v   v   v v v   v v
Crack sealing1   v v v v     v v v     v  
Partial-depth patch2   v v v     v v            
Full-depth patch/joint repair2 v   v v v v   v v v v   v v
Slab replacement2 v   v v     v   v v v   v v
Initial Pavement Condition Fair Poor Poor Poor Poor Poor Fair Fair Poor Fair Fair Fair Fair Fair

1Optional treatment

 

Table 44. Minimum restoration prior to AC overlay (***603).
Preparation Technique State
AL AZ AR CA IL IN IA MI MO MO(A) OK PA SD TN
Partial-depth patch1   v v v   v   v       v    
Full-depth patch/joint repair1   v v v       v   v v v v  
Joint sealing2     v                      
Crack sealing2     v                      
Subdrainage2           v           v   v
Diamond grinding2                           v
Initial Pavement Condition Fair Poor Poor Poor Poor Poor Fair Fair Poor Fair Fair Fair Fair Fair

1Optional treatment
2"Do not perform" treatment

 

Table 45. Minimum restoration prior to AC overlay with saw and seal (***604).
Preparation Technique State
AL AZ AR CA IL IN IA MI MO MO(A) OK PA SD TN
Saw and seal1 v v v v v v v v v v v v v v
Partial-depth patch2   v v v   v   v       v    
Full-depth patch/joint repair2   v v v v v   v v v v v v v
Crack sealing3     v                      
Joint sealing3     v                      
Diamond grinding3                           v
Subdrainage3                       v    
Initial Pavement Condition Fair Poor Poor Poor Poor Poor Fair Fair Poor Fair Fair Fair Fair Fair

1Required treatment
2Optional treatment
3"Do not perform" treatment

 

Table 46. Maximum restoration of bare PCC (***605).
Preparation Technique State
AL AZ AR CA IL IN IA MI MO MO(A) OK PA SD TN
Diamond grinding1 v v v 3 v   v   v v v v v v
Subdrainage1 v   v v v v v v v v v v v v
Joint sealing2 v v v   v   v v v v v v v v
Crack sealing2   v v   v   v v v v     v  
Partial-depth patch2   v v       v v       v    
Full-depth patch/joint repair2 v v v   v v v v v v v v v v
Full-depth slab replacement2       v                    
Load-transfer restoration2 v   v       v         v v  
Undersealing2 v       v       v v   v v  
Initial Pavement Condition Fair Poor Poor Poor Poor Poor Fair Fair Poor Fair Fair Fair Fair Fair

1Required treatment
2Optional treatment

 

Table 47. Maximum restoration prior to AC overlay (***606).
Preparation Technique State
AL AZ AR CA IL IN IA MI MO MO(A) OK PA SD TN
Subdrainage1 v   v v v v v v v v v v v v
Partial-depth patch2   v v v   v v v       v    
Full-depth patch/joint repair2 v v v v v v v v   v v v v v
Load-transfer restoration2 v   v       v         v v  
Undersealing2         v       v v   v v  
Joint sealing3     v                      
Crack sealing3     v                      
Diamond grinding3                           v
Initial Pavement Condition Fair Poor Poor Poor Poor Poor Fair Fair Poor Fair Fair Fair Fair Fair

1Required treatment
2Optional treatment
3"Do not perform" treatment

 

Table 48. Crack/break and seat with 102-mm (4-inch) AC overlay (***607).
Preparation Technique State
AL AZ AR CA IL IN IA MI MO MO(A) OK PA SD TN
Crack/break and seat1 v v v v v v v v v v   v v v
Subdrainage1 v   v v v v v   v v v v v v
Rubblizing2                     v      
Full-depth repair2                           v
Initial Pavement Condition Fair Poor Poor Poor Poor Poor Fair Fair Poor Fair Fair Fair Fair Fair

1Required treatment
2"Do not perform" treatment
v Procedure did not break through slabs.

 

Table 49. Crack/break and seat with 203-mm (8-inch) AC overlay (***608).
Preparation Technique State
AL AZ AR CA IL IN IA MI MO MO(A) OK PA SD TN
Crack/break and seat1 v v v v v v v v v v   v v v
Subdrainage1 v   v v v v v   v v v v v v
Rubblizing2                     v      
Full-depth repair2                           v
Initial Pavement Condition Fair Poor Poor Poor Poor Poor Fair Fair Poor Fair Fair Fair Fair Fair

1Required treatment
2"Do not perform" treatment
v Procedure did not break through slabs.

IMPACT ON EXPERIMENTAL FACTORIAL DESIGN

Based on the data available at the time of the IMS data request for each of these sites, the actual traffic and climatic information was used to reorganize the sites within the original design matrix. The climatic location of the Alabama site could not be verified at this time. In addition, the traffic levels for Alabama, Arizona, Arkansas, California, Missouri (A), and Tennessee could not be verified either. Additional information is needed in the IMS database to further verify the location of these sites within the design matrix.

According to the climatic specifications of less than 508 mm (20 inches) of precipitation signifying a "dry" climatic zone and a freezing index of less than 83.3 degree-days signifying a "no freeze" climatic zone, the SPS-6 sites should be placed in the cells shown in table 50. Actual climatic data were used to relocate each site into the appropriate location within the design matrix. Bolded sites indicate that the site was designed and nominated for a different climatic zone than that supported by the as-built climatic data. In addition, the South Dakota site does not meet the minimum traffic requirement of more than 200,000 ESALs per year.

As noted in table 50, many sites are now located in the wet-freeze climatic region. This will allow for a complete analysis of the wet-freeze climatic region. Unfortunately, many sites are now missing from the wet-no freeze, dry-freeze, and dry-no freeze zones. As mentioned earlier, each asterisk indicates that an additional site is needed to complete that portion of the design matrix. The impact of changing the climatic zones of the sites is only important in that it limits the range of climatic site conditions for which performance results are available for each climatic region. In other words, there is excellent coverage in the wet-freeze areas for both JPCP and JRCP, and excellent coverage for JPCP in wet-no freeze areas. There is no coverage of either JPCP or JRCP in dry areas.

 

Table 50. As-built sites as placed in original design factorial.
    Wet Dry
    Freeze No Freeze Freeze No Freeze
JPCP Fair MO(A), SD, TN AL, * ** *
Poor AZ, IN AR, CA ** *
JRCP Fair IA, MI, OK, PA ** *  
Poor IL, MO ** *  

Notes:

  • Each * indicates that an additional site is needed to complete the original design matrix.
  • Bolded sections were originally in another cell of the design matrix.
  • Italicized sections indicate that the site did not meet the minimum traffic requirements.
  • MO(A) is the second SPS-6 site constructed in Missouri; the first site is designated as MO.
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