Using Existing Pavement in Place and Achieving Long Life (2014)

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65 A p p e n d i x B Data available from the Long-Term Pavement Performance (LTPP) experiment provide valuable information on the materials, climate, and traffic of test sections with measured performance data. This information was an integral part of the project because it provides an indication of pavement life under various conditions. AC Renewal projects The following LTPP experiments were reviewed to determine the pavement life achieved for hot-mix asphalt (HMA)-surfaced pavements: • General Pavement Study (GPS)-6A: Existing AC Overlay on AC Pavement; • GPS-6B: AC Overlay with Conventional Asphalt Cement on AC Pavement; • GPS-7A: Existing AC Overlay on PCC Pavement; • GPS-7B: AC Overlay with Conventional Asphalt Cement on PCC Pavement; • Specific Pavement Study (SPS)-5: AC Overlay of AC Pave- ment; and • SPS-6: Rehabilitation of Jointed PCC Pavement. The LTPP DataPave Online database (Release 21, January 2007) was used as the primary data source. Layer Inventory information was extracted from the table TST_L05B in IMS module TST (Testing) and has been summarized by • Layer number, • Layer type, • Layer description, • Representative thickness, • Material type, and • Construction number. “Pavement Age” was calculated at different construction events for each section in a given state as follows: (1) age since initial construction, (2) age at the time of overlay, and (3) age since overlay construction. The initial date was taken as the “Traffic Opening Date” for GPS sections and the “Assigned Date” for SPS sections. Age at the time of overlay was calculated as the difference between “CN Change Date” for SPS-5, SPS-6, GPS-6B and GPS-7B sections, or “Major Improvement Date” for GPS-6A and GPS-7A sections (these sections have been fixed before their “Assign Date”) and the initial date, or the date of any previous fix. The latest “Survey Date” was taken as the end date. Performance data, including “Longitudinal Cracking,” “Alligator (Fatigue) Cracking,” “Transverse Cracking,” “Rut Depth,” and international roughness index (“IRI”), were plotted against pavement age. Sections with the longest overlay ages were selected within the experiment, and “Traffic Data” [equivalent single axle loads (ESALs)] corresponding to pavement age were extracted from “TRF_MON_EST_HIST.” In some cases, due to missing “Traffic Monitoring” data, ESAL counts were estimated for the latest reported “Survey Date” by fitting the recorded data and extrapolating. The following summarizes the main statistics obtained from each experiment, focusing only on (1) age at last survey, (2) original pavement type, and (3) overlay thickness. Note that the lower overlay ages do not necessarily imply poor perfor- mance, since these are ages at the latest survey and are not tied to any performance criterion. Older overlays merit further investigation. The next step is to look into the better-performing sections to determine potential long-life pavement candidates, if any. To do so, different criteria were considered for selecting sections. Initially, pavements with “Longer Lasting Overlay” were selected within each experiment. Tables B.1, B.4, B.7, B.10, B.13, and B.14 summarize the sections that met this criterion. Except for Asphalt Overlay over CRCP, the outcome of this exercise was not conclusive since overlay age is determined up to the latest survey date and not to the end of its life based on some perfor- mance threshold. Therefore, younger overlay structures may Synthesis of Data on Long-Term Pavement Performance

66 potentially live longer. Also, performance of a given pavement structure depends on traffic volume. Therefore, a relatively thick pavement structure that was exposed to low ESALs may not necessarily represent a good-performing pavement. Next, we selected sections within each experiment that have been subjected to “Heavy Volume of Traffic”; that is, cumulative ESAL counts within an experiment were extrapolated up to the latest survey date. Then, projected ESAL was normalized to pavement age. Within each experiment, sections of higher ESAL count per year were selected, and their performance was evaluated. Tables B.2, B.5, B.8, and B.11 represent such sections. Some sections have shown an acceptable level of performance after rehabilitation while serving higher traffic volume. Such cross sections can be candidates for perpetual pavement analysis. The third approach was to select “Good Performing” sections using “Fatigue Cracking” and “Rutting” performance as the critical distresses. Good-performing cross sections within each experiment were selected and the number of ESALs was pro- jected up to the latest survey date. These sections were catego- rized as “Thin,” “Medium,” and “Thick” structures as follows: • “Thin Structure” refers to any thickness of less than 5 in. for asphalt concrete layers and 9 in. for portland cement concrete layers. • “Medium Structure” refers to any thickness for asphalt concrete layers that is greater than 5 in. but less than 9 in. For portland cement concrete layers, these limits change to 9 and 12 in., respectively. • “Thick Structure” refers to any asphalt concrete layer and portland cement concrete layers with a thickness greater than 9 in. and 12 in., respectively. Tables B.3, B.6, B.9, and B.12 present such cross sections within the different experiments. Not all the sections were useful since either overlays were not old enough to represent a reasonable trend of performance, or sections were exposed to lower traffic volume. GPS-6A: Existing AC Overlay on AC Pavement There are a total of 51 sections in 25 states within this experi- ment. Figure B.1 summarizes the frequency of overlay age within the experiment. Tables B.1, B.2, and B.3 summarize the relevant inventory and performance information on sections with the longest overlay ages, those with high traffic loading, and those with the best performance in cracking and rutting. Summary Interpretation At first glance, no real trends can be observed in Table B.1. It shows that HMA overlays on existing HMA pavements can perform at an acceptable level for up to 30 or more years. However, the required overlay thickness (obviously) depends on the traffic loading: Section 19-6150 has received only a surface treatment and its cumulative ESAL is only 236,000, clearly indicating that it is a low-volume road. Also, it has extensive transverse cracking (at about 5 ft spacing). Section 48-1046 (Texas) has a 10-in. HMA overlay, which is expected for a cumulative traffic of 14.8 million ESALs. It has clearly reached its fatigue end life since it has more than 50% cracking. Section 48-6179 has a 4-in. HMA overlay with 1.8 million ESALs. Section 47-6015 was selected for mechanistic analysis. It is 30 years old with an original 8.8-in. HMA layer and a GPS 6A 0 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 Overlay Age (Year) N um be r o f P ro jec ts Figure B.1. Frequency of overlay age within experiment GPS-6A.

67 Table B.2. Summary of Sections Subjected to High-Volume Traffic within GPS-6A Experiment State SHRP ID Initial Structure Thickness (in.) Overlay Thickness (in.) Overlay Age (years) Traffic (KESAL) per Year Longitudinal Cracking (m) Fatigue Cracking (%) No. of Transverse Cracking Rut Depth (mm) IRI (m/km) GPS-6A 4 6053 3.2 4.2 16 1690 No data No data No data 13 1.604 4 6054 7.0 1.4 15 1085 14.3 20.6 23.0 9 1.316 4 6055 1.8 3.8 No data 814 No data No data No data 5 0.765 4 6060 3.9 3.4 13 943 0.0 0.0 0.0 55 0.502 18 6012 14.8 4.0 15 2137 0.0 0.0 0.0 11 2.957 19 6049 20.4 2.8 26 785 1.0 18.55 25.0 9 2.125 41 6011 6.1 6.8 22 1547 0.0 0.0 0.0 4 1.183 47 6015 8.8 5.5 19 986 0.0 0.0 0.0 3 0.588 Table B.1. Summary of Sections with the Longest Overlay Age within GPS-6A State SHRP ID Traffic Open Date Overlay Construction Date Overlay Thickness (in.) Overlay Age (years) Traffic (KESAL) Longitudinal Cracking (m) Fatigue Cracking (%) No. of Transverse Cracking Rut Depth (mm) IRI (m/km) 19 6150 8/1/1952 1965 0.4 34 236 0 3.95 102 10 1.830 48 1046 7/1/1956 1971 10.1 32 14798 0 52.83 35 8 2.782 48 6179 6/1/1965 1975 4.1 29 1806 1.20 0 18 11 1.702 Table B.3. Summary of Good-Performing Sections within GPS-6A Experiment State SHRP ID Age (years) Traffic (KESAL) Original Thickness (in.) Overlay Thickness (in.) Overlay Age (years) GPS-6A 30 7075 40 16618 3.40 Thin 3.70a 3.00 19 3.50 4 48 6179 38 2084 1.40 Thin 4.10 29 56 6029 29 892 1.90 Thin 2.70a 1.60 21 1.10 8 1 6019 20 6874 8.30 Medium 5.00a 2.80 13 2.40 8 47 6015 30 23647 8.80 Medium 5.50 19 48 6086 29 2771 8.50 Medium 1.50 16 49 1006 31 5556 9.20 Thick 1.30 15 56 6031 26 521 11.10 Thick 4.60a 2.30 14 2.30 7 56 6032 28 874 11.70 Thick 4.20a 2.30 12 1.00 9 1.00 0 a Mill and fill.

68 5.5-in. overlay. It has been subjected to 23.6 million ESALs and the overlay age is 19 years at the latest survey date. It has no fatigue, no longitudinal or transverse cracking, only 3 mm of rutting, and an international roughness index (IRI) of 0.6 m/km. GPS-6B: AC Overlay with Conventional Asphalt Cement on AC Pavement There are a total of 87 sections in 32 states within this experi- ment. Figure B.2 summarizes frequency of overlay age within the experiment. Tables B.4, B.5, and B.6 summarize the relevant inventory and performance information on sections with the longest overlay ages, those with high ESAL, and those with the best performance in cracking and rutting. Summary Interpretation Neither of the sections with the longest overlay age is promising because they both have fatigue and transverse cracking after 17 years. Two sections subjected to heavy traffic are promising: 18-2008 and 47-3108. They have very little to no cracking, low rutting and IRI values after 11 and 16 years, with 1.275 and 0.861 million ESAL/year, respectively. Two good-performing sections are promising: 6-8535 and 47-3108. They have very GPS 6B 0 2 4 6 8 10 12 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Overlay Age (Year) N um be r o f P ro jec ts Figure B.2. Frequency of overlay age within experiment GPS-6B. Table B.4. Inventory Information of Sections with the Longest Overlay Age within GPS-6B State SHRP ID Traffic Open Date Overlay Construction Date Overlay Thickness (in.) Overlay Age (years) Traffic (KESAL) Longitudinal Cracking (m) Fatigue Cracking (%) No. of Transverse Cracking Rut Depth (mm) IRI (m/km) 47 3109 11/1/1978 6/25/1989 1.70 17 1808 0 2.30 14 6 1.203 47 3110 8/1/1981 6/15/1989 1.40 17 2251 0 5.79 71 4 0.758 Table B.5. Inventory Information of Sections Subjected to High-Volume Traffic within GPS-6B Experiment State SHRP ID Initial Structure Thickness (in.) Overlay Thickness (in.) Overlay Age (years) Traffic (KESAL) per Year Longitudinal Cracking (m) Fatigue Cracking (%) No. of Transverse Cracking Rut Depth (mm) IRI (m/km) GPS-6B 18 2008 12.9 2.5 11 1275 0.0 0.0 0.0 1 0.541 36 1643 2.2 2.9 9 1017 0.0 37.12 19.0 4 1.078 47 1023 5.3 1.7 11 859 0.0 0.93 20.0 9 1.679 47 3108 5.5 2.7 16 861 0.0 0.07 2.0 6 0.782

69 little to no cracking, low rutting and IRI values after 13 and 16 years, with 16.7 and 28.4 million ESALs, respectively. Section 47-3108 was selected for mechanistic analysis. It is 33 years old with an original 5.5-in. HMA layer and a 2.7-in. overlay. It has been subjected to 28.4 million ESALs and the overlay age is 16 years at the latest survey date. It has no longitudinal cracking, very little fatigue and transverse crack- ing, 6 mm of rutting, and an IRI of 0.78 m/km. GPS-7A: Existing AC Overlay on PCC Pavement There are a total of 30 sections in 19 states within this experi- ment. Figure B.3 summarizes the frequency of overlay age within the experiment. Tables B.7, B.8, and B.9 summarize the relevant inventory and performance information on sections with the longest overlay ages, those with high ESAL, and those with the best performance in cracking and rutting. Summary Interpretation None of the sections with the longest overlay age is promising because they have a high level of transverse cracking after more than 20 years. One section subjected to heavy traffic may be promising: 13-7028. It has no longitudinal or fatigue cracking, but some transverse cracking. It has 7 mm of rutting and an IRI of 1.1 m/km after 12 years, with 16.8 million ESALs. Two good- performing sections are promising: 13-7028 and 31-7005. They Table B.6. Inventory Information of Good-Performing Sections within GPS-6B Experiment State SHRP ID Age (years) Traffic (KESAL) Original Thickness (in.) Overlay Thickness (in.) Overlay Age (years) GPS-6B 2 1002 21 772 3.30 Thin 2.00 7 2 1004 28 3900 3.60 Thin 1.80 14 6 8534 35 8348 4.80 Thin 5.70 13 30 7076 19 4412 4.50 Thin 2.40a 2.40 10 2.40 3 30 7088 24 7957 4.60 Thin 2.40a 2.40 4 1.70 10 30 8129 16 1544 3.00 Thin 3.80 1 40 4086 34 5962 4.30 Thin 3.60 15 40 4164 26 2455 4.60 Thin 1.00 10 48 1130 33 1885 2.30 Thin 1.60 13 56 2017 23 1432 2.40 Thin 1.20 6 56 2019 19 2289 3.40 Thin 2.70 8 56 7772 18 811 2.20 Thin 2.40 6 6 8535 37 16686 6.60 Medium 5.30 13 23 1028 32 5901 6.60 Medium 1.90 10 42 1597 23 442 6.40 Medium 6.30 3 42 1605 32 5165 8.10 Medium 2.70 8 47 2001 27 9849 6.80 Medium 6.60 15 47 3108 33 28429 5.50 Medium 2.70 16 47 9024 29 933 5.10 Medium 1.30 11 48 1096 25 3017 7.10 Medium 2.00 5 48 1111 33 3094 6.90 Medium 2.70 6 48 3835 12 2992 8.50 Medium 5.90 4 18 1037 23 2046 14.40 Thick 4.30 11 28 3094 24 6133 10.90 Thick 2.70 16 a Mill and fill.

70 Table B.7. Inventory Information of Sections with the Longest Overlay Age within GPS-7A State SHRP ID Original Pavement Typea Traffic Open Date Overlay Construction Date Overlay Thickness (in.) Overlay Age (years) Traffic (KESAL) Longitudinal Cracking (m) Fatigue Cracking (%) No. of Transverse Cracking Rut Depth (mm) IRI (m/km) 29 7054 JRCP 6/1/1957 1973 4.50 21 30246 No data No data No data 7 1.011 29 7073 JPCP 6/1/1964 1981 2.40 20 2314 0 0 70 3 1.501 41 7019 JRCP 6/1/1947 1976 2.10 22 7970 0 0 32 17 1.785 46 7049 JPCP 12/1/1954 1980 4.10 23 258 0 0 91 15 4.208 a JPCP, jointed plain concrete pavement; JRCP, jointed reinforced concrete pavement. Table B.8. Inventory Information of Sections Subjected to High Volume Traffic within GPS-7A Experiment State SHRP ID Initial Structure Thickness (in.) Original Pavement Typea Overlay Thickness (in.) Overlay Age (years) Traffic (KESAL) per Year Longitudinal Cracking (m) Fatigue Cracking (%) No. of Transverse Cracking Rut Depth (mm) IRI (m/km) GPS-7A 13 7028 9.1 JPCP 6.0 12 1366 0.0 0.0 27 7 1.118 17 5453 8.4 CRCP 2.7 13 1059 33.5 1.51 67 3 1.231 29 7054 10.1 JRCP 4.5 21 829 No data No data No data 7 1.011 39 7021 9.0 JRCP 2.6 14 1521 No data No data No data 6 2.444 41 7018 7.7 JRCP 1.6 14 771 0.0 0.0 9 18 1.542 a CRCP, continuously reinforced concrete pavement; JPCP, jointed plain concrete pavement; JRCP, jointed reinforced concrete pavement.

71 GPS 7A 0 1 2 3 4 5 6 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Overlay Age (Year) N um be r o f P ro jec ts Figure B.3. Frequency of overlay age within experiment GPS-7A. Table B.9. Inventory Information of Good-Performing Sections within GPS-7A Experiment State SHRP ID Age (years) Traffic (KESAL) Original Thicknessa (in.) Overlay Thickness (in.) Overlay Age (years) GPS-7A 44 7401 42 5129 8.20 Thin JRCP 5.20b 2.60 17 3.20 2 46 7049 48 283 7.40 Thin JPCP 4.10 23 13 7028 17 16763 9.10 Medium JPCP 7.00b 6.00 12 2.50 5 31 7005 44 17824 9.60 Medium JPCP 5.30b 4.50 12 2.00 10 31 7050 42 21857 9.00 Medium JRCP 4.50b 3.40 10 1.50 8 3.00 0 1.40 1 a JPCP, jointed plain concrete pavement; JRCP, jointed reinforced concrete pavement. b Mill and fill.

72 have very little to no cracking, low rutting and IRI values after 12 years, with 16.7 and 17.8 million ESALs, respectively. Section 13-7028 was selected for mechanistic analysis. It is 17 years old with an original 9-in. concrete slab and a 7-in. overlay. It has been subjected to 16.8 million ESALs and the overlay age is 12 years at the latest survey date. It has no longitudinal or fatigue cracking but has some transverse cracking, 7 mm of rutting, and an IRI of 1.1 m/km. GPS-7B: AC Overlay with Conventional Asphalt Cement on PCC Pavement There are a total of 43 sections in 18 states within this experi- ment. Figure B.4 summarizes the frequency of overlay age within the experiment. Tables B.10, B.11, and B.12 summarize the relevant inventory and performance information on sections with the longest overlay ages, those with high ESAL, and those with the best performance in cracking and rutting. Summary Interpretation One section with the longest overlay age may be promising: 42-1617. It has a 4.7-in. AC overlay over a continuously re inforced concrete pavement (CRCP). It has no longitudinal or transverse cracking and very little fatigue cracking and an IRI of 0.93 m/km, but has 9 mm of rutting and moderate traffic of 20 million ESALs. Two sections subjected to very heavy traffic (4.5 to 5.2 million ESAL/year) are promising: 18-5022 and 18-5518. They have 4- and 4.8-in. AC overlay over 9.8- and 9.3-in. CRCP pavements, respectively. They have no or very little cracking and less than 0.25 in. of rutting and an IRI of about 1 m/km. Out of the three good-performing sections, only one is promising since the other two have moderate traffic. Section 18-5022 is a 34-year-old CRCP with a 4-in. AC overlay that is 13 years old. It has been subjected to very heavy traffic of more than 177 million ESALs. It has been selected for fur- ther mechanistic analysis. SPS-5: AC Overlay of AC Pavement There are a total of 29 sections in 16 states within this experi- ment. Figure B.5 summarizes frequency of overlay age within the experiment. Table B.13 summarizes the relevant inventory and performance information on the sections with the longest overlay ages. None of the sections is promising for long life. SPS-6: Rehabilitation of Jointed PCC Pavement There are a total of 30 sections in 13 states within this experi- ment. Figure B.6 summarizes frequency of overlay age within the experiment. Table B.14 summarizes the relevant inventory and performance information on the sections with the longest overlay ages. The best-performing section (17-663) is 16 years old with an 8-in. AC overlay over a JRCP. It has no longitudinal or transverse cracking, only 2 mm of rutting, but about 5% fatigue cracking. Therefore, it does not promise to be a long- life pavement. Rubblized Sections in the SPS-6 Experiment The Strategic Highway Research Program (SHRP), during the planning of the Long Term Pavement Performance (LTPP) experiments, recognized an increasing interest in rubblizing portland cement concrete (PCC) slabs to reduce the occurrence of reflection cracks in HMA overlays. This repair strategy was GPS 7B 0 1 2 3 4 5 6 7 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Overlay Age (Year) N um be r o f P ro jec ts Figure B.4. Frequency of overlay age within experiment GPS-7B.

73 Table B.10. Inventory Information of Sections with the Longest Overlay Age within GPS-7B State SHRP ID Original Pavement Typea Traffic Open Date Overlay Construction Date Overlay Thickness (in.) Overlay Age (years) Traffic (KESAL) Longitudinal Cracking (m) Fatigue Cracking (%) No. of Transverse Cracking Rut Depth (mm) IRI (m/km) 19 9126 JRCP 1/1/1965 6/16/1989 5.20 15 28144 1.60 1.27 32 4 1.793 29 5473 JRCP 10/1/1960 5/27/1989 1.80 15 40541 0 0 19 4 1.148 39 5010 CRCP 7/1/1975 6/1/1990 2.80 15 7632 0 8.95 20 6 1.063 42 1613 JRCP 6/1/1990 6/4/1990 3.70 15 14123 0 0.50 17 4 0.952 42 1614 JRCP 6/1/1995 7/1/1989 4.40 16 7569 2.50 2.12 16 12 2.190 42 1617 CRCP 6/1/1972 8/13/1990 4.70 15 20308 0 0.95 0 9 0.934 a CRCP, continuously reinforced, concrete pavement; JRCP, jointed reinforced concrete pavement. Table B.11. Inventory Information of Sections Subjected to High-Volume Traffic within GPS-7B Experiment State SHRP ID Initial Structure Thickness (in.) Original Pavement Typea Overlay Thickness (in.) Overlay Age (years) Traffic (KESAL) per Year Longitudinal Cracking (m) Fatigue Cracking (%) No. of Transverse Cracking Rut Depth (mm) IRI (m/km) 9 5001 8.2 CRCP 4.7 8 946 0.0 8.2 9.0 9 1.311 18 3003 10.2 JPCP 4.5 11 1439 0.0 0.0 26.0 4 1.327 18 5022 9.8 CRCP 4.0 13 5170 0.0 0.0 0.0 6 1.011 GPS-7B 18 5518 9.3 CRCP 4.80 11 4495 0.0 0.23 5.0 7 0.996 29 5473 7.9 JRCP 1.8 15 1107 0.0 0.0 19.0 4 1.148 42 1613 10.2 JRCP 3.7 15 1027 0.0 0.5 17.0 4 0.952 54 4004 9.9 JRCP 5.7 7 1263 0.0 0.0 12.0 3 1.301 a CRCP, continuously reinforced, concrete pavement; JPCP, jointed plain concrete pavement; JRCP, jointed reinforced concrete pavement. Table B.12. Inventory Information of Good-Performing Sections within GPS-7B Experiment State SHRP ID Age (years) Traffic (KESAL) Original Thicknessa (in.) Overlay Thickness (in.) Overlay Age (years) 39 3013 35 3720 8.30 Thin JRCP 3.70 11 GPS-7B 18 5022 34 176836 9.80 Medium CRCP 4.00 13 29 5483 32 6746 9.00 Medium JRCP 3.00 13 a CRCP, continuously reinforced concrete pavement; JRCP, jointed reinforced concrete pavement.

74 SPS 5 0 5 10 15 20 25 30 35 40 45 50 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Overlay Age (Year) N um be r o f P ro jec ts Figure B.5. Frequency of overlay age within experiment SPS-5. SPS 6 0 5 10 15 20 25 30 35 40 45 50 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Overlay Age (Year) N um be r o f P ro jec ts Figure B.6. Frequency of overlay age within experiment SPS-6. included in the LTPP specific pavement study (SPS) experiment defined as SPS-6. However, only a few of these SPS-6 projects actually included the rubblization process. Those projects with rubblization test sections included Alabama, Arizona, Illinois, Michigan, Missouri, Oklahoma, and Pennsylvania, which are listed in Table B.15. Some of the rubblized test sec- tions had construction-related problems—soft foundations and nonuniform particle size distribution throughout the PCC slab thickness. The 2005 LTPP database was reviewed by Von Quintus et al. (2007) to determine the current performance trends of these sections. The load-related cracking is still considered minimal and the IRI values are low. In general, the thicker the overlay, the lower amount of cracking, with the exception for longitudi- nal cracking outside the wheelpath. The predominant distress exhibited along these test sections is longitudinal cracking outside the wheelpath area. The sections without edge drains or those with rubblized pieces less than 2 in. in size have the higher levels of cracking. pCC Renewal projects GPS-9: Unbonded Concrete Overlays The LTPP general pavement study experiment GPS-9 includes unbonded JPCP, JRCP, or CRCP overlays with a thickness of

75 Table B.13. Information of Sections with the Longest Overlay Age within SPS-5 State SHRP ID Assign Date Overlay Construction Date Overlay Thickness (in.) Overlay Age (years) Traffic (KESAL) Longitudinal Cracking (m) Fatigue Cracking (%) No. of Transverse Cracking Rut Depth (mm) IRI (m/km) 4 502 1/1/1987 4/20/1990 2.70 16 6386 0 54.72 0 11 3.663 4 503 1/1/1987 4/20/1990 4.70 16 6386 91.30 1.74 70 7 1.916 4 504 1/1/1987 4/20/1990 4.80 16 6386 0 0.04 17 3 1.495 4 505 1/1/1987 4/20/1990 2.80 16 6386 1.60 57.39 96 6 1.890 4 506 1/1/1987 4/20/1990 5.20 16 6386 1.70 0.43 17 4 1.538 4 507 1/1/1987 4/20/1990 6.80 16 6386 0 0 6 7 1.441 4 508 1/1/1987 4/20/1990 6.50 16 6386 13.70 0 55 7 1.272 4 509 1/1/1987 4/20/1990 3.90 16 6386 62.50 8.20 96 9 3.671 4 559 1/1/1987 4/20/1990 6.00 16 6386 1.90 0 51 4 1.505 4 560 1/1/1987 4/20/1990 2.20 16 6386 7.40 32.58 58 3 1.859 Table B.14. Information of Sections with the Longest Overlay Age within SPS-6 State SHRP ID Original Pavement Typea Assign Date Overlay Construction Date Overlay Thickness (in.) Overlay Age (years) Traffic (KESAL) Longitudinal Cracking (m) Fatigue Cracking (%) No. of Transverse Cracking Rut Depth (mm) IRI (m/km) 17 603 JRCP 1/1/1987 5/24/90 3.70 16 6747 0 14.78 0 2 1.569 17 659 JRCP 1/1/1987 6/1/90 3.30 16 6747 0 12.25 15 2 1.885 17 662 JRCP 1/1/1987 6/1/90 3.50 16 6747 0 27.04 0 2 1.844 17 663 JRCP 1/1/1987 6/1/90 8.0 16 6747 0 4.65 0 2 1.128 17 664 JRCP 1/1/1987 6/1/90 6.0 16 6747 0 21.89 0 3 1.369 a JRCP, jointed reinforced concrete pavement.

76 125 mm (5 in.) or more placed over an existing JPCP, JRCP, or CRCP. An interlayer used to prevent bonding of the two slabs was required. The overlaid concrete pavement may rest on a base or subbase or directly on the subgrade. Information about GPS-9 experiment (Unbonded PCC Overlay on PCC Pavement) was extracted from the LTPP DataPave Online (Release 21.0). There were 26 sections located in 14 states within this experiment. The continuously rein- forced concrete pavement overlays are presented separately from jointed pavements (JRCP and JPCP) since the perfor- mance criteria are not entirely identical. Furthermore, JRCP overlays were not considered since state departments of transportation (DOTs) do not use JRC pavement systems anymore. After the removal of JRC overlays, 14 JPCP and 4 CRCP overlays were considered in the subsequent sections of this appendix. Summary of Inventory Information The original construction date for the GPS-9 sections ranged from the early 1950s to the mid-1970s. The location of the various LTPP test sections is shown in Figure B.7. Table B.16 summarizes the maintenance events since over- lay became part of the LTPP experiment. The blank cells under the construction change reason indicate no maintenance. The overlay thicknesses of the various test sections range from 5 ft 8 in. to 10 ft 5 in. The distribution of unbonded overlay thickness is shown in Figure B.8. Unbonded concrete overlay projects are typically 4 ft 11 in. thick, depending on the level of traffic. Figure B.9 shows the distribution of the traffic (in ESALs) carried by the various test sections until the deassign date. The distribution of separator layer types commonly used in the LTPP test sections is shown in Figure B.10. Typically, a fine-graded asphalt surface mixture is used for the separator layer. The thickness of the separator layer is a function of (1) the condition of the existing pavement and (2) the type of preoverlay repairs. Figure B.11 shows the distribution of the thickness of the HMA separator layers used in the various sections. According to the review of the literature a minimum thickness of 1 in. is recommended for HMA separator layers. Thinner layers erode easily near joints and do not provide adequate isolation of the overlay from underlying PCC pavement. Figure B.12 shows a couple of cross sections with thick asphalt interlayer. Section 18-9020 actually consists of two interlayers, whereas section 48-9167 has one interlayer. Figure B.13 shows the distribution of transverse joint spacing. Based on the review of the literature, it is recommended to limit the joint spacing to 21 times the slab thickness. According to that rule of thumb, the transverse joint spacing of the GPS-9 Table B.15. LTPP SPS-6 Projects with Rubblized Test Sections Project Agency Rehabilitation Date Test Section Identification HMA Overlay Thickness (mm) Comment Alabama 6/1998 0661 102 Badger Breaker Machine (Model MHB); particles down to 3 in. in size. 0662 203 0663 241 Arizona 10/1990 0616 140 0619 140 Illinois 6/1990 0663 152 High-frequency breaking unit; less than 6 in. in size; edge drains placed. 0664 206 Michigan 5/1990 0659 178 Missouri 8/1992 0661 290 Edge drains placed. 0662 185 0663 292 No edge drains placed. 0664 175 Oklahoma 8/1992 0607 114 Resonant Frequency Breaker; surface, 2–3 in. in size; bottom, up to 8 in. in size; edge drains placed.0608 201 Pennsylvania 9/1992 0660 241 Edge drains placed. 0661 330 Source: Von Quintus et al. 2007.

77 sections should range between 10 and 18 ft (as shown by the dashed horizontal lines in Figure B.7). In general, the risk of premature cracking on unbonded PCC overlays can be mini- mized by limiting the joint spacing to 15 ft, even for very thick overlays. Figure B.14 shows the distribution of various load-transfer mechanisms used across transverse joints in the GPS-9 test sections. Joint performance in unbonded concrete overlays is enhanced due to the presence of the underlying pavement as “sleeper” slabs. The load transfer across joints from the under- lying slab can be maximized by mismatching joints. However, the use of doweled joints is highly recommended for overlays subjected to heavy truck traffic to avoid corner breaks and to minimize joint faulting. Summary of Overall Field Performance The pavement performance criteria selected for the summary include transverse cracking, IRI (and PSI), joint and crack faulting magnitude (JPCP), and punchouts (only for CRCP). The performance trends presented in this section are based on measurements documented in the latest year. It should be noted that some of the figures in subsequent sections show the nominal performance of the sections that might include confounding (interaction) effects of two or more factors. Transverse cracking. The box-and-whisker plot shown in Figures B.15 (for jointed concrete overlays) and B.20 (for CRC overlays) shows the distribution of percent cracking for the test sections. The box-and-whisker plots presented here display data as follows: the median is represented by the horizontal line inside the box. The top and bottom of the box repre- sent the third quartile (75th percentile) and the first quartile (25th percentile), respectively. The distance between these two is the interquartile range (IQR). In these plots, whiskers are drawn to the minimum and maximum observations. Figure B.16 shows the magnitude of cracking as a function of overlay thickness for the jointed concrete pavements. Sections 6-9048 and 20-9037 with 28 and 14 cracks, respectively, are among the sections presented in the first category (5.1 to 6.5 in.). Sections 6-9049 and 31-6701 with 26 and 7 cracks, respec- tively, are among the sections represented in the second cate- gory (6.6 to 8.0 in.). As expected, the thicker overlays (>9 in.) exhibit fewer transverse cracks. It is worth noting that 11 of the 14 jointed concrete pavement overlays have exhibited little or no cracking in 18 years of service. These test sections exhibit the promise of long-life performance. Figure B.17 shows the ©2011 Google Maps Source: © 2011 Google Maps. Figure B.7. Locations of GPS-9 sections.

78 Table B.16. GPS-9 Construction Events Since Overlay Became Part of LTPP Experiment Section ID Construction No. LTPP Assign Date Construction Change Reason 6-9048 1 7/1/1988 2 4/18/2001 PCC slab replacement 6-9049 1 6/26/1988 6-9107 1 7/1/1988 8-9019 1 7/20/1988 8-9020 1 7/20/1988 13-4118 1 1/1/1987 18-9020 1 1/1/1987 20-9037 1 1/1/1987 2 9/15/1992 Full-depth patching of PCC pavement other than at joint 27-9075 1 1/1/1987 28-7012 1 1/1/1987 2 3/15/1993 Asphalt concrete overlay, port- land cement concrete overlay 31-6701 1 8/1/1988 2 1/15/2000 Crack sealing, lane-shoulder longitudinal joint sealing 3 2/28/2002 Crack sealing, transverse joint sealing 4 3/9/2004 Partial-depth patching of PCC pavement other than at joint 5 2/15/2005 Partial-depth patching of PCC pavement other than at joint 40-4155 1 1/1/1987 42-1627 1 12/1/1988 48-3569 1 1/1/1987 48-3845 1 7/1/1989 48-9167 1 12/31/1987 48-9355 1 12/31/1988 89-9018 1 7/1/1988 Note: Section ID is the unique number given to each test section in the LTPP program. Each test section began in the LTPP program at construction number 1. Sequential numbers are added any time mainte- nance or rehabilitation activities occur on the test section. LTPP Assign Date represents the date that the test section entered the LTPP program (construction number 1) or the date maintenance and rehabilitation was completed on the test section (construction numbers greater than 1).

79 number of transverse cracks as a function of CRCP section. Fig- ures B.18 and B.19 show the percent cracking as a function of overlay thickness for the CRCPs, and average crack spacing as a function of overlay thickness, respectively. Figures B.20 and B.21 summarize the number of punchouts in the CRCP overlays. inTernaTional roughness index (iri). Figures B.22 through B.24 illustrate the progression of IRI and PSI for the various GPS-9 sections and the impact of overlay thickness on ride quality. JoinT and crack faulTing. Figures B.25 and B.26 summarize the amount of joint and crack wheelpath faulting for the vari- ous jointed concrete pavement overlays. In Figure B.26, all the sections that belong to the last category (overlay thicknesses of 9.6 to 11.0 in.) are doweled pavements. All the sections belonging to the first three categories are without dowels except for one section (section 89-9018, with overlay thick- ness of 6 ft, 4 in., is a doweled pavement). It should be noted that the overall magnitude of the faulting is below 0.25 in. (the threshold considered for long-life pavements) and there- fore does not appear to be an issue at this point. 0 2 4 6 8 10 12 6- 90 48 6- 90 49 6- 91 07 8- 90 19 8- 90 20 13 -4 11 8 18 -9 02 0 20 -9 03 7 27 -9 07 5 28 -7 01 2 31 -6 70 1 40 -4 15 5 42 -1 62 7 48 -3 56 9 48 -3 84 5 48 -9 16 7 48 -9 35 5 89 -9 01 8 Section ID O v er la y Th ic kn es s (In c he s) 0 5000 10000 15000 20000 25000 6- 90 48 6- 90 49 6- 91 07 8- 90 19 8- 90 20 13 -4 11 8 18 -9 02 0 20 -9 03 7 27 -9 07 5 28 -7 01 2 31 -6 70 1 40 -4 15 5 42 -1 62 7 48 -3 56 9 48 -3 84 5 48 -9 16 7 48 -9 35 5 89 -9 01 8 Section ID Es tim at ed E SA Ls * 10 00 Figure B.8. Overlay thicknesses. Figure B.9. Traffic after inclusion in the LTPP program.

80 impacT of inTerlayer design on performance. Figures B.27 and B.28 illustrate the impact of the interlayer type and thick- ness on transverse cracking of the overlay. In general, thicker interlayers tend to inhibit transverse cracking. Figure B.29 shows that thicker interlayers tend to be associated with less joint wheelpath faulting. impacT of load transfer mechanism on performance. Fig- ures B.30 through B.32 illustrate the impacts of dowels and increased pavement thickness on all pavement performance measures. In these figures, all the sections that belong to the first category (aggregate interlock) have overlay thicknesses of 9 in. or less. All the sections belonging to the second cat- egory (doweled) have overlay thicknesses of 10 in. or more except for one section (section 89-9018 has an overlay thick- ness of 6.4 in.). SPS-7: Bonded Concrete Overlays Information about the SPS-7 experiment (Bonded PCC Overlay on PCC Pavement) was extracted from the LTPP DataPave Online (Release 21.0). There were 39 sections located in four states within this experiment. CRCPs and PCPs (plain concrete pavements only used for SPS-7 overlays of CRCP) were separated from jointed pavements (JPCP), since the performance criteria are not entirely identical. PCP over- lays are bonded overlays of CRCP where additional steel was not included in the overlay. CRCP overlays are concrete over- lays to which steel was added so that the resulting pavement has two layers of steel. Furthermore, control sections with no over- lays (sections ending with 0701) were not considered. Another section that was not considered (29-0759) had an asphalt con- crete overlay. After the removal of these sections, data from 18 CRCPs, 9 JPCPs, and 8 PCPs are presented in the sub- sequent sections of this appendix. Summary of Inventory Information The location of the various SPS-7 test sections is shown in Figure B.33. Table B.17 summarizes the maintenance events since overlay became part of the LTPP experiment. The blank cells under the “construction change reason” indicate no maintenance. Figure B.34 shows the distribution of overlay age until the deassign date. It should be noted that all SPS-7 sections have been taken out of the LTPP study and additional data are not available. The overlay thicknesses of the various test sec- tions range from 3.1 to 6.5 in. The distribution of bonded overlay thickness is shown in Figures B.35 and B.36. All the Chip Seal, 4 Other, 1 Dense Graded Asphalt Concrete, 9 Open Graded Asphalt Concrete, 2 No Interlayer, 2 Figure B.10. Types of interlayer. 0 1 2 3 4 5 6 7 8 9 6- 90 48 6- 90 49 6- 91 07 8- 90 19 8- 90 20 13 -4 11 8 18 -9 02 0 20 -9 03 7 27 -9 07 5 28 -7 01 2 31 -6 70 1 40 -4 15 5 42 -1 62 7 48 -3 56 9 48 -3 84 5 48 -9 16 7 48 -9 35 5 89 -9 01 8 Section ID In te rla ye r T hi ck ne ss (In ch es ) Figure B.11. Interlayer thicknesses.

81 Figure B.12. Cross sections with thick interlayer. 0 5 10 15 20 6- 90 48 6- 90 49 6- 91 07 8- 90 19 8- 90 20 18 -9 02 0 20 -9 03 7 27 -9 07 5 28 -7 01 2 31 -6 70 1 42 -1 62 7 48 -9 16 7 48 -9 35 5 89 -9 01 8 Section ID A v er ag e Jo in t S pa ci ng (F ee t) Figure B.13. JPCP average joint spacing.

82 JPCP overlays had transverse joint spacing of 20 ft. The dis- tribution of bonding agent types commonly used is shown in Figure B.37. Figure B.38 shows the distribution of the surface prepara- tion methods used to create a bond in the various sections. The impact of the various surface preparations to create a bond on pavement performance is negligible. Summary of Overall Field Performance The pavement performance criteria selected for the sum- mary include transverse cracking, IRI (and PSI), joint and crack faulting magnitude (JPCP), and punchouts (for CRCP and PCP). The performance trends presented in this section are based on measurements documented before the test sec- tion was taken out of the LTPP study. Transverse cracking. Figure B.39 (box-and-whisker plot) shows the distribution of percent cracking across the JPCP sections. The box-and-whisker plots presented here display data as follows: the median is represented by the horizontal line inside the box. The top and bottom of the box represent the third quartile (75th percentile) and the first quartile (25th percentile), respectively. The distance between these two is the interquartile range (IQR). In these plots, whiskers are drawn to the minimum and maximum observations. Figure B.40 shows the magnitude of percent cracking as a function of overlay thickness for the joint concrete pavements. Figure B.41 (box-and-whisker plot) shows the distribu- tion of percent cracking across the PCP and CRCP sections. Figure B.42 shows the percent cracking as a function of over- lay thickness for the CRCPs and PCPs. Figure B.43 shows the distribution of the number of punch- outs for PCP and CRCP sections. Figure B.44 shows the number of punchouts as a function of overlay thickness for the CRCPs and PCPs. InternatIonal roughness index (IrI). Figures B.45 through B.47 illustrate the progression of IRI and PSI for the various SPS-7 sections and the impact of overlay thickness on ride quality. Summary AC Renewal Projects Four sections were selected for mechanistic analysis using the Mechanistic-Empirical Pavement Design Guide (MEPDG) Round Dowels, 5 Other, 1 Not Available, 2 Aggregate Interlock, 6 Figure B.14. JPCP load-transfer mechanisms. 0 5 10 15 20 25 30 6- 90 48 6- 90 49 6- 91 07 8- 90 19 8- 90 20 18 -9 02 0 20 -9 03 7 27 -9 07 5 28 -7 01 2 31 -6 70 1 42 -1 62 7 48 -9 16 7 48 -9 35 5 89 -9 01 8 Section ID To ta l N o. o f T ra n sv er se C ra ck s Figure B.15. Distribution of number of transverse cracks for JPCP sections.

83 and PerRoad software for performance prediction. They all met the criteria of “Heavy Traffic” and “Good Performance” and promise to be “long-life” pavements. Those sections are provided in Table B.18. PCC Renewal Projects In this appendix the performance of 18 GPS-9 sections and 35 SPS-7 sections has been summarized. A significant frac- tion of the GPS-9 test sections have a potential for long-life performance (50 plus years). Unfortunately, this cannot be verified based on field observations because all sections have been deassigned and no further data collection is planned. Therefore, the potential for long life was predicted using the MEPDG software. Reference Von Quintus, H. L., C. Rao, J. Mallela, B. Aho, Applied Research Associates, Incorporated, and Wisconsin Department of Transportation. 2007. Guidance, Parameters, and recommendations for rubblized Pavements. Project WHRP 06-13, Project 16730. National Technical Information Service, Alexandria, Va.

84 0 2 4 6 8 10 12 14 5.1" - 6.5" 6.6" - 8.0" 8.1" - 9.5" 9.6" - 11" Overlay Thickness Av g. No . o f T C (La st S ur v ey ) Figure B.16. JPCP overlay thickness versus average number of transverse cracks. 0 50 100 150 200 250 13-4118 40-4155 48-3569 48-3845 Section ID To ta l N o. o f T ra n sv er se C ra ck s Figure B.17. Distribution of number of transverse cracks for CRCP sections.

85 0 20 40 60 80 100 120 140 160 8" - 9.9" 10" - 11.9" Overlay Thickness Av g. No . o f T C (La st S ur v ey ) Figure B.18. CRCP overlay thickness versus average number of transverse cracks. 0 1 2 3 4 5 6 8" - 9.9" 10" - 11.9" Overlay Thickness Av g. Cr ac k Sp ac in g, ft . (La st Su rv ey ) Figure B.19. CRCP overlay thickness versus average crack spacing.

86 0 5 10 15 20 25 13-4118 40-4155 48-3569 48-3845 Section ID To ta l N o. o f P un ch -o ut s Figure B.20. Distribution of number of punchouts for CRCP sections. 0 2 4 6 8 10 12 8" - 9.9" 10" - 11.9" Overlay Thickness Av g. No . o f P u n c h- ou ts (L as t S ur v ey ) Figure B.21. CRCP overlay thickness versus average number of punchouts.

87 0 0.5 1 1.5 2 2.5 3 3.5 06 -9 04 8 06 -9 04 9 06 -9 10 7 08 -9 01 9 08 -9 02 0 13 -4 11 8 18 -9 02 0 20 -9 03 7 27 -9 07 5 28 -7 01 2 31 -6 70 1 40 -4 15 5 42 -1 62 7 48 -3 56 9 48 -3 84 5 48 -9 16 7 48 -9 35 5 89 -9 01 8 Section ID Av g. IR I (m /k m ) Figure B.22. Distribution of average IRI. 0 1 2 3 4 5 06 -9 04 8 06 -9 04 9 06 -9 10 7 08 -9 01 9 08 -9 02 0 13 -4 11 8 18 -9 02 0 20 -9 03 7 27 -9 07 5 28 -7 01 2 31 -6 70 1 40 -4 15 5 42 -1 62 7 48 -3 56 9 48 -3 84 5 48 -9 16 7 48 -9 35 5 89 -9 01 8 Section ID Av g. PS I Figure B.23. Distribution of average PSI.

88 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 5.1" - 6.5" 6.6" - 8" 8.1" - 9.5" 9.6" - 11" Overlay Thickness Av g. IR I (m /k m ) 0.0 1.0 2.0 3.0 4.0 5.0 Av g. PS I IRI PSI Figure B.24. Overlay thickness versus average IRI and average PSI. -0.5 0.5 1.5 2.5 3.5 4.5 5.5 06 -9 04 8 6- 90 49 6- 91 07 8- 90 19 8- 90 20 18 -9 02 0 20 -9 03 7 27 -9 07 5 28 -7 01 2 31 -6 70 1 42 -1 62 7 48 -9 16 7 48 -9 35 5 89 -9 01 8 Section ID Av g. W he el pa th F au lti n g (m m ) Figure B.25. Distribution of average wheelpath faulting by section.

89 0.00 0.50 1.00 1.50 2.00 2.50 3.00 5.1" - 6.5" 6.6" - 8.0" 8.1" - 9.5" 9.6" - 11.0" Overlay Thickness Av g. W he el pa th Fa ul tin g (m m ) Figure B.26. Overlay thickness versus average wheelpath faulting. 0 5 10 15 20 25 30 Dense Graded Asphalt Concrete Open Graded Asphalt Concrete Chip Seal Other No Interlayer Interlayer Type Av g. No . o f T C (La st S ur v ey ) Figure B.27. JPCP interlayer type versus average number of transverse cracks.

90 0 2 4 6 8 10 12 14 0" 0.1" - 1.9" 2" - 3.8" > 3.9" Interlayer Thickness Av g. No . o f T C (La st S ur v ey ) Figure B.28. JPCP interlayer thickness versus average number of transverse cracks. 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 0" 0.1" - 1.9" 2" - 3.8" > 3.9" Interlayer Thickness Av g. W he el pa th F au lti n g (m m ) Figure B.29. JPCP interlayer thickness versus average wheelpath faulting.

91 0.00 0.50 1.00 1.50 2.00 Aggregate Interlock Round Dowels Load Transfer Mechanism A vg . W he el pa th F au lti ng (m m) Figure B.30. JPCP load-transfer mechanism versus average wheelpath faulting. 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 Aggregate Interlock Round Dowels Load Transfer Mechanism Av g. IR I (m /k m ) 0.00 1.00 2.00 3.00 4.00 5.00 Av g. PS I IRI PSI Figure B.31. JPCP load-transfer mechanism versus average IRI and average PSI.

92 0 2 4 6 8 10 12 14 Aggregate Interlock Round Dowels Load Transfer Mechanism Av g. No . o f T C (La st S ur v ey ) Figure B.32. JPCP load-transfer mechanism versus average number of transverse cracks. Source: © 2011 Google Maps. Figure B.33. Locations of SPS-7 sections.

93 Table B.17. SPS-7 Construction Events Section ID Construction No. Construction Assign Date Construction Change Reason 19-0702 1 1/1/1992 2 4/3/1992 Full-depth transverse joint repair patch, partial-depth patching of PCC pavements at joints. 3 7/14/1992 Lane-shoulder longitudinal joint sealing, grinding surface, portland cement concrete overlay. 19-0703 1 1/1/1992 2 4/4/1992 Full-depth transverse joint repair patch, partial-depth patching of PCC pavements at joints. 3 7/10/1992 Lane-shoulder longitudinal joint sealing, grinding surface, portland cement concrete overlay. 19-0704 1 1/1/1992 2 4/6/1992 Full-depth transverse joint repair patch, partial depth patching of PCC pavements at joints. 3 7/10/1992 Lane-shoulder longitudinal joint sealing, portland cement concrete overlay. 19-0705 1 1/1/1992 2 4/6/1992 Full-depth transverse joint repair patch, partial depth patching of PCC pavements at joints. 3 7/10/1992 Lane-shoulder longitudinal joint sealing, portland cement concrete overlay. 19-0706 1 1/1/1992 2 4/6/1992 Partial-depth patching of PCC pavements at joints. 3 7/10/1992 Lane-shoulder longitudinal joint sealing, portland cement concrete overlay. 19-0707 1 1/1/1992 2 4/7/1992 Full-depth transverse joint repair patch. 3 7/10/1992 Lane-shoulder longitudinal joint sealing, portland cement concrete overlay. 19-0708 1 1/1/1992 2 7/10/1992 Lane-shoulder longitudinal joint sealing, grinding surface, portland cement concrete overlay. 19-0709 1 1/1/1992 2 4/6/1992 Partial-depth patching of PCC pavements at joints. 3 7/10/1992 Lane-shoulder longitudinal joint sealing, grinding surface, portland cement concrete overlay. 19-0759 1 1/1/1992 2 8/6/1993 Portland cement concrete overlay. 22-0702 1 1/1/1987 2 4/7/1992 Full-depth patching of PCC pavement other than at joint, grinding surface, portland cement concrete overlay, PCC shoulder restoration. 22-0703 1 1/1/1987 2 4/10/1992 Grinding surface, portland cement concrete overlay, PCC shoulder restoration. 22-0704 1 1/1/1987 2 4/21/1992 Portland cement concrete overlay, PCC shoulder restoration. 22-0705 1 1/1/1987 2 4/21/1992 Portland cement concrete overlay, PCC shoulder restoration. 22-0706 1 1/1/1987 2 4/22/1992 Portland cement concrete overlay, PCC shoulder restoration. 22-0707 1 1/1/1987 2 4/21/1992 Portland cement concrete overlay, PCC shoulder restoration. (continued on next page)

94 (continued on next page) 22-0708 1 1/1/1987 2 4/9/1992 Grinding surface, portland cement concrete overlay, PCC shoulder restoration. 22-0709 1 1/1/1987 2 4/9/1992 Grinding surface, portland cement concrete overlay, PCC shoulder restoration. 27-0702 1 1/1/1987 2 9/10/1990 Grinding surface, portland cement concrete overlay, longitudinal subdrains. 27-0703 1 1/1/1987 2 9/10/1990 Grinding surface, portland cement concrete overlay, longitudinal subdrains. 27-0704 1 1/1/1987 2 9/10/1990 Portland cement concrete overlay, longitudinal subdrains. 27-0705 1 1/1/1987 2 9/10/1990 Portland cement concrete overlay, longitudinal subdrains. 27-0706 1 1/1/1987 2 9/10/1990 Portland cement concrete overlay, longitudinal subdrains. 27-0707 1 1/1/1987 2 9/10/1990 Portland cement concrete overlay, longitudinal subdrains. 27-0708 1 1/1/1987 2 9/10/1990 Grinding surface, portland cement concrete overlay, longitudinal subdrains. 3 9/1/1998 Partial-depth patching of PCC pavement other than at joint. 4 7/1/2001 Partial-depth patching of PCC pavement other than at joint. 27-0709 1 1/1/1987 2 9/10/1990 Grinding surface, portland cement concrete overlay, longitudinal subdrains. 27-0759 1 1/1/1987 2 9/10/1990 Portland cement concrete overlay, longitudinal subdrains. 29-0702 1 1/1/1987 2 6/18/1990 AC shoulder restoration, grinding surface, portland cement concrete overlay. 29-0703 1 1/1/1987 2 6/15/1990 Transverse joint sealing, lane-shoulder longitudinal joint sealing, full-depth transverse joint repair patch, AC shoulder restoration, grinding surface, portland cement concrete overlay. 3 2/15/2000 Crack sealing, transverse joint sealing, lane-shoulder longitudinal joint sealing. 29-0704 1 1/1/1987 2 6/26/1990 AC shoulder restoration, portland cement concrete overlay. 3 2/15/2000 Crack sealing, transverse joint sealing, lane-shoulder longitudinal joint sealing. 29-0705 1 1/1/1987 2 6/28/1990 AC shoulder restoration, portland cement concrete overlay. 3 2/15/2000 Crack sealing, transverse joint sealing, lane-shoulder longitudinal joint sealing. 29-0706 1 1/1/1987 2 6/29/1990 AC shoulder restoration, portland cement concrete overlay. 3 2/15/2000 Crack sealing, transverse joint sealing, lane-shoulder longitudinal joint sealing. Table B.17. SPS-7 Construction Events (continued) Section ID Construction No. Construction Assign Date Construction Change Reason

95 27-0708 1 1/1/1987 2 9/10/1990 Grinding surface, portland cement concrete overlay, longitudinal subdrains. 3 9/1/1998 Partial-depth patching of PCC pavement other than at joint. 4 7/1/2001 Partial-depth patching of PCC pavement other than at joint. 27-0709 1 1/1/1987 2 9/10/1990 Grinding surface, portland cement concrete overlay, longitudinal subdrains. 27-0759 1 1/1/1987 2 9/10/1990 Portland cement concrete overlay, longitudinal subdrains. 29-0702 1 1/1/1987 2 6/18/1990 AC shoulder restoration, grinding surface, portland cement concrete overlay. 29-0703 1 1/1/1987 2 6/15/1990 Transverse joint sealing, lane-shoulder longitudinal joint sealing, full depth transverse joint repair patch, AC shoulder restoration, grinding surface, portland cement concrete overlay. 3 2/15/2000 Crack sealing, transverse joint sealing, lane-shoulder longitudinal joint sealing. 29-0704 1 1/1/1987 2 6/26/1990 AC shoulder restoration, portland cement concrete overlay. 3 2/15/2000 Crack sealing, transverse joint sealing, lane-shoulder longitudinal joint sealing. 29-0705 1 1/1/1987 2 6/28/1990 AC shoulder restoration, portland cement concrete overlay. 3 2/15/2000 Crack sealing, transverse joint sealing, lane-shoulder longitudinal joint sealing. 29-0706 1 1/1/1987 2 6/29/1990 AC shoulder restoration, portland cement concrete overlay. 3 2/15/2000 Crack sealing, transverse joint sealing, lane-shoulder longitudinal joint sealing. 29-0707 1 1/1/1987 2 6/29/1990 AC shoulder restoration, portland cement concrete overlay. 3 2/15/2000 Crack sealing, transverse joint sealing, lane-shoulder longitudinal joint sealing. 29-0708 1 1/1/1987 2 6/19/1990 AC shoulder restoration, grinding surface, portland cement concrete overlay. 3 2/15/2000 Crack sealing, transverse joint sealing, lane-shoulder longitudinal joint sealing. 29-0709 1 1/1/1987 2 6/19/1990 AC shoulder restoration, grinding surface, portland cement concrete overlay. 3 2/15/2000 Crack sealing, transverse joint sealing, lane-shoulder longitudinal joint sealing. 29-0760 1 1/1/1987 2 6/11/1990 Transverse joint sealing, lane-shoulder longitudinal joint sealing, full-depth transverse joint repair patch, AC shoulder restoration, grinding surface, portland cement concrete overlay. 3 2/15/2000 Crack sealing, transverse joint sealing, lane-shoulder longitudinal joint sealing. Table B.17. SPS-7 Construction Events (continued) Section ID Construction No. Construction Assign Date Construction Change Reason

96 0 2 4 6 8 10 12 14 16 18 19 -0 70 2 19 -0 70 4 19 -0 70 6 19 -0 70 8 19 -0 75 9 22 -0 70 3 22 -0 70 5 22 -0 70 7 22 -0 70 9 27 -0 70 3 27 -0 70 5 27 -0 70 7 27 -0 70 9 29 -0 70 2 29 -0 70 4 29 -0 70 6 29 -0 70 8 29 -0 76 0 Section ID Ag e Un til D e- As si gn D at e (Y ea rs ) Figure B.34. Overlay age until deassign date. 0 1 2 3 4 5 6 7 19 -0 70 2 19 -0 70 4 19 -0 70 6 19 -0 70 8 19 -0 75 9 22 -0 70 3 22 -0 70 5 22 -0 70 7 22 -0 70 9 27 -0 70 3 27 -0 70 5 27 -0 70 7 27 -0 70 9 29 -0 70 2 29 -0 70 4 29 -0 70 6 29 -0 70 8 29 -0 76 0 Section ID O ve rla y Th ic kn es s (In ch es ) Figure B.35. Overlay thicknesses.

97 4.24 4.60 4.71 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00 JPCP CRCP PCP Overlay Type Av g. O v er la y Th ic kn es s (in .) Figure B.36. Average overlay thickness for SPS-7 overlay types. None, 13 Not Available, 1 Water/Cement Grout, 21 Figure B.37. Distribution of types of bonding agents. Water Blast, 4 Shot Blast, 9 Mill, 13 Not Available, 9 Figure B.38. Distribution of surface preparation methods.

98 0 20 40 60 80 100 120 140 160 29-0702 29-0703 29-0704 29-0705 29-0706 29-0707 29-0708 29-0709 29-0760 Section ID To ta l N o. o f T ra ns ve rs e Cr ac ks Figure B.39. Distribution of number of transverse cracks by JPCP sections. 0 20 40 60 80 100 120 140 3.1" - 4.5" 4.6" - 6" Overlay Thickness Av g. No . o f T C (La st Su rv ey ) Figure B.40. JPCP overlay thickness versus number of transverse cracks.

99 0 20 40 60 80 100 120 3" - 3.9" 4" - 4.9" 5" - 5.9" 6" - 6.9" Overlay Thickness A vg . N o. o f T C (La st Su rv ey ) Figure B.42. CRCP and PCP overlay thickness versus number of transverse cracks. 0 50 100 150 200 250 19 -0 70 2 19 -0 70 4 19 -0 70 6 19 -0 70 8 19 -0 75 9 22 -0 70 3 22 -0 70 5 22 -0 70 7 22 -0 70 9 27 -0 70 3 27 -0 70 5 27 -0 70 7 27 -0 70 9 Section ID To ta l N o. o f T ra n sv er se C ra ck s Figure B.41. Distribution of number of transverse cracks for CRCP and PCP sections.

100 0 1 2 3 4 5 6 7 8 9 19 -0 70 2 19 -0 70 4 19 -0 70 6 19 -0 70 8 19 -0 75 9 22 -0 70 3 22 -0 70 5 22 -0 70 7 22 -0 70 9 27 -0 70 3 27 -0 70 5 27 -0 70 7 27 -0 70 9 Section ID To ta l N o. o f P un ch -o u ts Figure B.43. Distribution of number of punchouts for CRCP and PCP sections. 0 0.2 0.4 0.6 0.8 1 1.2 3" - 3.9" 4" - 4.9" 5" - 5.9" 6" - 6.9" Overlay Thickness A vg . N o. o f P un ch -o ut s (La st Su rv ey ) Figure B.44. CRCP and PCP overlay thickness versus number of punchouts.

101 0 1 2 3 4 5 19 -0 70 2 19 -0 70 4 19 -0 70 6 19 -0 70 8 19 -0 75 9 22 -0 70 3 22 -0 70 5 22 -0 70 7 22 -0 70 9 27 -0 70 3 27 -0 70 5 27 -0 70 7 27 -0 70 9 29 -0 70 2 29 -0 70 4 29 -0 70 6 29 -0 70 8 29 -0 76 0 Section ID A vg . P SI Figure B.46. Distribution of average PSI by section. 0 0.5 1 1.5 2 2.5 3 3.5 4 19 -0 70 2 19 -0 70 4 19 -0 70 6 19 -0 70 8 19 -0 75 9 22 -0 70 3 22 -0 70 5 22 -0 70 7 22 -0 70 9 27 -0 70 3 27 -0 70 5 27 -0 70 7 27 -0 70 9 29 -0 70 2 29 -0 70 4 29 -0 70 6 29 -0 70 8 29 -0 76 0 Section ID Av g. IR I (m /k m ) Figure B.45. Distribution of average IRI by section.

102 Table B.18. Summary of AC LTPP Section Analyzed Experiment State SHRP ID Age (years) Traffic (KESAL) Original Thickness (in.) Overlay Thickness (in.) Overlay Age (years) GPS-6A 47 6015 30 23647 8.8 Medium 5.5 19 GPS-6B 47 3108 33 28429 5.5 Medium 2.7 16 GPS-7A 13 7028 17 16763 9.1 Medium JPCP 7.0 6.0 12 2.5 5 GPS-7B 18 5022 34 176836 9.8 Medium CRCP 4.0 13 0 0.5 1 1.5 2 2.5 3 3.5 4 3" - 3.9" 4" - 4.9" 5" - 5.9" 6" - 6.9" Overlay Thickness Av g. IR I (m /k m ) 0 1 2 3 4 5 Av g. PS I IRI PSI Figure B.47. Overlay thickness versus average IRI and average PSI.