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

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109 A p p e n d i x d Rigid Renewal Thickness design Table development The rigid pavement “overlay” designs contained in the inter­ active software and design guidelines were developed by two separate design procedures: AASHTO 93 and the Mechanistic­ Empirical Pavement Design Guide (MEPDG) Version 1.1 (September 2009). Initial thicknesses were developed by use of AASHTO 93 as two­layer systems. The R23 team used these layer thicknesses to assemble the initial logic flow for develop­ ment of the R23 design guidelines. The eventual goal was to model the required portland cement concrete (PCC) thickness as three­layer systems. The MEPDG software was selected for this task because of its versatility and focus on long­lasting pavement design. Mechanistic-empirical pavement design Guide (MepdG) The MEPDG has numerous features and inputs that need to be addressed. The MEPDG has three levels of inputs, and for this assessment, Level 3 was used. Some of the required deci­ sions and inputs are the following: 1. There are three major input types for the MEPDG: traffic, climate, and structure. 2. One pavement type was analyzed via the MEPDG: jointed plain concrete pavement (JPCP), with three distress or performance types: joint faulting, transverse cracking, and international roughness index (IRI). The MEPDG inputs that follow are for JPCP only. 3. General information required to define the analysis period and type of design includes the following: a. Design life = 50 years. b. Construction month = June. c. Traffic opening month = July. d. Pavement type = JPCP. e. Shoulder condition = No tied shoulder. 4. For climate, data used to interpolate for Baltimore, Maryland, are given in Table D.1. 5. For traffic: a. General inputs for MEPDG are shown in Table D.2. b. Conversion of default load spectra (which was used to calculate performance for the various slab thicknesses) to equivalent single axle loads (ESALs; required for the R23 design guidelines) involved several steps. The fol­ lowing tables provide information on how this was done. The steps include the following: 44 The overall calculation of ESALs for a design life of 50 years is (ESALs/truck)(% of total truck traffic/ vehicle class)(10 vehicle classes)(AADT/2)(365) (((1 + in) – 1)/i) = Total ESALs, where i = truck growth rate, and n = 50 years. 44 ESALs/truck by vehicle class is the key element for converting load spectra to ESALs. Table D.3 shows a summary of ESALs/truck along with the percentage of total truck traffic (from Table 2.4.9 of NCHRP 2004b). 44 Tables D.4 through D.6 illustrate the needed informa­ tion for detailed calculations to estimate ESALs/truck. Table D.4 is from NCHRP (2004b) and shows the aver­ age number of axles per vehicle. Table D.5 illustrates how default load spectra for Class 4 single axles are converted to ESALs/axle. The value of ESALs/truck is then the sum of ESALs/axle multiplied by the average number of axles per truck. Table D.6 is a summary of ESALs/axle for the various vehicle classes and axle types. 44 Table D.7 illustrates the level of daily truck traffic required to achieve the design ESALs used in the R23 design guidelines. 6. For analysis parameters, performance criteria follow: a. The reliability for terminal IRI, transverse cracking, and mean joint faulting = 90%. b. For transverse slab cracking (JPCP, maximum allow­ able over the design period), the range is given as 10% to 45% of the slab (NCHRP 2004a). Use 10%. Development of Rigid and Flexible Renewal Thickness Design Tables

110 c. For transverse joint faulting (JPCP, upper limit over the design period), the range is given as 0.1 to 0.2 in. (NCHRP 2004a). Used 0.1 and 0.2 in. d. The smoothness range for terminal IRI is given as 150 to 250 in./mi (NCHRP 2004a). Used 170 in./mi (or 2.7 m/km, which is the FHWA break point from “acceptable” to “not acceptable”). Refer to Table D.8. 44 For initial IRI (as­constructed smoothness), the range is given as 50 to 100 in./mi (NCHRP 2004a). Used 60 in./mi (or about 1.0 m/km). 44 Terminal IRI = 170 in./mi. 7. For structure and materials: a. For PCC/JPCP properties (Layer 1), see Tables D.9 through D.12. b. For base properties (Layer 2), refer to Tables D.13 through D.16. c. For Layer 3, refer to Tables D.17 and D.18. d. Layer 4 is the same as Layer 3, but the thickness is semi­infinite. e. All runs were done without tied shoulders. f. Values of surface shortwave absorptivity included range between 0 and 1, with 1 implying that all solar energy is absorbed by the pavement surface. Use default = 0.85 [recommended by NCHRP (2004a)]. Ranges provided by FHWA are included in Table D.19. Table D.1. Location Information for Climate Data Baltimore- Washington International Airport Ronald Reagan National Airport Washington Dulles International Airport York Airport New Castle County Airport Hagerstown Regional Airport Latitude (degrees) 39.1 38.52 38.56 39.55 39.4 39.43 Longitude (degrees) -76.41 -77.02 -77.27 -76.52 -75.36 -77.44 Elevation (ft) 196 3 309 475 95 737 Distance from given location (mi) 0.0 28.0 44.2 52.7 67.3 67.7 Table D.2. General Inputs Number of lanes in design direction 2 Percent of trucks in design direction (%) 50 Percent of trucks in design lane (%) 100 Operational speed (mph) 60 Table D.3. Calculation Process for Converting Load Spectra to ESALs Vehicle Class ESAL/Trucka Total Truck Trafficb (%) 4 0.67 3.3 5 0.30 34.0 6 0.68 11.7 7 1.34 1.6 8 0.69 9.9 9 1.03 36.2 10 1.06 1.0 11 1.69 1.8 12 1.42 0.2 13 2.18 0.3 a ESAL/truck based on Level 3 default values from two sources: (1) Table 2.4.11 from NCHRP 2004b, “Suggested Default Values for the Average Number of Single, Tandem, and Tridem Axles Per Truck Class,” and (2) ESALs/axle calculated from MEPDG default axle load spectra [such as Tables 2.4.9 (single axles) and 2.4.10 (tandem axles) from NCHRP 2004b]. Refer to Tables D.4 through D.6. b Percentages for total truck traffic are from Table 2.4.4 (NCHRP 2004b) for TTC 9 (intermediate light and single- trailer truck route). Table D.4. Average Number of Single, Tandem, Tridem, and Quad Axles per Truck Vehicle Classification Number of Axles per Truck Singles Tandems Tridems Quads 4 1.62 0.39 0 0 5 2.00 0 0 0 6 1.02 0.99 0 0 7 1.00 0.26 0.83 0 8 2.38 0.67 0 0 9 1.13 1.93 0 0 10 1.19 1.09 0.89 0 11 4.29 0.26 0.06 0 12 3.52 1.14 0.06 0 13 2.15 2.13 0.35 0 Note: Based on LTPP data from NCHRP 2004b.

111 Sub sequently, an additional faulting level equal to 0.2 in. along with higher cement content was examined due to the extreme slab thickness for weak subgrade (5,000 psi). The results from these additional runs produced the slab thick­ nesses shown in Table D.21. Final Rigid Renewal Design Table The final slab thicknesses selected for use in the R23 design guidelines are shown in the far right column in Table D.22. Additional thicknesses are shown for (1) AASHTO 93 and (2) Washington State Department of Transportation (WSDOT) design thicknesses from their Pavement Policy document. The WSDOT pavement design tables were used because WSDOT had just developed those tables based on extensive MEPDG runs calibrated with detailed performance data from their PMS. Thus, those tables were the best indicator of where other states may be in a couple of years using the MEPDG design procedures. The final slab thicknesses are a composite of all of these inputs. Table D.5. Example Data for Conversion of Single Axle Load Distribution Mean Axle Load (lb) ESAL/Axlea Axleb (%) Mean Axle Load (lb) ESAL/Axlea Axleb (%) 3,000 0.0008 1.80 22,000 2.23 0.66 4,000 0.0023 0.96 23,000 2.66 0.56 5,000 0.006 2.91 24,000 3.16 0.37 6,000 0.0123 3.99 25,000 3.72 0.31 7,000 0.0229 6.80 26,000 4.35 0.18 8,000 0.039 11.45 27,000 5.06 0.18 9,000 0.0625 11.28 28,000 5.85 0.14 10,000 0.095 11.04 29,000 6.74 0.08 11,000 0.139 9.86 30,000 7.72 0.05 12,000 0.198 8.53 31,000 8.80 0.04 13,000 0.272 7.32 32,000 9.99 0.04 14,000 0.366 5.55 33,000 11.3 0.04 15,000 0.482 4.23 34,000 12.7 0.03 16,000 0.624 3.11 35,000 14.3 0.02 17,000 0.80 2.54 36,000 16.0 0.02 18,000 1.00 1.98 37,000 17.8 0.01 19,000 1.24 1.53 38,000 19.9 0.01 20,000 1.52 1.19 39,000 22.0 0.01 21,000 1.85 1.16 40,000 24.4 0.01 S(ESAL/Axle)(Axle%)c Note: Default values for ESAL/Axle for Vehicle Class 4. a ESAL/Axle approximated with (Mean Axle Load/18,000). b Axle percentages from Table 2.4.9 of NCHRP 2004b. c S [(ESAL/Axle)(Axle Percentage)] = 0.35 ESAL/Class 4 Axle. g. For JPCP design features, input the following: 44 Slab thickness: varies. 44 Permanent curl or warp effective temperature differ­ ence is -10°F. [recommended by NCHRP (2004a)]. h. For joint design: 44 For joint spacing, fix as 15 ft. 44 For dowel transverse joints, the dowel diameter is 1.5 in., and dowel spacing should be 12 in. 8. Other considerations: a. Consider reliability for performance predictions (Fig­ ure D.1). b. Figures D.2 and D.3 below show that the application of reliability shifts the predicted performance upward (in this case, an illustration of slab cracking). Trial Runs The MEPDG runs are summarized in Tables D.20 and D.21. The runs in Table D.20 used a faulting limit of 0.1 in.

112 Table D.6. ESAL/Axle for All Vehicle Classes from Default Load Spectra Vehicle Classification Single Axle Tandem Axle Tridem Axle 4 0.35a 0.27 0 5 0.15 0.16 0 6 0.29 0.39 0 7 0.66 0.80 0.58 8 0.25 0.15 0 9 0.20 0.42 0 10 0.21 0.56 0.22 11 0.37 0.32 0.10 12 0.29 0.33 0.34 13 0.29 0.62 0.61 a See example calculation in Table D.5. Table D.7. Daily Trucks to Achieve Design ESALs Along with Level 3 Default Load Spectra Average Annual Daily Trucks to Achieve Design ESAL Level with Default Load Spectra (Two Way) ESALs (millions) 500 10 1,250 25 2,500 50 5,000 100 10,000 200 Table D.8. FHWA Smoothness Criteria FHWA Ride Quality Terms All Functional Classifications IRI [m/km (in./mi)] PSR Rating Good <1.5 (95) Good Acceptable ≤2.7 (170) Acceptable Not acceptable >2.7 (170) Not acceptable Table D.9. General Properties General Properties PCC material JPCP Layer thickness (in.) Varied Unit weight (pcf) 150 Poisson’s ratio 0.2 Table D.10. Thermal Properties Thermal Properties Coefficient of thermal expansion (per °F × 10-6) 5.5 Thermal conductivity (Btu/h-ft-°F) 1.25a Heat capacity (Btu/lb-°F) 0.28a a See NCHRP 2004a. Table D.11. Mixture Properties Mixture Properties Cement type Type II Cementitious material content (lb/yd3) 500 and 560a Water-to-cement ratio 0.42 Aggregate type Limestone PCC zero-stress temperature (°F) Derived Ultimate shrinkage at 40% RH (microstrain) Derived Reversible shrinkage (% of ultimate shrinkage) 50 Time to develop 50% of ultimate shrinkage (days) 35 Curing method Curing compound a A range of cementitious contents could be used. For example, Minnesota specifies a minimum cement content of 530 lb/yd3, Missouri 560 lb/yd3, and WSDOT 564 lb/yd3 (see R23 Guide, Chapter 4, Specifications). FHWA (2007) notes that Germany and the Netherlands specify a minimum content of 540 lb/yd3. Austria uses 540 lb/yd3 for fix-form paving and 594 lb/yd3 for slip-form paving. Thus, 500 lb/yd3 represents a lower bound and 560 lb/yd3 is the middle of the range. Table D.12. Strength Properties Strength Properties Input level Level 3 28-day PCC modulus of rupture (psi) 690 28-day PCC compressive strength (psi) NA Table D.13. AC General Properties Layer 2: Asphalt Concrete Material type Asphalt concrete General reference temperature (°F) 70 Layer thickness (in.) 10 Poisson’s ratio 0.35 (user entered) Erodibility index Erosion resistant (Class 3) PCC-base interface Full friction contact Loss of full friction (age in months) 361

113 Table D.17. Subgrade Type Layer 3: A-6 Unbound material A-6 Thickness (in.) 12 Table D.18. Subgrade Strength Properties Strength Properties Input level Level 3 Analysis type Representative value (user input modulus) Poisson’s ratio 0.35 Coefficient of lateral pressure, Ko 0.5 Modulus (input) (psi) 5000 Moisture content (%) -9999 Table D.19. Surface Properties Material Surface Shortwave Absorptivity Weathered asphalt (gray) 0.80–0.90 Fresh asphalt (black) 0.90–0.98 Aged PCC layer 0.70–0.90 Figure D.1. Slab cracking. Table D.14. AC Volumetric Properties HMA Volumetric Properties as Built Effective binder content (%) 11.6 Air voids (%) 7 Total unit weight (pcf) 150 Table D.15. AC Mixture Properties Asphalt Mix Cumulative % retained, ¾-in. sieve 0 Cumulative % retained, ³⁄8-in. sieve 23 Cumulative % retained, #4 sieve 40 % passing, #200 sieve 6 Table D.16. AC Binder Properties Asphalt Binder Option Superpave binder grading A 9.4610 (correlated) VTS -3.1340 (correlated)

114 Source: NCHRP 2004a. Figure D.2. Joint faulting for no-dowel condition. Figure D.3. Joint faulting ranging from a no-dowel condition up to dowel diameter of 1.5 in. Source: NCHRP 2004a.

115 Table D.20. Initial MEPDG Runs with Limiting Joint Faulting Set  0.1 in. and Cement Content  500 lb/yd3 Traffic MESAL/ AADTT Performance Criteria Subgrade Modulus 5,000 psi 10,000 psi 20,000 psi PCC Depth DP RP A PCC Depth DP RP A PCC Depth DP RP A 10/500 Terminal IRI 8.25 82.6 99.88 Pass 7.75 80 99.94 Pass 7.75 80.2 99.94 Pass Transverse cracking 2.1 92.12 Pass 0 99.96 Pass 1.7 93.79 Pass Mean joint faulting 0.017 99.95 Pass 0.016 99.97 Pass 0.013 99.99 Pass 25/1250 Terminal IRI 9.00 89.4 99.45 Pass 8.75 88.2 99.56 Pass 8.50 87.7 99.61 Pass Transverse cracking 1.2 95.89 Pass 1.6 94.45 Pass 2.4 91.14 Pass Mean joint faulting 0.033 98.87 Pass 0.03 99.3 Pass 0.027 99.55 Pass 50/2500 Terminal IRI 9.25 100.3 97.46 Pass 9.25 97.3 98.22 Pass 9.25 96.1 98.48 Pass Transverse cracking 2 92.69 Pass 1.8 93.67 Pass 2.5 90.5 Pass Mean joint faulting 0.053 91.94 Pass 0.047 94.75 Pass 0.044 96.11 Pass 100/5000 Terminal IRI 12.25 99.1 97.77 Pass 12.00 97.9 98.06 Pass 11.50 99.2 97.73 Pass Transverse cracking 0 99.96 Pass 0 99.79 Pass 0.2 99.24 Pass Mean joint faulting 0.056 90.03 Pass 0.053 91.6 Pass 0.055 90.4 Pass 200/10000 Terminal IRI 19.25a 108.4 94.53 Pass 15.5a 97.7 98.07 Pass 15a 98.2 97.95 Pass Transverse cracking 0 99.96 Pass 0 99.96 Pass 0 99.96 Pass Mean joint faulting 0.076 73.59 Fail 0.055 90.65 Pass 0.056 90.22 Pass a Mean joint faulting fails at 19.5 in., which is likely caused by load transfer (dowel) failure. Note: Limiting values: (1) terminal IRI = 170 in./mi, (2) transverse cracking = 10%, and (3) mean joint faulting = 0.1 in. A, acceptable; AADTT, average annual daily truck traffic; DP, damage prediction; RP, reliability prediction. Table D.21. Supplemental MEPDG Runs with Limiting Joint Faulting  0.2 and Cement Content  560 lb/yd3 Traffic MESAL/ AADTT Performance Criteria DT Subgrade Modulus 5,000 psi 10,000 psi 20,000 psi PCC Depth DP RP A PCC Depth DP RP A PCC Depth DP RP A 200/10000 PCC% = 560 lb/yd3 Terminal IRI 170 11.75 116.9 90.30 Pass 11.25 117.1 90.19 Pass 11.25 116.9 90.30 Pass Transverse cracking 10 0.1 99.72 Pass 0.5 98.26 Pass 1.5 94.93 Pass Mean joint faulting 0.2 0.089 99.72 Pass 0.089 99.74 Pass 0.087 99.79 Pass Note: A, acceptable; AADTT, average annual daily truck traffic; DP, damage prediction; DT, distress target (limiting value); RP, reliability prediction.

116 study team to match a shorter span of time with D = 0.1. Additionally: 1. One level of limiting horizontal tensile strain (fatigue endur­ ance limit) at the bottom of the HMA was used: 100 µe. 2. One processed layer thickness was used: 10 in. Earlier work had applied two processed layer thicknesses, but the thinner of these was discarded as unrealistic. 3. The climate (temperatures) that directly influence the stiff­ ness of the HMA were initially based on five cities: a. Minneapolis, Minnesota (used in the example runs below with PG 64­34). b. San Francisco, California. c. Phoenix, Arizona. d. Dallas, Texas. e. Baltimore, Maryland. The results from the initial design runs indicated that the thickness values for San Francisco and Dallas fell within the range of values for the other three cities and did not affect the averages significantly. For that reason, San Francisco and Dallas were eliminated, leaving Minneapolis, Phoenix, and Baltimore. Seasonal temperature characterization was required for each location, as shown in Table D.24. Trial Runs With a criterion for obtaining HMA thicknesses that results in a target value of ≥ 50 years for D = 0.1, selected cases were run. Since D = 0.1 seemed extremely conservative, it was decided to try HMA thicknesses that result in a value of ≥ 10 years for D = 0.1 as well. Note that ≥ 10 years for D = 0.1 is about the same as ≥ 50 years for D = 0.5, but years were easier to change in the program than D values. Note that a damage ratio of D = 1.0 would predict full­depth fatigue cracking in 50 years. All PerRoad runs are shown in Tables D.25 through D.36. Flexible Renewal Thickness design Table development The flexible pavement “overlay” designs contained in the inter­ active software and design guides were developed by two sepa­ rate design procedures: AASHTO 93 and PerRoad 3.5 (Asphalt Pavement Alliance). The decision was made to exclusively apply PerRoad due to its improved versatility. The software was obtained from www.eng.auburn.edu/users/timmdav/Software .html. The newest version is PerRoad 3.5, dated April 2010. Determine HMA Thicknesses The pavement structures, as modeled, contained three layers, which were the hot­mix asphalt (HMA) overlay over an exist­ ing processed layer (pulverized HMA, rubblized PCC, or crack and seat PCC), over subgrade. The layer moduli for the processed layers were of special interest. A range of moduli was determined and summarized in Table D.23. The ranges associated with each of these moduli are rather wide and were considered in setting up the PerRoad runs. To achieve a conservative set of guidelines, the final selection of processed layer moduli were somewhat lower. The four moduli selected were (1) 30 ksi, (2) 50 ksi, (3) 75 ksi, and (4) 100 ksi. These moduli cover the lower end of the expected field moduli for the processed layers. Three subgrade moduli were selected: (1) 5 ksi, (2) 10 ksi, and (3) 20 ksi. These moduli span the majority of subgrades encountered in the field. The overall goal is to determine the HMA thickness that will achieve a target value of either ≥ 10 years or ≥ 50 years for D = 0.1 for the given inputs. In PerRoad, D = 0.1 (in lieu of the commonly used D = 1.0 for a damage function) is recom­ mended by the developer of the software, David Timm. It reflects a conservative view for assessing high­volume, long­ life pavement designs. The 10­year criterion was a way for the Table D.22. AASHTO 93, WSDOT, MEPDG, and SHRP 2 R23 Rigid Design Results ESALs (millions) AASHTO 93 for k  500 pci Design Thicknesses from WSDOT Pavement Policy Thickness Range for MEPDG for MR  5–10 ksia PCC Slab Thickness for R23 Study (in.) ≤10 10.0 9.0 7.75–8.25 9.0 10–25 11.5 10.0 8.75–9.0 10.0 25–50 12.5 11.0 9.25 11.0 50–100 14.0 12.0 11.5–12.25 12.0 100–200 15.5 13.0 11.25–15.5 13.0 a For ESALs = 200 million, results generated using both levels of PCC cement content (500 and 560 lb/yd3). Results from all other ESAL levels generated using one cement content (500 lb/yd3).

117 FHWA, U.S. Department of Transportation. www.fhwa.dot.gov/ engineering/geotech/pubs/05037/05d.cfm. Federal Highway Administration. 2007. Long-Life Concrete Pavements in Europe and Canada. Report FHWA­PL­07­027. FHWA, U.S. Depart­ ment of Transportation. National Cooperative Highway Research Program (NCHRP). 2004a. Part 3: Design Analysis. Chapter 4: Design of New and Reconstructed Rigid Pavements. Guide for Mechanistic-Empirical Design of New and Rehabilitated Pavement Structures. NCHRP Project 1­37A. TRB, National Research Council, Washington, D.C. National Cooperative Highway Research Program (NCHRP). 2004b. Part 2: Design Inputs. Chapter 4: Traffic. Guide for Mechanistic- Empirical Design of New and Rehabilitated Pavement Structures. NCHRP Project 1­37A. TRB, National Research Council, Wash­ ington, D.C. Pearce, E. A., and C. G. Smith. 1990. The World Weather Guide, 2nd ed. Hutchinson Publications, London. Final Design Tables The final flexible renewal thickness design tables were devel­ oped based on the numerous runs made with PerRoads, the MEPDG, and AASHTO 93 design guidelines. Further refinements were made in consultations with state highway agency personnel and industry representatives. Tables D.37 through D.39 provide details on the final thickness design recommendations. References Federal Highway Administration. 2006. Geotechnical Inputs for Pavement Design: Thermo­Hydraulic Properties (Section 5.5). Geotechnical Aspects of Pavements: Reference Manual. Report FHWA NHI­05­037.

118 Table D.23. Layer Moduli Properties Material Description Minimum Modulus (psi) Maximum Modulus (psi) Typical Modulus (psi) AC Asphalt concrete 50,000 4,000,000 Cracked AC Cracked asphalt concrete 50,000 500,000 Pulverized HMA 40,000 PCC Portland cement concrete 2,000,000 7,000,000 4,000,000 Rubblized PCCP Rubblized concrete 40,000 700,000 150,000 Crack and seat PCCP Crack and seated concrete 200,000 800,000 200,000 Break and seat PCCP Break and seated concrete 250,000 2,000,000 Granular base Granular base 5,000 50,000 Soil Soil 3,000 40,000 Rock Bedrock 500,000 1,000,000 Other User defined 50 10,000,000 Table D.24. Seasonal Properties City Overall Mean Temperature Seasonal Duration (months and weeks) and Temperature Minneapolis 45°F Winter Nov., Dec., Jan., Feb. 17 weeks 21°F Spring March, April, May 13 weeks 45°F Summer June, July, Aug. 13 weeks 70°F Fall Sept., Oct. 9 weeks 56°F Phoenix 70°F Winter Dec., Jan., Feb. 13 weeks 54°F Spring March, April, May 13 weeks 68°F Summer June, July, Aug., Sept. 17 weeks 87°F Fall Oct., Nov. 9 weeks 66°F Baltimore 56°F Winter Dec., Jan., Feb. 13 weeks 35°F Spring March, April, May 13 weeks 54°F Summer June, July, Aug., Sept. 17 weeks 74°F Fall Oct., Nov. 9 weeks 53°F Sources: Pearce and Smith 1990; www.climatestations.com.

119 Table D.25. Summary of PerRoad Solutions for Subgrade  5 ksi, Processed Existing Pavement  30 ksi ESALs (millions) PerRoad Minneapolis, 10 years, D  0.1 PerRoad Phoenix, 10 years, D  0.1 PerRoad Baltimore, 10 years, D  0.1 PerRoad Baltimore, 50 years, D  0.1 R23 Selected Thickness ≤10 10.5 12 10 12 10 10–25 12.5 13.5 11 12.5 11 25–50 13 14.5 11.5 12.5 12 50–100 13.5 15 12 13 13 100–200 14 15.5 12.5 13 14 Table D.26. Summary of PerRoad Solutions for Subgrade  10 ksi, Processed Existing Pavement  30 ksi ESALs (millions) PerRoad Minneapolis, 10 years, D  0.1 PerRoad Phoenix, 10 years, D  0.1 PerRoad Baltimore, 10 years, D  0.1 PerRoad Baltimore, 50 years, D  0.1 R23 Selected Thickness ≤10 10 11.5 9.5 11 10 10–25 11.5 13 10.5 11.5 11 25–50 12 13.5 11 12 12 50–100 12.5 14 11.5 12 12 100–200 13 14.5 11.5 12.5 13 Table D.27. Summary of PerRoad Solutions for Subgrade  20 ksi, Processed Existing Pavement  30 ksi ESALs (millions) PerRoad Minneapolis, 10 years, D  0.1 PerRoad Phoenix, 10 years, D  0.1 PerRoad Baltimore, 10 years, D  0.1 PerRoad Baltimore, 50 years, D  0.1 R23 Selected Thickness ≤10 9.5 11 9 10.5 9.5 10–25 11 12 10 11 10 25–50 11.5 13 10.5 11 11 50–100 12 13.5 10.5 11.5 11.5 100–200 12.5 13.5 11 11.5 12 Table D.28. Summary of PerRoad Solutions for Subgrade  5 ksi, Processed Existing Pavement  50 ksi ESALs (millions) PerRoad Minneapolis, 10 years, D  0.1 PerRoad Phoenix, 10 years, D  0.1 PerRoad Baltimore, 10 years, D  0.1 PerRoad Baltimore, 50 years, D  0.1 R23 Selected Thickness ≤10 9 10 8.5 10 9 10–25 10.5 11.5 9.5 10.5 10 25–50 11 12 10 11 11 50–100 11.5 12.5 10.5 11 11.5 100–200 12 13 10.5 11.5 12

120 Table D.29. Summary of PerRoad Solutions for Subgrade  10 ksi, Processed Existing Pavement  50 ksi ESALs (millions) PerRoad Minneapolis, 10 years, D  0.1 PerRoad Phoenix, 10 years, D  0.1 PerRoad Baltimore, 10 years, D  0.1 PerRoad Baltimore, 50 years, D  0.1 R23 Selected Thickness ≤10 8.5 9.5 7.5 9.5 8 10–25 9.5 10.5 9 10 9 25–50 10 11.5 9 10 9.5 50–100 10.5 12 9.5 10.5 10 100–200 11 12 10 10.5 11 Table D.30. Summary of PerRoad Solutions for Subgrade  20 ksi, Processed Existing Pavement  50 ksi ESALs (millions) PerRoad Minneapolis, 10 years, D  0.1 PerRoad Phoenix, 10 years, D  0.1 PerRoad Baltimore, 10 years, D  0.1 PerRoad Baltimore, 50 years, D  0.1 R23 Selected Thickness ≤10 8 9 7 8.5 7.5 10–25 9 10 8.5 9 8.5 25–50 9.5 10.5 8.5 9 9 50–100 10 11 9 9.5 9.5 100–200 10.5 11.5 9 9.5 10 Table D.31. Summary of PerRoad Solutions for Subgrade  5 ksi, Processed Existing Pavement  75 ksi ESALs (millions) PerRoad Minneapolis, 10 years, D  0.1 PerRoad Phoenix, 10 years, D  0.1 PerRoad Baltimore, 10 years, D  0.1 PerRoad Baltimore, 50 years, D  0.1 R23 Selected Thickness ≤10 7 8 7 8.5 7.5 10–25 8.5 9 8 8.5 8.5 25–50 9 9.5 8.5 9 9 50–100 9.5 10 8.5 9 9.5 100–200 10 10.5 9 9.5 10 Table D.32. Summary of PerRoad Solutions for Subgrade  10 ksi, Processed Existing Pavement  75 ksi ESALs (millions) PerRoad Minneapolis, 10 years, D  0.1 PerRoad Phoenix, 10 years, D  0.1 PerRoad Baltimore, 10 years, D  0.1 PerRoad Baltimore, 50 years, D  0.1 R23 Selected Thickness ≤10 6.5 7.5 6.5 8 7 10–25 8 8.5 7.5 8 8 25–50 8.5 9 7.5 8.5 8.5 50–100 8.5 9.5 8 8.5 8.5 100–200 9 9.5 8 8.5 9

121 Table D.36. Summary of PerRoad Solutions for Subgrade  20 ksi, Processed Existing Pavement  100 ksi ESALs (millions) PerRoad Minneapolis, 10 years, D  0.1 PerRoad Phoenix, 10 years, D  0.1 PerRoad Baltimore, 10 years, D  0.1 PerRoad Baltimore, 50 years, D  0.1 R23 Selected Thickness ≤10 5 6 5 6 5.5 10–25 6 6.5 6 6.5 6 25–50 6.5 7 6 6.5 6.5 50–100 6.5 7 6.5 6.5 6.5 100–200 7 7.5 6.5 7 7 Table D.34. Summary of PerRoad Solutions for Subgrade  5 ksi, Processed Existing Pavement  100 ksi ESALs (millions) PerRoad Minneapolis, 10 years, D  0.1 PerRoad Phoenix, 10 years, D  0.1 PerRoad Baltimore, 10 years, D  0.1 PerRoad Baltimore, 50 years, D  0.1 R23 Selected Thickness ≤ 10 5.5 6 5.5 7 6 10–25 6.5 7 6.5 7 6.5 25–50 7 7.5 7 7 7 50–100 7.5 7.5 7 7.5 7.5 100–200 7.5 8 7 7.5 7.5 Table D.33. Summary of PerRoad Solutions for Subgrade  20 ksi, Processed Existing Pavement  75 ksi ESALs (millions) PerRoad Minneapolis, 10 years, D  0.1 PerRoad Phoenix, 10 years, D  0.1 PerRoad Baltimore, 10 years, D  0.1 PerRoad Baltimore, 50 years, D  0.1 R23 Selected Thickness ≤10 6.5 7 6 7.5 6.5 10–25 7.5 8 7 7.5 7 25–50 8 8.5 7.5 8 7.5 50–100 8 9 7.5 8 8 100–200 8.5 9 8 8 8.5 Table D.35. Summary of PerRoad Solutions for Subgrade  10 ksi, Processed Existing Pavement  100 ksi ESALs (millions) PerRoad Minneapolis, 10 years, D  0.1 PerRoad Phoenix, 10 years, D  0.1 PerRoad Baltimore, 10 years, D  0.1 PerRoad Baltimore, 50 years, D  0.1 R23 Selected Thickness ≤10 5.5 6 5 6.5 6 10–25 6.5 6.5 6 6.5 6.5 25–50 6.5 7 6.5 7 7 50–100 7 7.5 6.5 7 7 100–200 7 7.5 7 7 7

122 Table D.39. Final Flexible Renewal Thickness Design Table for Flexible Designs for Subgrade MR  20,000 psi ESALs (millions) Existing Pavement or Base Modulus 30,000 psi 50,000 psi 75,000 psi 100,000 psi ≤10 9.5 7.5 6.5 5.5 10–25 10.0 8.5 7.0 6.0 25–50 11.0 9.0 7.5 6.5 50–100 11.5 9.5 8.0 6.5 100–200 12.0 10.0 8.5 7.0 Table D.38. Final Flexible Renewal Thickness Design Table for Flexible Designs for Subgrade MR  10,000 psi ESALs (millions) Existing Pavement or Base Modulus 30,000 psi 50,000 psi 75,000 psi 100,000 psi ≤10 10.0 8.0 7.0 6.0 10–25 11.0 9.0 8.0 6.5 25–50 12.0 9.5 8.5 7.0 50–100 12.0 10.0 8.5 7.0 100–200 13.0 11.0 9.0 7.0 Table D.37. Final Flexible Renewal Thickness Design Table for Flexible Designs for Subgrade MR  5,000 psi ESALs (millions) Existing Pavement or Base Modulus 30,000 psi 50,000 psi 75,000 psi 100,000 psi ≤10 10.0 9.0 8.0 6.0 10–25 11.0 10.0 8.5 6.5 25–50 12.0 11.0 9.0 7.0 50–100 13.0 11.5 9.5 7.5 100–200 14.0 12.0 10.0 7.5