cover

Concrete Pavement Design Detailsand Construction Practices

Companion Workbook1986/1993 AASHTO Guide Procedure1998 AASHTO Supplement Procedure

Prepared for Federal Highway Administration, Pavements Division400 Seventh Street SW, Washington, DC 20590

and National Highway Institute4600 North Fairfax Drive, Suite 700, Arlington, VA 22203

Prepared by Kathleen T. Hall73 Bedford Road, Mundelein, IL 60060

and Kurt D. Smith, Applied Pavement Technology, Inc.3001 Research Road, Suite C, Champaign, IL 61822

If you have comments or questions about this workbook, please contact:

Katie Hall or Kurt Smithkthall@wwa.com kurtsmith@aol.com847-549-8410 217-398-3977

Contents of this Workbook

Worksheet Description

cover cover page and table of contents

roadmap roadmap to worksheets in this companion workbook

k correlation k value correlations to soil type and properties

k backcalc k value backcalculation equations

98 k steps description of steps in determining design k value for 1998 AASHTO method

98 fill-rigid adjustment to k value for embankment and/or shallow rigid layer for 1998 AASHTO method

98 seasonal k calculation of seasonally adjusted design k value for 1998 AASHTO method

98 AASHTO concrete slab thickness design by 1998 AASHTO method

98 fault chk faulting check for undoweled and doweled pavements for 1998 AASHTO method

climate climatic data for major US cities

86 seasonal k calculation of seasonally adjusted design k value for 1986/1993 AASHTO method

86 AASHTO concrete slab thickness design by 1986/1993 AASHTO method

roadmap

Roadmap for this Companion Workbook

Design by 1986/1993 Design by 1998 AASHTOAASHTO Guide Method Supplement Method

k correlation

k backcalc

climate

98 k steps

98 fill-rigid

98 seasonal k86 seasonal k

98 AASHTO86 AASHTO

98 fault chk

k correlation

Correlations Between K Value, Soil Type, Soil Properties, and Degree of Saturation

0

50

100

150

200

250

50 60 70 80 90 100

Degree of saturation (percent)

Subg

rade

k v

alue

(psi

/in) A-6

A-7-6A-7-5A-5A-4

AASHTO Description Unified Dry Density CBR k valueClass Class (lb/cu ft) (percent) (psi/in)

Coarse-Grained SoilsA-1-a, well graded

gravel GW, GP125 – 140 60 – 80 300 – 450

A-1-a, poorly graded 120 – 130 35 – 60 300 – 400A-1-b coarse sand SW 110 – 130 20 – 40 200 – 400A-3 fine sand SP 105 – 120 15 – 25 150 – 300

A-2 Soils (Granular Materials with High Fines):A-2-4, gravelly silty gravel

GM 130 – 145 40 – 80 300 – 500A-2-5, gravelly silty sandy gravel

A-2-4, sandy silty sandSM 120 – 135 20 – 40 300 – 400

A-2-5, sandy silty gravelly sand

A-2-6, gravelly clayey gravelGC 120 – 140 20 – 40 200 – 450

A-2-7, gravelly clayey sandy gravel

A-2-6, sandy clayey sandSC 105 – 130 10 – 20 150 – 350

A-2-7, sandy clayey gravelly sand

Fine-Grained Soils (See Note):

A-4silt

ML, OL90 – 105 4 – 8 25 – 165

silt/sand/gravel mix 100 – 125 5 – 15 40 – 220

A-5 poorly graded silt MH 80 - 100 4 – 8 25 – 190

A-6 plastic clay CL 100 – 125 5 – 15 25 – 255

A-7-5moderately plastic

elastic clayCL, OL 90 – 125 4 – 15 25 – 215

A-7-6highly plastic

elastic clayCH, OH 80 – 110 3 – 5 40 - 220

The recommended k value ranges apply to a homogeneous layer at least 10 ft thick. If an embankment layer less than 10 ft thick exists over a softer subgrade, the k value of the underlying soil should be estimated from the above table and adjusted for the type and thickness of embankment material (see fill-rigid worksheet). The k value should also be adjusted if a stiff layer (e.g., bedrock) exists within 10 ft of the top of the soil (see fill-rigid worksheet).

The k value of fine-grained soil is highly dependent on the degree of saturation. See chart below.

k backcalc

Backcalculation of k Value from Deflections

Equations are provided below for backcalulating the dynamic k value, including correction for finite slab size,from deflections measured with a falling weight deflectometer or similar device, using the SHRP sensor configuration.

In the calculations below, the backcalculated dynamic k value is divided by 2 to obtain an estimated static k valuefor use in the AASHTO design procedures.

For the purpose of backcalculating k value, it is not necessary to normalize the deflections to a particular load level,nor is it necessary to know the layer thicknesses, nor to make any adjustments to the deflections for temperature. However, deflections measured when the slab is curled out of contact with the base or foundation should not be used to backcalculate k values without adjustment.

Enter the slab length (joint spacing) and slab width in feet below for use in the slab size correction.

Slab length 15 ft Calculated L 13.42 ftSlab width 12 ft

Bare Concrete Pavement

station k static load P d0 d8 d12 d18 d24 d36 d60 AREA7 l init d0* k init AF d0 AF l k adj k staticpsi/in pounds mils mils mils mils mils mils mils in in psi/in psi/in psi/in

1 106 8990 4.18 3.98 3.84 3.61 3.36 2.88 2.05 45.0 40.71 0.1237 160 0.868 0.934 212 106

Composite Pavement

station k static load P d12 d18 d24 d36 d60 AREA5 l init d12* k init AF d0 AF l k adj k staticpsi/in pounds mils mils mils mils mils in in psi/in psi/in psi/in

1 98 9025 3.49 3.32 3.13 2.73 2.02 37.8 48.83 0.1189 129 0.823 0.896 195 98

98 k steps

Steps in Determining k Value for Use in 1998 AASHTO Supplement Procedure

or or

Plate load test method

Measure k according to AASHTO T221 or T222, using a 30-in-diameter plate. In the repetitive test (T221), k is the ratio of load to elastic (recoverable) deformation. In the nonrepetitive test (T222) k is the load-deformation ratio at a deformation of 0.05 in.

Backcalculation method

Backcalculate dynamic k from deflections measured on in-service pavement. Divide the mean backcalculated k by 2 to estimate the static k.

See k backcalc worksheet.

Correlation method

Estimate k for one or more seasons from correlations with soil type, density, CBR, and degree of saturation.

See k correlation worksheet.

Fill/rigid layer adjustmentsfor correlation method

Correlations of k to soil type and properties apply to a homogeneous soil layer at least 10 ft [3 m] thick. If an embankment layer less than 10 ft [3 m] thick exists or will be placed over a softer soil, the k value of the underlying soil should be estimated from the available correlations and adjusted for the type and thickness of embankment.

If a stiff layer (e.g., bedrock) exists within 10 ft [3 m] of the top of the soil, the k value should be adjusted.

See 98 fill-rigid worksheet.

Fill/rigid layer adjustmentsfor backcalculation method

No fill or rigid layer adjustments are needed if the type and depth of fill and the depth to a rigid layer are the same for the pavement being designed and the pavement on which the deflections were measured.

A fill adjustment and/or a rigid layer adjustment is needed if the fill and rigid layer characteristics of the pavement being designed differ from those of the pavement tested.

See 98 fill-rigid worksheet.

Fill/rigid layer adjustmentsfor plate load testing method

AASHTO T 221 and T 222 specify that if the pavement is to be built on an embankment, the plate bearing tests should be conducted on a test embankment.

If the testing is not conducted on a test embankment equal in material and thickness to the embankment which wll be constructed, a fill adjustment is needed. See 98 fill-rigid worksheet.

The effect of a rigid layer is reflected in the plate load test results; no adjustment is needed.

Assign k to seasons of the year

Among the factors which should be considered in assigning seasonal k values are the seasonal movement of the water table, seasonal precipitation levels, winter frost depths, number of freeze-thaw cycles, and the extent of frost protection provided by embankment material.

A ''frozen" k may not be appropriate for winter, even in a cold climate, if the frost will not remain in a significant thickness (a few feet) of the subgrade throughout the winter. A k value of 500 psi/in is reasonable for a subgrade frozen to a significant depth.

The seasonal variation in degree of saturation is difficult to predict, but in locations where a water table is constantly present at a depth of less than about 10 ft, it is reasonable to expect that fine-grained subgrades will remain at least 70 to 90 percent saturation, and may be completely saturated for substantial periods in the spring. The highest position of the water table, but not its annual variation, can be determined from county soil reports.

See 98 seasonal k worksheet.

Calculate seasonally adjusted k value for use in design

The seasonally adjusted design k value is a damage-weighted average k which yields the same predicted performance over the course of a year as the k values assigned to the different seasons.

See 98 seasonal k worksheet.

98 fill-rigid

> 10 ft

< 10 ft

246

8

10

12 Thickness of fill (ft) Density of fill (lb/cu ft)

Depth torigid layer

200400600psi/in

200 400 600 psi/in

90 100 110 120 130 140 150

200

400

psi/in

Enter with k fornatural subgrade

Adjusted k value

1 ft = 0.305 m,1 psi/in = 0.27 kPa/mm,1 lb/cu ft = 159 N/cu m

98 seasonal k

Seasonally Adjusted Design K Value for 1998 AASHTO Supplement Procedure

Enter the number of months for each season, so that total number of months is twelve.Enter a k value for each season.

Season Months k value W' log Relative(psi/in) (millions) Damage

spring 3 50 6.90 0.1450summer 3 125 4.81 0.2078

fall 3 125 4.81 0.2078winter 3 250 3.33 0.3000

Weighted Mean Relative Damage 0.2151Weighted Mean W' (millions) 4.648

Seasonally adjusted effective k value (psi/in) 135

For the purpose of calculating the seasonally adjusted design k value, a trial slab thickness is calculated using

parameter symbol value units

slab thickness D 11.80 inarithmetic average k value 138 psi/in

estimated future ESALs 49,988,514 design reliability R 90 %overall standard deviation 0.35mean 28-day concrete elastic modulus 4,200,000 psimean 28-day concrete flexural strength 600 psiconcrete Poisson's ratio µ 0.15 base elastic modulus 25,000 psibase thickness 12 inslab/base friction coefficient f 1.5design k value k 135 psi/ininitial serviceability 4.3terminal serviceability 2.5joint spacing 20 ftedge support adjustment factor E 1.00mean annual temperature temp 67.5 deg Fmean annual precipitation precip 55.8 inmean annual wind speed wind 7.7 mph

Values for the following parameters are calculated from the trial thickness and above inputs.

standard normal deviate -1.282effective positive temperature differential TD 11.12 deg Fslab length in inches L 240 inratio of stress with friction to stress with bond F 1.04 radius of relative stiffness l 45.73 inlog of slope of TD effect on stress log b -1.254stress due to load sigma l 123.70 psitotal stress due to load and temperature sigma t 208.96 psi

Values for the following parameters are calculated for the trial thickness and AASHO Road Test constants.

effective positive temperature differential TD 9.37 deg Fratio of stress with friction to stress with bond F 1.04 radius of relative stiffness l 48.31 inlog of slope of TD effect on stress log b -1.428stress due to load sigma l 132.79 psitotal stress due to load and temperature sigma t 187.04 psi

Values for the following parameters are calculated to determine the trial thickness for the design ESALs.

allowable log ESALs for 50% reliability, new design log W' 7.37allowable log W for 50% reliability, AASHO Road Test log W 7.89log rho term log R 8.08serviceability loss term G -0.19beta term B 1.01allowable ESALs for design reliability, new design W' 8,357,394 expected ESALs for design reliability, new design 49,988,514 ratio of expected to allowable ESALs 5.98

Values for the following parameters are calculated during the seasonally adjusted effective k value calculation.

allowable ESALs for design reliability, new design 8.36 millionsweighted mean W' 4.65 millionsratio weighted mean W' to allowable ESALs 0.556

Press the "solve for seasonally adjusted k value" button.Use this seasonally adjusted design k value in the 98 AASHTO thickness design worksheet.

the inputs from the 98 AASHTO worksheet and the arithmetic average of the seasonal k values above.

kave

The values for the following parameters are taken from the 98 AASHTO worksheet.

W18

So

Ec

S'c

Eb

Hb

P1

P2

ZR

W18R

Comments

This value will be updated amd copied to the 98 AASHTO worksheet whenever you click the recalculate seasonally adjusted effective k value button on that worksheet.G16:

Fine-grained soils 3,000 to 40,000 psiSand 10,000 to 25,000 psiAggregate 15,000 to 45,000 psiLime-stabilized clay 20,000 to 70,000 psiAsphalt-treated base 300,000 to 600,000 psiCement-treated base 1000 * (500 + compressive strength, psi)Lean concrete base 1000 * (500 + compressive strength, psi)

G38:

Fine-grained soil 0.5 to 2.0Sand 0.5 to 1.0Aggregate 0.7 to 2.0Polyethlyene 0.5 to 1.0Lime-stabilized clay 3.0 to 5.3Cement-treated base 8 to 63Asphalt-treated base 3.7 to 10Lean concrete base without curing compound > 36 with curing compound 3.5 to 4.5

G40:

1.00 for 12-ft lane and AC shoulder0.94 for 12-ft lane and tied PCC shoulder0.92 for widened PCC slab

G45:

98 AASHTO

1998 AASHTO Supplement Procedure for Concrete Pavement Thickness Design

Enter values for the following parameters in the 1998 AASHTO concrete pavement performance model.

parameter symbol value units

slab thickness D 15.37 inestimated future ESALs 49,988,514 ESALsdesign reliability R 90 %overall standard deviation 0.35mean 28-day concrete elastic modulus 4,200,000 psimean 28-day concrete flexural strength 600 psiconcrete Poisson's ratio µ 0.15 base elastic modulus 25,000 psibase thickness 12 inslab/base friction coefficient f 1.5k value k 135 psi/ininitial serviceability 4.3terminal serviceability 2.5joint spacing L 20 ftedge support adjustment factor E 1.00mean annual temperature temp 67.5 deg Fmean annual precipitation precip 55.8 inmean annual wind speed wind 7.7 mph

Values for the following parameters are calculated from the above inputs.

standard normal deviate -1.282 okeffective positive temperature differential TD 12.15 deg F okslab length in inches L 240 in okratio of stress with friction to stress with bond F 1.00 okradius of relative stiffness l 55.74 in oklog of slope of TD effect on stress log b -1.273 okstress due to load sigma l 82.21 psi oktotal stress due to load and temperature sigma t 135.21 psi ok

Values for the following parameters are calculated for AASHO Road Test constants.

effective positive temperature differential TD 10.46 deg F okratio of stress with friction to stress with bond F 1.00 okradius of relative stiffness l 58.89 in oklog of slope of TD effect on stress log b -1.438 ok now (had 68 instead of 6)stress due to load sigma l 87.47 psi oktotal stress due to load and temperature sigma t 120.64 psi ok

Values for the following parameters are calculated to determine the required slab thickness for the design ESALs.

allowable log ESALs for 50% reliability, new design log W' 8.15 okallowable log W for 50% reliability, AASHO Road Test log W 8.67 oklog rho term log R 8.86 okserviceability loss term G -0.19 okbeta term B 1.00 okallowable ESALs for design reliability, new design W' 49,988,514 okexpected ESALs for design reliability, new design 49,988,514 okratio of expected to allowable ESALs 1.00 ok

Whenever you change input values below, first click the button "recalculate seasonally adjusted effective k value"before solving for the required slab thickness or allowable ESALs.

W18

So

Ec

S'c

Eb

Hb

P1

P2

ZR

W18R

98 fault chk

Joint Faulting Check for 1998 AASHTO Supplement Procedure

Predicted faulting doweled 0.07 in undoweled 0.11 in

Enter values for the following parameters to calculate faulting for doweled or undoweled joints.

parameter symbol value units

dowel diameter dowel 1.25 incumulative ESALs cesal 40 millionsage age 20 yearsmodified drainage coefficient 1.00friction adjustment factor con 0.80annual temperature range trange 85 deg FFreezing Index FI 200 F deg-daysbase type basetype 0widened slab widen 0days above 90 deg F days90 30

joint spacing jtspace 20 ftdistribution factor 0.35 inmoment of inertia dowel x-section I 0.1198relative stiffness dowel-concrete beta 0.6060average joint opening opening 0.049 inconcrete bearing stress bstress 1412 psiannual precipitation precip 55.80 in

Cd

The values below are calculated or taken from the 98 AASHTO worksheet.

fd

in4

climate

Climatic Data for Use With 1998 AASHTO Supplement Thickness and Faulting Models

Location Location Location

ALABAMA KANSAS OKLAHOMA Birmingham 62 52 7 74 0 Topeka 54 29 10 673 0 Oklahoma City 60 31 13 195 59 Mobile 68 65 9 16 61 Wichita 56 40 12 494 50 Tulsa 60 39 10 231 60 Montgomery 68 49 7 27 52 KENTUCKY OREGON ALASKA Lexington 55 46 7 448 0 Medford 54 20 5 61 31 Anchorage 35 15 7 2385 0 Louisville 56 44 8 380 0 Portland 53 37 8 45 0 Fairbanks 26 10 6 5601 0 LOUISIANA Salem 52 40 7 41 0 King Salmon 33 19 11 2898 0 Baton Rouge 68 56 8 12 74 PENNSYLVANIA ARIZONA Lake Charles 68 53 9 7 48 Harrisburg 53 39 8 454 0 Flagstaff 45 21 7 585 0 New Orleans 68 60 8 10 30 Philadelphia 54 41 10 376 0 Phoenix 71 7 6 0 157 Shreveport 65 44 9 37 75 Pittsburgh 50 36 9 686 0 Tucson 68 11 8 0 133 MAINE RHODE ISLAND ARKANSAS Caribou 39 37 11 2224 0 Providence 50 45 11 513 0 Little Rock 62 49 8 102 64 Portland 45 44 9 966 0 SOUTH CAROLINA CALIFORNIA MARYLAND Charleston 65 52 9 19 6 Bakersfield 66 6 6 6 98 Baltimore 55 42 9 306 0 Columbia 63 49 7 54 46 Fresno 63 11 6 0 101 MASSACHUSETTS SOUTH DAKOTA Los Angeles 63 12 8 0 0 Boston 52 44 12 446 0 Huron 45 19 12 1840 0 Sacramento 61 17 8 0 63 Worcester 47 48 12 860 0 Rapid City 47 16 11 1232 0 San Diego 64 9 7 0 0 MICHIGAN TENNESSEE San Francisco 57 20 11 0 0 Detroit 49 4 10 857 0 Chattanooga 59 53 6 140 0 Santa Barbara 59 16 6 0 0 Flint 47 29 11 1015 0 Knoxville 59 47 7 184 0 COLORADO Grand Rapids 48 34 10 996 0 Memphis 62 52 9 105 61 Colorado Springs 49 15 10 588 0 MINNESOTA Nashville 59 48 8 213 0 Denver 50 15 9 544 0 Duluth 38 30 11 2472 0 TEXAS CONNECTICUT Minneapolis 45 26 11 1848 0 Amarillo 57 19 14 200 41 Hartford 50 44 9 690 0 MISSISSIPPI Brownsville 74 25 12 0 97 DC Jackson 65 53 7 52 82 Corpus Christi 72 30 12 0 87 Washington 58 39 9 200 0 MISSOURI Dallas 66 29 11 40 89 DELAWARE Kansas City 56 35 11 724 0 El Paso 63 8 9 0 98 Wilmington 54 41 9 371 0 MONTANA Galveston 70 40 11 0 0 FLORIDA Great Falls 45 15 13 1513 0 Houston 68 45 8 0 76 Jacksonville 68 53 8 9 56 NEBRASKA Lubbock 60 18 12 76 56 Miami 76 58 9 0 0 Omaha 50 30 11 1042 0 Midland 64 14 11 22 93 Orlando 72 48 9 0 85 NEVADA San Antonio 69 29 9 5 95 Tallahassee 67 65 6 11 82 Las Vegas 66 4 9 0 127 Waco 67 31 11 27 96 Tampa 72 47 9 0 12 Reno 49 7 7 258 39 Wichita Falls 64 27 12 91 85 West Palm Beach 75 60 9 0 0 NEW JERSEY UTAH GEORGIA Atlantic City 53 42 10 374 0 Salt Lake City 52 15 9 519 38 Atlanta 61 49 9 81 0 NEW MEXICO VERMONT Augusta 63 43 7 40 52 Albuquerque 56 8 9 122 53 Burlington 44 34 9 1464 0 Macon 65 45 8 27 69 NEW YORK VIRGINIA Savannah 66 50 8 14 38 Albany 47 36 9 1004 0 Norfolk 60 45 11 111 0 HAWAII Buffalo 48 38 12 860 0 Richmond 58 44 8 175 0 Hilo 74 128 7 0 0 New York City 55 44 12 321 0 Roanoke 56 39 8 227 0 Honolulu 77 23 12 0 0 Rochester 48 31 10 852 0 WASHINGTON IDAHO Syracuse 48 39 10 922 0 Olympia 50 51 7 72 0 Boise 51 12 9 576 23 NORTH CAROLINA Seattle 53 39 9 31 0 Pocatello 47 11 10 958 0 Charlotte 60 43 8 78 0 Spokane 47 17 9 686 0 ILLINOIS Greensboro 58 42 8 137 0 WEST VIRGINIA Chicago 49 33 10 1017 0 Raleigh 59 42 8 104 0 Charleston 55 42 6 377 0 Peoria 50 35 10 988 0 Wilmington 63 53 9 41 0 Huntington 55 41 7 369 0 Springfield 53 34 11 828 0 NORTH DAKOTA WISCONSIN INDIANA Bismarck 41 15 10 2319 0 Green Bay 44 28 10 1630 0 Evansville 56 42 8 483 0 Fargo 41 20 12 2598 0 Madison 45 31 10 1461 0 Fort Wayne 50 34 10 910 0 OHIO Milwaukee 46 31 12 1202 0 Indianapolis 52 39 10 727 0 Akron-Canton 50 36 10 757 0 WYOMING South Bend 49 38 10 878 0 Cleveland 50 35 11 768 0 Casper 45 11 13 1128 0 IOWA Columbus 52 37 9 678 0 Cheyenne 46 13 13 834 0 Des Moines 50 31 11 1202 0 Dayton 52 35 10 690 0 Sioux City 48 25 11 1366 0 Youngstown 48 37 10 861 0 Waterloo 46 33 11 1602 0

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86 seasonal k

Seasonally Adjusted Design K Value for 1986/1993 AASHTO Guide Procedure

Enter the number of months for each season, so that total number of months is twelve.Enter a k value for each season.

Season Months k value W' log Relative(psi/in) (millions) Damage

spring 3 50 43.69 0.0229summer 3 150 51.05 0.0196

fall 3 150 51.05 0.0196winter 3 200 53.56 0.0187

Weighted Mean Relative Damage 0.0202Weighted Mean W' (millions) 49.545

Seasonally adjusted effective k value (psi/in) 124

For the purpose of calculating the seasonally adjusted design k value, a trial slab thickness is calculated using

parameter symbol value units

slab thickness D 14.82 inarithmetic average k value 138 psi/in

estimated future ESALs 3,716,407 design reliability R 97 %overall standard deviation 0.37mean 28-day concrete elastic modulus 4,200,000 psimean 28-day concrete flexural strength 600 psibase elastic modulus 25,000 psibase thickness 8 inDepth to rigid foundation 20 ftdesign k value k 124 psi/ininitial serviceability 4.3terminal serviceability 2.5drainage coefficient 1.00load transfer coefficient J 3.2

Values for the following parameters are calculated from the trial thickness and above inputs.

standard normal deviate -1.881composite k value for semi-infinite foundation 169 psi/incomposite k value for finite depth to rigid layer 145 psi/inallowable log ESALs for design reliability log W' 7.70allowable ESALs for design reliability W' 49,552,485 expected ESALs 3,716,407 ratio of expected to allowable ESALs 0.07

Values for the following parameters are calculated during the seasonally adjusted effective k value calculation.

allowable ESALs for design reliability, new design 49.55 millionsweighted mean W' 49.54 millionsratio weighted mean W' to allowable ESALs 1.000

Press the "solve for seasonally adjusted k value" button.Use this seasonally adjusted design k value in the 86 AASHTO thickness design worksheet.

the inputs from the 86 AASHTO worksheet and the arithmetic average of the seasonal k values above.

kave

The values for the following parameters are taken from the 86 AASHTO worksheet.

W18

So

Ec

S'cEb

Hb

Hrig

P1

P2

Cd

ZR

kinf

kfin

W18

86 AASHTO

1986 AASHTO Guide Procedure for Concrete Pavement Thickness Design

Enter values for the following parameters in the 1986/1993 AASHTO concrete pavement performance model.

parameter symbol value units

slab thickness D 10.00 inestimated future ESALs 3,716,407 design reliability R 97 %overall standard deviation 0.37mean 28-day concrete elastic modulus 4,200,000 psimean 28-day concrete flexural strength 600 psibase elastic modulus 25,000 psibase thickness 8 indepth to rigid foundation 20 ftroadbed soil k value k 124 psi/ininitial serviceability 4.3terminal serviceability 2.5drainage coefficient 1.00load transfer coefficient J 3.2

Values for the following parameters are calculated to determine the required slab thickness for the design ESALs.

standard normal deviate -1.881composite k value for semi-infinite foundation 169 psi/incomposite k value for finite depth to rigid layer 145 psi/inallowable log ESALs for design reliability log W' 6.57allowable ESALs for design reliability W' 3,716,407 expected ESALs 3,716,407 ratio of expected to allowable ESALs 1.00

Whenever you change input values below, first click the button "recalculate seasonally adjusted effective k value"before solving for the required slab thickness or allowable ESALs.

W18

So

Ec

S'cEb

Hb

Hrig

P1

P2

Cd

ZR

kinf

kfin

W18