1. Streets and Local Roads
Proper Design Details for PCC Pavement Performance
Mike Byers
Indiana Chapter – American Concrete Pavement Association

2. American Concrete Pavement Association
Streets & Local Roads
Chapter/States Associations of ACPA
North Dakota
Northwest
Minnesota
Michigan
South Dakota
Wisconsin
Northeast
Colorado-
Wyoming
Iowa
Indiana
Illinois
Ohio
Utah
Western States
Missouri-Kansas
Kentucky
Oklahoma-Arkansas
Southeast
Louisiana
American Concrete Pavement Association

3. SLR Pavement Markets New/Reconstruction of Concrete Pavements
Concrete Overlays
Unbonded
Whitetopping
Ultra-Thin Whitetopping (UTW)
Concrete Inlays
Intersections
Roundabouts
Bus Pads
Alleys
Concrete Pavement Restoration

4. Thickness Design Procedures
Empirical Design Procedures
Based on observed performance
AASHO Road Test
Mechanistic Design Procedures
Based on mathematically calculated pavement responses
PCA Design Procedure (PCAPAV)
StreetPave (ACPA Design Method)
Ottawa, Illinois (approximately 80 miles southwest of Chicago) between 1956 and 1960

5. New Design Tools for SLR
MEPDG – Mechanistic-Emperical Design Guide
StreetPave Software
Concrete Thickness
Asphalt Institute Design Thickness
Life Cycle Cost Analysis
Information Sheet IS184
Thickness Design Manual for Concrete Streets and Local Roads EB109
Equivalent Pavement Design Charts
The design tools are primarily intended for concrete pavement designs for new construction for all categories of streets and local roads pavements.
These are base on the PCAPAV “Thickness Design for Concrete Highway and Street Pavements (SLR Only) and the accompanying software. These projects are budgeted for 2004 but work is currently underway. The thickness guide will be primary a rewrite of our current metric version for SLR pavements only.
The equivalent design charts are tools requested during the Chapter/State meetings and is a simple comparisons of equivalent Concrete to Asphalt cross sections incorporating the Structural Number concept.
What’s Equivalent

6. Equivalent Pavement Design

7. StreetPave Software
Concrete pavement thickness design based on revised criteria
Asphalt equivalent section based on converted total carrying capacity
Life-Cycle cost analysis based on initial costs of equivalent pavements and predicted maintenance

8. Different Pavement Types
Concrete Section
Asphalt Section
Asphalt Layer
Subbase
Base
Subgrade
Subbase
Subgrade

9. How Pavements Carry Loads
7000 lb.
7000 lb.
pressure < 1-3 psi
pressure » 6-10 psi
Concrete’s Rigidness spreads the load over a large area
and keeps pressures on the subgrade low.

10. Comparison of Concrete vs. Asphalt
It’s not the same old Asphalt and Concrete anymore!
Just look at the Gas Pumps!
Gasoline prices are a good indicator of what asphalt pavement cost!
Reproducing the graphics from ENR demonstrating the cost increase of Asphalt vs. the Cost Increase of Concrete

11. Life-Cycle Cost Analysis
Equivalent Uniform Annual Cost:
Combines all present and future costs (benefits) into equal annual payments
Costs
Initial Cost
Rehabilitation Cost
Maintenance Cost
Salvage
Value
Years
Costs
Equivalent Uniform Annual Cost
Years

12. Streets and Local Roads Thickness Design Procedure
Surface smoothness or rideability
Thickness Design
Longitudinal joint
Transverse joint
Surface Texture
Concrete materials
Dowel bars
Tiebars
Subgrade
Subbase or base

13. Concrete Pavement Types
Jointed Plain
Undoweled
Doweled
Jointed Reinforced
Continuously Reinforced

14. Jointed Plain
Plan
8 – 15 ft
Profile or

15. Jointed Plain

16. Agencies Designing Jointed Plain Concrete Highway Pavements
Use jointed plain designs
Do not use jointed plain designs

17. Concrete Pavement Design Requires Selecting Appropriate Features
Subgrade modification
Drainage system
Subbase
Joint Spacing
15 ft
18 ft
Dowels
Thickness
6 in
8 in
10 in
Reinforcement
Joint Sealant
None
Hot pour
Silicone
Preformed
Surface Texture
Transverse tine
Burlap drag
Shoulder
Asphalt
Concrete

18. Optimize Cost Performance
Now Using Mechanistic-Empirical Design (MEPDG) to Optimize

19. Principles of Design Load stresses Curling/Warping stresses
Thickness
Curling/Warping stresses
Jointing
Volume change stresses

20. SLR Pavement Design Street classification and traffic Geometric design
Subgrades and subbases
Concrete quality
Thickness design
Jointing
Construction specifications

21. Street Class Description Light Residential Residential Collector
Two-way Average Daily Traffic (ADT)
Two-way Average Daily Truck Traffic (ADTT)
Typical Range of Slab Thickness
Light Residential
Short streets in subdivisions and similar residential areas – often not through-streets.
Less than 200
2-4
in.
( mm)
Residential
Through-streets in subdivisions and similar residential areas that occasionally carry a heavy vehicle (truck or bus).
200-1,000
10-50
in.
( mm)
Collector
Streets that collect traffic from several residential subdivisions, and that may serve buses and trucks.
1,000-8,000
50-500
in.
( mm)
Business
Streets that provide access to shopping and urban central business districts.
11,000-17,000
in.
( mm)
Industrial
Streets that provide access to industrial areas or parks, and typically carry heavier trucks than the business class.
2,000-4,000
in.
( mm)
Arterial
Streets that serve traffic from major expressways and carry traffic through metropolitan areas. Truck and bus routes are primarily on these roads.
4,000-15,000 (minor)
4,000-30,000 (major)
700-1,500
in. ( mm)
in. ( mm)

22. Geometric Design Utilities Increase Edge Support Street Widths
Integral Curb
Tied Curb & Gutter
Widened Lanes (2 feet no parking)
Parking Lanes
Rural Areas – Tied Concrete Shoulders
Street Widths
Minimum width of 25 ft.
Maximum Cross Slope of 2 percent (¼” per ft.)
Traffic Lanes feet
Parking Lanes 7-8 feet
Notes:
Utilities should be located outside pavement structure whenever possible.
StreetPave treats each of the above category the same for additional edge support and typically will reduce the cross-sectional thickness by approximately 1 inch.
Pavement lane widths greater than 14 (stripped) may cause drives to try and pass, especially on the right.
Parking lanes of 6 ft. are not recommended.

23. For Concrete Pavements
Subbase vs. NO Subbase
For Concrete Pavements
Subbase
Subgrade

24. For Concrete Pavements
Subgrade and Subbases
For Concrete Pavements
Subbase
Subgrade

25. Subgrade and Subbases Subgrade Subbase
Natural ground, graded, and compacted on which the pavement is built.
Subbase
Layer of material directly below the concrete pavement.

26. GOOD PAVEMENT PERFORMANCE
UNIFORMITY:
The Key To
GOOD PAVEMENT PERFORMANCE
As well as being Drainable and Compactable

27. Design for Uniform Support
Three Major Causes for Non-Uniform Support
Expansive Soils
Differential Frost Heave
Pumping (loss of support)

28. Subbase vs. NO Subbase Presence of fine-grained soil Presence of water
Sufficient volume of trucks to cause soil pumping (> 100 trucks/day)
Pavements on > 15% grade

29. Subgrade Properties Modulus of Subgrade Reaction, k-value
Plate-Load Test
Reaction
Stacked Plates
Pressure Gauge
Subgrade
Plate load on subgrade Plate deflection on subgrade
k =
5.0 psi in
k =
= 100 psi / in.

30. Subgrade Properties Plate-load test is rarely performed
time consuming & expensive
Estimate k-value by correlation to other tests
e.g. California Bearing Ratio (CBR) or R-value tests
Lean concrete subbases increases k-value substantially

31. Subgrade Properties Correlated k-values for Subgrade Support Type
Amount of Support
Historical
k-values (pci)
California
Bearing Ratio (CBR), %
(ASTM D 1183)
Resistance
Value
(R-value)
(ASTM D 2844)
Fine-grained with high amounts of silt/clay
Low
Sand and sand-gravel with moderate silt/clay
Medium
Sand and sand-gravel with little or no silt/clay
High

32. Subgrade and Subbases Design Summary
Subgrade strength is not a critical element in the thickness design.
Has little impact on thickness.
Need to know if pavement is on:
Subgrade (k  25 MPa/m (100 psi/in.)),
Granular subbase (k  40 MPa/m (150 psi/in.)),
Asphalt treated subbase (k  80 MPa/m (300 psi/in.))
Cement treated/lean concrete subbase (k  125 MPa/m (500 psi/in.)).

33. Subgrade and Subbases Performance Summary
Proper design and construction are absolutely necessary if the pavement is to perform.
Must be uniform throughout pavement’s life.
Poor subgrade/subbase preparation can not be overcome with thickness.
Any concrete pavement, built of any thickness, will have problems on a poorly designed and constructed subgrade or subbase.

34. Subbase Effects
At the AASHO Road Test, concrete pavements with granular bases could carry about 30% more traffic.
The current design procedures allows concrete pavements built with granular bases to carry about 5 - 8% more traffic.

35. Drainable Subbase?? Aggregate Quality – marginal D-cracking?
Traffic Level – high volume may warrant drainable subbase
Edge drains behind curb still good detail

36. Concrete Quality Portland Cement Supplementary Cementitious Materials
Aggregates
Chemical Admixtures
Water
Testing

37. Maximum size aggregate Total target air content, percent *
Concrete Quality
Recommended Air Contents for Durable Concrete
Maximum size aggregate
Total target air content, percent *
in. mm
Severe Exposure
Moderate Exposure
3/8
9.5
7.5 6
1/2
12.5 7
5.5
3/4
19.0 5 1
25.0
4.5 1½
37.5 2
50.0 4
Suggest 6.5

38. Maximum water-cementitious ratio by weight
Concrete Quality
Maximum Permissible Water-Cement Ratio for Durable Concrete Pavement
Type of exposure
Maximum water-cementitious ratio by weight
Freezing/thawing with deicing chemicals
0.45
Severe sulfate exposure [water-soluble sulfate (SO4) in soil > 0.20 % by weight]
Moderate sulfate exposure [water-soluble sulfate (SO4) in soil of 0.10 to 0.20 % by weight]
0.50
INDOT max 0.42

39. Basics of Thickness Design
When a pavement is subjected to traffic loadings the pavement reacts by bending and creating both compressive and flexure stresses. Since the Stresses ratio is much greater for flexural than compressive, the flexural strength governs the thickness design

42. The latest design and cost analysis tool from ACPA…
Determine and compare thickness requirements and costs for concrete and asphalt pavements using StreetPave. Features:
Updated mechanistic design method for concrete pavement
Fatigue and erosion analysis
Jointing spacing & load transfer recommendations
Thickness rounding and reliability considerations
Analysis of existing concrete pavements
Asphalt design based on the Asphalt Institute method
Comparison to equivalent concrete pavement
Life cycle cost analysis module
Printable summary reports and charts
Design summary
Design factor sensitivity & life-cycle plots
User-friendly format and features
Walkthrough Wizard
Help information for all inputs
Compatible with Windows™ 95, 98, NT, 2000, XP

43. Thickness Design for Streets and Local Roads
StreetPave User Inputs & Outputs
Global Settings
Region
Units (English or Metric)
Terminal Serviceability
Percent Slabs Cracked at end of design Life
Design Life
Reliability
Traffic
Pavement Properties
Thickness/Dowel/Jointing Recommendations

44. Design Example – Inputs
Design life = 30 years
k-value = 100 pci
Concrete flexural strength = 600 psi
Load transfer (dowels) = yes
Edge support = yes
Traffic category = Collector
2-way ADTT = 100
Reliability = 80%
Percent Slabs Cracked = 15%

45. Thickness Design Procedure
Design controlled by:
Fatigue usually controls design of light-traffic pavements
Single-axles usually cause more fatigue damage
Erosion usually controls design of undoweled medium- and heavy-traffic pavements
Tandem-axles usually cause more erosion damage
Tridem-axles usually cause more erosion damage

46. Thickness Design Procedure Concrete Properties
Flexural Strength (Modulus of Rupture, ASTM C 78)
Avg. 28-day strength in 3rd-point loading
Other Factors
Concrete Strength Gain with Age
Fatigue Properties
Third-point Loading
d=L/ 6
L/3
Span Length = L

47. Thickness Design Procedure Concrete Properties
Compressive Strength f’c
Head of Testing Machine
S’c = 8-10 Ö f’c
Cylinder Depth
f’c = Compressive Strength (psi) S’c = Flexural Strength (psi)

48. Basics of Thickness Design Stress / Fatigue
Compressive strength: ~4000 psi
Flexural strength: ~600 psi
When a pavement is subjected to traffic loadings the pavement reacts by bending and creating both compressive and flexure stresses. Since the Stresses ratio is much greater for flexural than compressive, the flexural strength governs the thickness design

49. Source (Modeled after) RD102, Evaluation of the Long-Term Properties of Concrete, by Sharon Wood.

50. Concrete Strength Properties
If specify minimum flexural strength at 28-day of 550 psi & allow 10% of beams to fall below minimum:
STEP 1
Estimate SDEV:
9% for typical ready mix.
SDEV = 550 * 0.09 = 50 psi
STEP 2
S’c design = S’c minimum + z * SDEV
S’c design = * 50
S’c design = 614 psi
Fig Concrete strength gain versus time for concrete exposed to outdoor conditions. Concrete continues to gain strength for many years when moisture is provided by rainfall and other environmental sources (Wood 1992).

51. Thickness Design Procedure Concrete Properties
Comparison of f’c, MR, and Required Thickness
Compressive Strength (psi)
Flexural Strength (psi)
Design Thickness (inches)
3000
450 – 550 (500)
6.5 (6.43)
PCA 7.0
4000
510 – 630 (600)
5.5 (5.25)
PCA 6.5
5000
570 – 710 (700)
5.0 (4.86)
PCA 6.0
Life 30 years, Collector (2), k-value 162, Reliability 80 %, plus C & G, 2 % annual growth

52. Design Period/Life 20 to 35 years is commonly used
Shorter or longer design period may be economically justified in some cases
High performance concrete pavements
Long-life pavements
A special haul road to be used for only a few years
Cross-overs
Temporary lanes

53. Design Reliability
Practically everything associated with pavement design is variable
Variability in mean design inputs—traffic, materials, subgrade, climate, and so on
Error in performance prediction models
In StreetPave design, the fatigue variability can be modeled and applied as an adjustment factor

54. Recommended Reliability
Levels of Reliability for Pavement Design
Functional Classification of Roadway
Recommended Reliability
Urban
Rural
Interstates, Freeways, and Tollways
80 – 99
Principal Arterials
75 – 95
Collectors
Residential & Local Roads
50 – 80
The American Concrete Pavement Association design procedure incorporates reliability as an input variable. Reliability, simply stated, is the factor of safety of the pavement design. It is a measure of how likely the specified design will perform before “failure.” This design procedure predicts when the pavement will “fail” either due to fatigue (a crack will form) or erosion (the subgrade material will pump out from underneath the pavement).
The recommended level of reliability depends on the type of roadway that is being designed. A relatively high reliability is used for high-traffic, high-speed roadways, while low-traffic, low-speed roads typically need a low level of reliability. The importance of this innovation is that it allows the design professional to use lower levels of reliability to produce design thicknesses more practical for streets and local road design. Table 12 lists the recommended reliability levels for roadway design, dependent on the classification of the facility.
The design tables 13(a) and 13(b) were developed using a reliability value of 80 percent, which is common for most street and local road applications and takes into account the variations in materials and layer thicknesses for each traffic category.

55. Recommended Percent of Slabs Cracked at End of Design Life
Thickness Design
Combined Reliability & Slabs Cracked Spreadsheet
Recommended Levels of Slab Cracking by Roadway Type
Roadway Type
Recommended Percent of Slabs Cracked at End of Design Life
(Default)
15%
Interstate Highways, Expressways, Tollways, Turnpikes 5%
State Roads, Arterials
10%
Collectors, County Roads
Residential Streets
25%
The design procedure also incorporates the amount of slab cracking as another factor used to evaluate the predicted long-term pavement performance. Primarily, this factor assists in planning future maintenance or pavement preservation activities at the end of the pavement’s design life. For Tables 13(a) and 13(b), the percent slabs cracked at the end of the design life was set at 15 percent for all roadway classifications, which reduces the overall repairs required to extend the pavement service life past the design period. For additional information on concrete pavement preservation or restoration, see American Concrete Pavement Association publication The Concrete Pavement Restoration Guide, Reference 9.

60. Basics of Thickness Design Deflection / Erosion
Higher k-value will lower deflections
Load transfer will lower deflections

61. Concrete Pavement Design For Municipal Streets
Load Transfer (slabs ability to share its load with neighboring slabs)
Dowels
Aggregate Interlock
Edge Support
Tied curb & gutter
Integral curb & gutter
Parking lane
Tied concrete L
= x U
= 0
Poor Load Transfer
Emphasize that:
Adequate load transfer reduces vertical movement at the joints, minimizing joint-related distresses.
Typical load transfer mechanisms are aggregate interlock and dowel bars. Also, stabilized bases can be used to reduce to potential of pumping
Note to the speaker: Stabilized bases are developed using procedures and techniques by which otherwise unsuitable soils may be improved. In many instances, the existing subgrade soils are unsatisfactory in their natural state but can be altered through stabilization to improve the material properties to meet the requirements of subbase and base layer materials. In some instances, stabilized bases are used to improve the structural integrity of the pavement layers supporting the pavement surface.
Many factors influence the type of stabilizing material selected for a particular project, such as the type of soil. In addition, different stabilizers are used for different reasons, such as strength gain, waterproofing, or water retarding. Therefore, some stabilizing materials are more appropriate for a given soil type than others. Stabilizing admixtures include cement, lime, lime flyash, bitumen (asphalt), and calcium or sodium chloride.
The use of edge support will reduce the stresses at the pavement edge and reduce the overall cross-sectional thickness. In residential and collector, and minor arterials this would typically be 1 inch major arterials this thickness reduction is approximately 1.5 inches.
Good Load Transfer L
= x/2 U

62. Dowels vs. NO Dowels Load Transfer
= x U
= 0
Poor Load Transfer
The slabs ability to share its load with its neighboring slab
Dowels
High Traffic Volumes
(Pavements > 8 in.)
(> 120 Trucks/day)
Aggregate Interlock
Low Traffic Volumes
(Pavements < 7 in.)
Good Load Transfer L
= x U

63. Load Transfer Efficiency
Load Transfer Mechanism
LTE, %
aggregate interlock stabilized base
dowel bars
These are the expected average performance ranges of load transfer efficiency for highway pavements over the life of the pavement for each load transfer mechanism listed. The load transfer performance will depend on the selected materials and the quality of construction within a given project.
As you can see from these ranges, dowel bars provide the best and most reliable load transfer.

64. Shear between aggregate particles below the initial saw cut
Aggregate Interlock
Shear between aggregate particles below the initial saw cut

65. Aggregate Interlock

66. Design - Erosion Conditions for Pumping
Subgrade soil that will go into Suspension
Free water between slab and subgrade
Frequent heavy wheel loads / large deflections

67. Dowel bars Lengths from 15-18 in. 6.0 in. min. embedment length
Diameter
in. for SLR
Epoxy or other coating used in harsher climates for corrosion protection

68. Dowel Recommendations
Dowels recommended when ADTT is greater than or equal to 80:
If pavement thickness is 6” or less dowels not recommended
If pavement thickness is 6.5” to 7.5” use 1” dowels
If pavement thickness is 8” or greater use 1¼“ dowels
Note: Due to rounding at a thickness of 6.01 inches the recommended thickness is rounded up to the nearest 0.5 inch 6.5 inches. In these cases, dowels may or may not be recommended. The use of a non-pumping subgrade/subbase could be used in place of 1” dowels.

69. Faulting Model Faulting, in 0.20 Dense-graded base No dowel 0.15
Permeable base
No dowel
0.10
Dense-graded base
1-in dowel
0.10 in of faulting typically becomes uncomfortable to the driving public, as well as the vehicular commerce, and triggers rehabilitation.
The “beige” faulting trend increases very rapidly as ESALs accumulate.
The “orange” faulting trend is similar.
The “light blue” trend becomes uncomfortable around 15 million ESALs.
The “dark blue” trend remains well below the uncomfortable threshold for rehabilitation.
Therefore, dowels reduce faulting better than nondoweled JPCP or permeable bases.
Faulting is just one of the distresses caused by poor load transfer.
0.05
Dense-graded base
1.25-in dowel
0.00 5 10 15 20
Traffic, million ESALs

70. Construction of Concrete Pavement
Plant Operations
Central Mixed Concrete
Truck Mixed Concrete
Paving Operations
Slipform Paving
Fixed Form Paving
Saw & Seal
Central Mix Concrete Batch Plant

71. Construction Specifications
Smoothness
10-20 ft. Straightedge
Profilograph Index
Texture
Speeds less than 40 mph
Burlap Drag
Astroturf Drag

72. Curing and Protection
Fig An excellent method of wet curing is to completely cover the surface with wet burlap and keep it continuously wet during the curing period. (69946)

73. Curing
Curing is one of the most important steps in quality concrete construction and one of the most neglected.
Effective curing is absolutely essential for surface durability.
Durability = resistance to freeze-thaw

74. Curing Curing requires adequate — Moisture Temperature Time
If any of these factors are neglected, the desired properties will not develop
Fig Curing should begin as soon as the concrete stiffens enough to prevent marring or erosion of the surface. Burlap sprayed with water is an effective method for moist curing. (69973)

75. Membrane Curing of Concrete
Evaporation from water surface
Curing membrane
Partially saturated
Saturated
Concrete

76. Curing
The simplest, most economical and widely used method is a liquid membrane which is sprayed on the surface of a slab as soon as possible after finishing.
Apply at manufacture’s rate of coverage.
Perform field check to verify application rate.

77. Effect of Adequate Curing on Hardened Concrete
Increased
Strength
Watertightness
Abrasion resistance
Freeze-thaw resistance
Volume stability

78. Effect of Curing on Strength Development

79. The latest design and cost analysis tool from ACPA…
Determine and compare thickness requirements and costs for concrete and asphalt pavements using StreetPave. Features:
Updated mechanistic design method for concrete pavement
Fatigue and erosion analysis
Jointing spacing & load transfer recommendations
Thickness rounding and reliability considerations
Analysis of existing concrete pavements
Asphalt design based on the Asphalt Institute method
Comparison to equivalent concrete pavement
Life cycle cost analysis module
Printable summary reports and charts
Design summary
Design factor sensitivity & life-cycle plots
User-friendly format and features
Walkthrough Wizard
Help information for all inputs
Compatible with Windows™ 95, 98, NT, 2000, XP

80. SLR Publications www.pavement.com Information Sheet-
Maturity Testing of Concrete-
Information Sheet- (IS
Concrete Pavement for
GA Business &Commuter Aircraft
Longevity and Performance
of DG Pavements
Specification Guideline for
Dowel Bar Retrofit
Engineering Bulletin- (EB
Early Cracking Causes/Solutions
Engineering Bulletin-(EB
Life Cycle Cost Analysis

81. Indiana Concrete Resources
Jerry Larson
Mike Byers
Pat Long
Chris Tull, P.E., LEED AP

82. Contacts for further information
Questions?
Contacts for further information
INDIANA CHAPTER

83. Thank You
It is vital to our program for people to get involved in the Streets and Local Roads program. The SLR subcommittee will met twice in These meetings are where key areas of our promotion initiative are discussed and future products/programs are outlined. Get involved!