Pervious Concrete Pavement 4825 Butler Road, Glyndon Maryland

1
Pervious Concrete Pavement4825 Butler Road,
Glyndon Maryland
2
Demonstration PanelOctober 12, 2007
3
Pervious Concrete Pavement4825 Butler Road,
Glyndon Maryland
4
Pervious Concrete Pavement4825 Butler Road,
Glyndon Maryland
5
Pervious Pavement Section

6
Underdrains
7
Inlet Detail
8
Observation Wells
9
Pervious Concrete Pavement4825 Butler Road,
Glyndon Maryland
Work In Progress
10
Specifications and Testing forPervious
Concrete

• Rod Meyers, P.E., CDT, BASF
• Matt Cockerham, North Star

11
Specifications and Testing forPervious
Concrete

• Desired Plastic Properties
• Desired In Place Properties
• Common Specification Provisions

12
Desired Plastic PropertiesBatching Consistency

• ASTM C 143,
• Slump Test,
• does not apply

13
Desired Plastic PropertiesStable Paste

• Improves
• permeability
• Improves abrasion resistance
• Improves cold weather durability

14
Desired Plastic PropertiesWorkability

• Maintains w/cm
• Permits timely unloading, placement, finishing,
  and curing

15
Desired In Place PropertiesPercolation

• 3 to 5 gal/ft2/min
• 288 in./hr to
• 480 in./hr
  
• 4.8 in./min to
• 3.2 in/min

16
Desired In Place PropertiesPercolation

• ASTM developing test method to measure
  percolation
• Constant head method

17
Percolation as a Function of Void Content
18
Measuring VoidsTesting Fresh Density

• Sample in accordance with ASTM C 172
• Sample every 100 cubic yards
• Within /- 5 lb/ft3 of specified density

19
Testing Fresh Density ASTM C1688 Density and
Void Content of Freshly Mixed Pervious Concrete

• 0.25 ft3 measure (standard air pot)
• Standard Proctor Hammer
• Fill in two lifts
• Drop hammer 20 times/lift

20
Testing Fresh DensityAlternate Methods

• ASTM C29 Jigging Procedure
• ASTM C138 Rodding Procedure
• Filling an empty unit weight bucket

21
Testing Fresh DensityComparing Methods
22
Usable Voids vrs. Gravimetric VoidsEffective
Porosity vrs. Total Voids
Usable Voids, 0.898 (Gravimetric
Voids, ) 3.1
23
Usable Voids vrs. Gravimetric Voids
A 4 inch thick pervious pavement with 15 usable
(effective) voids will store 0.60 inches of
rainwater (4 0.15 0.60)
24
Desired In Place PropertiesMechanical Strength

• Rigid Pavement
• Flexural Strength

25
Compressive Strength vrs. Void Content
26
Flexural Strength vrs. Void Content
Flexural Strength, Fmr 832.8 20.3 (void
content, ), psi
27
Pavement Serviceability

• AASHTO Road Test
• Relationship between serviceability and load
  repetitions

28
Designing Pavements to Account for Fatigue
29
Estimating Flexural Stress
ACI 330 Guide for The Design and Construction
of Concrete Parking Lots
30
Desired In Place PropertiesAbrasion Resistance

• Strong, dense surface
• Good curing

31
Desired In Place PropertiesCold Weather
Durability

• Freeze-thaw Durability
• Frost Heave

32
Frost Heave

• Frost Penetration Depth in MD 30
• FAA recommends 65 of the frost depth contain
  non-frost-susceptible material
• For 30 FPD, depth of pervious material (concrete
  plus base) shall be 20 inches

33
Cold Weather Durability

• ASTM C 666 testing has indicated low durability
• Field service says otherwise

34
Mix Design Development for Pervious Concrete in
Cold WeatherSponsored byIowa Department of
Transportation National Concrete Technology
Pavement Technology CenterIowa Concrete Paving
Association
35
Conclusions

• Failure due to freeze-thaw cycles are the result
  of aggregate deterioration or cement paste matrix
  failure
• Sand, latex and air entrainment admixture
  improved freeze-thaw durability

36
The Effect of Coarse Aggregate on the Freeze-Thaw
Durability of Pervious ConcreteJohn T Kevern,
University of Missouri-Kansas CityKejin Wang,
Iowa State UniversityVernon R Schaefer, Iowa
State University
37
Conclusion and Recommendations

• Aggregate absorption has the greatest effect on
  freeze-thaw durability

38
Review of Maryland Aggregates
39
Suggested Methods to Improve Cold Weather
Durability

• Use 8 to 24 of Open Graded Base
• Use Sound Aggregates
• Use Air Entraining Admixture
• Use 5 to 10 Fine Aggregate
• Place perforated PVC pipe in base to capture and
  remove water

40
SpecificationsCommon Provisions
41
Contractor QualificationsOptions On Site

• 1 NRMCA Certified Pervious Concrete Craftsman
• 3 NRMCA Certified Pervious Concrete Installers
• 5 NRMCA Certified Pervious Concrete Technicians

42
Pre-paving Conference

• Within two weeks of first placement
• In attendance
• Owners Representative
• Contractor
• Concrete Supplier
• Concrete Foreman
• Testing Agency

43
Test Panel

• Minimum 225 ft2
• Use proposed mix design and materials
• Use proposed placement equipment
• Include at least one typical joint

44
Test Panel

• Fresh density with /- 5.0 lb/ft3
• Three cores average thickness not more than ¼
  less or 1.5 more than specified thickness
• Single core not more than ½ less than
• specified thickness

45
Testing Thickness

• Average of three cores more than 1-1/2 greater
  than specified thickness
• No single core more than ½ less than specified
  thickness

46
Testing Thickness

• Three cores per 5,000 ft2
• Average of three cores not more than ¼ less than
  specified thickness

47
Testing In Place Density

• Three cores per 5,000 ft2
• Minimum nominal diameter of 4 inches
• Measure density in accordance with ASTM C140
• Hardened density shall be within /- 5 of
  approved hardened density from test panels

48
Subgrade Preparation

• Maintain final subgrade elevation
• Permeability testing Portland Cement Association
  recommends
• Soils with a percolation rates of ½
  in/hr.
• ASTM D 3385, Double-ring Infiltrometer
  
• testing
• Subgrade support minimum density of 92 maximum
  dry density
• Subgrade in moist condition within 3 of optimum
  moisture content

49
Base Materials

• Open graded aggregate
• 30 to 40 void content
• Elevation of base shall be maintained during
  placement of concrete.

50
Concrete Materials

• Comply with ASTM C 94
• Aggregates Max. size 1/3 thickness
• Aggregates Use 3/8 maximum size
• Admixtures for controlling hydration may be used
  and facilitate handling of plastic concrete

51
Isolation Joint Materials

• ASTM D994, D1751, D1752

52
Curing Material

• Clear 6 mil or thicker polyethylene
• Not acceptable
• Woven materials,
• such as burlap
• and geotextile
• fabric
• Wax-based curing
• compounds

53
Forms

• Height equal to the thickness of the pavement
• Held in place by stakes and braced to prohibit
  movement from pressure of concrete and thrust of
  machinery

54
Setting Formwork

• Utilize form release agent
• May use previously placed pavement
• Limit placement width to 20 feet

55
Batching and Mixing

• Comply with ASTM C 94
• Discharge completed within 60 minutes of
  introduction of water to cement.

56
Placing and Finishing

• Deposit concrete on prewetted material
• Spread using come-along, square-ended tools,
  rakes.
• Water may be added to obtain required
  consistency. Minimum 30 mixer revolutions.

57
Placing and Finishing

• Strike off with vibrating screed.

58
Placing and Finishing

• Strike off with paving machine

59
Placing and Finishing

• Compactive effort 10 psi, minimum
• Do not use steel trowels, power finishing
  equipment

60
Final Surface Texture

• Cross-roll to compact concrete to dense, pervious
  surface

61
Final Surface Texture

• Compact slab edges with hand tools
• Compact concrete to dense, pervious surface
• Edging radius of not less than 1/4

62
Tolerances

• Elevation 3/4, -0
• Thickness 1-1/2 , - ¼
• Contraction joint depth 1/4, - 0

63
Contraction Joints

• Joints as shown on plans or as approved
• ¼ to 1/3 pavement thickness
• Early-entry dry-cut saw 1 minimum

64
Contraction Joints

• Spacing not exceed 20 feet
• Aspect ratio 125 maximum

65
Contraction Joints

• Angle at intersections 80o to 100o
• Intersect free edges at 90o, 1.5 lap

66
Contraction Joints

• Align with curb joints within ¼

67
Curing

• Begin curing with 20 minutes of concrete
  discharge
• Cover surface with 6 mil minimum polyethylene
• Cover exposed edges
• Cure for uninterrupted 7 days minimum

68
Good References

• ACI 522.1-08 Specification for Pervious Concrete
  Pavement
• County of Fairfax, Letter 08-01
• Ohio Ready Mixed Concrete Association
• Carolinas Ready Mixed Concrete Association
• Tennessee Ready Mixed Concrete Association
• Georgia Concrete Promotion Association

69
Thank you