MATERIALS
•Surfacing StandardsSurfacing Standards
•Soil and Aggregate PropertiesSoil and Aggregate Properties
•Aggregate DesignAggregate Design
•Soil StabilizationSoil Stabilization
•CompactionCompaction
•Quality Control/Sampling and TestingQuality Control/Sampling and Testing
•Quarry Development and ReclamationQuarry Development and Reclamation

Babeldoab Island, Palau
Hydrated tubular halloysite soil
Bob Gavenda NRCS

Dust and Palliatives
D. Elton

STABILIZERS AND DUSTSTABILIZERS AND DUST
SUPPRESSANTSSUPPRESSANTS
• Cement, Lime, Fly Ash, Asphalt,Cement, Lime, Fly Ash, Asphalt, WaterWater
• Moisture Absorbing Products (Hygroscopic materials):Moisture Absorbing Products (Hygroscopic materials):
 Calcium chlorideCalcium chloride
 Magnesium chlorideMagnesium chloride
 Sodium chlorideSodium chloride
• Organic Petroleum Products:Organic Petroleum Products:
 Asphalt emulsionsAsphalt emulsions
 Liquid asphaltLiquid asphalt
 Dust oilsDust oils
 Modified asphalt emulsionModified asphalt emulsion
• Organic Non-Petroleum Products:Organic Non-Petroleum Products:
 LignosulfonatesLignosulfonates
 Animal FatsAnimal Fats
 Tree Resins, MolassesTree Resins, Molasses
 Tall Oils, Vegetable OilsTall Oils, Vegetable Oils
• Enzymes, Synthetic Polymers, Clay AdditivesEnzymes, Synthetic Polymers, Clay Additives

Surfacing Alternatives

Aggregate Use
and Requirements

Aggregate Surface Design (30 mm, high quality)
0
100
200
300
400
500
600
700
0 10000 20000 30000 40000 50000 60000
Traffic, 18-kip ESALs
AggregateThickness,mm
CBR - 3
CBR - 5
CBR - 8
CBR - 12
Aggregate Surface Design for 30mm Minus
Aggregate of High Quality

Quality Control

DCP

You Get What You Inspect,
Not What You Expect

Compaction

Drainage

Separation/Reinforcement

Unpaved Road DesignUnpaved Road Design
00
2020
4040
6060
8080
100100
120120
00
0.50.5
1.01.0
1.51.5
2.02.0
2.52.5
3.03.0
3.53.5
4.04.0
00
11
22
33
44
55
66
77
88
99
1010
1111
1212
1313
CONEINDEXCONEINDEX
CBRCBR
SHEARSTRENGTH,PSI(C)SHEARSTRENGTH,PSI(C)
Relationship between shear strength, CBR, & cone indexRelationship between shear strength, CBR, & cone index
C = 4.8 PSIC = 4.8 PSI
FOR CBR = 1FOR CBR = 1
Bearing
Capacity
Factors
Unreinforced:
With Geotextile:
With Geogrid/Geotextile:
Typically CBR < 4
NNCC = 2.8= 2.8
NNCC = 5.0= 5.0
NNCC = 5.7= 5.7
With Geogrid:
(CBR > 4)
NNCC = 5.7= 5.7

24 “
15 “
13 “
WITHOUT GEOTEXTILE
WITH GEOTEXTILE
WITH GEOGRID/GEOTEXTILE
Unpaved Road DesignUnpaved Road Design

Materials Removal
Black Cotton Soil

Materials Improvement

Grid RollerGrid Roller

Roadside Borrow Areas

Quarry Development
and Reclamation

What is Important?What is Important?
• Know your Soils and Traffic
• Select the Appropriate Surfacing Standard
• Use Appropriate Aggregate Gradation
• Consider In-place Soil Stabilization
• Use Cost-Effective Local Materials
• Use Adequate Q C /Sampling & Testing
• Compact your Soils and Aggregates
• Drain your Materials
• Develop Quarries…then Reclaim Them