PAVING MATERIALSPAVING MATERIALS

MODULE 5MODULE 5

Pavement Design Pavement Design Terms and ConceptsTerms and Concepts

Technically, what is a Technically, what is a pavement?pavement?

““Black TopBlack Top” or “” or “TarvyTarvy” ?” ?

““to pave” means “to cover with to pave” means “to cover with asphalt, gravel, concrete, asphalt, gravel, concrete, macadam, etc.”macadam, etc.”

A surface ?

Why build pavements?Why build pavements?

Originally, footpaths sufficedOriginally, footpaths sufficed

Increasing traffic and loadsIncreasing traffic and loads

TransportatioTransportationn

Quality Issues: drainage, Quality Issues: drainage, subgrade materials subgrade materials

John Macadam, John Macadam, 1756 - 1756 -

18361836

5.01 Define the term pavement as 5.01 Define the term pavement as it is given by the MTO's Pavement it is given by the MTO's Pavement Design and Rehabilitation Manual .Design and Rehabilitation Manual .

"Pavements are "Pavements are layeredlayered structures structures of selected and processed of selected and processed materials which have been materials which have been designed to resist surficial wear, designed to resist surficial wear, to support wheel loads and to support wheel loads and provide drainage of water."provide drainage of water."

PAVEMENT TYPESPAVEMENT TYPES5.02 Identify the various pavement 5.02 Identify the various pavement

types types according to the following according to the following three three classification methods:classification methods:a) Surface Typea) Surface Typeb) Load Transmissionb) Load Transmissionc) Compositionc) Composition

a) Surface Type: Bound or a) Surface Type: Bound or UnboundUnbound

b) Load Transmission

FLEXIBLE

RIGID40 kN Load

40 kN Load

Typical deflection signatures

Stress is transmitted

through bound surface layer to underlying

granular layers

Bound surface (slab) distributes stress

over a broader area, thus reducing the amount of stress transmitted to

underlying material

c) Composition: Type of materials c) Composition: Type of materials used and arrangement/installation used and arrangement/installation

techniquetechnique Portland Cement Concrete (PCC)Portland Cement Concrete (PCC)

Asphalt Cement Concrete (Hot or Cold Mix)Asphalt Cement Concrete (Hot or Cold Mix)

Surface TreatmentSurface Treatment

MulchMulch

5.03 Identify the 3 key 5.03 Identify the 3 key components to a pavement components to a pavement structure.structure.

SURFACESURFACE

GRANULAR BASEGRANULAR BASE

GRANULAR GRANULAR SUBBASESUBBASE

5.04 List the 4 functions of 5.04 List the 4 functions of bituminous surface materials.bituminous surface materials.

provides resistance to surface wearprovides resistance to surface wear

reduces surface water infiltrationreduces surface water infiltration

provides a smooth and rideable finishprovides a smooth and rideable finish

provides structural support to wheel provides structural support to wheel loadsloads

5.05 Identify the two broad classes 5.05 Identify the two broad classes of asphalt pavement surfaces and of asphalt pavement surfaces and

give examples for each.give examples for each.

MIX SYSTEMSMIX SYSTEMS Hot and Cold Mixed Asphaltic ConcreteHot and Cold Mixed Asphaltic Concrete Hot and Cold Mixed Stabilized BaseHot and Cold Mixed Stabilized Base Recycled Hot and Cold Mixed Asphaltic Recycled Hot and Cold Mixed Asphaltic

ConcreteConcrete Travel Plant Mixes (cold)Travel Plant Mixes (cold) Slurry SealSlurry Seal

LAYERED SYSTEMSLAYERED SYSTEMS Penetration PrimerPenetration Primer Surface TreatmentSurface Treatment MacadamMacadam

5.06 Describe the materials and 5.06 Describe the materials and manufacture of Hot Mix Asphaltic manufacture of Hot Mix Asphaltic

Concrete.Concrete.Materials:Materials: a mixture of fine and coarse aggregate a mixture of fine and coarse aggregate

with asphalt cementwith asphalt cement

Manufacture:Manufacture: components are heated and mixed in a components are heated and mixed in a

central plantcentral plant mixture is hauled to site in special trucks mixture is hauled to site in special trucks

and placed on the road using an asphalt and placed on the road using an asphalt spreaderspreader

Manufacture (Continued):Manufacture (Continued): designed, manufactured and placed designed, manufactured and placed

within specified tolerances for use on within specified tolerances for use on high traffic volume roadshigh traffic volume roads

5.07 Identify the use(s) of the 5.07 Identify the use(s) of the following MTO designations: HL 1, following MTO designations: HL 1, 2, 3, 4 and 8; HL 3 Fine; HL 3, 4 2, 3, 4 and 8; HL 3 Fine; HL 3, 4

and 8 Modified; Heavy Duty and 8 Modified; Heavy Duty Binder; DFC; OFC; and Electrically Binder; DFC; OFC; and Electrically

Conductive Mix.Conductive Mix.These MTO mixes are described in These MTO mixes are described in Table 5.01

5.08 Describe the materials and 5.08 Describe the materials and manufacture of Cold Mix Asphaltic manufacture of Cold Mix Asphaltic

Concrete.Concrete.Materials:Materials: a mixture of emulsified asphalt or liquid a mixture of emulsified asphalt or liquid

(cutback) asphalt and aggregate(cutback) asphalt and aggregateManufacture:Manufacture: components are mixed at ambient air components are mixed at ambient air

temperaturetemperature can be mixed in a central plant or in-situ can be mixed in a central plant or in-situ

on the road surface with a travelling on the road surface with a travelling mixer such as the Midland Mix Paver or mixer such as the Midland Mix Paver or road mix mulch pavements road mix mulch pavements

Manufacture (Continued):Manufacture (Continued): aggregate and emulsified asphalt are aggregate and emulsified asphalt are

delivered to Midland Mix Paver separately delivered to Midland Mix Paver separately and blended in a pug milland blended in a pug mill

augers distribute mixture to a screed augers distribute mixture to a screed which uniformly controls the thickness of which uniformly controls the thickness of the cold mix layerthe cold mix layer

once the emulsified asphalt in the once the emulsified asphalt in the mixture surface starts to break or set, the mixture surface starts to break or set, the mixture is compactedmixture is compacted

use in Ontario generally restricted to low use in Ontario generally restricted to low volume rural roads, where HMAC surfaced volume rural roads, where HMAC surfaced pavements are not requiredpavements are not required

5.09 Describe the materials 5.09 Describe the materials used and general placement used and general placement

method for Surface method for Surface Treatments.Treatments.

consist of an application of emulsified or consist of an application of emulsified or liquid asphalt and select aggregate over a liquid asphalt and select aggregate over a prepared granular base or existing surface prepared granular base or existing surface

5.10 List the reasons for applying 5.10 List the reasons for applying surface treatments to:surface treatments to:

a) granular road surfacesa) granular road surfaces, and, andb) existing surface treatments or b) existing surface treatments or asphaltic concreteasphaltic concrete

a)a) to control water to control water infiltration, provide infiltration, provide frictional resistance, frictional resistance, improve ride quality improve ride quality & control dust and & control dust and

stone pick-upstone pick-up

b)b) to restore to restore frictional resistance frictional resistance and reduce water and reduce water

infiltrationinfiltration

in general, on light to medium volume in general, on light to medium volume roadsroads

5.11 Describe the 5.11 Describe the materials/placement and primary materials/placement and primary application for: Mulch Pavements, application for: Mulch Pavements, Slurry Seals, Fog Seals, Primers, Slurry Seals, Fog Seals, Primers, Tack Coats and Granular Seals.Tack Coats and Granular Seals.

These treatments are described in These treatments are described in Table 5.02

5.12 Identify the origin of asphalt 5.12 Identify the origin of asphalt cement and the MTO grade cement and the MTO grade

specifications (test and specifications (test and designations).designations).

the majority of asphalt cements come from the majority of asphalt cements come from petroleum distillation as do liquid (cutback) petroleum distillation as do liquid (cutback) asphalts and asphalt emulsions asphalts and asphalt emulsions (see next (see next slide)slide)

MTO has graded asphalt cements by standard MTO has graded asphalt cements by standard penetration number (PEN); eg: 85/100 penetration number (PEN); eg: 85/100 (hardest), 150/200, 300/400, 500+ (softest)(hardest), 150/200, 300/400, 500+ (softest)

SUPERPAVE is a new mix design method that SUPERPAVE is a new mix design method that replaces this grading system replaces this grading system

Atkins, 2nd Ed.

5.13 Describe the 2 conflicting 5.13 Describe the 2 conflicting problems related to asphalt problems related to asphalt

cement grade faced in Ontario.cement grade faced in Ontario. if a soft grade is used then rutting is a if a soft grade is used then rutting is a

problem in the hot summersproblem in the hot summers

if a hard grade is used then low if a hard grade is used then low temperature (transverse) cracking is a temperature (transverse) cracking is a problem in the winterproblem in the winter

Before:After: