5-1 Bituminous Road Material

7/31/2019 5-1 Bituminous Road Material

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AggregatesBituminous (asphalt) or Portland cementconcrete pavement

Good quality(AASHTO standard or Item 7-3 ofDPWH)

The aggregates shall consist of hard durable particles or fragments ofcrushed stone, crushed slag, or crushed rock or natural gravel


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Aggregates

How to test for good quality:

1. Test for strength2. Test for soundness

3. Test for affinity and swell

4. Test for shape and texture.

5. Test for resistant to polishing

6. Degradation Test


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1.) TEST OF STRENGTH

Rattler test1. Cylinder is rotated 500 revolutions at speed of 30 to 33rounds per minute.

2. After testing the sample will pass on to No. 12 sieve.

3. The FHWA recommended that aggregates for a densegraded mixture shall have 50 or less coefficient of wear.

4. For open graded mixture, the requirement is 40 or less.

Aggregates


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2.)TEST FOR SOUNDNESS

Soundness - resistance of materials to deteriorationfrom the effect of action (ex: freezing and thawing)

The common test for soundness is the application with

sodium or magnesium sulfate.

Aggregates


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3.)TEST FOR AFFINITY AND SWELL Strong and durable pavement must have binder that

adhere or stick firmly to the aggregate particles.Or else The pavement will disintegrate under traffic

Pavement is to pit when aggregates are pulled off by runningwheels

Hydrophilic - when the aggregate has greater affinity forwater than asphalt.

Aggregates


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4.)TEST FOR SHAPE AND TEXTUREConcrete: rounded, smooth surface

Pavement: angular, cubical, rough surface

(!) Avoid thin or elongated piece of dirt

Note:

AASHTO Standard Specification for asphalt pavement aggregate hasno specific stipulation as to the control of the shape or surface

texture.

Aggregates


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5.)TEST FOR RESISTANCE TO POLISHINGhigh coefficient of friction between the tire and the road

surface.

A good asphalt or concrete road design is when the rubber

tire is in direct contact with the aggregate and notwith the binder

Aggregates


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6.)TEST FOR DEGRADATION

Measured through mechanical agitation in water underdesignation test T-210 of AASHTO.

Aggregates


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7.)PARTICLE SIZE1. Dense graded pavement ranges from coarse to dust.

2. Open graded pavement one or more layer of thecoarse rock is uniform in size

3. Sheet asphalt carefully graded sand and mineraldust.

Aggregates


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Aggregate for Bituminous Pavement

88% to 96% by weight or more than 75% by volume.

AASHTO standard specifications provides:The aggregates shall consist ofhard, durable particles

of fragments ofstone orgravelandsandor other finemineral particles free from vegetable matter and lumps

or balls of clay and of such nature that it can becompacted readily to form afirm, stable layer.


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1. Coarse aggregate material retained on 2.00mm No. 10 sieve shallhave a mass percent of wear bynot more than 45.

2. When crushed aggregate is specified, not less than 50 masspercent of the particles retained on the 4.75mm (No. 4) sieve

shall have at least one fractured face.

3. The fraction passing the 0.75mm (No.200) sieve should not begreater than 2/3 of the fraction passing the 0.425mm (No.40)sieve.

4. The fraction passing the 0.75mm (No.40) sieve shall have a liquidlimit not greater than 35 and a plasticity index range of 4 to 9

when tested by AASHTO T-89 and T-90.

Aggregate for Bituminous Pavement

- DPWH


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Aggregate for Portland Cement

Concrete Pavement

High quality concretePass tests for strength, soundness, wear or the

combination of these three.

1. The presence of organic impurities may cause slow ornon-hardening of the concrete.

AASHTO T-21 standard test:Aggregate+mixture of sodium hydrochloride solution= when the treated aggregate turns dark= presence oforganic materials


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Aggregate for Portland Cement Concrete Pavement

2. The strength is measured by the compression tests ofsand-cement mortar.

3. Soundness is measured by the resistance todeterioration under the action of Sodium or Magnesium

Sulfate (5 cycles). AASHTO specification of maximumloss: 10%.

4. For Coarse aggregate the requirement consists ofcrushed stone, gravelblast furnace, slag, or approved

inert materials of similar characteristics or combinationthereof having hard, strong durable pieces free fromadherent coatings.


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The DPWH Standard Specifications classify aggregateunder item 703 and specifically provides that:

1. Aggregate shall consist of hard, durable particles orfragments of crushed stone, crush slug or naturalgravel.

2. Coarse Aggregate material retained on the 2.00 mm(No. 10) sieve and shall have a percentage of water not

more than 50 for sub-base and not more than 45 forbase and surface courses (AASHTO designation test T-96).


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3. Fine aggregate material passing the No. 10 sieveconsisting of natural crushed sand and fine mineralparticles. The fraction passing the 0.075mm (N0.200) sieveshould not be greater than 0.66 (2/3) of the fractionpassing the 0.425mm (No. 40) sieve.

4. Base Course the fraction passing the 0.425mm (No. 40)sieve shall have a liquid limit of not more than 25 and aplastic index not greater than 6. For sub-base course, theliquid limit should not be greater than 35, and plastic indexnot greater than 12.

5. Surface Coarse -the fraction passing the 0.425mm (No. 40)sieve shall have a liquid limit not more than 35 andplasticity index not less than 4 nor exceed 9.



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Mineral FillerGraded mixture + dust additives =increase inthe strength of road pavement

Dust additives (mineral filler) reduces the void contentsin the mixture Classifications:

1. Finely powdered limestone

2. Slag3. Hydrated Lime

4. Portland Cement

5. Trap rock dust

6. Fly ash


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Mineral Filler

DPWH Standard Specifications:

Mineral filler shall consist of finely divided mineral mattersuch as rock dust, slag dust, hydrated lime, hydrauliccement, fly ash or other suitable mineral matter. It shall be

free from organic impurities and at the time of use shall besufficientlydry to flow freely and shall be essentiallyfree fromagglomerations

AASHTO M-17 (Percentage passing): No. 30 (0.66mm) sieve 50 No. 50 (0.30mm) sieve 95-100 No. 200 (0.075mm) sieve 70-100


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Bituminous Material- is a viscous liquid used as binder for aggregates in roadconstruction

1. Bituminous material is in liquid form when mixed orcombined with aggregates.Produced by: heating the hard asphalt, by dissolving in solvent or by

emulsifying in water


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Bituminous Material

2. Asphalt binder(action) depends on its type and the aggregate it is

combined with

(purpose) to resist the abrasive force brought about

by heavy traffic.

3. Road pavement

Coarse particles and asphalt - heavy binder is needed

requiring more asphalts.Fine particles - cohesion will be developed by surfacetension in the thin asphalt film; less viscous asphalt isrequired.


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Bituminous BindersAsphalt cement- binder for almost all high types of bituminouspavement

- is a semi-solid hydrocarbon retained after fuel andlubricating oils are removed from petroleum

Softest grade: 200-300 penetration

Hardest grade: 60-70 penetrations

Penetration - consistencies of asphalt cement (AASHTO-T49).

Grading procedure: Viscosity Test > Penetration Test


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Bituminous Binders

CUTBACK OR LIQUID ASPHALT1. Liquid asphalt - petroleum product consisting of asphalt

cement with a liquid distillate (diesel, kerosene orgasoline)

Disadvantages of cutback:A. It is a usable fuelB. It is an air pollutant

3. Classifications:

A. Slow curing (SC) road soilB. Medium curing (MC) cutback asphaltC. Rapid Curing (RC) cutback asphalt


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Bituminous Binders

Emulsified Asphalt- A kind of mixture wherein the minute globules of

asphalt disperses in water

- Asphalt content: 55%-70% by weight

- Emulsion: applied or mixed at normal temperature

Characteristics:

1. Excellent with wet aggregate

2. Alternate to cutback asphalt3. The Cationic Emulsion

4. Rejuvenating Agent


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Bituminous Binders

Bitumen Rubber Mixture

1929, Holland: experimentation of bitumen rubbermixture for road pavement

Concept was adopted in US and European countries(1947)

An appraisal of the real economic value of the addition of rubber toasphalt must wait on further observation of the behavior of

experimental pavements under the influence of age, weather andtraffic.


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Bituminous Binders

Epoxy Resin as Binders produced in a clear, dark, rigid and flexible form for

application to either concrete or asphalt pavement

Hardening: resin + catalyst hardener =thermosetting* It will not soften under the influence of heat or the action of solvent like

water or petroleum products


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Bituminous Binders

Test for Bituminous Binders1. Test of consistencyis subdivided into:

A. Kinematics Viscosity test AASHTO T-202

B. Saybolt-Fural test AASHTO T-72C. Engler specific gravity test AASHTO T-54

D. The float test AASHTO T-50

E. Penetration test AASHTO T-49

F. Softening point test AASHTO T-53


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Test for Bituminous Binders

2. Test for durability AASHTO T-52

3. Test for solubility AASHTO T-44

4. Distillation test AASHTO T-78

5. Thin film oven test AASHTO T-179

6. Flashpoint AASHTO T-48-79

7. Test for homogeneity of petroleum asphaltAASHTO 102

Bituminous Binders


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Bituminous Binders

Test for Bituminous Binders

8. Special test for Emulsion asphalt AASHTO T-59

A. Test for demulsibilityB. Test for settlement

C. Sieve test

D. Cement mixing test

E. Particle charge and PH testsF. Miscibility and freezing test


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John Anzel S. Buena 4 CE- D

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5-1 Bituminous Road Material

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