5-1 bituminous road material
Post on 04-Apr-2018
233 Views
Preview:
TRANSCRIPT
-
7/31/2019 5-1 Bituminous Road Material
1/28
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
-
7/31/2019 5-1 Bituminous Road Material
2/28
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
-
7/31/2019 5-1 Bituminous Road Material
3/28
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
-
7/31/2019 5-1 Bituminous Road Material
4/28
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
-
7/31/2019 5-1 Bituminous Road Material
5/28
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
-
7/31/2019 5-1 Bituminous Road Material
6/28
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
-
7/31/2019 5-1 Bituminous Road Material
7/28
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
-
7/31/2019 5-1 Bituminous Road Material
8/28
6.)TEST FOR DEGRADATION
Measured through mechanical agitation in water underdesignation test T-210 of AASHTO.
Aggregates
-
7/31/2019 5-1 Bituminous Road Material
9/28
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
-
7/31/2019 5-1 Bituminous Road Material
10/28
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.
-
7/31/2019 5-1 Bituminous Road Material
11/28
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
-
7/31/2019 5-1 Bituminous Road Material
12/28
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
-
7/31/2019 5-1 Bituminous Road Material
13/28
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.
-
7/31/2019 5-1 Bituminous Road Material
14/28
Aggregate for Portland Cement Concrete Pavement
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).
-
7/31/2019 5-1 Bituminous Road Material
15/28
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.
Aggregate for Portland Cement Concrete Pavement
-
7/31/2019 5-1 Bituminous Road Material
16/28
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
-
7/31/2019 5-1 Bituminous Road Material
17/28
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
-
7/31/2019 5-1 Bituminous Road Material
18/28
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
-
7/31/2019 5-1 Bituminous Road Material
19/28
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.
-
7/31/2019 5-1 Bituminous Road Material
20/28
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
-
7/31/2019 5-1 Bituminous Road Material
21/28
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
-
7/31/2019 5-1 Bituminous Road Material
22/28
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
-
7/31/2019 5-1 Bituminous Road Material
23/28
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.
-
7/31/2019 5-1 Bituminous Road Material
24/28
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
-
7/31/2019 5-1 Bituminous Road Material
25/28
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
-
7/31/2019 5-1 Bituminous Road Material
26/28
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
-
7/31/2019 5-1 Bituminous Road Material
27/28
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
-
7/31/2019 5-1 Bituminous Road Material
28/28
John Anzel S. Buena 4 CE- D
top related