1. BITUMINOUS
MATERIALS AND
MIXTURES

2. SPECIFIC OBJECTIVES:
 define bitumen
 be familiarize and understand the
bituminous materials and mixtures
At the end of the lesson, the student should
be able to:

3. BITUMINOUS MATERIALS AND MIXTURES
BITUMEN
- road-surfacing material: a mixture of hydrocarbons
derived from petroleum and found in substances such
as asphalt and tar that are used for road surfacing and
roofing
BITUMENS

4. BITUMINOUS MATERIALS
Bitumen
Asphalt Tars Pitches
Natural deposit Petroleum Asphalt
Native Asphalt Rock Asphalt
Asphalt Cement
(solid or semisolid)
Cutback Asphalt
(liquid)
Emulsified Asphalt
(liquid)
Blown Asphalt
(semisolid)
Slow Curing Medium Curing Rapid Curing

5. BITUMINOUS MATERIALS AND MIXTURES
ASPHALT
- semisolid bituminous substance: cementitious
materials in which the predominant constituent
materials are bitumens

6. TARS and PITCHES
Tar
- thick black liquid: a thick
black liquid obtained through
the destructive distillation of an
organic substance such as
wood or coal
*produced by the destructive distillation
of bituminous coal called bituminous
coal tar which is most commonly
used tar in pavement construction
COAL TAR

7. TARS and PITCHES
Crude tar
- contains a large amount of water as well as some
fuel oils
- viscous liquid produced at the end of the distillation
process
Pitches
-substance obtained from tar:
a dark sticky substance obtained
from tar and used in the building
trade, especially for
waterproofing roofs
-liquefied gradually when
heated

8. TYPES OF NATURAL DEPOSIT
ASPHALTS
1. Natural Rock Asphalts
2. Native Asphalts (Lake Asphalts)

9. TYPES OF ASPHALTS
1. Natural Rock Asphalts
- found in many parts of the
world as deposits of
sandstones or limestone filled
with asphalts through
geologic process

10. TYPES OF ASPHALTS
2. Native Asphalts (lake asphalts)
- bitumens mixed with water, fine siliceous silt,
clay and organic mater (found in Lake Trinidad)

11. PETROLEUM ASPHALTS
 Refining and distillation of petroleum results in
various types of asphalt or asphaltic material
Distillation
-process in which various fractions (products)
are separated out of the crude by raising its
temperature in stages

12. PETROLEUM REFINING PROCESS
1. Fractional Distillation
2. Destructive Distillation (cracking)

13. PETROLEUM REFINING PROCESS
1. Fractional Distillation
- involves the separation of
crude oil into various materials
without significant changes in
the chemical composition of
each materials

14. PETROLEUM REFINING PROCESS
2. Destructive Distillation
- involves the application of intense heat [temperature
as high as 1100oF (593oC)] and high pressure [as
high as 735psi (5MPa)], which cause chemical
changes in material

15. Petroleum asphalts are classified into
four types
1. Asphalt Cements
2. Cutback Asphalts
3. Emulsified Asphalts
4. Air-Blown Asphalts
Cutback Asphalts are further divided into
three types
• Slow Curing
• Medium Curing
• Rapid Curing

16. Asphalt Cement
- (also called paving asphalt)
- very sticky and highly viscous especially
prepared with the quality and consistency
required in the manufacture of asphalt
pavements (hot mix pavements)

17. Cutback Asphalt
- asphalt cement that is liquefied by blending
with petroleum solvent (called diluents)

18. CURING UNDER CUTBACK ASPHALT
1. Slow Curing
2. Medium Curing
3. Rapid Curing

19. CURING UNDER CUTBACK ASPHALT
1. Slow Curing
- asphalt cement
blended with oils of
low volatility, such
as diesel oil.
- its viscosity
value is low and
hardens very
slowly

20. CURING UNDER CUTBACK ASPHALT
2. Medium Curing
- obtained by blending asphalt cement
with kerosene-type diluents of medium
volatility

21. CURING UNDER CUTBACK ASPHALT
3. Rapid Curing
- asphalt cement-blended with
naphtha or gasoline-type diluents
of high volatility

22. DISADVANTAGES OF CUTBACK
ASPHALTS
• The volatile distillate may evaporate in the air
and add to air pollution
• The distillate in the cutback asphalt poses and
toxicity hazards.

23. EMULSIFIED AND BLOWN ASPHALT
Emulsified Asphalt
- composed of asphalt
cement and water
that contains a small
amount of an
emulsifying agent
(soaps, water-soluble
chemicals and fine clay)

24. ADVANTAGES OF EMULSIFIED
ASPHALTS
• It can be applied during damp weather and with
aggregates that are cold or hot
• Also eliminates the use of fuel required to heat
and dry the aggregates in the asphalt cement
mixtures

25. DISADVANTAGE OF EMULSIFIED
ASPHALTS
• Because the asphalt is suspended in water, it is
susceptible to being washed off a road surface
by rainwater if not sufficiently cured

26. EMULSIFIED AND BLOWN ASPHALT
Blown Asphalt
- obtained by blowing
air through the
semisolid residue
obtained during the
later stages of the
distillation process

27. PROPERTIES OF ASPHALT
• Adhesion
• Consistency
• Specific Gravity
• Durability
• Rate of Curing
• Ductility
• Aging and Hardening
• Resistance to reaction with water
• Temperature Susceptibility

28. PROPERTIES OF ASPHALT
Specific Gravity
- normally measured using pycnometer
Specific Gravity of Asphalt
- is the ratio of the mass of the given volume of
the material at 77oF (25oC) or at 60oF (15.6oC) to
the mass of an equal volume of water at the
same temperature.

29. PROPERTIES OF ASPHALT
Specific Gravity of Petroleum Asphalt
- value close to unity (0.95-1.05)
Specific Gravity of Road Tars
- varies between 1.08-1.24

30. PROPERTIES OF ASPHALT
Knowledge of specific gravity is essential:
• to determine the percentage of voids in a
compacted material
• its measurement is required to convert the
volume measurement of asphalt to the units of
mass.

31. PROPERTIES OF ASPHALT
Durability
- the property that permits a pavement material to
withstand the detrimental effects of moisture, air,
and temperature
Oxidation
- chemical reaction that takes place when
asphalt is exposed to the oxygen in air

32. PROPERTIES OF ASPHALT
Volatilization
- process by which lighter hydrocarbons from
the asphalts are evaporated
- affects by the temperature.

33. PROPERTIES OF ASPHALT
RATE OF CURING
Curing
-the process of evaporation of solvents from
cutback asphalts, and the attendant thickening
of the material
-the change in consistency of an asphaltic
material due to the progressive loss of diluents
by evaporation

34. RATE OF CURING
PROPERTIES OF ASPHALT
- is the time required for a cutback asphalt to
harden (from its original liquid consistency) and
develop a consistency that is satisfactory for the
function as a binder in pavements is an important
property of cutback asphalt

35. PROPERTIES OF ASPHALT
RATE OF CURING

36. PROPERTIES OF ASPHALT
In emulsified asphalts
- the rate of evaporation of water depends on
the weather conditions, such as humidity and
temperature
RATE OF CURING
*with favorable weather conditions, the water evaporates
quickly and curing progresses rapidly

37. PROPERTIES OF ASPHALT
Age Hardening
- process of natural hardening of asphalt
Rate of Hardening
- decreases with time and is insignificant beyond
1 year
*this process happens even when oxidation and
volatilization are prevented from occurring

38. PROPERTIES OF ASPHALT
Resistance to Action of Water
*the asphalt materials for pavements should be able to
withstand the effects of water
*complete drying of the aggregate particles prior to
mixing improves pavement performance

39. PROPERTIES OF ASPHALT
Ductility
*ductility material with sufficient bonding
characteristics, such as asphalts and tars,
exhibit adhesive and cohesive properties

40. PROPERTIES OF ASPHALT
Temperature Susceptibility
Asphalt A
Asphalt B
(A & B are of identical
viscosity grade
T1
Temperature susceptibility of asphalts

41. PROPERTIES OF ASPHALT
Hardening and Aging
Original
Aged (Rolling thin film oven
test)
Hardening of asphalt after exposure to high temperatures

42. ASPHALT AGGREGATES
Asphalt cements are graded according to
four different systems:
• Viscosity grading system
• Viscosity after-aging grading system
• Penetration grading system
• Performance-based grading system

43. PERFORMANCE-BASED GRADING
The research studies carried out in the
program concluded that asphalt pavements
often fails or crack due to three major reasons:
1. Pavement Deformations or rutting at high
temperatures, as asphalt softens and the binder
loses elasticity

44. three major reasons of cracking of asphalt pavements
2. Fatigue resulting from high pavement loads or aging
3. Low-temperature cracks, as asphalt becomes brittle and
the pavement shrinks in cold weather

45. CUTBACK ASPHALT GRADES
Cutback asphalts
- are graded based on their kinematic
viscosity at 140oF (60oC) in centistoke

46. ASPHALT CONCRETE
- used for construction of
asphalt pavement, in which
is also called flexible
concrete, due to its ability to
conform to settlement of the
foundation

47. • Hot-Mixed Asphalt
>or hot-laid bituminous mixtures
• Cold-Mixed Asphalt
>or cold-laid bituminous mixtures
TYPES OF ASPHALT CONCRETE

48. TYPES OF ASPHALT CONCRETE
Hot-Mixed, hot-laid bituminous mixture
- fine aggregate, or a mixture of coarse and
fine aggregate, with or without mineral filter,
uniformly mixed with asphalt cement, tar, or
emulsified asphalts

49. TYPES OF ASPHALT CONCRETE
Cold-Mixed, cold-laid bituminous mixture
- is coarse aggregate, fine aggregate, or a
mixture of coarse and fine aggregates, with or
without filter, uniformly mixed with liquid
bitumen and laid at or near ambient
temperature

50. TYPES OF ASPHALT CONCRETE
Asphalt Rubber
- or crumb rubber
- which is recycled
product from old tires is
used in hot-mixed
asphalt pavements to
improve the binding
property of aggregates

51. TYPES OF ASPHALT CONCRETE
Glasphalt
- is the term used to describe asphalt that is party
replaced by glass

52. ASPHALT PAVEMENT
Asphalt (flexible) pavement
- has sufficiently bending resistance to
maintain intimate contact with the underlying
structure or base, yet has the required stability
to support traffic loads

53. ASPHALT PAVEMENT

54. ELEMENTS OF FLEXIBLE
PAVEMENTS
• Subgrade
• Subbase Course
• Base Course
• Surface Course

55. ELEMENTS OF FLEXIBLE PAVEMENTS
Subgrade
- also called prepares roadbed
- consist of natural or imported soil, such
as in an embankment, improved by
stabilization

56. ELEMENTS OF FLEXIBLE PAVEMENTS
Subbase
- is a layer
between the subgrade
and the base course
- made from
minerals generally
superior to that of
subgrade

57. ELEMENTS OF FLEXIBLE PAVEMENTS
Base Course
- or base layer,
lies directly beneath
the wearing surface
- it can also be
constructed as an
asphalt concrete base
(asphalt base course)
or as an untreated
aggregate base

58. The base layer is generally identified
by the type of material used:
• Aggregate
• Asphalt cement
• Asphalt-treated permeable
• Cement treated
• Cement-treated permeable
• Lean concrete

59. The base layer is generally identified by
the type of material used:
Aggregate

60. The base layer is generally identified by
the type of material used:
Asphalt Cement

61. The base layer is generally identified by
the type of material used:
Asphalt-treated Permeable

62. The base layer is generally identified by
the type of material used:
Cement treated

63. The base layer is generally identified by
the type of material used:
Cement-treated Permeable

64. The base layer is generally identified by
the type of material used:
Lean Concrete

65. ADVANTAGES OF USING ASPHALT CONCRETE AS
CONSTRUCTION MATERIAL
 Economical
 Durable
 Safe
 Recyclable
 Quick and easy to
repair

66. DISADVANTAGES OF USING ASPHALT CONCRETE AS
CONSTRUCTION MATERIAL
 More maintenance
 Prone to crack
 Substantial training for
installers
 Can cause pollution
 Require heavy
equipment

67. ASPHALT LABORATORY TESTS
 Ductility Test
 Extraction Test
 Penetration Test
 Specific Gravity Test
 Marshal Stability Test

68. ASPHALT LABORATORY TESTS
 Ductility Test
The ductility of a
bituminous material is
measured by the distance in
cm to which it will elongate
before breaking when a
standard briquette specimen
of the material is pulled
apart at a specified speed
and a specified
temperature.

69. ASPHALT LABORATORY TESTS
 Extraction Test
The extraction
test involves adding a solvent
to the asphalt mixture to
dissolve the asphalt cement.
Then the asphalt concrete
and solvent are centrifuged to
assure that all the asphalt is
dissolved leaving a clean
aggregate.

70. ASPHALT LABORATORY TESTS
 Penetration Test
Penetration value test on
bitumen is a measure of
hardness or consistency of
bituminous material.
... Penetration value is the
vertical distance traversed or
penetrated by the point of a
standard needle into the
bituminous material under
specific conditions of load,
time and temperature.

71. ASPHALT LABORATORY TESTS
 Specific Gravity Test
Because the specific
gravity of asphalt binders change
with temperature, specific gravity
tests are useful in making volume
corrections based on temperature.

72. ASPHALT LABORATORY TESTS
 Marshall Stability Test
The marshall stability of mix is
defined as a maximum load
carried by a compacted specimen
at a standard test temperature of
60ºC. The flow value is
deformation the marshall
test specimen under goes during
the loading up to the maximum
load, 0.25 mm units.