87% passengers and65% of goods in the
country are transported by roads.
• Road transportation is increasing @ 7-10% ,every
year.
• The number of vehicles plying on the road is
increasing @ 12% annually.
• PRADHAN MANTRI GRAM SADAK
YOGANA (PMGSY).
REQUIRMENT OF BITUMENOR
PROPERTIES
• THE BITUMEN SHOULD POSSESS ADEQUATE
VISCOSITY WHILE MIXING AND COMPACTION.
• IT SHOULD NOT BE HIGHLY TEMPERATURE
SUCEPTIBLE.
• IN THE PRESENCE OF WATER IT SHOULD NOT
STRIP OFF FROM AGGREGATE.
16.
LLiimmiittaattiioonnss ooff CCoonnvveennttiioonnaall
BBiittuummeenn
Brittleness at Low Temperature
Becomes Soft In Hot Climatic Conditions
High Temperature Susceptibility
Susceptible To Deformation (Rutting)
Fatigue Failure (Cracking)
Poor Adhesion
17.
MEMBERS OF BITUMENFAMILY
• ASPHALT:- when bitumen contains
some inert material or mineral.
• LAKE ASPHALT, ROCK ASPHALT.
• LAKE ASPHALT:- IT IS FOUND IN WELL
DEFINED SURFACE DEPOSITES IT CONTAINS:-
• BINDER - 54%.
• MINERAL MATTER - 36%.
• ORGANIC MATTER - 10%.
18.
o Requirements offppaavviinngg bbiittuummeenn
Requirements for Paving Bitumen Type I
Requirements for Grades
S 35 S 45 S 55 S 65 S 90 S 200
Methods of Test Ref.
To
1 2 3 4 5 6 7 8 9
i) Specific gravity at 27°c
Min.
0.99 0.99 0.99 0.99 0.99 0.99 IS 1202 : 1978
ii) Water percent by mass
Max.
0.2 0.2 0.2 0.2 0.2 0.2 IS 1211 : 1978
iii) Softening point °c 50 to 65 45 to 60 45 to 60 40 to 55 35 to 50 30 to 45 IS 1205 : 1978
iv) Penetration at 25°c 100g, 5
sec., 1/10 mm
30 to 40 40 to 50 50 to 60 60 to 70 175 to
225
175 to
225
IS 1208 : 1978
v) Penetration ratio, Min. 35 35 35 35 35 35 -
vi) Ductility at 27°, cm,
Min.
50 75 75 75 - - IS 1208 : 1978
Sl. Characteristics
No.
19.
CHEMISTRY OF BITUMEN.
• The configuration of internal structure of bitumen
is largely determined by the chemical constitution
of the molecular species of predominantly
hydrocarbon nature with a small amount of
functional group containing nitrogen,oxygen and
sulphur atoms.
• Bitumen also contains trace quantities of metals
like vanadium,nickel,iron,magnesium& calcium
which occur in the form of inorganic salts and
oxides.
FOUR PRINCIPLE MECHANISMOF
BITUMEN HARDENING.
• 1) OXIDATION - Due to presence of excessive
polar aromatics.
• 2) LOSS OF VOLATILES -
Temperature,condition of
exposure.
• 3) PHYSICAL HARDENIND- When bitumen is
attributed to reorientation of its
molecules.
• 4) EXUDATIVE HARDENING - Due to
presence of napthenic
aromatics of lower molecular
weight.