method of rubberization

1. SUBMITTED BY :-
ABDULLA SHAFI

2. INDRODUCTION
 LATEX IS THE MOST EFFECTIVE FORM OF
NATURAL RUBBER FOR ROAD CONSTRUCTION
 BOTH CENTRIFUGED AND CREAMED SKIM IS
USED
 BUT FIELD LATEX IS MORE SUITABLE FOR ROAD-
MAKING IN THE NATURAL RUBBER-PRODUCING
COUNTRIES

3. TECHNIQUE OF RUBBERISATION
 Rubberized bitumen is made by incorporation of latex
in a bituminous compound
 On incorporation of rubber, bitumen undergoes
changes in its properties
 It depends on
Type & grade of rubber used
Ratio of bitumen to rubber
Methods of incorporation
 For maximum effectiveness, rubber must dissolve in
bitumen

4.  The rubber increase
Viscosity
Strength
Heat resistance of the system
 Though different polymers and rubbers are used to
modify bitumen NR latex is best among there

5. PREPARATION OF NATURAL
RUBBER MODIFIED BITUMEN
 In situ mixing
 Bitumen was heated to about 140°C.
 Small amounts (1%) of kerosene was added as viscosity
modifier.
 To boiling bitumen, natural rubber latex as specially
preserved field latex (about 2% by weight of bitumen) was
added,
 Stirred well and kept for about 2 hours for
homogenization
 Uniformly blended NRMB thus obtained was used for the
Rubberization of roads.

6. PROPERTIES
 Unaffected by changes in atmospheric temperature
 Improve skid resistance due to increased aggregate
retention and elimination of bleeding.
 Rubber increases the resistance to flow of bitumen at
high temperature
 Improves the resistance to brittle fracture at low
temperature.

7. ADVANTAGES OF THE USE OF
RUBBER-MODIFIED BITUMEN IN
ROAD CONSTRUCTION
 Increase in useful service life
 Improved resistance to cracking at low temperature
 Better resistance to fatting up or bleeding of bitumen
under hot condition
 Improved skid resistance
 Increased fuel economy
 Better grip and cornering
 Low repairs and maintenance cost (about 33% savings)

8. LIMITATIONS
 `Mixing of latex on spot is difficult because;
 Time consuming
 Non uniform mixing due to lack of experience of
workers
 These result in variation of properties
 So Rubber board in collaboration with kochi refineries
limited developed a pre-mix of rubber with bitumen
 This can be directly used for road surfacing

11. REFERENCE
 Google
 Wikipedia
 Rubber board India website

12. THANK YOU