1. Modification of Asphalt by the
use of Crumb rubber
PRESENTED BY:
MUHAMMAD ALEEM

2. Sequences of Presentation
 What is asphalt
 Why incorporation is needed
 Incorporation of Crumb Rubber
 Environmental aspects of Rubber
 Engineering benefits of Rubber
 Economical benefits
 Experimental investigation
 Amount of incorporation and its effects

3. What is Asphalt?
According to ASTM
“A dark brown to black cementitious material in which the predominant
constituents are bitumen's which occur in nature or are obtained in the
petroleum processing”

4. Why incorporation is needed?
In Asphalt deterioration problems occur:
 Rutting

5. Contd…
 fatigue cracking
 thermal cracking

6. Incorporation OF Crumb
Rubber

7. What is Asphalt Rubber?
According to ASTM
Asphalt-Rubber is a blend of asphalt cement, reclaimed tire rubber and
certain additives, in which the rubber component is at least 15% by
weight of the total blend and has reacted in the hot asphalt cement
sufficiently to causes welling of the rubber particles.”

8. Why are we Adding Rubber in Asphalt?
Environmental aspects
Tire burning
Land Filling

9. Why are we Adding Rubber in Asphalt?
Engineering Benefits
 Freeze and thaw
 Prevent bleeding
 Prevent flushing, and drain-down
 Resilient modulus
 Creep Stiffness
 Strain

10. Economical benefits
 An aid to increase performance life
 Save Money in reduced maintenance
 Save money in project cost through reduced thickness
 Increase safety and reduce noise

11. Experimental Investigation
 Selection of materials
 Sieve Analysis
 Marshall Stability Test
Compressive Strength
Accumulated Strain
Resilient Modulus
Resilient Strain
Creep Stiffness

12. Amount of incorporation with Asphalt
 The Use of Crumb Rubber was
 0 % (Conventional Asphalt)
 5%
 10 %
 15 %
 20 %

13. Effect of % of Incorporation on different
properties
 Resilient Modulus ~ Crumb Rubber

14. Effect of % of Incorporation on different
properties
 Creep Stiffness ~ Crumb rubber

15. Effect of % of Incorporation on different properties
Resilient Strain ~ Crumb Rubber

16. Effect of % of Incorporation on different
properties
Accumulated Strain ~ Crumb rubber

17. Conclusion
The generated results showed that the value for resilient
modulus and creep stiffness is more as compared to the
conventional asphalt and in the accumulated strain the values
are much lesser which is positive approach.