Modification of Asphalt by the

use of Crumb rubber

PRESENTED BY:

MUHAMMAD ALEEM

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

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”

Why incorporation is needed?

In Asphalt deterioration problems occur:

Rutting

Contd…

fatigue cracking

thermal cracking

Incorporation OF Crumb

Rubber

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.”

Why are we Adding Rubber in Asphalt?

Environmental aspects

Tire burning

Land Filling

Why are we Adding Rubber in Asphalt?

Engineering Benefits

Freeze and thaw

Prevent bleeding

Prevent flushing, and drain-down

Resilient modulus

Creep Stiffness

Strain

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

Experimental Investigation

Selection of materials

Sieve Analysis

Marshall Stability Test

Compressive Strength

Accumulated Strain

Resilient Modulus

Resilient Strain

Creep Stiffness

Amount of incorporation with Asphalt

The Use of Crumb Rubber was

0 % (Conventional Asphalt)

5%

10 %

15 %

20 %

Effect of % of Incorporation on different

properties

Resilient Modulus ~ Crumb Rubber

Effect of % of Incorporation on different

properties

Creep Stiffness ~ Crumb rubber

Effect of % of Incorporation on different properties

Resilient Strain ~ Crumb Rubber

Effect of % of Incorporation on different

properties

Accumulated Strain ~ Crumb rubber

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.