Aims: Aim of this experimental study is at examining the changes in some properties and
chemical functionalities of AC 20 grade bitumen modified with natural rubber latex (L).
Background: Bitumen was used mainly as a binder in asphalt pavements for road construction in
many developing countries. In recent times more roads were being constructed for the speedy delivery
of goods and services in Ghana. There was also a general increase in vehicle ownership resulting
in increased pressures from vehicle tyres. These pressures had led to high level of stresses exerted on
asphalt surfaces which was exhibited in deformation, surface cracking, fatigue and reflective cracking
which could result in dangerous traffic conditions.
Objective: Problems such as change in temperatures, cracks caused by traffic loads, moisture exposure
which weakens adhesion of the binder to aggregates etc. are improved by the application of
Method: Such the ASTM D5 – 97 and the ASTM D 36 – 70 and the ASTM D-2170-10 and the
ASTM D 70 – 76 and the ASTM D 1754 and the ASTM D3143 standards were used to measure the
penetration point, the softening point temprature and the kinematic viscosity and the specific gravity
and short term aging test and the flash point.
Result: The results of this study present a general improvement in penetration, softening point viscosity
and aging when conventional bitumen is modified with Natural latex rubber L.
Conclusion: Result obtained for rheological properties of bitumen upon addition of latex showed an
optimum at 5%.
Other: Short term aging test results indicated that addition of the optimum composition of natural
rubber latex at 5% of bitumen showed significant improvement on the rheological properties tested and
hence could serve as a good material for modification of bitumen for sustainable road construction.