Attached
Ground Rubber Tyre (GRT) is one of the modifiers used for the modification of
bitumen. The main application of bitumen isfor road construction as a binder. There
are two advantages if' GRT can be used on a large scale for the modification of this
binder. Since GRT is very much cheaper than any other polymer modifier. cost of
modification is minimal. On the other hand if this becomes an outlet for waste tyres, it
would help to mitigate the environmental impact immensely.
Studies with GRT for this purpose have not been reported in Sri Lanka. Although
some studies have been carried out in the country using latex on modification of bitumen.
none of the Sri Lankan roads has so far been rubberised. Rubberisation of roads is not a
new concept and research in this area has been carried out for one and a half centuries.
This study is an initial step in investigating the methods of incorporation of CRT into
bitumen to improve the desirable properties of bitumen mainly for road applications with
the aim of rubberisation of roads in Sri Lanka. Various polymer materials have been
triedfor modification of properties of bitumen. It has been established that rubberisation
ofroads improves the road performance and also the service life.
In this research work. some properties of bitumen modified with GRT at different
levels under different mixing conditions were studied to ascertain the optimum level and
the best mixing conditions 0.( incorporation of GRT into bitumen to achieve the optimum
propertiesfor application in road construction.
Out of the 3 characteristics tested. 2 of the vital properties namely softening point
and penetration were found to be substantially improved by incorporation of GRT info
bitumen. However. strength properties of modified bitumen were found to be affected by
GRT due to the failure of ductility and therefore further research has to be carried out to
improve these properties.