Abstract:
A number of proposed highways in Sri Lanka are to be constructed over sites underlain by soft peaty
clays, due to scarcity of lands. In order to ensure that the in service settlements of these roads are _4
small enough and the roads could functions satisfactorily, number of special ground improvement
techniques are to be adopted. Another, alternate approach that could be considered is the use of a
lightweight fill material in the construction. Extremely lightweight fill materials such as expanded
and extruded polystyrene blocks were used in a number of developed countries in the construction of
road embankments over soft ground and in landslide repair. However, these material are to be
imported to the country and would be very expensive. As such, from a local point of view a process
involving the use of such materials would not be economically competitive. In order to find an
economically feasible solution, the lightweight fill materials should be developed with the locally
available inexpensive raw material.
