New types of composites have been produced by the
recently developed techniques of impregnating porous materials like concrete
with sulphur. Sulphur impregnation has shown great improvement in strength.
Physical properties have been found to improve by several hundred per cent and
large improvements in water impermeability and resistance to corrosion gave
also been achieved.
In the past, some attempts have been
made to use sulphur as a binding material instead of cement. Sulphur is heated
to bring it not molten condition to which condition to which coarse and fine
aggregates are poured and mixed together
. On cooling, this mixture gave
fairly good strength, exhibited acid resistance and also other chemical
resistance, but it proved to be costlier than ordinary cement concrete.
Recently, use of sulphur was made
to impregnate lean porous concrete to improve its strength and other useful
properties considerably. In this method, the quantity of sulphur used is also
comparatively less and thereby the processes is made economical. It is reported
that compressive strength of about 100 MPa could be achieved in about 2 days
time. The following procedures have been reported in making sulphur-infiltrated
Application of Sulphur -
The sulphur-infiltration can be
employed in the precast industry. This method of achieving high strength can be
used in the manufacture of pre-cast roofing elements, fencing posts. Sewer
pipes, and railway sleepers, sulphur-infiltrated concrete should find
considerable use in industrial situations. Where high corrosion resistant
concrete is required. This method cannot be conveniently applied to cats-in
Preliminary studies have
indicated that sulphur-infiltrated precast concrete units are cheaper than
commercial concrete. The added cost of sulphur and process should be offset by
considerable savings in concrete.
The techniques are simple,
effective and inexpensive. The tremendous strength gained in pressure
application, where in immersion accompanied by evacuation may also offset the
extra cost. The attainment of strength in about two days time makes this process
all the more attractive.