The paper describes briefly the results obtained from a total number of 12 comparative static and dynamic load tests on the presently used steel railway sleepers (broad gauge) and newly developed equivalent sleeper substitutes out of ductile iron developed by M/s, Tor Isteg Steel Corporation. The ductile iron sleepers have not only the advantage of extremely improved corrosion resistance as against steel sleepers but offer also the added advantage of some of the possibility of casting some of the railfastening devices integrally with the sleeper, The results of the tests conducted so far indicate that the ductile iron used in the trial sleeper castings possessed static tensile strength comparable to that of steel and satisfied very closely the minimum static strength requirements specified by the Railways for the basic steel material. The static bending moment capacity of the rail seat section of the ductile iron sleeper was very much superior to that of the steel sleeper. The percentage elongation and the fatigue strength behaviour of the ductile iron sleeper were however inferior to that of the steel sleeper. This is believed to be largely due to the relatively high phosphorus content in the trial casting material and can be improved by suitably altering the composition. It has been shown that it is possible to improve further the behaviour of the ductile iron sleepers also by readjusting the cross-sectional characteristic in an optimum fashion.
展开▼
