Flexural Experiments on B58 Type Railway Sleepers with Different Dosages of Steel Fibers

Abstract

The flexural strengths and toughnesses of 15 post-tensioned B58 type railway sleepers produced at the Turkish State Railroads Sivas Plant using C40 class concrete with addition of hooked steel fibers at dosages of 0, 20, 30, 40, 50 kg/m3 were experimentally determined. Four-point flexural experiments were applied to them in one month after their production and proper curing. Three cylindrical samples of 15×30 cm dimensions taken from the first and the fourth batches apiece were subjected to standard compression tests with compressometer rings mounted on each sample after having been cured in 21 °C water tank for 28 days, resulting in their compressive strengths and elasticity moduluses. Modeling a railway sleeper as a post-tensioned reinforced-concrete beam, the maximum load it can resist in the experimented configuration was calculated by the ultimate-strength method using its dimensions and material properties. The experimentally-measured maximum load carried by the reference sleeper without any steel fibers was found to be 1.34 times the theoretically-calculated value, and the same ratio was found to be 1.59 for the sleepers having steel fibers of 40 kg/m3 dosage, accounting for an increase of 18%. And, the experimentally-measured toughness of the sleepers with 40 kg/m3 dosage steel fibers was found to be 23% greater than that of the reference sleepers.