Improving the mechanical performance of railway concrete sleepers using recycled materials: An experimental and numerical study

This paper explores the use of three waste materials available in vast quantities, including waste tires, glass bottles and bamboo furniture, in the manufacture of railway sleepers. Mechanical properties of recycled concrete have been studied to establish an optimal mix suitable for concrete railway sleeper manufacturing. Thus, 5%, 10%, 15% and 20% recycled rubber sands (RRS) by volume of fine aggregate are used instead of 30# and 60# mesh sizes of fine aggregate. Moreover, 20%, 40%, 60%, 80% and 100% of aggregate volume are replaced by recycled glass aggregate (RGA) particles. Furthermore, different percentages of recycled bamboo fibers (RBF) have been used as 1%, 2% and 3% by volume of concrete. According to the optimal concrete mixtures of RRS, RGA and RBF, twelve concrete railway sleepers are manufactured and tested for middle and rail seat bending strengths. Results show that ref. sleeper has almost 16% and 24% lower strengths than RGA sleeper in middle and rail seat, respectively, while ref. sleeper have higher strengths by 16% and 13%, and 18% and 7% than RRS sleeper (M60-R5) and RBF sleeper (B2) in middle and rail seat, respectively. The FEM results show that the ([Formula: see text]) of the RGA sleeper is the minimum ratio by 1.11 and 1.13 for rail seat and middle of sleeper, respectively, which is the best performance. In RBF sleeper FEM model, Bamboo fiber can only bear 5% and 8% of total stress in middle and rail seat, respectively, due to low mechanical properties of fibers.