In recent years, an increase in the quantity of reinforcing bars has been demanded in the design of reinforced concrete (RC) structures to improve earthquake resistance. The Railway Technical Research Institute (RTRI) has developed a design method to apply high-performance materials such as high-strength concrete, high-fluidity concrete, and high-strength reinforcing bars to railway RC structures.
      Cyclic loading tests were performed using a column-type specimen (Fig. 1) to evaluate the seismic performance. The experiment showed the same performance as those of conventional reinforcing bars, even when the quantity of reinforcing bars is reduced by 50% (Fig. 2). The new design method was therefore proposed.
      Additionally, crack-property analysis of the high-strength concrete showed that the maximum crack width can be reduced, increasing resistance against cracks.
      The results of this study will be reflected in "Design Standard for Railway Structures (Concrete Structures)."