| 摘要 |
PROBLEM TO BE SOLVED: To provide a sleeper for railroad capable of enduring huge load of rolling stock, suppressing resonance phenomenon to reduce vibration and noise, being simply constructed in the same way as a wooden sleeper, and being used even in a branch part where vibration is large and position correction of track is frequently performed. SOLUTION: This sleeper for railroad comprises a thermosetting urethane foam, vinyl polymer particles which are scattered like particles away from each other in a cell wall of the thermosetting urethane, foam and whose glass transition point is in the range of 0 to 50°C, and a long fiber reinforcing material scattered in the thermosetting urethane foam so that the longitudinal direction becomes parallel for the longitudinal direction of the thermosetting urethane foam. COPYRIGHT: (C)2003,JPO |
