| 摘要 |
A railroad crosstie (tie) may be fabricated from a composite material including a fiber reinforced polymer shell manufactured by pultrusion or other process, and filled by a suitable material, typically selected from expanded elastomeric polymer (such as polyurethane resin or other polymer), concrete, lightweight concrete formed by conventional aggregate, sand, cement, water, and an ultra light filler such as natural materials, sawdust, beads of expanded polymer such as expanded polystyrene, microspheres of glass or plastic, a recycled wooden tie in conjunction with any of the above, or the like. Fasteners may be driven such as spikes, threaded, such as screws, lag screws, spreading screws, rivets, or the like into apertures, pilot holes, or directly into fill absent apertures therein. |
| 主权项 |
1. An apparatus comprising:
a shell comprising a matrix reinforced by a reinforcement constituted as fiber; a fill comprising a solid acting as a structural material and being selected from wood, concrete, lightweight concrete, polymer, filled polymer, composite polymer, expanded polymer, and a combination thereof; the fill, having a density less than that of the matrix; and a fastener providing compression against an outer surface of the shell in response to engagement of the fill by the fastener. |
