| Popis: |
Sleepers are elements of the upper structure of the railway track. When choosing a material for the manufacture of sleepers, we are based on such basic factors as cost for the whole life cycle and performance characteristics. In connection with the depletion of wood stocks in the world and the short life of wooden sleepers, the process of using sleepers made of reinforced concrete, metal and plastic goes intensively. The service life of pine sleepers is no more than 12-15 years, reinforced concrete sleepers are about 30-50 years old, plastic ones are up to 40 years old, and metal ones are 50-60 years old. However, wooden sleepers differ in the least cost, they practically do not have restrictions on the laying areas, and in some cases have a clear advantage over other materials. Reinforced concrete, metal and plastic sleepers are more expensive than wooden ones, have a longer payback period and are recommended to be laid on roads with high freight intensity, where they can pay off as quickly as possible. It is possible to reduce the shortcomings of sleepers made of natural wood, using modified hardwood for their manufacture, which, by pressing, will be stronger than the sleepers made of natural wood, which, in its physical and mechanical properties, is not inferior to sleepers made of natural coniferous wood. However, a certain disadvantage of the modified wood is its ability to change size and shape with increasing humidity. Stabilization of sizes and forms of modified wood can be increased by impregnating it with the composition of antiseptic with stabilizer. The predicted service life of sleepers from modified wood can be significantly higher than that of wooden sleepers made of natural coniferous wood. |
