Reinforced cement concrete sleepers are two types:
- Through type
- Block and tie type
Through type R.C.C. Sleeper:
This is also known as one piece or mono-block sleeper. In this type of sleepers, cracks develop on the tension side when stressed. These cracks are very small ad almost invisible but tend to enlarge with the repetition of impact loading, causing failure.
Block and tie type R.C.C.Sleeper:
This type of sleeper consists of two R.C.C. blocks connected by a metal tie of inverted T-section. These sleepers are not subjected to any degree of tensile stress as in through type.
Advantages of R.C.C. Sleepers:
- Concrete sleepers have a long life, generally 40 to 60 years.
- These are free from natural decay and attack by insects’ etc.
- These sleepers require fewer fittings.
- Track circuiting is possible in these sleepers.
- These sleepers provide more lateral and longitudinal rigidity as compared to other sleepers.
- The maintenance cost is low.
- Due to higher elastic modulus, these can withstand the stresses due to fast-moving trains.
- Due to heavyweight, handling and transportation of these sleepers are Difficult.
- If not handled properly, the chance of breaking is more.
- The renewal of track laid with these sleepers is difficult.
- The scrap value is nil.