Quality Control of Pre-stressed Concrete Sleepers in Sudan Railways

Nowadays, railway transport plays a very important role in the transport system in a period of positive growth of commerce, economy and industry. In accordance with other modes of transport, railway is the most stable mode for transporting, safety, capability carrying, social and economic benefits. Sleepers have major roles in the complex railway system and distributed the load from rails when train goes through to the ballast. This study discussed pre-stressed concrete sleepers in Sudan railways and compare them with other varies of sleepers taken in consideration the service life, handling, weight of sleeper, damage, suitability for fastening and vibration resistance. On the other side explained the manufacturing stages that sleepers undergoes and the quality control accompanying them. A numerical static analysis for a pre-stressed concrete mono-block railway sleeper is carried out using finite element package named "ANSYS 15". Using SOLID65 solid element, the compressive strength of concrete is facilitated using plasticity algorithm while the concrete cracking in tension zone is accommodated by the nonlinear material model. Since the section of concrete sleeper is fully pre-stressed by nature, the smeared crack analogy is impracticable. Discrete reinforcement modeling with truss elements, LINK8, is then more suitable to utilize. Perfect bonding is presumed herein between concrete and pre-stressing wires. Thus, the results of the analysis that evaluate the effect of cables in deformed shape, strains, stress of pre-stressed concrete sleepers are compared to the solid concrete sleepers. Therefore, the insight into static behaviors will not only result in a safer and more reliable design method for railway infrastructure, but it can also translate and apply to other civil concrete structures.