The proper fabrication of concrete-embedded tracks is a prerequisite for their long-term durability and their economic efficiency. Frequent defects which are caused either during fabrication or during operation are (partially) debonding between the pre-fabricated sleepers and the site-mixed concrete. This paper deals with the Pulse-ESPI-Technique as a measuring method which enables to detect th...

this study investigates propagation of mode i crack in b70 pre-stressed concrete sleepers by fracture mechanics approach. a new experimental analysis is done for notched b70 pre-stressed concrete sleepers with replica test and image analysis. a scanning electron microscope test (sem) and an image analysis are applied for the replica test in order to determine crack length and crack mouth openin...

initial cracks occur in high strength concrete sleepers for various reasons, such as shrinkage and wrong curing and long lifetime of over 50 years of sleepers. these cracks may lead to complete failure of the structure. in order to more accurately design the sleepers, fracture mechanics (not strength of materials) should be incorporated. in order to achieve this purpose, it is important to fore...

This study investigates propagation of mode I crack in B70 pre-stressed concrete sleepers by fracture mechanics approach. A new experimental analysis is done for notched B70 pre-stressed concrete sleepers with Replica test and image analysis. A scanning electron microscope test (SEM) and an image analysis are applied for the Replica test in order to determine crack length and crack mouth openin...

Abstract This paper presents experimental verification of indirect tests for the determination stress-crack opening curve concrete, based on method described in RILEM TC 187-SOC report and submitted to ACI Committee 446 Fracture Toughness Testing Concrete, which relies standard cohesive model. In such method, a bilinear approximation softening is determined from three-point bending notched spec...

The load generated during train operation is transmitted to sleepers through rails, and then from trackbeds. As one of the important components track structure, are very service-life safety railways. running speed will produce different frequencies on rails. To explore response under cyclical loads, this research used discrete element method simulate rails sleepers, realizes loading by applying...

Concrete sleepers have been widely used throughout the world as an alternative for timber sleepers. In North America, heavy-haul railroads have increased their use of concrete sleepers in recent years for a variety of factors. According to an international survey conducted by researchers at the University of Illinois at Urbana-Champaign (UIUC), railroad industry representatives consider center ...

Abstract: the article provides a calculation justification of proposed railway structure on reinforced concrete sleeper-free base, for which an analysis existing methodology calculating track strength is carried out, according to dynamic loads acting from rolling stock are determined. The applied sleeper-less structures and results measurements emerging stresses in substructure, measured depth ...