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Slab track with flexible noise-reducing rail fixings, built by German company Max Bögl, on the Nürnberg–Ingolstadt high-speed line. A ballastless track or slab track is a type of railway track infrastructure in which the traditional elastic combination of sleepers and ballast is replaced by a rigid construction of concrete or asphalt.
A railway track (CwthE and UIC terminology) or railroad track (NAmE), also known as permanent way (CwthE) [1] or "P Way" BrE [2] and Indian English), is the structure on a railway or railroad consisting of the rails, fasteners, sleepers (railroad ties in American English) and ballast (or slab track), plus the underlying subgrade.
The Wood–Armer method is a structural analysis method based on finite element analysis used to design the reinforcement for concrete slabs. [1] This method provides simple equations to design a concrete slab based on the output from a finite element analysis software.
FWD data is most often used to calculate stiffness-related parameters of a pavement structure. The process of calculating the elastic moduli of individual layers in a multi-layer system (e.g. asphalt concrete on top of a base course on top of the subgrade) based on surface deflections is known as "backcalculation", as there is no closed-form solution.
Wooden ties are used on many traditional railways. In the background is a track with concrete ties. A railroad tie, crosstie (American English), railway tie (Canadian English) or railway sleeper (Australian and British English) is a rectangular support for the rails in railroad tracks.
Slab track consists of a continuous concrete roadbed without division into separate sleepers, and these are most often used in tunnels. British Rail experimented with slabs during the late 1960s and laid several miles alongside the main running lines north of Derby. [citation needed]
Track consists of two parallel steel rails, anchored perpendicular to members called sleepers (ties) of timber, concrete, steel, or plastic to maintain a consistent distance apart, or rail gauge. Other variations are also possible, such as "slab track", in which the rails are fastened to a concrete foundation resting on a prepared subsurface.
Concrete has a very low coefficient of thermal expansion, and as it matures concrete shrinks. All concrete structures will crack to some extent, due to shrinkage and tension. Concrete which is subjected to long-duration forces is prone to creep. The density of concrete varies, but is around 2,400 kilograms per cubic metre (150 lb/cu ft). [1]