3.1.4 Monolithic Designs
These designs are consisted of only a continuous monolithic concrete layer and direct rail fastening adjusted on it. The sleepers designs are established either as monolithic concrete layer produced by a concrete paver or as prefabricated slabs connected together (Esveld, Lichtberger). The direct rail fastening used for this system are very effective in bridges making them lighter and eliminate problems associating the sleeperless (Esveld). The monolithic designs are stiff and rigid enough to behave structurally as a continuous supported elastic beam under traffic loading. The rigidity of this system makes it suitable for use in soft soils. The loads are distributed across a much longer and wider area (Esveld). Attention must be paid to the crack formation of the concrete bearing layer (CBL) and proper measures have to be taken to prevent cracking caused by the rail fastening.