FREMGANGSMAATE FOR AA LAST- OG DEFORMASJONSSTABILISERE KONSTRUKSJONER, SOM JERNBANESPOR OG LIGNENDE, VED HJELP AV SPENNARMERTE BETONGELEMENTER.

摘要

Method of conferring load and deformation stability on railway tracks by means of partially prestressed concrete structures, for instance concrete sleepers. The prestressing forces in the tendons during casting and curing may amount to one half of the value for full prestressing. In conjunction with both normal loads and sporadically occurring overloads, the magnitudes of the deformations in the sleepers will be regulated by the stiffness of the sleepers, the modulus of subgrade reaction of the ballast, and the ability of the rails to transmit force. Owing to enhanced deformability of the concrete sleepers in consequence of the reduced prestressing force in the tendons, considerable load energy can be absorbed without the occurrence of permanent damage. The structure as a whole is given such properties that the sleepers exhibit only elastic deformations, and that the cracks which occur in the concrete cross section in tension are completely closed after the load has ceased to act.