Tag Archive for Tag: concrete constructions

Tag: concrete constructions Monitoring techniques for prestressed concrete constructions

General remarks The main difficulty in assessing the condition of prestressed concrete structures is that failure of the prestressed members may occur as a sudden collapse without any visible warning signs. An example is the Ynys y Gwas bridge in Great Britain. It collapsed in 1985 after 32 years in service as a result of tendon corrosion, a short time

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Tag: concrete constructions Historical review concrete constructions

Although some early post-tensioned slab structures were constructed in Europe, the first real development of this method took place in the USA and Australia. The first post-tensioned slabs were erected in the USA in 1955, using unbonded post-tensioning. In succeeding years, numerous post-tensioned slabs were designed and constructed for use in the lift slab method of construction. Post- tensioning enabled

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Tag: concrete constructions Forms of prestressed concrete constructions

Two different methods exist for assembling and prestressing steel tendons:10 (i) pre-tensioning, where the prestressed tendons are surrounded directly by con- crete, and (ii) post-tensioning, where the prestressing steels run along ducts which are then filled by injection with mortar. A third method, unbonded tendons in greased ducts, is a new technique that has several advantages over traditional post-tensioning with

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