Comportamiento en rotura y en servicio de puentes de vigas prefabricadas in situ con continuidad en negativos

Behaviour in failure and service of bridge decks built with in situ precast beams made continuous over the supports

In this paper the results of tests undertaken within the framework of a theoretical and experimental program carried out in the Structural Concrete Department of the Civil Engineering School of Madrid is presented. This project was intended to study the ultimate bearing capacity and the serviceability conditions of continuous prestressed bridges built using precast beams. In the specimens studied, continuity has been achieved by concreting a slab at the bottom of the cross section in the proximity of the supports (1/5 of the adjacent spans) connected to the precast beams by means of transverse reinforcement and by transmitting the tensile forces at the top of the cross section using the reinforcement of the top slab which is continuous. In the available bibliography, other references dealing with continuous precast beams can be found. Two structural models were built using a scale factor of 1:4. The structures were modeled after a bridge deck, built with in situ precast beams made continuous over the support. These were built in different phases in order to reproduce the construction sequence of the real structures. In order to be able to analyze these experimental results, care has been taken to fully determine the characteristics of the materials used in the construction of the structures. The results of the mechanical extensometer were tested with satisfactory results against the results of the strain gauges in order to evaluate the reliability of the tests.