1. Field of the Invention
The present invention relates to a method for connecting precast concrete beams in construction work, for example, bridge superstructures.
2. Description of the Prior Art
In recent years, precast concrete beams for the bridge superstructures have occasionally been connected to make a continuous beam, because it is possible to employ smaller concrete sections, thus reducing the dead weight of structure and attaining the resulting economy.
Several methods are being used for connection of precast concrete beams. Most methods utilize the following: (a) precast concrete beams are supported by the piers, (b) concrete is placed into the gaps between the ends of beams, and (c) tendons or reinforcing bars are utilized so that structural continuity is achieved.
In these methods, however, structural continuity is effective only for loads that are applied after the structural continuity is achieved.
The self-weight of beams is applied before the structural connection, and so the structural continuity is not effective for this load.
So, in order to attain full economy, an active method is needed to make it possible so that structural continuity is effective for the self-weight of precast concrete beams.
USPTO Backgrounds
USPTO Backgrounds