Post-cast strip structure of prestressed concrete plate

Abstract

The invention discloses a post-cast strip structure of a prestressed concrete plate. The post-cast strip structure comprises two longitudinal post-tensioning unbonded prestressed reinforcing bars (3) arranged in precast concrete (1) on two sides of a first longitudinal non-prestressed reinforcing bar (6) and second longitudinal non-prestressed reinforcing bars (7) substituting original post-cast strips' longitudinal post-tensioning unbonded prestressed reinforcing bars (4) by adopting an equal-strength principle and in post-cast strips (2), the second longitudinal non-prestressed reinforcing bars (7) are located on two horizontal sides of the longitudinal post-tensioning unbonded prestressed reinforcing bars (3) in the precast concrete (1), and two ends of the second longitudinal non-prestressed reinforcing bars (7) extend to the precast concrete (1) of one end of a post-cast strip. By the arrangement, same bearing force can be guaranteed, cement consumption can be reduced, the construction of the post-cast strip is simplified, and concrete cracks in the post-cast strip are prevented.

Description

technical field [0001] The invention relates to the technical field of civil engineering construction, in particular to a post-cast belt structure of a prestressed concrete panel. Background technique [0002] Prestressed concrete panels include floor panels for large buildings and roof panels for large buildings. Due to functional requirements, the area of ​​the panel is getting larger and larger, such as 50 square meters and above is called a large area, such as the length of 100 meters and above is called super long. Considering the stiffness of the panel, crack resistance requirements and construction, the structure of the prestressed concrete panel is more reasonable and economical. [0003] However, in the construction of large-area panels, especially the concrete pouring process, due to various reasons such as operation, material supply, transportation, work type coordination, and manual organization, it is necessary to pour the panel concrete in sections and set up ...

AI Technical Summary

Problems solved by technology

Of course, the post-cast tape structure also brings new problems: such as figure 1 , figure 2 , as shown, in the post-casting zone, the concrete must be poured afterward, and of course the unbonded prestressed steel bars cannot be continuously arranged, let alone stretched simultaneously with the unbonded prestressed steel bars in the first-cast concrete, so the unbonded prestressed steel bars cannot be stretched simultaneously The prestressed steel bars must be disconnected at the post-cast belt, and the tension ends and anchor devices of the unbonded pre-stressed steel bars in the first-cast concrete can only be installed on the first-cast concrete side walls on both sides of the post-cast belt.

Under the premise of ensuring the same bearing capacity, the cost of materials such as cement and steel bars is increased, especially the construction of the post-cast belt is complicated

In addition, there must be an overlapping area between the stretching and anchoring end of the longitudinal unbonded prestressed steel bar stretching into the post-casting zone of the first poured concrete and the tensioning and anchoring section of the longitudinal unbonded prestressed steel bar of the first poured concrete , it will also cause secondary stress to the concrete in the overlapping section of the pre-tensioned unbonded prestressed steel bars of the panel when the longitudinal unbonded prestressed steel bars of the post-tensioned post-cast belt are stretched. Any increase or decrease in stress will have an adverse effect on the stress of the panel, especially at the tension and anchorage ends, which are prone to cracks. These are the difficulties and safety hazards brought about by the post-cast belt structure of prestressed reinforced concrete panels.

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