Prefabricating method for UHPC small box beam end diaphragm

Abstract

The invention discloses a prefabricating method for a UHPC small box beam end diaphragm. A box beam body is prefabricated by adopting ultra-high-performance concrete, the diaphragm is prefabricated atthe end of the box beam body after the box beam body reaches the preset strength, a cast-in-situ material of the diaphragm adopts ultra-high-performance concrete or common concrete, retard-bonded prestressed tendon tensioning operation is conducted after the diaphragm reaches the preset strength, and finally high-pressure steam curing is conducted on the whole box beam body. The prefabricated boxbeam body is adopted and cooperates with post-poured UHPC or common concrete to form the diaphragm, the cast-in-situ end partition and the prefabricated UHPC box beam body can be effectively connected into a whole, the thickness of the diaphragm can be selectively adjusted according to the pouring concrete material, the prefabricating efficiency of the UHPC small box beam end diaphragm is effectively improved, and the prefabricating method is more suitable for bridge industry assembly line production.

Description

technical field [0001] The invention relates to the technical field of bridge engineering structures, in particular to a prefabrication method for a diaphragm at the end of a UHPC small box girder. Background technique [0002] In recent years, my country has actively explored and enriched green bridge construction methods with high speed, low road interference and quietness, vigorously advocated prefabricated construction of bridges, and actively explored the application of new materials in prefabricated bridges, and built a large number of representative bridges. The prefabricated bridges, industrialized production and prefabricated construction of bridges have become a major trend. [0003] Although there are various types of prefabricated bridges, they all have their own shortcomings: the steel structure has a large amount of on-site welding (bolts), and the steel bridge deck has fatigue cracking problems; the steel-concrete composite structure has a large self-weight, an...

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Problems solved by technology

[0003] Although there are various types of prefabricated bridges, they all have their own shortcomings: the steel structure has a large amount of on-site welding (bolts), and the steel bridge deck has fatigue cracking problems; the steel-concrete composite structure has a large self-weight, and the bridge deck can only partially Prefabrication, large amount of on-site pouring; prestressed reinforced concrete structure is heavy, the horizontal connection is easy to be damaged, and there are many durability diseases

UHPC materials have been greatly developed in the field of bridges in countries such as France and Malaysia, but in my country, their theoretical research is mostly concentrated in the three forms of T-beam, wide box girder and π-beam, and the research on UHPC small box girder is basically It is blank, but the T-beam structure has many horizontal connections, and there are many joints on site, which is not conducive to rapid construction; the wide box girder realizes prefabricated construction through the longitudinal division of the box girder, and the on-site construction work is heavy and complicated; the π-beam There are only longitudinal joints on the bridge deck, which is convenient for on-site construction, and the prestressing force is cancelled, which avoids the difference in the anti-arching of the main girder caused by the prestressing tension, thereby ensuring the quality of the transverse joints and reducing the thickness of the bridge deck pavement. Lack of prestress leads to bridge span limitation

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