Prefabrication method of pre-embedded steel plate type UHPC small box girder end diaphragm

Abstract

The invention discloses a prefabrication method of a pre-embedded steel plate type UHPC small box girder end diaphragm. The prefabrication method comprises the steps of prefabricating a box girder body with ultra-high performance concrete; prefabricating the end diaphragm at the end of the box girder body after the box girder body meets the requirement for preset strength, wherein the cast-in-situmaterial of the end diaphragm is the ultra-high performance concrete or common concrete; after the end diaphragm meets the requirement for preset strength, carrying out slow bond prestressed reinforcement tension operation; and carrying out high-pressure steam curing on the whole box girder body finally. According to the prefabrication method of the pre-embedded steel plate type UHPC small box girder end diaphragm, the prefabricated box girder body is adopted to be used in cooperation with post-poured UHPC or common concrete to form the end diaphragm, the cast-in-place end diaphragm and the prefabricated UHPC small box girder body can be effectively connected to form a whole, the thickness of the end diaphragm can be selectively adjusted according to the poured concrete material, the efficiency of fabrication of the UHPC small box girder end diaphragm can be effectively improved, and therefore, the UHPC small box girder end diaphragm can be more applicable to bridge industry flow lineproduction.

Description

technical field [0001] The invention relates to the technical field of bridge engineering structures, in particular to a prefabrication method for a prefabricated steel plate type UHPC small box girder end diaphragm. 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 la...

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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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