CN114934437A - Ultra-high performance concrete segmental beam mixed and bundled in vivo and in vitro and construction method - Google Patents

Abstract

The invention discloses an ultra-high performance concrete segmental beam mixed and bundled in vivo and in vitro and a construction method thereof, comprising more than one main beam segment with the length not exceeding 30 meters; the plurality of main beam segments are connected end to form a beam and are connected by adopting an external beam; in the more than three main beam sections, except for two main beam sections at two ends, other main beam sections are all universal sections; each universal segment is provided with a pretensioned in-vivo bundle and is manufactured in a factory; two ends of each universal section are provided with a middle partition plate and a shear key. During construction, all universal sections and two main beam sections positioned at two ends of a beam are manufactured in a factory and transported to a construction site after the construction is finished; and then tensioning the extracorporeal bundles on site for assembly. The application of the invention can solve the problem of incompact grouting of the post-tensioned precast beam pipeline, reduce the arrangement of the prestressed pipeline, reduce the size of the member, realize the lightening of the main beam with large span, adopt the long section type and be more convenient for construction.

Description

Ultra-high performance concrete segmental beam mixed and bundled in vivo and in vitro and construction method

Technical Field

The invention relates to the technical field, in particular to an in-vivo and in-vitro mixed beam-matching ultrahigh-performance concrete segmental beam and a construction method thereof.

Background

The ultra-high performance concrete is a new variety of cement-based structural engineering material with clear performance indexes. Compared with common concrete, the ultra-high performance concrete has the characteristics of ultra-high strength, ultra-high toughness, ultra-high durability and the like. The ultra-high performance concrete is applied to structural engineering, so that the structure can be lightened, and the service life of the structure can be prolonged.

Compared with common concrete, the compressive strength of the ultra-high performance concrete is greatly improved, and the tensile strength is improved, but the tensile strength is obviously improved, which is not as good as the compressive capacity of the ultra-high performance concrete. Therefore, in the design of the main beam, the ideal design is combined with prestress, and the ultrahigh compression resistance of the ultrahigh-performance concrete is fully utilized by tensioning the prestress steel beams, so that the ultrahigh-performance concrete stores larger prestress for resisting the load, and the crack resistance of the ultrahigh-performance concrete in the normal use limit state is greatly improved.

For a prestressed system, a prestressed tendon duct needs to be reserved for post-tensioning prestressing, and grouting is carried out after tensioning is finished. The ultra-high performance concrete is adopted in the structure, the structure is expected to be light, the wall thickness of the structure is reduced, the reduction of the wall thickness is limited by the size requirement of a post-tensioned prestressed duct, and meanwhile, the strength matching property of the grouting material and the main UHPC material is required to be further researched. Meanwhile, the post-tensioning method also has the problem of incompact grouting, so that a pre-tensioning method in-vivo prestressed system or an in-vitro prestressed system is an ideal choice for the UHPC main body beam.

Compared with an external prestressed system, the efficiency of the internal prestressed system is better. When the span of the main beam is small (below 30m), a pretensioning method in-vivo prestress system can be adopted; when the span of the main beam is large (larger than 30m), the main beam needs to be segmented for transportation and other reasons, and the pretensioning method internal prestress system is not suitable. Therefore, the invention provides an ultra-high performance concrete segmental beam structure which is formed by mixing and bundling in a pretensioning method and outside a body.

Disclosure of Invention

In view of the defects of the prior art, the invention provides the ultrahigh-performance concrete segmental beam mixed and bundled in vivo and in vitro and the construction method thereof, the internal bundling adopts a pre-tensioning process, the purpose of realizing the purpose that the structure can avoid the problems caused by post-tensioning steel bundling is realized, and simultaneously, the characteristics of the ultrahigh-performance concrete are better utilized to achieve the lightening of the structure.

In order to achieve the purpose, the invention discloses an ultra-high performance concrete segmental beam which is mixed and bundled in vivo and in vitro; including more than one main beam segment of no more than 30 meters in length.

The plurality of main beam segments are connected end to form a beam and are connected by adopting an external beam;

among the three or more main beam segments, the other main beam segments are common segments except for two main beam segments at both ends;

each universal section is provided with a pretensioned in-vivo bundle and is manufactured in a factory or is independently used as a beam with the length of 20-30 meters;

and the end part of the two ends of each universal section, which is connected with the other main beam section, is provided with a middle partition plate and a shear key.

Preferably, each of said main beam sections is box-shaped, channel-shaped or i-shaped in cross-section.

Preferably, the span of the beam formed by the three main beam sections is 30-90 m; the span of a beam formed by the four main beam sections is 90-120 meters; the span of the beam formed by the five main beam sections is 120-150 meters.

Preferably, each of the universal segments has a length of 20 to 30 meters.

Preferably, a shearing member is arranged between every two adjacent main beam sections.

The invention also provides a construction method of the ultra-high performance concrete segmental beam mixed and bundled in vivo and in vitro, which comprises the following steps:

step 1, manufacturing all the universal segments;

step 2, manufacturing two main beam sections positioned at two ends of the beam;

step 3, transporting all the universal sections and the two main beam sections positioned at the two ends of the beam to a construction site;

step 4, assembling all the general sections and the two main beam sections positioned at the two ends of the beam on the ground of a construction site if the hoisting capacity allows, tensioning the external beam and anchoring, and hoisting to a bridge position after assembling is completed; and if the weight of the assembled beam body exceeds the hoisting capacity, temporary supports are arranged, all the general sections and the two main beam sections positioned at the two ends of the beam are hoisted to bridge positions respectively, and then the external beam is tensioned and assembled.

Preferably, in step 1, the manufacturing of each universal segment includes the following steps:

step 1.1, installing a template on a pre-tensioning method pedestal, and tensioning a corresponding pre-tensioning method in-vivo bundle;

step 1.2, pouring ultra-high performance concrete, and reserving a corresponding shear key at a position corresponding to the end part of each universal section;

step 1.3, shearing the prestressed tendons when the strength of the ultrahigh-performance concrete reaches the design strength;

and 1.4, removing each universal segment from the bench for maintenance.

Preferably, in step 2, the step of manufacturing each main beam segment at two ends of the beam comprises the following steps:

step 2.1, installing a template, and pouring ultra-high performance concrete;

and 2.2, removing the template when the strength of the ultrahigh-performance concrete reaches the designed strength, and curing to the age according to the regulations.

The invention has the beneficial effects that:

the application of the invention can solve the problem of incompact grouting of the post-tensioned precast beam pipeline, reduce the arrangement of the prestressed pipeline, greatly reduce the size of components, realize the lightening of the main girder with long span, reduce the number of sections of the bridge with long span by adopting the long section type and facilitate the construction.

The conception, the specific structure and the technical effects of the present invention will be further described with reference to the accompanying drawings to fully understand the objects, the features and the effects of the present invention.

Drawings

FIG. 1 illustrates a side view of a main beam segment according to an embodiment of the present invention.

FIG. 2 illustrates a cross-sectional view of a main beam segment in accordance with an embodiment of the present invention.

Fig. 3 is a schematic side view of a structure of a plurality of main beam segments connected in sequence and provided with an external beam according to an embodiment of the present invention.

FIG. 4 illustrates a cross-sectional view of a main beam segment with an external bundle in accordance with an embodiment of the present invention.

Fig. 5 is a schematic view showing a state in which the main beam section is disposed at the upper end of the temporary support in one embodiment of the present invention.

Detailed Description

Examples

As shown in fig. 1 to 4, ultra-high performance concrete segmental beams bundled in vivo and in vitro are mixed; including more than one main beam segment of no more than 30 meters in length.

Wherein, a plurality of main beam segments are connected end to form a beam and are connected by adopting an external beam 2;

in the more than three main beam sections, except for two main beam sections at two ends, other main beam sections are all universal sections;

each universal section is provided with a pretensioned in-vivo bundle 1, and is manufactured in a factory or is independently used as a beam with the length of 20-30 meters;

the end part of the two ends of each universal section connected with the other main beam section is provided with a middle partition plate and a shear key.

According to the invention, the problem of incompact grouting of the post-tensioning precast beam pipeline is solved by mixed beam matching of the pre-tensioning in-vivo beam 1 and the in-vitro beam 2;

the middle partition plate can be used as a steering device of the external beam to realize steering of the external beam, and the shear keys of the segmental beams can be arranged at the middle partition plate to realize shear connection of the segmental beams, so that the problem that the shear keys cannot be effectively arranged because the wall thickness of the ultrahigh-performance concrete beam is thin is solved;

moreover, the arrangement of prestressed pipelines is reduced by the pretensioning method, the size of the member is greatly reduced, the characteristics of the ultra-high performance concrete are exerted, and the lightening of the main girder with the large span is realized; in addition, a long section mode is adopted, the number of sections of the large-span bridge is reduced, and the construction is convenient.

In some embodiments, each main beam section is box-shaped, channel-shaped, or i-shaped in cross-section.

In certain embodiments, the span of a beam of three main beam segments is 30 to 90 meters; the span of a beam formed by the four main beam sections is 90-120 meters; the span of a beam consisting of five main beam segments is 120 to 150 meters.

In certain embodiments, each universal segment is 20 meters to 30 meters in length.

In certain embodiments, a shear member is disposed between each two adjacent main beam segments.

The invention also provides a construction method of the ultra-high performance concrete segmental beam mixed and bundled in vivo and in vitro, which comprises the following steps:

step 1, manufacturing all universal segments;

step 2, manufacturing two main beam sections positioned at two ends of the beam;

step 3, transporting all the universal sections and the two main beam sections positioned at the two ends of the beam to a construction site;

step 4, assembling all the general sections and two main beam sections positioned at two ends of the beam on the ground of a construction site if the hoisting capacity allows, tensioning the external beam 2 and anchoring, and hoisting to a bridge position after assembling is completed;

as shown in fig. 5, if the weight of the assembled beam body exceeds the hoisting capacity, a temporary support 3 is arranged, all the general sections and two main beam sections at two ends of the beam are respectively hoisted to the bridge position, and then the external tension body 2 is assembled.

In some embodiments, step 1, the manufacturing of each universal segment comprises the following steps:

step 1.1, installing a template on a pre-tensioning method pedestal, and tensioning a corresponding pre-tensioning method in-vivo bundle 1;

step 1.2, pouring ultra-high performance concrete, and reserving corresponding shear keys at positions corresponding to the end parts of all the universal sections;

step 1.3, shearing the prestressed tendons when the strength of the ultrahigh-performance concrete reaches the design strength;

and 1.4, removing each universal segment from the bench for maintenance.

In certain embodiments, in step 2, fabricating each main beam segment at both ends of the beam comprises the steps of:

step 2.1, installing a template, and pouring ultra-high performance concrete;

and 2.2, removing the template when the strength of the ultrahigh-performance concrete reaches the designed strength, and curing to the age according to the regulations.

The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.

Claims (8)

1. The ultra-high performance concrete section beam is mixed and bundled in vivo and in vitro; it is characterized by comprising more than one main beam section with the length not exceeding 30 meters;

the plurality of main beam sections are connected end to form a beam and are connected by adopting an external beam (2);

among the three or more main beam segments, the other main beam segments are common segments except for two main beam segments at both ends;

each universal segment is provided with a pretensioned in-vivo bundle (1) and is manufactured in a factory or is independently used as a beam with the length of 20-30 meters;

and the end part of the two ends of each universal section, which is connected with the other main beam section, is provided with a middle partition plate and a shear key.

2. The ultra-high performance concrete segmented beam in combination and bundled in vitro and in vivo as claimed in claim 1, wherein each of the main beam segments has a box-shaped, channel-shaped or I-shaped cross section.

3. The ultra-high performance concrete segmented beam mixed in-vivo and in-vitro bundling according to claim 1, wherein the span of the beam formed by the three main beam segments is 30-90 m; the span of a beam formed by the four main beam sections is 90-120 m; the span of the beam formed by the five main beam sections is 120-150 meters.

4. The ultra-high performance concrete segmented beam in combination and bundled in vitro and in vivo as claimed in claim 1, wherein the length of each universal segment is 20 m to 30 m.

5. The ultra-high performance concrete segmented beam in vivo and in vitro mixed bundle preparation according to claim 1, wherein a shearing force member is arranged between every two adjacent main beam segments.

6. The construction method of the ultra-high performance concrete segmental beam mixed and bundled in vivo and in vitro according to claim 1, which is characterized by comprising the following steps:

step 1, manufacturing all the universal segments;

step 2, manufacturing two main beam sections positioned at two ends of the beam;

step 3, transporting all the universal sections and the two main beam sections positioned at the two ends of the beam to a construction site;

step 4, assembling all the general sections and the two main beam sections positioned at the two ends of the beam on the ground of a construction site if the hoisting capacity allows, tensioning the external beam (2) and anchoring, and hoisting to a bridge position after assembling is completed; if the weight of the assembled beam body exceeds the hoisting capacity, a temporary support (3) is arranged, all the general sections and the two main beam sections positioned at the two ends of the beam are respectively hoisted to bridge positions, and then the external beam (2) is tensioned for assembly.

7. The construction method of the ultra-high performance concrete segmental beam mixed and bundled in vivo and in vitro according to claim 6, wherein in the step 1, the manufacture of each universal segment comprises the following steps:

step 1.1, installing a template on a pre-tensioning method pedestal, and tensioning a corresponding pre-tensioning method in-vivo bundle (1);

step 1.2, pouring ultra-high performance concrete, and reserving a corresponding shear key at a position corresponding to the end part of each universal section;

step 1.3, shearing the prestressed tendons when the strength of the ultrahigh-performance concrete reaches the design strength;

and 1.4, removing each universal segment from the bench for maintenance.

8. The method for constructing an ultra-high performance concrete segmental beam mixed and bundled in vivo and in vitro according to claim 6, wherein in the step 2, the step of manufacturing each main beam segment at two ends of the beam comprises the following steps:

step 2.1, installing a template, and pouring ultra-high performance concrete;

and 2.2, removing the template when the strength of the ultrahigh-performance concrete reaches the designed strength, and curing to the age according to the regulations.

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