COMPOSITE CAPPING BEAM WITH STEEL BEAM AND ULTRA-HIGH-PERFORMANCE CONCRETE PLATE AND CONSTRUCTION METHOD THEREFOR

Abstract

Disclosed is a composite capping beam with a steel beam and an ultra-high-performance concrete plate. The composite capping beam includes a steel beam and an ultra-high-performance concrete (UHPC) plate, where the steel beam includes a bottom plate and web plates, the web plates are arranged at two sides of the bottom plate in a longitudinal bridge direction, bottoms of the web plates extend downwards to be provided with lower extension sections, and the UHPC plate is clamped in a cavity defined by the lower extension sections and the bottom plate. The present disclosure further provides a construction method for the composite capping beam with a steel beam and an ultra-high-performance concrete plate. The composite capping beam with a steel beam and an ultra-high-performance concrete plate according to the present disclosure is small in hoisting weight and economical.

Claims

1. A composite capping beam with a steel beam and an ultra-high-performance concrete plate, comprising a steel beam (1) and an ultra-high-performance concrete (UHPC) plate (2), wherein the steel beam (1) comprises a bottom plate (16) and web plates (15), the web plates (15) are arranged at two sides of the bottom plate (16) in a longitudinal bridge direction, bottoms of the web plates (15) extend downwards to be provided with lower extension sections (151), and the UHPC plate (2) is clamped in a cavity defined by the lower extension sections (151) and the bottom plate (16).

2. The composite capping beam with a steel beam and an ultra-high-performance concrete plate according to claim 1, wherein a thickness of the UHPC plate (2) does not exceed 1/5 of a height of the composite capping beam.

3. The composite capping beam with a steel beam and an ultra-high-performance concrete plate according to claim 1, wherein a height of the lower extension sections (151) is equal to a thickness of the UHPC plate (2).

4. The composite capping beam with a steel beam and an ultra-high-performance concrete plate according to claim 1, wherein the bottom plate (16) and the lower extension sections (151) are provided with a plurality of shear connectors (5), and the UHPC plate (2) is fixedly arranged in the cavity defined by the lower extension sections (151) and the bottom plate (16) by means of the shear connectors (5).

5. The composite capping beam with a steel beam and an ultra-high-performance concrete plate according to claim 1, wherein the steel beam (1) is of a variable section structure, and a section gradually expands in a direction from a cantilever end to a center of the composite capping beam and then becomes a uniform section; and a height of an end of the steel beam (1) is 1200 mm-1500 mm, and a height of a central part is 1/6-1/4.5 of a length of a cantilever of the composite capping beam.

6. The composite capping beam with a steel beam and an ultra-high-performance concrete plate according to claim 1, wherein the UHPC plate (2) is of a variable section structure, and a section gradually expands in a direction from a cantilever end to a center of the composite capping beam and then becomes a uniform section; and a thickness of an end of the UHPC plate (2) is 150 mm-250 mm, and a thickness of a central part is 400 mm-500 mm.

7. The composite capping beam with a steel beam and an ultra-high-performance concrete plate according to claim 1, wherein the steel beam (1) further comprises a top plate (11), the top plate (11) is arranged on a top of the web plates (15), the top plate (11) is provided with a plurality of transverse-bridge stiffening ribs (12) arranged in a transverse bridge direction, the web plate (15) is provided with a plurality of vertical stiffening ribs (13) arranged vertically at intervals, and a plurality of diaphragms (14) vertically arranged are arranged between the top plate (11), the web plates (15) and the bottom plate (16) at intervals.

8. The composite capping beam with a steel beam and an ultra-high-performance concrete plate according to claim 7, wherein the top plate (11) has a thickness of 30 mm-70 mm, the web plates (15) have a thickness of 14 mm-25 mm, the bottom plate (16) has a thickness of 16 mm-20 mm, the transverse-bridge stiffening ribs (12) have a thickness of 20 mm-30 mm, the vertical stiffening ribs (13) have a thickness of 20 mm-24 mm, the diaphragms (14) have a thickness of 16 mm-20 mm, an interval between the adjacent transverse-bridge stiffening ribs (12) is 1000 mm-1300 mm, and an interval between the adjacent vertical stiffening ribs (13) and an interval between the adjacent diaphragms (14) are both 2000 mm-2400 mm; and the steel beam (1) is made of steel having a strength grade of Q420 or above.

9. A construction method for the composite capping beam with a steel beam and an ultra-high-performance concrete plate according to claim 1, comprising the following steps: S1: pre-assembling and forming a steel beam (1), wherein when the steel beam (1) is formed, lower extension sections (151) and a bottom plate (16) are fixedly provided with shear connectors (5); and S2: controlling an opening of a cavity defined by the lower extension sections (151) and the bottom plate (16) to be upward, pouring UHPC into the cavity, and conducting curing to obtain an UHPC plate (2), that is, prefabricating the composite capping beam with a steel beam and an ultra-high-performance concrete plate.

10. The construction method according to claim 9, wherein in S2, a pier-beam splicing part (3) is formed through pouring while the UHPC is poured, a form is mounted before the pier-beam splicing part (3) is formed through pouring, a pier-column connector (31) is pre-embedded, and the form is demolished and curing is conducted after pouring is completed.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0038] To describe the technical solutions in examples of the present disclosure or in the prior art more clearly, the accompanying drawings required for describing the examples or the prior art will be briefly described below. Apparently, the accompanying drawings in the following description show some embodiments of the present disclosure, and a person of ordinary skill in the art may still derive other drawings from these accompanying drawings without creative efforts.

[0039] FIG. 1 is a structural diagram of a front view of a composite capping beam with a steel beam and an ultra-high-performance concrete plate in Embodiment 1;

[0040] FIG. 2 is a top plan view of a composite capping beam with a steel beam and an ultra-high-performance concrete plate in Embodiment 1;

[0041] FIG. 3 is a bottom plan view of a composite capping beam with a steel beam and an ultra-high-performance concrete plate in Embodiment 1;

[0042] FIG. 4 is a sectional view along A-A in FIG. 1;

[0043] FIG. 5 is a sectional view along B-B in FIG. 1; and

[0044] FIG. 6 is a sectional view along C-C in FIG. 1.

REFERENCE NUMERALS

[0045] 1, steel beam; 11, top plate; 12, transverse-bridge stiffening rib; 13, vertical stiffening rib; 14, diaphragm; 15, web plate; 151, lower extension section; 16, bottom plate; 2, UHPC plate; 3, pier-beam splicing part; 31, pier-column connector; 4, support; and 5, shear connector.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0046] In order to facilitate understanding of the present disclosure, the present disclosure is described in detail below in conjunction with the accompanying drawings of the description and the preferred embodiments, but the protection scope of the present disclosure is not limited to the following specific embodiments.

[0047] Unless otherwise defined, all technical terms used hereinafter have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are merely for the purpose of describing specific embodiments, and are not intended to limit the protection scope of the present disclosure.

[0048] Unless otherwise specified, various raw materials, reagents, instruments, devices, etc. used in the present disclosure can be purchased from the market or can be prepared by existing methods.

EMBODIMENT

[0049] As shown in FIGS. 1-6, a composite capping beam with a steel beam and an ultra-high-performance concrete plate according to the embodiment includes a steel beam 1 and an ultra-high-performance concrete UHPC plate 2. The steel beam 1 includes a bottom plate 16 and web plates 15. The web plates 15 are arranged at two sides of the bottom plate 16 in a longitudinal bridge direction, and bottoms of the web plates 15 extend downwards to be provided with lower extension sections 151. The UHPC plate 2 is clamped in a cavity defined by the lower extension sections 151 and the bottom plate 16. The web plates 15 are seamlessly fixed to the two sides of the bottom plate 16 in the longitudinal bridge direction, such that a bottom surface of the cavity and two sides in the longitudinal bridge direction are in a sealed state, so as to be conducive to later pouring of the UHPC plate 2. In addition, the UHPC plate 2 obtained through pouring is a solid plate, and is fixedly connected to the steel beam 1 into a whole.

[0050] In the embodiment, a thickness of the UHPC plate 2 does not exceed 1/5 of a height of the composite capping beam.

[0051] In the embodiment, a height of the lower extension sections 151 is equal to a thickness of the UHPC plate 2.

[0052] As shown in FIGS. 4-6, in the embodiment, the bottom plate 16 and the lower extension sections 151 are provided with a plurality of shear connectors 5, and the UHPC plate 2 is fixedly arranged in the cavity defined by the lower extension sections 151 and the bottom plate 16 by means of the shear connectors 5. Cheese head studs may be used as the shear connectors 5.

[0053] In the embodiment, the steel beam 1 is of a variable section structure, and a section gradually expands in a direction from a cantilever end to a center of the composite capping beam and then becomes a uniform section. A height of an end of the steel beam 1 is 1200 mm-1500 mm (for example, may be 1200 mm), and a height of a central part is 1/6-1/4.5 of a length of a cantilever of the composite capping beam (for example, may be 2200 mm).

[0054] In the embodiment, the UHPC plate 2 is of a variable section structure, and a section gradually expands in a direction from a cantilever end to a center of the composite capping beam and then becomes a uniform section. A thickness of an end of the UHPC plate 2 is 150 mm-250 mm (for example, may be 150 mm), and a thickness of a central part is 400 mm-500 mm (for example, may be 400 mm).

[0055] In the embodiment, the steel beam 1 further includes a top plate 11, the top plate 11 is arranged on a top of the web plates 15, the top plate 11 is provided with a plurality of transverse-bridge stiffening ribs 12 arranged in a transverse bridge direction, the web plate 15 is provided with a plurality of vertical stiffening ribs 13 arranged vertically at intervals, and a plurality of diaphragms 14 vertically arranged are arranged between the top plate 11, the web plates 15 and the bottom plate 16 at intervals.

[0056] In the embodiment, the top plate 11 has a thickness of 30 mm-70 mm (for example, may be 30 mm, 50 mm, or 40 mm), the web plates 15 have a thickness of 14 mm-25 mm (for example, may be 16 mm, 18 mm, or 14 mm), the bottom plate 16 has a thickness of 16 mm-20 mm (for example, may be 16 mm or 20 mm), the transverse-bridge stiffening ribs 12 have a thickness of 20 mm-30 mm (for example, may be 20 mm), the vertical stiffening ribs 13 have a thickness of 20 mm-24 mm (for example, may be 20 mm), the diaphragms 14 have a thickness of 16 mm-20 mm (for example, may be 16 mm), an interval between the adjacent transverse-bridge stiffening ribs 12 is 1000 mm-1300 mm (for example, may be 1220 mm), and an interval between the adjacent vertical stiffening ribs 13 and an interval between the adjacent diaphragms 14 are both 2000 mm-2400 mm (for example, may both be 2315 mm). The steel beam 1 is made of steel having a strength grade of Q420 or above.

[0057] In the embodiment, the top plate 11 is provided with a support 4 configured to bear a load of an upper structure.

[0058] In the embodiment, a volume fraction of steel fibers of ultra-high-performance concrete configured for pouring may be 1.5%. The ultra-high-performance concrete having a compressive strength of 140 MPa is selected and an expanding agent is added, so as to control shrinkage. In this way, tight connection of composite sections is ensured while compressive performance requirements of the UHPC plate 2 are ensured.

[0059] In the embodiment, the UHPC plate 2 formed by pouring the ultra-high-performance concrete is completely controlled in a compression zone of the composite section, such that compressive performance of the ultra-high-performance concrete is fully exerted, and the composite capping beam is small in weight and high in strength, may easily control a beam height, and may better adapt to height limit requirements of urban bridges.

[0060] A prefabrication and construction method for the composite capping beam with a steel beam and an ultra-high-performance concrete plate according to the embodiment includes the following steps: [0061] S1: prefabrication work of the composite capping beam with a steel beam and an ultra-high-performance concrete plate is completed in a factory, and specific steps are as follows: [0062] S1.1: shear connectors 5 are welded onto web plates 15 and a bottom plate 16 according to design requirements; [0063] S1.2: a top plate 11, transverse-bridge stiffening ribs 12, vertical stiffening ribs 13, diaphragms 14, the web plates 15 and the bottom plate 16 are welded in the factory, and assembly is conducted to form a steel beam 1; [0064] S1.3: the steel beam 1 is overturned to enable an opening of a cavity formed by the web plates 15 and the bottom plate 16 to face upwards, steel bars are bound according to the design requirements, a form is erected above the opening of the cavity so as to be configured to form a pier-beam splicing part 3 through pouring, a pier-column connector 31 is pre-embedded, then ultra-high-performance concrete is poured, and steam curing is conducted; and [0065] S1.4: the form is demolished and properly stored after a strength of the ultra-high-performance concrete satisfies the design requirements, that is, fabrication of a prefabricated unit of the composite capping beam with a steel beam and an ultra-high-performance concrete plate is completed. [0066] S2: the composite capping beam unit prefabricated in S1 is transported to a construction site, and hoisting and mounting are conducted, so as to form pier-column connection. [0067] S3: a support 4 is mounted on the top plate 11 after structure curing according to the design requirements, that is, prefabrication and mounting construction of the composite capping beam with a steel beam and an ultra-high-performance concrete plate are completed.