Connection end structure of a precast UHPC bridge deck slab

Abstract

A connecting end structure of a precast UHPC bridge deck slab, which mainly solves the technical problem of complex connection of bridge deck slabs. The key points of the technical solution are as follows: a joint end with a stepped special-shaped structure is provided on any one side or 2-4 side faces of the upper part of the precast bridge deck slab, that is, the thickness of the joint end is less than the thickness of the middle part of the precast bridge deck slab. A tooth groove structure is provided on the joint end. The steel bars extending from the upper layer of the precast bridge deck slab in the tooth groove structure are partially wrapped. The tooth groove structure, the joint end and the precast bridge deck slab are integrally formed by cast-in-place at one time. It is mainly used for the joints of bridge deck slabs.

Description

Technical Field

[0001] The invention relates to a structure of a UHPC bridge deck prefabricated plate, in particular to a connection end structure of a UHPC bridge deck prefabricated plate. Background Art

[0002] As an important part of the bridge structure, the bridge deck not only bears the direct effect of vehicle loads but also provides a working surface for the pavement structure on it. It is the component most directly affected by adverse factors such as overload, corrosion, and fatigue. Therefore, its working state will directly affect the service life of the main structure of the bridge and the comfort of driving. The traditional steel-concrete bridge deck composite structure uses ordinary concrete for the bridge deck. Due to the low tensile strength of concrete, the deck thickness is large and the structure has a large deadweight, which is difficult to meet the needs of the main beam of a long-span bridge. It is also easy to crack near wet joints, negative bending moment areas, and cable anchorage areas, which affects the service life of the main structure and pavement structure of the bridge. Ultra-high performance concrete (UHPC) has the advantages of high elastic modulus, high compressive and tensile strength, and good creep characteristics. (Using prefabricated ultra-high performance concrete to make bridge decks) can reduce the size of the structure, reduce the deadweight of the structure, improve the effectiveness of the structure in resisting loads and increase the ability to span, and provide a good working surface for the pavement structure.

[0003] At present, the assembly prefabrication rapid construction technology in the field of bridge construction has been vigorously studied, developed and applied by the country and the industry; ultra-high performance concrete bridge structures have been valued and gradually developed and applied in prefabrication and assembly technology due to their light weight and high strength, but there is no engineering application experience in the country for ultra-high performance concrete prefabricated bridge decks. Due to the ultra-thin components of ultra-high performance concrete prefabricated panels and the density of the reinforcement in the panels, the construction of cast-in-place wet joints brings two major problems. The first problem is the influence of the reserved density of steel bars in wet joints. There are two traditional methods: one is to reserve ring steel bars in the prefabricated panels, and connect them through the reserved ring steel bars in the adjacent prefabricated panels to ensure the effective connection of the wet joints, but due to the presence of ring steel bars, it is difficult to install and disassemble the template of the prefabricated panels, and it is easy to damage the components when removing the template; the second is to reserve enough long steel bars in the prefabricated panels, and the reserved steel bars are connected into a whole by binding or welding to ensure the effective connection of the wet joints. Due to the density of the steel bars in the panels, when the prefabricated panels are installed, the steel bars in the adjacent prefabricated panels are prone to overlap and stagger, which brings difficulties to the installation of the prefabricated panels. The second problem is that the bottom of the reserved steel bars is hollow and the gap with the bottom surface is very small, which makes it extremely difficult to fill the UHPC concrete densely: due to the ultra-thin precast panels and limited structural dimensions, the upper joint embedded steel bars are generally exposed in the tooth grooves of the precast panels. When pouring wet joint ultra-high performance concrete, the bottom of the steel bars is prone to looseness, resulting in weak links in the wet joint structure. There is no corresponding solution for traditional structures. Summary of the invention

[0004] The object of the present invention is to provide a connecting end structure of a UHPC bridge deck precast slab, which is convenient for installing precast bridge decks and strengthens the connection of precast bridge decks.

[0005] The technical solution adopted by the present invention to solve its technical problems is: a stepped special-shaped structure joint end is provided on any one side or 2 - 4 side surfaces of the upper part of the precast bridge deck, that is, the thickness of the joint end is less than the thickness of the middle part of the precast bridge deck. A tooth groove structure is provided on the joint end. The steel bars extending from the upper layer of the precast bridge deck in the tooth groove structure are in a partially wrapped state. The tooth groove structure, the joint end and the precast bridge deck are integrally formed by one-time pouring.

[0006] The precast bridge deck of the present invention is provided with more than two layers of steel bars inside. The steel bars all extend out of the joint end, that is, the internal steel bars extend out of the joint end according to the design requirements, which is beneficial to strengthening the joint strength during the cast-in-place joint.

[0007] The internal steel bars of the precast bridge deck of the present invention include upper joint embedded steel bars 211 and lower joint embedded steel bars 212. The upper joint embedded steel bars provided inside the precast bridge deck are radially exposed at the upper part of the joint end, that is, they are not embedded in the joint end; the stepped surface of the joint end is a special-shaped step 21, and the tooth groove structure is provided on the special-shaped step 21.

[0008] The upper joint embedded steel bars provided inside the precast bridge deck of the present invention are respectively partially wrapped by a convex platform structure 23 on the special-shaped step 21 at the upper part of the joint end, that is, the upper joint embedded steel bars are partially radially exposed on the stepped surface of the joint end, that is, they are not completely embedded in the joint end. The joint end and all the convex platform structures 23 at the upper part of the joint end are integrally formed with the precast bridge deck through a mold, so as to form a tooth groove-like structure on the stepped surface of the joint end.

[0009] The upper joint embedded steel bars provided inside the precast bridge deck of the present invention are radially exposed at the upper part of the joint end, and the steel bars are exposed at the upper part of the joint end;

[0010] Optionally, one-third of the radial direction is embedded in the precast bridge deck, and two-thirds are exposed outside the precast bridge deck, and the end part can expose the convex platform structure;

[0011] Optionally, two-thirds of the radial direction is embedded in the precast bridge deck, and one-third is exposed outside the precast bridge deck, and the end part can expose the convex platform structure;

[0012] Preferably, one-half of the radial direction is embedded in the precast bridge deck, and one-half is exposed outside the precast bridge deck, and the end part can expose the convex platform structure.

[0013] A nail 24 is set up inside the joint end of the precast bridge deck of the present invention, and the upper end part thereof is exposed outside the joint end.

[0014] The upper-layer joint embedded steel bars 211 and the lower-layer joint embedded steel bars 212 of the present invention both extend 25 - 40 cm out of the precast bridge deck.

[0015] The height of the boss structure 23 of the present invention wrapping the upper-layer joint embedded steel bar (211) is 1 / 3 - 2 / 3 of the diameter of the extended upper-layer steel bar 211, and the width of the boss structure 23 is 1 - 3 times the diameter of the upper-layer joint embedded steel bar (211);

[0016] The length of the boss structure 23 of the present invention is the length of the part of the precast bridge deck 2 wrapping the steel bar special-shaped step 21.

[0017] When casting the precast bridge deck of the present invention, a form box is arranged in the mold for precasting.

[0018] The present invention is mainly used for the construction of ultra-high performance concrete bridge decks, especially for ultra-high performance concrete bridge deck slabs.

[0019] The beneficial effects of the present invention are: the cast-in-place joint structure of the present invention is convenient for construction and simple to operate, and can efficiently complete the bridge deck paving work. Description of the Drawings

[0020] Figure 1 is a partial structural schematic diagram of the precast bridge deck of the present invention;

[0021] Figure 2 is a side structural schematic diagram of the present invention;

[0022] Figure 3 is a structural schematic diagram of the present invention installed on a bridge;

[0023] Figure 4 is a schematic diagram of half of the upper-layer joint embedded steel bar embedded in the present invention;

[0024] Figure 5 is a schematic diagram of one-third of the upper-layer joint embedded steel bar embedded in the present invention;

[0025] Figure 6 is a schematic diagram of two-thirds of the upper-layer joint embedded steel bar embedded in the present invention.

[0026] In the figure: 1 - bridge, 2 - precast bridge deck, 21 - longitudinal panel, 22 - transverse panel, 23 - boss structure, 24 - upright nail, 211 - upper-layer joint embedded steel bar, 212 - lower-layer joint embedded steel bar. Detailed Description of the Embodiment

[0027] The following further describes the present invention in detail with reference to the drawings and embodiments.

[0028] Embodiment 1, refer to Figures 1 to 6, on either side or 2 - 4 sides of the upper part of the precast bridge deck, there is a joint end with a stepped special-shaped structure, that is, the thickness of the joint end is less than the thickness of the middle part of the precast bridge deck. A tooth groove structure is provided on the joint end, and the steel bars of the upper layer extending out of the precast bridge deck in the tooth groove structure are partially wrapped. The tooth groove structure, the joint end and the precast bridge deck are integrally formed by in-situ casting at one time.

[0029] Example 2, refer to Figures 1 to 6 , the internal steel bars of the precast bridge deck of the present invention extend out of the joint end, that is, the internal steel bars extend out of the joint end according to the design requirements, which is beneficial to strengthening the joint strength during in-situ casting of the joint. The rest is the same as Example 1.

[0030] Example 3, refer to Figures 1 to 6 , the upper joint embedded steel bars provided inside the precast bridge deck of the present invention are radially exposed above the joint end, that is, they are not embedded in the joint end. The stepped surface of the joint end is a special-shaped step 21, and the tooth groove structure is provided on the special-shaped step 21. The rest is the same as the above-mentioned examples.

[0031] Example 4, refer to Figures 1 to 6 , the upper joint embedded steel bars provided inside the precast bridge deck of the present invention are respectively partially wrapped by the convex platform structure 23 on the special-shaped step 21 above the joint end, that is, the upper joint embedded steel bars are partially radially exposed on the stepped surface of the joint end, that is, they are not completely embedded in the joint end. All the joint ends and the convex platform structures 23 above the joint ends are integrally formed with the precast bridge deck through a mold by in-situ casting at one time, so that the stepped surface of the joint end forms a longitudinal tooth groove-like structure. The rest is the same as the above-mentioned examples.

[0032] Example 5, refer to Figures 1 to 6 , the upper joint embedded steel bars provided inside the precast bridge deck of the present invention are radially exposed above the joint end, and the steel bars are exposed above the joint end. The rest is the same as the above-mentioned examples.

[0033] Example 6, refer to Figures 1 to 6 , optionally, one-third of the radial direction can be embedded in the precast bridge deck, and two-thirds can be exposed outside the precast bridge deck, and the end can expose the convex platform structure;

[0034] Optionally, two-thirds of the radial direction can be embedded in the precast bridge deck, and one-third can be exposed outside the precast bridge deck, and the end can expose the convex platform structure;

[0035] Preferably, one-half of the radial direction is embedded in the precast bridge deck, and one-half is exposed outside the precast bridge deck, and the end can expose the convex platform structure. The rest is the same as the above-mentioned examples.

[0036] Example 7, refer to Figures 1 to 6 , the upper end of the internal stud provided in the precast bridge deck of the present invention is exposed outside the joint end. The rest is the same as the above-mentioned examples.

[0037] Example 8, refer to Figures 1 to 6 , formation of the step: When casting the in-situ precast bridge deck, a form box is arranged in the mold, and it is precast. The rest is the same as the above embodiments.

[0038] Example 9, refer to Figures 1 to 6 , the upper layer of steel bars inside the precast bridge deck of the present invention extends out of the bottom plane of the L-shaped step, and a partially wrapped state is formed between the outer edge of the extended upper layer of steel bars and the bottom plane of the L-shaped step. The upper layer of steel bars inside the precast bridge deck is partially wrapped by the UHPC convex platform structure at the joint end, that is, the upper layer of steel bars is partially radially exposed on the L-shaped step surface at the joint end, that is, it is not completely embedded in the joint end. All the L-shaped convex platform structures at the upper part of the joint end are formed by casting in one go through the mold when precasting the bridge deck. The longitudinal tooth-shaped structure formed on the L-shaped step surface at the joint end and the UHPC precast slab become an integral structure. The upper end of the internal stud in the precast bridge deck is exposed out of the L-shaped step plane. The rest is the same as the above embodiments.

Claims

1. A connecting end structure of a precast slab for a UHPC bridge deck, characterized in that: On either side or on 2 - 4 sides of the upper part of the precast bridge deck, there is a joint end with a stepped special-shaped structure, that is, the thickness of the joint end is less than the thickness of the middle part of the precast bridge deck. A tooth groove structure is provided on the joint end. The steel bars of the upper extension layer of the precast bridge deck in the tooth groove structure are in a partially wrapped state. The tooth groove structure, the joint end and the precast bridge deck are an integral body formed by one-time pouring.

2. The connecting end structure of the UHPC bridge deck precast slab according to claim 1, characterized in that: The internal steel bars of the precast bridge deck extend out of the joint end.

3. The connecting end structure of the UHPC bridge deck precast slab according to claim 1, characterized in that: The internal steel bars of the precast bridge deck include upper joint embedded steel bars (211) and lower joint embedded steel bars (212). The upper joint embedded steel bars inside the precast bridge deck are radially exposed at the upper part of the joint end. The stepped surface of the joint end is a special-shaped step (21), and the tooth groove structure is arranged on the special-shaped step (21).

4. The connecting end structure of the UHPC bridge deck precast slab according to claim 3, characterized in that: The upper joint embedded steel bars inside the precast bridge deck are partially wrapped by the boss structures (23) on the special-shaped step (21) at the upper part of the joint end, that is, the upper joint embedded steel bars are partially radially exposed on the stepped surface of the joint end, that is, they are not completely embedded in the joint end. All the boss structures (23) at the joint end and the upper part of the joint end are formed by one-time pouring with the precast bridge deck through a mold, so that the stepped surface of the joint end forms a tooth groove-like structure.

5. The connecting end structure of the UHPC bridge deck precast slab according to claim 1, characterized in that: A nail (24) is set inside the joint end of the precast bridge deck, and the upper end of the nail exposes out of the joint end.

6. The connecting end structure of the UHPC bridge deck precast slab according to claim 4, characterized in that: Both the upper joint embedded steel bars (211) and the lower joint embedded steel bars (212) extend out of the precast bridge deck (2) by 5 - 40 cm.

7. The connecting end structure of the UHPC bridge deck precast slab according to claim 4, characterized in that: The height of the boss structure (23) wrapping the extended upper joint embedded steel bar (211) is 1 / 3 - 2 / 3 of the diameter of the extended upper joint embedded steel bar (211), and the width of the boss structure (23) is 1 - 3 times the diameter of the extended upper joint embedded steel bar (211).

8. The connecting end structure of the UHPC bridge deck precast slab according to claim 4, characterized in that: The length of the boss structure (23) is the length of the special-shaped step (21) of the precast bridge deck (2) that partially wraps the steel bars.

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