A T-shaped special-shaped wet joint structure between precast UHPC bridge decks

Abstract

A T-shaped special-shaped wet joint structure between precast UHPC bridge deck slabs, which mainly solves the technical problem of complex connection of bridge deck slabs. The key points of its technical solution are as follows: A joint end with a stepped structure is set on any one side or 2-4 side surfaces 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, and the joint end and the precast bridge deck slab are an integrally cast-in-place whole; there is a clearance fit between two adjacent precast bridge deck slabs of the joint. Since the corresponding joint ends of two adjacent precast bridge deck slabs are stepped structures, a T-shaped space structure is formed between two adjacent precast bridge deck slabs, and a T-shaped cast-in-place joint structure is formed by casting concrete. It is mainly used for manufacturing bridge deck slabs.

Description

Technical Field

[0001] The present invention relates to a T-shaped special-shaped wet joint structure between precast slabs for UHPC bridge decks. Background Art

[0002] As an important part of the bridge structure, the bridge deck not only bears the direct action of vehicle loads but also provides a working surface for the paving structure above it. It is the component most directly affected by adverse factors such as overloading, corrosion, and fatigue. Therefore, its working state will directly affect the service life of the main bridge structure and the driving comfort. In the traditional steel-concrete bridge deck composite structure, ordinary concrete is used for the bridge deck. Due to the relatively low tensile strength of concrete, the slab thickness is relatively large, the structural self-weight is relatively large, it is difficult to meet the requirements of long-span bridge main girders, and it is easy to crack near wet joints, negative moment areas, stay cable anchorage areas, etc., affecting the service life of the main bridge structure and the paving structure. Ultra-high performance concrete has the advantages of high elastic modulus, high compressive and tensile strength, and good creep characteristics. (Using precast ultra-high performance concrete to make the bridge deck) can reduce the structural size, reduce the structural self-weight, improve the effectiveness of the structure to resist loads and increase the spanning ability, and at the same time provide a good working surface for the paving structure.

[0003] At present, the rapid construction technology of assembled prefabrication 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 received attention and have been gradually developed and applied in prefabricated assembly technology due to their light weight and high strength. However, in terms of ultra-high performance concrete precast bridge decks, there is no engineering application experience in China. Due to the ultra-thin precast components of ultra-high performance concrete and the dense reinforcement in the slab, it brings two major problems to the construction of cast-in-place wet joints. The first problem is the influence of the dense reinforcement reserved in the wet joint. There are two traditional methods: one is to reserve circular reinforcement in the precast slab and connect the circular reinforcement reserved in two adjacent precast slabs to ensure the effective connection of the wet joint. However, due to the existence of the circular reinforcement, it is difficult to install and disassemble the formwork of the precast slab, and when removing the formwork, it is easy to damage the component; the other is to reserve enough long reinforcement in the precast slab, and the reserved reinforcement is connected into a whole by binding or welding to ensure the effective connection of the wet joint. Due to the dense reinforcement in the slab, when installing the precast slab, the reinforcement in adjacent precast slabs is prone to overlap and cross, bringing difficulties to the installation of the precast slab. The second problem is the problem of the bottom void of the reserved reinforcement. Since the precast slab is ultra-thin, generally the upper reinforcement is exposed in the tooth grooves of the precast slab. When pouring the ultra-high performance concrete of the wet joint, it is very difficult to compact the bottom of the reinforcement, resulting in weak links in the wet joint structure, and there is no corresponding solution in the traditional structure. Summary of the Invention

[0004] The purpose of the present invention is to provide a T-shaped cast-in-place joint structure that is convenient for installing and disassembling 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 as follows: on any one side, or on 2 - 4 side surfaces 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 extending from the upper layer 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 an integral formed by one-time casting; there is a clearance fit between two adjacent precast bridge decks of the joint. Since the corresponding joint ends of two adjacent precast bridge decks are stepped structures, a T-shaped space structure is formed between two adjacent precast bridge decks, and a T-shaped cast-in-place joint structure is formed by cast-in-place concrete.

[0006] Two UHPC bridge deck precast slabs with a stepped structure in which the steel bars are partially wrapped are lapped on the same steel beam at the joint end of the present invention. There is a gap of 10 - 60 cm between the two UHPC bridge deck precast slabs. The steel beam slab is below this gap. 1 - 3 rows of vertical stud bolts are welded on the steel beam slab to form a T-shaped special-shaped space structure; a tooth groove structure is provided on the joint end of the UHPC bridge deck precast slab. The steel bars extending from the upper layer 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 an integral preformed by one-time; longitudinal reinforcing bars (4) in the same direction as the extending steel bars of the UHPC bridge deck precast slab and transverse steel bars in a direction perpendicular thereto are arranged in the T-shaped special-shaped space. The longitudinal reinforcing bars are arranged in parallel with the gap of the extending steel bars of the UHPC bridge deck precast slab without any welding. A cast-in-place joint structure is formed by cast-in-place UHPC concrete to transfer the tensile force meeting the design requirements.

[0007] 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 cast-in-place joint.

[0008] The internal steel bars of the precast bridge deck of the present invention include two or more upper-layer joint embedded steel bars and two or more lower-layer joint embedded steel bars. Both the upper-layer joint embedded steel bars and the lower-layer joint embedded steel bars extend out of the precast bridge deck by 2 to the T-shaped cast-in-place joint 3. The upper-layer joint embedded steel bars of two adjacent precast bridge decks 2 correspond to each other, and the lower-layer joint embedded steel bars correspond to each other. Both the upper-layer joint embedded steel bars and the lower-layer joint embedded steel bars extend into the cast-in-place joint of the T-shaped special-shaped space. The positions of the upper-layer joint embedded steel bars of two adjacent precast bridge decks (2) correspond to each other, and the positions of the lower-layer joint embedded steel bars also correspond to each other.

[0009] 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 inside the precast bridge deck are radially exposed at the upper part of the joint end, that is, they are not embedded inside 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.

[0010] The upper joint embedded steel bars inside the precast bridge deck of the present invention are radially exposed at the upper part of the joint end, and the stepped surface of the joint end is a special-shaped step 21; the upper steel bars inside the precast bridge deck are partially wrapped by the boss structures 23 at the upper part of the joint end, that is, the upper steel bars are radially exposed at the upper part of the stepped surface of the joint end, that is, they are not completely embedded inside 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 casting 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.

[0011] A joint strengthening steel bar 4 is arranged between two adjacent upper joint embedded steel bars and the corresponding two upper joint embedded steel bars or between two lower joint embedded steel bars and the corresponding two lower joint embedded steel bars. The length of the joint strengthening steel bar 4 is the width of the T-shaped cast-in-place joint 3.

[0012] The longitudinal steel bar strengthening steel bar (4) with the same direction of two adjacent upper joint embedded and extended steel bars of the present invention is arranged in the middle of the two joint embedded and extended steel bars. The length of the joint strengthening steel bar (4) is more than 1 mm less than the width of the T-shaped special-shaped space.

[0013] Both the upper joint embedded steel bars 211 and the lower joint embedded steel bars 212 of the present invention extend out of the precast bridge deck by 25 - 40 cm. The upper joint embedded steel bars 211 and the lower joint embedded steel bars 212 of two adjacent precast bridge decks 2 correspond to each other, and the docking gap is not less than 10 mm and not more than 50 mm.

[0014] The semi-wrapped special-shaped step 21 of the present invention is provided with upright nails 24. The exposed height of the upright nails 24 is not less than 5 mm and not more than 40 mm.

[0015] The interval between two adjacent precast bridge decks 2 of the present invention is 5 - 40 cm.

[0016] 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. The width of the boss structure 23 is 1 - 3 times the diameter of the extended upper joint embedded steel bar 211; the length of the boss structure 23 is the length of the part of the precast bridge deck 2 wrapping the steel bar special-shaped step 21.

[0017] The upper joint embedded steel bars provided in the precast bridge deck of the present invention are respectively partially wrapped by the convex platform structures 23 on the special-shaped steps 21 at the upper part of the joint end, that is, the upper joint embedded steel bars are radially exposed on the step surface at the joint end, that is, they are not completely embedded in the joint end. All the convex platform structures 23 at the joint end and the upper part of the joint end are integrally cast with the precast bridge deck through a mold, so that the step surface at the joint end forms a longitudinal tooth-shaped groove structure.

[0018] The upper joint embedded steel bars provided in 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;

[0019] Optionally, one-third of the diameter is embedded in the precast bridge deck, and two-thirds are exposed outside the precast bridge deck, and the end can expose the convex platform structure;

[0020] Optionally, two-thirds of the diameter is embedded in the precast bridge deck, and one-third is exposed outside the precast bridge deck, and the end can expose the convex platform structure;

[0021] Preferably, one-half of the diameter 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.

[0022] The beneficial effects of the present invention are:

[0023] 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 laying work. Description of the Drawings

[0024] Figure 1 It is a partial structural schematic diagram of the precast bridge deck of the present invention;

[0025] Figure 2 It is a side view of the present invention;

[0026] Figure 3 It is a structural schematic diagram of the present invention arranged on the main beam;

[0027] Figure 4 It is a top view of the present invention;

[0028] Figure 5 It is a structural schematic diagram of the present invention forming a T-shaped cast-in-place joint;

[0029] Figure 6 It is a structural schematic diagram of the present invention with the bridge deck completely laid;

[0030] Figure 7 It is a schematic diagram of one-half embedding of the upper joint embedded steel bars of the present invention;

[0031] Figure 8 It is a schematic diagram of one-third embedding of the upper joint embedded steel bars of the present invention;

[0032] Figure 9 It is a schematic diagram of embedding two-thirds of the upper joint embedded steel bars of the present invention.

[0033] In the figure: 1 - bridge, 2 - precast bridge deck, 21 - special-shaped step, 211 - upper joint embedded steel bar, 212 - lower joint embedded steel bar, 3 - T-shaped cast-in-place joint, 24 - vertical nail, 4 - joint reinforcement bar, 211' - upper joint embedded steel bar of adjacent precast bridge decks, 212' - lower joint embedded steel bar of adjacent precast bridge decks. Specific embodiments

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0035] Example 1, referring to Figures 1 to 9 , the present invention includes a steel beam and multiple precast bridge decks erected on the steel beam, and is characterized in that: a cuboid is removed from the upper end side of the precast bridge deck to form a tooth groove; a T-shaped cast-in-place joint is formed at intervals between adjacent two precast bridge decks; a plurality of upper joint embedded steel bars and a plurality of lower joint embedded steel bars are arranged along the bridge deck on the precast bridge deck; a ultra-high performance concrete structural block is provided on the tooth groove, and the ultra-high performance concrete structural block wraps one-third to two-thirds of the upper joint embedded steel bars; ultra-high performance concrete is cast in the T-shaped cast-in-place joint; adjacent two precast bridge decks are connected into a whole through ultra-high performance concrete.

[0036] Example 2, referring to Figures 1 to 9 , the ultra-high performance concrete protection block of the present invention wraps two-thirds of the upper joint embedded steel bar 211, and the rest is the same as the above embodiment.

[0037] Example 3, referring to Figures 1 to 9 , the ultra-high performance concrete protection block of the present invention wraps one-third of the upper joint embedded steel bar 211, and the rest is the same as the above embodiment.

[0038] Example 4, referring to Figures 1 to 9 , preferably, the ultra-high performance concrete protection block of the present invention wraps one-half of the upper joint embedded steel bar, and the rest is the same as the above embodiment.

[0039] Example 5, referring to Figures 1 to 9 , the upper joint embedded steel bar and the lower joint embedded steel bar of the present invention both extend out of the precast bridge deck into the T-shaped cast-in-place joint, and the upper joint embedded steel bars and the lower joint embedded steel bars of adjacent two precast bridge decks correspond to each other and are not tied or welded, and the rest is the same as the above embodiment.

[0040] Example 6, referring to Figures 1 to 9 , the height of the tooth groove at the upper end of the precast bridge deck of the present invention is 3 - 7 cm and the width is 5 - 20 cm, and the rest is the same as the above embodiment.

[0041] Example 7, refer to Figures 1 to 9 , the interval between two adjacent precast bridge decks of the present invention is 5 - 40 cm, and the rest is the same as the above embodiments.

[0042] Example 8, refer to Figures 1 to 9 , both the upper joint embedded steel bars and the lower joint embedded steel bars of the present invention extend out of the precast bridge deck by 25 - 40 cm, and the rest is the same as the above embodiments.

[0043] Example 9, refer to Figures 1 to 9 , the width of the ultra-high performance concrete structural block of the present invention is 1 - 3 times greater than the diameter of the upper joint embedded steel bar, and the length of the ultra-high performance concrete structural block is the width of the tooth groove at the upper end of the precast bridge deck, and the rest is the same as the above embodiments.

[0044] Example 10, refer to Figures 1 to 9 , the main beam of the present invention includes a T-shaped steel composite beam, a steel box composite beam, an I-shaped steel composite beam or a steel truss composite beam, and the rest is the same as the above embodiments.

[0045] Example 11, refer to Figures 1 to 9 , one or more stud bolts are provided on the tooth groove of the precast bridge deck of the present invention, and the rest is the same as the above embodiments.

[0046] Example 12, refer to Figures 1 to 9 , a joint strengthening steel bar is placed parallel in the middle between two adjacent upper joint embedded steel bars or two adjacent lower joint embedded steel bars. The joint strengthening steel bars are respectively placed in the middle between two adjacent upper joint embedded steel bars or two adjacent lower joint embedded steel bars of the precast bridge deck. The length of the joint strengthening steel bar is the width of the T-shaped cast-in-place joint, and the rest is the same as the above embodiments.

[0047] Example 13, a T-shaped special-shaped wet joint structure between UHPC bridge deck precast slabs, includes a steel beam, multiple UHPC precast bridge decks erected on the steel beam, and cast-in-place UHPC formed by the interval between two adjacent UHPC precast slabs. It is characterized in that: the precast bridge deck includes a semi-wrapped steel bar special-shaped step. The semi-wrapped steel bar special-shaped step, the upper plane of the steel beam, the steel beam extended stud bolt, the gap between two adjacent precast bridge decks, the extended upper steel bar of the precast bridge deck, the extended lower steel bar of the precast bridge deck, the extended stud bolt on the semi-wrapped special-shaped step of the precast bridge deck, the strengthening steel bar, and the cast-in-place UHPC form a T-shaped cast-in-place joint; the semi-wrapped steel bar special-shaped step of the UHPC precast bridge deck is composed of multiple UHPC structural blocks, the extended upper steel bar and the extended stud bolt semi-wrapped by the UHPC structural blocks to form a regular concave-convex step. The extended upper steel bars and the extended lower steel bars of two adjacent precast bridge decks are butt-jointed one by one. The strengthening steel bars are placed out of position on both sides and do not need to be tied (or welded). After pouring the cast-in-place UHPC, two adjacent precast bridge decks are connected into a whole.

Claims

1. A T-shaped special-shaped wet joint structure between precast UHPC bridge decks, characterized in that: Two UHPC bridge deck precast slabs with a stepped structure partially wrapped by steel bars at the joint ends are lapped on the same steel beam. There is a 10 - 60 cm gap between the two UHPC bridge deck precast slabs. Under this gap is the steel beam plate, and 1 - 3 rows of vertical stud bolts are welded on the steel beam plate to form a T-shaped special-shaped space structure; a tooth groove structure is provided at the joint end of the UHPC bridge deck precast slab. In the tooth groove structure, the steel bars extending out of the upper layer of the precast bridge deck are partially wrapped. The tooth groove structure, the joint end and the precast bridge deck are an integrally precast and formed whole; in the T-shaped special-shaped space, joint strengthening steel bars in the same direction as the steel bars extending out of the UHPC bridge deck precast slab and transverse steel bars in the direction perpendicular to it are arranged. The joint strengthening steel bars are arranged in parallel with the gap between the steel bars extending out of the UHPC bridge deck precast slab without any welding. Through cast-in-place UHPC concrete, a cast-in-place joint structure is formed. The upper-layer joint embedded steel bars provided in the precast bridge deck are radially exposed at the upper part of the steel bars at 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); the upper-layer steel bars provided in the precast bridge deck are partially wrapped by the boss structures (23) respectively at the upper part of the joint end, that is, the upper-layer steel bars are radially exposed at the upper part of the stepped surface of the joint end. All the boss structures (23) at the joint end and the upper part of the joint end are formed by casting with the precast bridge deck in one time through a mold, so that the stepped surface of the joint end forms a tooth groove-like structure.

2. The T-shaped special-shaped wet joint structure between the UHPC bridge deck precast slabs according to claim 1, characterized in that: The internal steel bars of the precast bridge deck include two or more upper-layer joint embedded steel bars and two or more lower-layer joint embedded steel bars. Both the upper-layer joint embedded steel bars and the lower-layer joint embedded steel bars extend into the cast-in-place joint in the T-shaped special-shaped space. The positions of the upper-layer joint embedded steel bars of two adjacent precast bridge decks (2) correspond to each other, and the positions of the lower-layer joint embedded steel bars also correspond to each other.

3. The T-shaped special-shaped wet joint structure between the UHPC bridge deck precast slabs according to claim 1, characterized in that: The joint strengthening steel bars with the same direction for two adjacent upper-layer joint embedded and extended steel bars are arranged in the middle of the two joint embedded and extended steel bars. The length of the joint strengthening steel bar (4) is more than 1 mm less than the width of the T-shaped special-shaped space.

4. The T-shaped special-shaped wet joint structure between the precast UHPC bridge decks according to claim 3, characterized in that: Both the upper-layer joint embedded steel bars (211) and the lower-layer joint embedded steel bars (212) extend 5 - 40 cm out of the precast bridge deck (2). The upper-layer joint embedded steel bars (211) and the lower-layer joint embedded steel bars (212) of two adjacent precast bridge decks (2) correspond to each other, and the butt joint gap is not less than 10 mm and not more than 50 mm.

5. The T-shaped special-shaped wet joint structure between precast UHPC bridge decks according to claim 1, characterized in that: Vertical nails (24) are provided on the semi-wrapped special-shaped step (21). The exposed height of the vertical nails (24) is not less than 5 mm and not more than 40 mm.

6. The T-shaped special-shaped wet joint structure between precast UHPC bridge decks according to claim 1, characterized in that: The interval between two adjacent precast bridge decks (2) is 5 - 40 cm.

7. The T-shaped special-shaped wet joint structure between the precast UHPC bridge decks according to claim 1, characterized in that: The height of the boss structure (23) wrapping the extended upper-layer joint embedded steel bar (211) is 1 / 3 - 2 / 3 of the diameter of the extended upper-layer joint embedded steel bar (211). The width of the boss structure (23) is 1 - 3 times the diameter of the extended upper-layer joint embedded steel bar (211); the length of the boss structure (23) is the length of the partially wrapped steel bar special-shaped step (21) of the precast bridge deck (2).

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