A low-shrinkage formwork-free bridge deck joint structure and construction method

Abstract

The present invention provides a low-shrinkage formwork-free bridge deck joint structure and construction method. The low-shrinkage formwork-free bridge deck joint structure includes a plurality of precast beams, with a joint space reserved between two adjacent precast beams; a precast block, the precast block is installed in the joint space, and a pouring space is reserved between the precast block and two adjacent precast beams; a plurality of first ring bars, the first ring bars are installed in the precast beams, and both sides of the first ring bars extend outside the precast beams; a plurality of second ring bars, the second ring bars are installed in the precast blocks, and both sides of the second ring bars extend outside the precast blocks, and the second ring bars are staggered with the first ring bars. The low-shrinkage formwork-free bridge deck joint structure and construction method provided by the present invention have the advantages of formwork-free construction, simple process, small amount of cast-in-place joints, and reasonable structure.

Description

Technical Field

[0001] The invention relates to the technical field of construction, and in particular to a low-shrinkage formwork-free bridge deck joint structure and a construction method. Background Art

[0002] Conventional precast concrete bridges can be divided into precast small box beams, precast T beams, precast composite beams, etc. according to the cross-section. They are usually constructed by precasting in pieces, with the flanges of the precast beams extending out to connect the steel bars, and then pouring the cast-in-place joints, that is, using the structural wet joint treatment method, such as Figure 1 shown.

[0003] The structural wet joint treatment method has the following problems:

[0004] 1. The joint reinforcement is tied on site, which requires a lot of field work;

[0005] 2. The joint concrete is cast in situ, and the age is quite different from that of the precast beam, which is prone to shrinkage cracks along the joint interface;

[0006] 3. The joint is located in the positive bending moment area, and the lower edge is under tension. The quality of the joint directly affects the safety and durability of the structure.

[0007] 4. The quality of cast-in-place is uncontrollable and there is late shrinkage. The joint is at the position of maximum positive bending moment and the stress is very critical, so it is necessary to improve it.

[0008] The conventional improvement plan is to change cast-in-place concrete to cast-in-place UHPC (ultra-high performance concrete). The demand for UHPC is large and the project cost increases significantly.

[0009] Therefore, it is necessary to provide a new low-shrinkage formwork-free bridge deck joint structure and construction method to solve the above technical problems. Summary of the invention

[0010] The technical problem solved by the invention is to provide a low-shrinkage formwork-free bridge deck joint structure and construction method which is formwork-free, has simple procedures, a small amount of cast-in-place joints, and a reasonable structure.

[0011] In order to solve the above technical problems, the present invention provides a low-shrinkage formwork-free bridge deck joint structure comprising: a plurality of precast beams, the plurality of precast beams are arranged at intervals along the length direction of the bridge, and a joint space is reserved between two adjacent precast beams; a first annular rib is embedded in the precast beam, and the first annular rib comprises a first arc-shaped force-bearing section extending from the precast beam and into the joint space;

[0012] A prefabricated block, the prefabricated block is installed in the joint space, and a pouring space is reserved between the prefabricated block and the prefabricated beam; a second annular rib is embedded in the prefabricated block, the second annular rib includes a second arc-shaped force-bearing section extending from the prefabricated block and extending into the pouring space; the second arc-shaped force-bearing section overlaps and is fixedly connected with the first arc-shaped force-bearing section in the pouring space; a hollow embedded sleeve is also embedded in the prefabricated block, and the embedded sleeve passes through the prefabricated block in a vertical direction;

[0013] A UHPC grouting layer is formed by pouring UHPC concrete in the pouring space to wrap the first arc-shaped stress-bearing section and the second arc-shaped stress-bearing section, and connect the prefabricated block and the prefabricated beam as a whole.

[0014] Preferably, a fixing device is installed on the prefabricated block, and the fixing device is in contact with the two prefabricated beams on both sides of the prefabricated block.

[0015] Preferably, the fixing device includes a first screw rod, a first rod clamp is installed on the first screw rod, the bottom end of the first screw rod passes through the embedded sleeve and is threadedly installed with a nut assembly, the nut assembly is in contact with the prefabricated block, the first rod clamp is sleeved with a cross bar, two second rod clamps are symmetrically sleeved on the cross bar, the second rod clamp is sleeved with a second screw rod, the bottom end of the second screw rod is installed with a rod seat, and the rod seat is in contact with the corresponding prefabricated beam.

[0016] Preferably, the prefabricated block is in an inverted T-shape, and comprises a strip and a flange, a plurality of longitudinal ribs are arranged inside the strip, and transverse ribs are arranged inside the flange.

[0017] Preferably, the length of the two ends of the longitudinal reinforcement extending from the two sides of the prefabricated block is greater than the anchoring length.

[0018] Preferably, the first annular rib and the second annular rib each include two straight segments and two arc segments, and the two straight segments are parallel to each other.

[0019] Preferably, a grout-stopping strip is provided on the top side of the flange, and the contact surfaces between the side surface of the strip, the top surface of the flange and the UHPC grouting layer are all roughened surfaces.

[0020] Preferably, the first screw and the second screw both include a lower screw, a thread groove is formed on the top side of the lower screw, an inner screw is threadedly mounted in the thread groove, the bottom end of the inner screw extends out of the thread groove and is rotatably sleeved with an upper screw, a handle is fixedly sleeved on the inner screw, and an anti-slip groove is provided on the handle.

[0021] Preferably, a groove is provided at the bottom end of the upper screw rod, a plurality of bearings are installed in the groove, the inner ring of the bearing is fixedly sleeved with the inner screw rod, the first rod clamp and the second rod clamp are both sleeved with the upper screw rod, and the rod seat is connected to the lower screw rod.

[0022] A construction method for a low-shrinkage formwork-free bridge deck joint structure, characterized in that it comprises the following steps:

[0023] S1: erect the precast beams in place and roughly place the precast blocks in place;

[0024] S2: By adjusting the height of the rod clamp, the height, angle and tightness of the prefabricated block and the prefabricated beam can be adjusted;

[0025] S3: Casting joint UHPC grouting after precise positioning;

[0026] S4: After the UHPC grouting reaches the required strength, loosen and remove the nut assembly, and the fixture can be moved to the next work site for reuse.

[0027] Compared with the related art, the low-shrinkage formwork-free bridge deck joint structure and construction method provided by the present invention have the following beneficial effects:

[0028] 1. No formwork required for construction, simple process;

[0029] 2. The amount of cast-in-place joints is small, and small construction machines and tools can meet the requirements;

[0030] 3. The part with the largest bending moment is the prefabricated structure, and the stress-bearing performance is reliable;

[0031] 4. The bending moment at the cast-in-place joint is close to 0, and the structure is more reasonable;

[0032] 5. Compared with full UHPC joints, the amount of UHPC is small and economical;

[0033] 6. The fixtures used for construction are reusable and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a structural schematic diagram of the treatment method of structural wet joints;

[0035] Figure 2 A structural schematic diagram of a preferred embodiment of the low-shrinkage formwork-free bridge deck joint structure provided by the present invention;

[0036] Figure 3 for Figure 2 Schematic diagram of the A region structure;

[0037] Figure 4 It is a structural schematic diagram of a prefabricated block;

[0038] Figure 5 This is a schematic structural diagram of a second embodiment of the low-shrinkage formwork-free bridge deck joint structure provided by the present invention.

[0039] Numbers in the figure: 1. precast beam, 2. first ring reinforcement, 3. precast block, 4. second ring reinforcement, 5. UHPC grouting, 6. embedded casing, 7. first screw rod, 8. first rod clamp, 9. cross bar, 10. nut assembly, 11. second rod clamp, 12. second screw rod, 13. rod seat, 14. grouting stop strip, 15. longitudinal reinforcement, 16. transverse reinforcement, 17. roughened surface, 18. lower screw rod, 19. threaded groove, 20. inner screw rod, 21. handle, 22. anti-slip groove, 23. upper screw rod, 24. groove, 25. bearing. DETAILED DESCRIPTION

[0040] The present invention will be further described below in conjunction with the accompanying drawings and implementation modes.

[0041] First embodiment:

[0042] Please refer to Figure 1-Figure 4 In the first embodiment of the present invention, the low-shrinkage formwork-free bridge deck joint structure comprises: a plurality of precast beams 1, the plurality of precast beams 1 are arranged at intervals along the length direction of the bridge, and a joint space is reserved between two adjacent precast beams 1; a first annular reinforcement 2 is embedded in the precast beam, and the first annular reinforcement 2 comprises a first arc-shaped force-bearing section extending from the precast beam 1 and extending into the joint space;

[0043] A prefabricated block 3, wherein the prefabricated block 3 is installed in the joint space, and a pouring space is reserved between the prefabricated block 3 and the prefabricated beam 1; a second annular rib 4 is embedded in the prefabricated block 3, and the second annular rib 4 includes a second arc-shaped force-bearing section extending from the prefabricated block 3 and extending into the pouring space; the second arc-shaped force-bearing section overlaps and is fixedly connected with the first arc-shaped force-bearing section in the pouring space; a hollow embedded sleeve 6 is also embedded in the prefabricated block 3, and the embedded sleeve 6 passes through the prefabricated block 3 in the vertical direction;

[0044] A UHPC grouting layer 5 is formed by pouring UHPC concrete in the pouring space to wrap the first arc-shaped stress-bearing section and the second arc-shaped stress-bearing section, and connect the precast block 3 and the precast beam 1 as a whole.

[0045] The first annular reinforcement 2 and the second annular reinforcement 4 extend to the UHPC grouting layer 5 at both ends in order to strengthen the connection strength between the prefabricated beam 1 and the prefabricated block 3 and make the prefabricated block 3 more stable.

[0046] The UHPC grouting layer 5 is made of UHPC concrete grouting. UHPC concrete is ultra-high performance concrete, referred to as UHPC (Ultra-High Performance Concrete), also known as reactive powder concrete (RPC). UHPC concrete is an ultra-high strength cement-based material with high strength, high toughness and low porosity. Its basic preparation principle is: by improving the fineness and activity of the components and not using coarse aggregates, the defects (pores and micro cracks) inside the material are minimized to obtain ultra-high strength and high durability.

[0047] A fixing device is installed on the prefabricated block 3, and the fixing device is in contact with the two prefabricated beams 1 on both sides of the prefabricated block 3. The fixing device is used to fix the prefabricated block 3 in the joint space before the UHPC concrete solidifies.

[0048] The fixing device includes a first screw rod 7, a first rod clamp 8 is installed on the first screw rod 7, the bottom end of the first screw rod 7 passes through the embedded sleeve 6 and is threadedly installed with a nut assembly 10, the nut assembly 10 is in contact with the prefabricated block 3, a cross bar 9 is sleeved on the first rod clamp 8, two second rod clamps 11 are symmetrically sleeved on the cross bar 9, a second screw rod 12 is sleeved on the second rod clamp 11, a rod seat 13 is installed at the bottom end of the second screw rod 12, and the rod seat 13 is in contact with the corresponding prefabricated beam 1.

[0049] The prefabricated block 3 is in an inverted T shape, and includes a strip and a flange. A plurality of longitudinal ribs 15 are arranged inside the strip, and transverse ribs 16 are arranged inside the flange. The inverted T shape of the prefabricated block 3 is to prevent the grouting concrete from leaking from the bottom side of the pouring space before solidification.

[0050] The length of the two ends of the longitudinal reinforcement 15 extending out of the two sides of the prefabricated block 3 is greater than the anchoring length.

[0051] The first annular rib 2 and the second annular rib 4 each include two straight segments and two arc segments, the two straight segments are parallel to each other, and two ends of the arc segment are fixedly connected to the two straight segments respectively.

[0052] The low-shrinkage formwork-free bridge deck joint construction method provided by the present invention is:

[0053] S1: erecting the precast beam 1 in place and roughly placing the precast block 3 in place;

[0054] S2: By adjusting the height of the rod clamp, the height and angle of the prefabricated block 3 and the tightness matching the prefabricated beam 1 are adjusted;

[0055] S3: Casting joint UHPC grouting after precise positioning;

[0056] S4: After the UHPC grouting reaches the required strength, the nut assembly 10 is loosened and removed, and the fixture can be moved to the next work site for reuse.

[0057] The working principle of the low-shrinkage formwork-free bridge deck joint structure provided by the present invention is as follows:

[0058] First, the prefabricated beam 1 is erected in place, and a joint space is reserved between two adjacent prefabricated beams 1. The prefabricated block 3 is roughly in place, that is, the prefabricated block 3 is placed in the corresponding joint space, and a pouring space is reserved between the prefabricated block 3 and the two adjacent prefabricated beams 1. Then, the fixing device is installed, that is, the first screw rod 7 is inserted into the embedded sleeve 6, and the nut assembly 10 is installed on the bottom end of the first screw rod 7. Then, the first rod clamp 8, the cross bar 9, the nut assembly 10, the second rod clamp 11, the second screw rod 12, and the rod seat 13 are assembled. By adjusting the height of the first rod clamp 8 and the second rod clamp 11, the height, angle and tightness of the prefabricated block 3 are adjusted to match the prefabricated beam. After precise positioning, UHPC grouting is poured into the pouring space. After the UHPC grouting reaches the strength after curing, the nut assembly 10 is loosened and removed, and the fixing device can be moved to the next work site for reuse.

[0059] Compared with the related art, the low-shrinkage formwork-free bridge deck joint structure and construction method provided by the present invention have the following beneficial effects:

[0060] 1. No formwork required for construction, simple process;

[0061] 2. The amount of cast-in-place joints is small, and small construction machines and tools can meet the requirements;

[0062] 3. The part with the largest bending moment is the prefabricated structure, and the stress-bearing performance is reliable;

[0063] 4. The bending moment at the cast-in-place joint is close to 0, and the structure is more reasonable;

[0064] 5. Compared with full UHPC joints, the amount of UHPC is small and economical;

[0065] 6. The fixtures used for construction are reusable and environmentally friendly.

[0066] Second embodiment

[0067] Based on the low-shrinkage formwork-free bridge deck joint structure provided by the first embodiment of the present application, the second embodiment of the present application proposes another low-shrinkage formwork-free bridge deck joint structure. The second embodiment is only a preferred embodiment of the first embodiment, and the implementation of the second embodiment will not affect the independent implementation of the first embodiment.

[0068] The second embodiment of the present invention is further described below in conjunction with the accompanying drawings and implementation modes.

[0069] Please refer to Figure 5 The difference between this embodiment and the first embodiment is that the invention provides a low-shrinkage template-free bridge deck joint structure, and the second screw rod 12 includes a lower screw rod 18, a thread groove 19 is opened on the top side of the lower screw rod 18, an inner screw rod 20 is installed in the inner thread of the thread groove 19, the bottom end of the inner screw rod 20 extends to the outside of the thread groove 19 and is rotatably sleeved with an upper screw rod 23, a handle 21 is fixedly sleeved on the inner screw rod 20, and an anti-slip groove 22 is provided on the handle 21.

[0070] A groove 24 is formed at the bottom end of the upper screw rod 23, and a plurality of bearings 25 are installed in the groove 24. The inner ring of the bearing 25 is fixedly sleeved with the inner screw rod 20, the first rod clamp 8 and the second rod clamp 11 are both sleeved with the upper screw rod 23, and the rod seat 13 is connected to the lower screw rod 18.

[0071] Through the cooperation of the lower screw rod 18, the handle 21 and the upper screw rod 23, it is convenient to adjust the length of the second screw rod 12, and it is convenient to adjust the height and angle of the prefabricated block 3 and the tightness matching the prefabricated beam.

[0072] When it is necessary to adjust the height, angle and tightness of the prefabricated block 3 to match the prefabricated beam, the length of the second screw rod 12 needs to be adjusted, and the handle 21 is held by hand to rotate. Due to the rod seat 13, the lower screw rod 18 is fixed and cannot be rotated. At this time, the inner screw rod 20 rotates in the thread groove 19 and moves upward at the same time. The inner screw rod 20 drives the upper screw rod 23 to move upward, and the upper screw rod 23 drives the cross bar 9 to move upward. The cross bar 9 drives the first screw rod 7 to move upward through the first rod clamp 8, thereby achieving the purpose of adjusting the height, angle and tightness of the prefabricated block 3 to match the prefabricated beam.

[0073] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A low-shrinkage formwork-free bridge deck joint structure, characterized in that: include: A plurality of precast beams, wherein the plurality of precast beams are arranged at intervals along the length direction of the bridge, and a joint space is reserved between two adjacent precast beams; a first annular reinforcement is embedded in the precast beam, and the first annular reinforcement includes a first arc-shaped force-bearing section extending from the precast beam and into the joint space; A prefabricated block, the prefabricated block is installed in the joint space, and a pouring space is reserved between the prefabricated block and the prefabricated beam; a second annular rib is embedded in the prefabricated block, the second annular rib includes a second arc-shaped force-bearing section extending from the prefabricated block and extending into the pouring space; the second arc-shaped force-bearing section overlaps and is fixedly connected with the first arc-shaped force-bearing section in the pouring space; a hollow embedded sleeve is also embedded in the prefabricated block, and the embedded sleeve passes through the prefabricated block in a vertical direction; A UHPC grouting layer, wherein the UHPC grouting layer is formed by pouring UHPC concrete in the pouring space to wrap the first arc-shaped stress-bearing section and the second arc-shaped stress-bearing section and connect the precast block and the precast beam as a whole; A fixing device is installed on the prefabricated block, and the fixing device is in contact with the two prefabricated beams on both sides of the prefabricated block; The fixing device includes a first screw rod, a first rod clamp is installed on the first screw rod, the bottom end of the first screw rod passes through the embedded sleeve and is threadedly installed with a nut assembly, the nut assembly is in contact with the prefabricated block, the first rod clamp is sleeved with a cross bar, two second rod clamps are symmetrically sleeved on the cross bar, the second rod clamp is sleeved with a second screw rod, the bottom end of the second screw rod is installed with a rod seat, and the rod seat is in contact with the corresponding prefabricated beam.

2. The low-shrinkage formwork-free bridge deck joint structure according to claim 1, characterized in that: The prefabricated block is in an inverted T shape and comprises a strip block and a flange. A plurality of longitudinal ribs are arranged inside the strip block, and transverse ribs are arranged inside the flange.

3. The low shrinkage formwork-free bridge deck joint structure according to claim 2, characterized in that: The length of the two ends of the longitudinal reinforcement extending out of the two sides of the prefabricated block is greater than the anchoring length.

4. The low-shrinkage formwork-free bridge deck joint structure according to claim 1, characterized in that: The first annular rib and the second annular rib each include two straight segments and two arc segments, and the two straight segments are parallel to each other.

5. The low shrinkage formwork-free bridge deck joint structure according to claim 2, characterized in that: A grout-stopping strip is arranged on the top side of the flange, and the contact surfaces between the side surface of the strip block, the top surface of the flange and the UHPC grouting layer are all roughened surfaces.

6. The low shrinkage formwork-free bridge deck joint structure according to claim 1, characterized in that: The first screw and the second screw both include a lower screw, a thread groove is formed on the top side of the lower screw, an inner screw is threadedly mounted in the thread groove, the bottom end of the inner screw extends out of the thread groove and is rotatably sleeved with an upper screw, a handle is fixedly sleeved on the inner screw, and an anti-slip groove is provided on the handle.

7. The low shrinkage formwork-free bridge deck joint structure according to claim 6, characterized in that: A groove is provided at the bottom end of the upper screw rod, and a plurality of bearings are installed in the groove. The inner ring of the bearing is fixedly sleeved with the inner screw rod, the first rod clamp and the second rod clamp are both sleeved with the upper screw rod, and the rod seat is connected to the lower screw rod.

8. A construction method for a low-shrinkage formwork-free bridge deck joint structure as claimed in claim 1, characterized in that: The following steps are involved: S1: erect the precast beams in place and roughly place the precast blocks in place; S2: By adjusting the height of the rod clamp, the height, angle and tightness of the prefabricated block and the prefabricated beam can be adjusted; S3: Casting joint UHPC grouting after precise positioning; S4: After the UHPC grouting reaches the required strength, loosen and remove the nut assembly, and the fixture can be moved to the next work site for reuse.

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