Beam lower hanging structure and construction method

Abstract

The invention belongs to the technical field of building construction, and particularly relates to a beam lower hanging structure and a construction method.The beam lower hanging structure comprises a cast-in-place concrete structural beam, a lower hanging plate and a prefabricated concrete batten, the prefabricated concrete batten is manufactured through a pedestal, and holes are formed in the pedestal in an array mode; the cast-in-place concrete structural beam is poured on the prefabricated concrete batten, and the lower hanging plate is poured on the side, away from the cast-in-place concrete structural beam, of the prefabricated concrete batten. The construction method comprises the steps of manufacturing the prefabricated concrete battens and pre-burying the steel bars, building the support system, installing the prefabricated concrete battens, casting the concrete structural beams in place and constructing the joint parts. Compared with the prior art, the prefabricated batten serves as a cast-in-place concrete structural beam bottom die, meanwhile, the vertical steel bars carried by the prefabricated batten are pre-buried in a concrete structural beam, and a large number of steel bar planting procedures in the later period are avoided through one-time forming.

Description

Technical Field

[0001] The invention relates to the technical field of building construction, and in particular to a beam underhang structure and a construction method. Background Art

[0002] With the promotion of prefabricated buildings, the external walls are required to adopt non-masonry forms or large-span windows. When the top of the window does not reach the bottom of the beam, the lintel on the window cannot meet the requirements due to its limited span, and the non-masonry requirement cannot be used to seal the space between the top of the window and the bottom of the beam in the form of lintel + masonry. At this time, designers often use concrete slabs with the same wall thickness hanging from the structural beam to solve this problem. During the construction process, there are two ways to connect the vertical steel bars of the lower hanging plate to the beam: one is to drill holes and embed steel bars at the bottom of the beam after the construction of the concrete structural beam is completed; the other is to drill holes in the template at the bottom of the beam during the construction stage of the concrete structural beam, and pre-embed the vertical steel bars through the template holes. However, the two commonly used construction measures have the following problems: The first type: drilling and embedding of reinforcement after the construction of concrete structural beams is completed, which has the problems of large workload, poor on-site reinforcement effect, difficulty in pulling out the reinforcement, difficulty in reaching the depth required for the straight anchor of the reinforcement, certain damage to the bottom structure of the concrete structural beam, and poor durability; the second type: drilling holes in the bottom formwork of the beam to embed reinforcement during the construction of the structural beam has the problem of large number of holes in the bottom formwork, large damage to the formwork, and difficulty in multiple turnovers, and leakage during the concrete pouring process due to the large number of holes in the bottom. There is also a treatment method of using steel sections as keels for encapsulation of the lower hanging plate with a small height, but this construction method has the problem of unstable window fixation, and certain hidden dangers in the insulation and waterproofing of the exterior wall.

[0003] The present invention solves the above problems by prefabricating a concrete strip plate with the same width as the beam, pre-embedding the vertical steel bars of the lower hanging beam plate into the concrete structural beam and serving as the bottom formwork of the concrete structural beam. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention develops a beam hanging structure and a construction method. The prefabricated strip plate serves as the bottom formwork of the cast-in-place concrete structure beam, and the vertical steel bars it carries are embedded in the concrete structure beam. The one-time forming avoids a large number of subsequent reinforcement planting processes.

[0005] The technical solution to the technical problem solved by the present invention is: a beam hanging structure, comprising a cast-in-place concrete structural beam, a hanging plate and a precast concrete slat, the precast concrete slat is made by a pedestal, an array of holes is arranged on the pedestal, the cast-in-place concrete structural beam is cast on the precast concrete slat, and the hanging plate is cast on the side of the precast concrete slat away from the cast-in-place concrete structural beam.

[0006] Preferably, pre-embedded steel bars of the lower hanging plate are arranged in the holes.

[0007] Preferably, the protruding length of the embedded steel bars of the lower hanging plate on the side close to the precast concrete slat is the height of the precast concrete slat plus the anchoring length of the concrete structural beam.

[0008] Preferably, the length of the embedded steel bars of the lower hanging plate extending away from the side of the precast concrete slab is the height of the lower hanging plate minus the thickness of the steel bar protective layer.

[0009] Preferably, the pedestal is provided with an array of slots for assisting in fixing the side forms of the precast concrete slabs.

[0010] Preferably, the length of the precast concrete slats is less than or equal to 2 meters, and a joint is provided between two adjacent concrete slats. The joint is made of a tied steel bar skeleton and poured with concrete.

[0011] A beam hanging construction method uses a beam hanging structure to construct a beam hanging plate, specifically comprising the following steps: Step 1: Make a pedestal, set holes for the embedded steel bars of the lower hanging plate to pass through on the pedestal according to the diameter of the steel bars, and set slots for assisting the fixing of the side formwork of the precast concrete slab according to the width of the beam; Step 2: Tie the steel bar skeleton of the precast concrete slab on the pedestal and insert the reserved steel bars of the lower hanging plate through the holes; Step 3: Install the side formwork of the precast concrete slats on the pedestal; Step 4: pouring concrete of the precast concrete slab to complete the precast work of the precast concrete slab; Step 5: After the strength of the precast concrete slab reaches the required level, the side formwork and pedestal are removed and stored; Step 6: Install the support system of the cast-in-place concrete structural beam, and then install the prefabricated parts on the support system as the bottom formwork of the cast-in-place concrete structural beam; Step 7: Tie the steel bars at the joints between two adjacent prefabricated parts and install the bottom formwork; Step 8: Tie the steel bars of the cast-in-place reinforced concrete structural beams; Step 9: Install the side formwork of the cast-in-place reinforced concrete structural beam and joints; Step 10: pouring concrete of cast-in-place concrete structural beams and joints; Step 11: After the strength of the cast-in-place concrete structural beam reaches the required level, remove the formwork and support system; Step 12: Carry out the reinforcement binding and concrete pouring work of the hanging plate under the beam.

[0012] In the step 1, the hole array is set, the spacing of the holes is the spacing of the steel bars in the drawing, and the diameter is the diameter of the steel bars in the drawing.

[0013] In step 2, the length of the embedded steel bars of the lower hanging plate extending from the side of the pedestal close to the precast concrete slats is the height of the precast concrete slats plus the anchorage length of the cast-in-place concrete structural beam.

[0014] In step 2, the embedded steel bars of the lower hanging plate extend out from the side of the pedestal away from the precast concrete slab by a length equal to the height of the lower hanging plate minus the thickness of the steel bar protective layer.

[0015] The effects provided in the content of the invention are only the effects of the embodiments, rather than all the effects of the invention. The above technical solution has the following advantages or beneficial effects: 1. Prefabricate concrete slabs in processing plants or centralized processing sites on site, which increases the turnover rate and utilization rate of the pedestal, eliminates the need to support the bottom formwork of cast-in-place concrete structural beams, saves materials, and speeds up construction progress; 2. While the prefabricated strips are used as the bottom formwork of the cast-in-place concrete structural beam, the vertical steel bars they carry are embedded in the concrete structural beam, and the one-time forming avoids a large number of rebar planting processes in the later stage; 3. It can be applied to different cast-in-place structural beams and different heights of hanging plates in combination structure construction, with strong applicability; 4. It can avoid the process of drilling holes in the bottom formwork to reserve steel bars or planting steel bars later, saving construction costs and speeding up construction progress; 5. As the prefabricated strips are the same width as the beams, the height can be 200mm, which generally will not affect the architectural effect. You can communicate with the design institute to add them to the design drawings, saving construction costs while ensuring benefits; 6. Design the length of precast concrete slabs to be less than or equal to 2m to facilitate manual handling during construction and save storage space; 7. The length of the embedded steel bars in the lower hanging plate when making the precast concrete slab can ensure that it is anchored on the cast-in-place concrete structural beam, avoiding the overlapping operation after planting the bars and improving the stability of the overall structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is the main view of the structure hanging under the beam; Figure 2 This is a top view of the pedestal; Figure 3 This is the right view of the structure hanging under the beam.

[0017] Among them: 1. Cast-in-place concrete structural beam; 2. Embedded steel bars in the lower hanging plate; 3. Precast concrete slats; 4. Lower hanging plate; 5. Slots; 6. Holes; 7. Base; 8. Joints. DETAILED DESCRIPTION

[0018] In order to clearly illustrate the technical features of the present invention, the present invention is described in detail below through specific implementation methods and in conjunction with the accompanying drawings.

[0019] Example 1 See also Figures 1 to 3 A beam hanging structure includes a cast-in-place concrete structural beam 1, a hanging plate 4 and a precast concrete slat 3. The precast concrete slat 3 is made by a pedestal 7. The pedestal 7 is provided with an array of holes 6. The cast-in-place concrete structural beam 1 is cast on the precast concrete slat 3. The height of the precast concrete slat 3 is generally set to 200 mm. The hanging plate 4 is cast on the side of the precast concrete slat 3 away from the cast-in-place concrete structural beam 1.

[0020] The holes 6 are provided with pre-embedded steel bars 2 for the lower hanging plate.

[0021] The protruding length of the embedded steel bars 2 of the lower hanging plate close to the precast concrete strip 3 is the height of the precast concrete strip 3 plus the anchoring length of the concrete structural beam.

[0022] The length of the embedded steel bars 2 on the lower hanging plate away from the precast concrete slab 3 is the height of the lower hanging plate 4 minus the thickness of the steel bar protective layer.

[0023] The base 7 is provided with an array of slots 5 for assisting in fixing the side molds of the precast concrete slab 3 .

[0024] The length of the precast concrete slats 3 is less than or equal to 2 meters, and a joint 8 is provided between two adjacent concrete slats. The joint 8 is made of a tied steel bar skeleton and poured with concrete.

[0025] A beam hanging construction method uses a beam hanging structure to construct a beam hanging plate 4, specifically comprising the following steps: First, make the pedestal 7. The pedestal 7 is usually made of 3.5mm thick aluminum alloy. Aluminum alloys of different thicknesses can be selected according to actual engineering requirements, but it must be ensured that its strength is sufficient to withstand various stresses during the construction process so that its deformation is controlled within the allowable range of the specification. On the pedestal 7, holes 6 for the embedded steel bars 2 of the lower hanging plate are set according to the diameter of the steel bars. These holes 6 are arranged in an array, and their spacing is set according to the steel bar spacing in the drawings. The diameter also matches the steel bar diameter required by the drawings to ensure that the subsequently inserted steel bars can be accurately positioned and that the integrity and structural stress performance of the steel bar skeleton meet the design expectations. At the same time, a slot 5 for assisting the fixing of the side mold of the precast concrete slab 3 is set according to the width of the beam. The slot 5 can effectively limit the displacement of the side mold, provide stable lateral support for the side mold, and ensure the processing accuracy of the precast concrete slab 3.

[0026] The steel skeleton of the precast concrete slats 3 is tied on the manufactured pedestal 7. The reserved steel bars of the lower hanging plate 4 are inserted through the pre-set holes 6 on the pedestal 7. At this time, the protruding length of the pre-embedded steel bars 2 of the lower hanging plate on both sides of the pedestal 7 needs to be strictly controlled. On the side of the pedestal 7 close to the precast concrete slats 3, the protruding length is the height of the precast concrete slats 3 plus the anchoring length of the cast-in-place concrete structural beam 1. When the precast concrete slats 3 are connected to the cast-in-place concrete structural beam 1, this design has sufficient anchoring length to fully bond the steel bars to the cast-in-place beam concrete, ensuring the reliability of the structural connection. On the side of the pedestal 7 away from the precast concrete slats 3, the protruding length of the pre-embedded steel bars 2 of the lower hanging plate is the height of the lower hanging plate 4 minus the thickness of the steel bar protective layer. The steel bar length reserves the thickness of the protective layer, which can prevent the steel bar from rusting in the later stage, thereby extending the service life of the structure.

[0027] The side form of the precast concrete strip 3 is installed on the pedestal 7 and supported and reinforced. After the side form is initially positioned by the slot 5 on the pedestal 7, a suitable support structure is used to reinforce the side form, such as using wood, steel pipes and other materials to build a support system. The rigidity of the support structure is used to resist the squeezing effect of the side pressure on the side form during the concrete pouring process and the expansion generated during the concrete curing process, to prevent the side form from deformation and displacement, and to ensure that the precast concrete strip 3 meets the requirements.

[0028] After completing the above preparations, the concrete pouring of the precast concrete slab 3 is carried out. The concrete mix ratio needs to be determined according to the engineering design requirements to ensure the strength, durability and other performance indicators of the concrete. At the same time, the concrete is vibrated with appropriate vibrating equipment to discharge the bubbles inside the concrete and make the structure more compact.

[0029] When the strength of the precast concrete strip 3 reaches the design requirements, the side form and the pedestal 7 are removed, and the removal sequence should follow the principle of first support and then removal, and then removal. The precast concrete strip 3 after removal is stored, and the removed side form and pedestal 7 are reused.

[0030] The support system for installing the cast-in-place concrete structural beam 1 needs to be determined according to factors such as the span and load of the beam to ensure that it has sufficient bearing capacity, rigidity and stability. Common support systems include fastener-type steel pipe supports, bowl-hook-type steel pipe supports, etc. After the support is built, the prefabricated precast concrete slats 3 are installed on the support system as the bottom formwork of the cast-in-place concrete structural beam 1. At this time, the embedded steel bars 2 of the lower hanging plate are installed in place synchronously with the installation of the precast concrete slats 3, which facilitates the connection between the subsequent beam lower hanging plate 4 and the cast-in-place beam, reduces the workload and construction difficulty of on-site steel bar installation, improves construction efficiency, and because the steel bars are accurately pre-positioned, it is beneficial to ensure the quality of the structural connection.

[0031] The joint 8 between two adjacent prefabricated parts needs to be processed by tying the steel bars there, connecting the steel bars of the adjacent prefabricated parts, forming a continuous steel skeleton, and enhancing the structural integrity of the joint. At the same time, the bottom mold of the joint 8 is installed, and the installation of the bottom mold must ensure that it is flat with the bottom of the prefabricated concrete strip 3 to prevent leakage during concrete pouring.

[0032] According to the design drawings, the steel bars of the cast-in-place reinforced concrete structural beams are tied to the support system. The specifications, quantity, spacing and anchorage length of the steel bars are arranged according to the design drawings.

[0033] Install the cast-in-place reinforced concrete structural beam and the side formwork of the joint 8. During the installation of the side formwork, attention should be paid to sealing and fixing to prevent problems such as leakage and expansion of the formwork during the concrete pouring process. The side formwork of the beam can be reinforced by tension bolts, etc. The side formwork of the joint 8 should be closely fitted with the side of the adjacent precast concrete strip 3 and the side formwork of the beam.

[0034] The concrete pouring of the cast-in-place concrete structure beam 1 and the joint 8 is carried out. For the beam body, due to its large volume, a layered pouring and layered vibration method can be adopted to ensure the density and uniformity of the concrete.

[0035] When the strength of the cast-in-place concrete structural beam 1 reaches the design requirements, the template and the support system are removed. The side template is removed first, and then the bottom template and the support system of the joint part 8 are removed.

[0036] Then just can carry out the steel bar binding and concrete pouring work of the hanging plate 4 under the beam. At this moment, the pre-buried steel bar 2 of the hanging plate under the beam is in place, and only the remaining steel bars need to be supplemented with binding according to the design requirements, and then concrete pouring is carried out.

[0037] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Based on the technical solution of the present invention, various modifications or variations that can be made by those skilled in the art without creative work are still within the scope of protection of the present invention.

Claims

1. A beam hanging structure, characterized in that: The invention comprises a cast-in-place concrete structural beam (1), a lower hanging plate (4) and a precast concrete strip plate (3), wherein the precast concrete strip plate (3) is manufactured by means of a pedestal (7), an array of holes (6) is arranged on the pedestal (7), the cast-in-place concrete structural beam (1) is cast on the precast concrete strip plate (3), and the lower hanging plate (4) is cast on a side of the precast concrete strip plate (3) away from the cast-in-place concrete structural beam (1).

2. A beam hanging structure according to claim 1, characterized in that: The holes (6) are provided with pre-embedded steel bars (2) for the lower hanging plate.

3. A beam hanging structure according to claim 2, characterized in that: The length of the embedded steel bars (2) of the lower hanging plate protruding from the side close to the precast concrete strip (3) is the height of the precast concrete strip (3) plus the anchoring length of the concrete structural beam.

4. The under-beam hanging structure according to claim 3 is characterized in that: The length of the embedded steel bars (2) of the lower hanging plate extending away from the precast concrete slab (3) is the height of the lower hanging plate (4) minus the thickness of the steel bar protective layer.

5. The under-beam hanging structure according to claim 4, characterized in that: The pedestal (7) is provided with an array of slots (5) for assisting in fixing the side formwork of the precast concrete slab (3).

6. The under-beam hanging structure according to claim 5, characterized in that: The length of the precast concrete strips (3) is less than or equal to 2 meters, and a joint portion (8) is provided between two adjacent concrete strips. The joint portion (8) is made of a tied steel bar skeleton and is cast with concrete.

7. A beam hanging construction method, characterized in that: The construction of the beam-hanging plate (4) using the beam-hanging structure described in claim 6 specifically comprises the following steps: Step 1: making a pedestal (7), setting holes (6) for the embedded steel bars (2) of the lower hanging plate to pass through on the pedestal (7) according to the diameter of the steel bars, and setting slots (5) for assisting the fixing of the side form of the precast concrete slab (3) according to the width of the beam; Step 2: Tie the steel bar skeleton of the precast concrete slab (3) on the pedestal (7), and insert the reserved steel bars of the lower hanging plate (4) through the holes (6); Step 3: Install the side form of the precast concrete slab (3) on the pedestal (7); Step 4: pouring concrete of the precast concrete slats (3) to complete the precast work of the precast concrete slats (3); Step 5: After the precast concrete slab (3) reaches the required strength, the side formwork and the pedestal (7) are removed and stored; Step 6: installing a support system for the cast-in-place concrete structural beam (1), and then installing the prefabricated components on the support system to serve as a bottom formwork for the cast-in-place concrete structural beam (1); Step 7: Tie the steel bars at the joint (8) between two adjacent prefabricated parts and install the bottom formwork; Step 8: Tie the steel bars of the cast-in-place reinforced concrete structural beams; Step 9: Install the side formwork of the cast-in-place reinforced concrete structural beam and the joint (8); Step 10: pouring concrete of the cast-in-place concrete structural beam (1) and the joint (8); Step 11: After the strength of the cast-in-place concrete structural beam (1) reaches the required level, the formwork and support system are removed; Step 12: Tie the steel bars and pour the concrete for the hanging plate (4) under the beam.

8. A beam hanging construction method according to claim 7, characterized in that: In step 1, the holes (6) are arranged in an array, the spacing of the holes (6) is the spacing of the steel bars, and the diameter is the diameter of the steel bars.

9. A beam hanging construction method according to claim 7, characterized in that: In step 2, the embedded steel bars (2) of the lower hanging plate extend out from the side of the pedestal (7) close to the precast concrete strip (3) by a length equal to the height of the precast concrete strip (3) plus the anchoring length of the cast-in-place concrete structural beam (1).

10. A beam hanging construction method according to claim 7, characterized in that: In step 2, the embedded steel bars (2) of the lower hanging plate extend out from the side of the pedestal (7) away from the precast concrete slab (3) by a length equal to the height of the lower hanging plate (4) minus the thickness of the steel bar protective layer.

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