Prefabricated-cast-in-situ combined construction column and construction method thereof

Abstract

The application discloses a prefabricated-cast-in-situ combined construction column and a construction method thereof, and relates to the technical field of secondary structures in building engineering. The construction column comprises a lower cast-in-situ section, a middle prefabricated section and an upper cast-in-situ section in the height direction. Two outer side embedded connecting holes are arranged in the middle prefabricated section. When a formwork is supported on site, a non-removable prefabricated concrete outer formwork is supported on the outer side surfaces of the upper and lower cast-in-situ sections, a tension bolt is arranged to pass through the connecting holes of the prefabricated section at the height of the prefabricated section, the tension bolt is fastened to pass through the non-removable outer formwork at the height of the cast-in-situ section without contacting the aerated block. A key groove is arranged on the inner surface of the non-removable outer formwork, and the key groove is overlapped with a cast-in-situ core to form a non-removable formwork for the outer skin of the column after pouring. A zigzag-shaped groove is formed by arranging a masonry at the corresponding height of the upper and lower cast-in-situ sections and filling the zigzag-shaped groove with cast-in-situ concrete. The wall body in the prefabricated section is laid flat. The middle prefabricated load-bearing section is used as a formwork tension support point, the non-removable outer formwork is used to replace the formwork removal, and the elastic buffer side is connected with the masonry. The formwork is reliably supported without penetrating the wall, and the brittle aerated block is protected from being damaged.

Description

Technical Field

[0001] This invention relates to the field of masonry secondary structure construction technology in building engineering, specifically to a precast-cast-in-place composite structural column and its construction method. Background Technology

[0002] In masonry structures and frame-infill wall structures, structural columns are an important seismic-resistant structural measure for secondary structures. Current codes require that the walls be built before the columns are poured in the masonry, with toothed joints and tie bars in the walls. Traditional formwork for structural columns requires passing the tie bars / bolts through the mortar joints, which cuts the mortar bond and weakens the interlocking between blocks. This can easily cause cracking and loosening in aerated concrete blocks, which have low strength and are brittle. Furthermore, the holes need to be sealed after demolding, posing risks of leakage and thermal bridging.

[0003] Several publicly available technologies exist for formwork erection that eliminates the need for through-wall penetration. These include: using tie bolts embedded in toothed or staggered joints to achieve through-wall positioning (e.g., CN104453226A); employing precast components as non-removable formwork with pre-drilled holes for tie bolts (e.g., CN119243897A, CN114961105A); and constructing prefabricated structural columns by vertically splicing multiple precast sections (e.g., CN108104372A, CN220451235U, CN105155726A). Additionally, there are solutions that connect precast columns to the wall side using flat iron (e.g., CN106284846A).

[0004] However, all of the above solutions have the following unresolved technical gaps: (1) In the scheme of using prefabricated components as “formwork”, the prefabricated components are not part of the load-bearing column body of the structural column, and the column-wall integrity and seismic performance are not improved simultaneously; and the demolding process may still bring problems such as complicated procedures and uneven column surface.

[0005] (2) Although the fully prefabricated vertical splicing scheme achieves factory production, the prefabricated sections and the surrounding masonry are all rigid or grouted connections, making it difficult to retain the toothed joint for seismic interlocking between the column and the aerated concrete block. Furthermore, under temperature shrinkage and seismic action, the deformation of the aerated concrete block and the concrete is not coordinated, and the rigid contact is prone to local stress concentration, which will crush the aerated concrete block and chip off the corners.

[0006] (3) Existing side connection schemes (such as flat iron) are rigid connections without buffer transitions, which will still damage brittle aerated blocks when deformation is not coordinated.

[0007] Therefore, there is an urgent need for a new structural column and construction method that can reliably support the formwork without penetrating the wall, eliminate the need for formwork removal, and form a "rigid connection + elastic buffer" collaborative structure between the column and the aerated concrete block, thereby protecting the aerated concrete block from damage while improving the overall integrity of the secondary structure. Summary of the Invention

[0008] To address the shortcomings of existing technologies, this invention provides a precast-cast-in-place composite structural column and its construction method.

[0009] To achieve the above objectives, the present invention is implemented through the following technical solution: a precast-cast-in-place combined structural column, which includes a lower cast-in-place section 3, a middle precast section 2 and an upper cast-in-place section 1 in sequence along the height direction of the structural column.

[0010] The central precast section 2 is a reinforced concrete load-bearing component precast in the factory and forms part of the structural column body. Its two outer sides are respectively pre-embedded with connection holes 4 for horizontal insertion of tie bolts. At the height of the precast section, the outer skin of the column is formed by the concrete of the precast section itself, and no additional formwork is required.

[0011] The lower cast-in-place section 3 and the upper cast-in-place section 1 are constructed on-site with formwork erected. Their outer sides are supported by a non-removable precast concrete outer formwork 6, similar to the bottom formwork of a non-removable composite floor slab. The tie bolts 7 pass through the pre-embedded connection holes 4 on the outer side of the middle precast section 2 at the height of the precast section and through the tie holes 4 reserved on the non-removable outer formwork 6 at the height of the cast-in-place section to fasten the formwork on both sides. The tie bolts 7 do not contact the aerated block masonry wall 5.

[0012] The toothed joint 9 is formed by leaving aerated block masonry within the height range corresponding to the lower cast-in-place section 3 and the upper cast-in-place section 1, and filling it with cast-in-place concrete to form a toothed interlocking joint; the masonry is laid flat within the height range corresponding to the middle precast section 2.

[0013] At least one side of the prefabricated middle section 2 is fixedly connected to the aerated block masonry wall 5 by a pre-embedded connector 8, and an elastic buffer pad 12 is sandwiched between the two.

[0014] The interface between the precast middle section 2 and the upper and lower cast-in-place sections is provided with shear keyways 11 and filled with high-strength grout. The longitudinal reinforcement of the upper and lower cast-in-place sections is continuously connected by steel bar connecting sleeves 10 embedded in the precast section 2.

[0015] Furthermore, the non-removable outer formwork 6 is a factory-prefabricated thin concrete slab with shear keyways 11 or rough surfaces on its inner surface. It overlaps with the cast-in-place concrete of the cast-in-place sections 1 and 3 to form an integral structure, similar to the overlap of the non-removable composite floor slab bottom formwork and the cast-in-place layer. The outer surface of the non-removable outer formwork 6 has sleeves or nuts with pre-embedded tie holes 4, which are matched with tie bolts 7. After pouring, the non-removable outer formwork 6 remains on the structural column as the column skin and does not need to be removed. The column surface is flat and does not require plastering.

[0016] Furthermore, the non-removable outer mold 6 and the central prefabricated section 2 are connected on the outer side by tongue and groove joints, pre-embedded connectors or grouting material, so that the outer skin of the column is continuous and the appearance is consistent.

[0017] Furthermore, the elastic buffer pad 12 is a closed-cell elastomer layer of rubber / EVA / EPS foam / polyurethane pre-applied to the side of the prefabricated section 2 in the factory, with a thickness of 5-20mm; it is provided with through holes for the connector 8 to pass through, and the connector 8 passes through the buffer pad and connects to the wall tie bar, realizing the integration of "buffering + connection".

[0018] Furthermore, the middle prefabricated section 2 has interlocking grooves on its side, and the aerated blocks are embedded in the grooves for construction. An elastic buffer pad 12 is sandwiched between the inner wall of the groove and the block, forming a dual connection of mechanical interlocking and elastic buffering.

[0019] A construction method for the above-mentioned structural column includes: S1, Factory prefabricated middle prefabricated section 2 including outer side connecting hole 4 sleeve, upper and lower mating surface sleeve 10, side connecting piece 8, mating surface keyway 11, side buffer pad layer 12 and non-removable outer mold 6 inner surface keyway, outer surface pull hole 4. S2. The cavity between the upper and lower cast-in-place sections is reserved in the masonry wall, and toothed joints and tie bars are reserved at the corresponding heights of the upper and lower cast-in-place sections; S3. Hoist the precast section 2 into place, and connect the connector 8 through the buffer pad 12 to the tie bar; S4. Install the non-removable outer formwork 6 on the outer side of the upper and lower cast-in-place sections, and connect it with the outer side of the precast section 2 as a continuous outer skin. The tie bolts 7 pass through the precast section connection hole 4 at the height of the precast section and through the tie hole 4 of the non-removable outer formwork at the height of the cast-in-place section, and are fastened without contacting the masonry. S5. Pour concrete to overlap with the keyway 11 on the inner surface of the non-removable outer formwork 6, and inject grouting material into the bonding surface. S6. After curing, the outer formwork can be left as the column outer skin without removing the formwork, and the wall does not need to be patched.

[0020] This invention provides a precast-cast-in-place composite structural column and its construction method. Compared with the prior art, it has the following advantages: (1) No need to pass through the wall and multiple functions: The tie bolts 7 only pass horizontally through the pre-embedded connection holes 4 on the outer side of the middle precast section 2 or the tie holes 4 reserved on the non-removable outer formwork 6, without contacting the mortar joints of the aerated block or the toothed joint, thus protecting the integrity of the masonry; at the same time, the precast section 2 serves as a load-bearing column section, and also as a rigid internal support and tie point for the formwork of the upper and lower cast-in-place sections.

[0021] (2) No need to remove the outer formwork, saves process and the column surface is flat: The formwork 6 adopts the type of precast concrete outer formwork that can be removed and the bottom formwork of the floor slab. Its inner surface keyway 11 is superimposed with the cast-in-place core to form a whole. After pouring, it is left on the column as the outer skin of the column, which saves the formwork removal process, the column surface is flat and does not need to be plastered, and the tie hole 4 is left with the outer formwork, so the wall does not need to be filled. -- Unlike the existing solution of "precast components as a whole formwork", the formwork of this invention can be removed and only covers the outer side of the upper and lower cast-in-place sections. The middle precast section 2 is the load-bearing column body. The three together constitute the whole structural column.

[0022] (3) Elastic buffer side connection, special protection against damage to aerated concrete blocks: The prefabricated section 2 is rigidly connected to the masonry through the pre-embedded connector 8 to ensure the integrity. An elastic buffer pad 12 is sandwiched between the two to absorb the difference in deformation under temperature shrinkage and seismic action and resolve local stress concentration, fundamentally preventing the brittle aerated concrete blocks from being crushed and chipped at the corners - which is not available in existing rigid side connections such as flat iron and fully prefabricated rigid splicing schemes.

[0023] (4) Retain the toothed joint seismic structure: The lower cast-in-place section 1 and the upper cast-in-place section 3 are connected to the masonry with toothed joints 9, which also takes into account the seismic performance of traditional structural columns; the longitudinal reinforcement is continuous through the inner sleeve 10 of the precast section 2, so that the stress is continuous. The wall in the middle precast section is flat and connected by side connection + buffer, which works with the toothed joints of the upper and lower cast-in-place sections to improve the overall integrity.

[0024] (5) Strong integrity, controllable quality and high efficiency: the precast sections are produced in the factory and the keyway 11+ grouting of the bonding surface ensures that the new and old concrete are stressed together; the removal of the outer formwork reduces on-site wet work and formwork removal process, and reduces the dependence on the skill level of workers. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall elevation of the aerated concrete block masonry wall of the present invention; Figure 2 This is a cross-sectional view of the prefabricated section in the middle of the present invention; Figure 3 This is a detailed view of the nodes of the prefabricated section in the middle of the present invention; Figure 4 This is a cross-sectional view of the cast-in-place section of the present invention; Attached reference numerals: 1. Upper cast-in-place section (with external formwork that does not need to be removed); 2. Middle precast section (load-bearing component); 3. Lower cast-in-place section (with external formwork that does not need to be removed); 4. Tie hole / connection hole; 5. Aerated concrete block masonry wall; 6. Precast external formwork that does not need to be removed; 7. Tie bolt; 8. Side connector of precast section; 9. Toothed joint; 10. Longitudinal reinforcement / reinforcement connecting sleeve; 11. Shear keyway / rough surface; 12. Elastic buffer layer. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Please see Figures 1 to 2This application provides a precast-cast-in-place composite structural column, which includes a lower cast-in-place section 3, a middle precast section 2 and an upper cast-in-place section 1 along the height direction; the middle precast section 2 is a reinforced concrete load-bearing component precast in the factory, which constitutes part of the column body, and its two outer sides are pre-embedded with connection holes 4 (with metal sleeves or pre-embedded nuts); the lower cast-in-place section 3 and the upper cast-in-place section 1 are cast on the construction site with formwork.

[0028] The location of the non-removable external formwork and template: Template 6 is a factory-precast concrete external formwork (similar to the bottom formwork of a non-removable composite floor slab), supported on the two outer sides of the structural column (the two outward-facing sides perpendicular to the wall, see...). Figure 4 (Thin plates at the top and bottom).

[0029] At the height of the precast section, the column skin is formed by the concrete of the precast section itself, and no additional formwork is required (see...). Figure 2 At the height of the cast-in-place section, an outer formwork 6 that can be erected without dismantling is provided on the outer side.

[0030] The tie bolt 7 passes through the pre-embedded connection hole 4 on the outer side of the middle precast section 2 at the height of the precast section, and through the tie hole 4 reserved on the outer surface of the non-removable outer formwork 6 at the height of the cast-in-place section, to tighten the outer formwork on both sides; the tie bolt 7 does not contact the aerated block masonry wall 5 throughout the process. After pouring, the non-removable outer formwork 6 remains on the structural column as the column skin, which does not need to be removed, the column surface is flat and does not need to be plastered, and the wall does not need to be patched.

[0031] No need to disassemble the outer mold for overlapping: such as Figure 4 As shown, the inner surface of the non-removable outer formwork 6 is provided with shear keyways 11 (or a rough surface). After the cast-in-place concrete section is poured in, it overlaps with the inner surface of the outer formwork to form a whole. The non-removable outer formwork 6 is connected to the outer side of the middle precast section 2 through tongue and groove joints, embedded connectors, or grouting material (see...). Figure 3 This ensures that the outer skin of the entire structural column is continuous and has a consistent appearance.

[0032] Toothed joint setting: Toothed joint 9 is not set by structural columns, but by the aerated block masonry leaving an advance and retreat joint in the corresponding height range of the lower cast-in-place section 3 and the upper cast-in-place section 1 according to the specifications, with an advance and retreat of about 60mm for every 300mm of height; when the cast-in-place concrete is poured, it is filled into the joint to form a toothed interlocking joint.

[0033] Within the corresponding height range of the central prefabricated section 2, because the factory prefabrication cannot interlock with the on-site masonry, the wall is laid flat, relying on the side connectors 8 and the elastic buffer pad 12 to connect with the wall (see...). Figure 1 The precast section is flush with the wall within its height range (without toothed joints). To ensure the strength and stability of the connection between the precast section and the wall, sintered bricks can be filled at the reserved toothed joints. The sintered bricks can be fixed with expansion bolts and connectors 8.

[0034] The side of the prefabricated section 2 in the middle is fixedly connected to the aerated block masonry wall 5 through the pre-embedded connector 8, and an elastic buffer layer 12 is sandwiched between the two. The closed-cell elastomer layer, such as rubber / EVA / EPS foam, with a thickness of 5-20mm, is pre-applied by the factory. The connector 8 passes through the through hole on the buffer layer 12 and is welded / bolted to the wall tie bar to form a rigid connection and elastic buffer synergistic structure, which absorbs the deformation difference and prevents the aerated block from being crushed.

[0035] like Figure 3 As shown, the upper and lower joint surfaces of the precast section 2 in the middle are processed into rough surfaces or equipped with shear keyways 11. After the cast-in-place concrete and joint grout are poured in, a toothed lock is formed. The precast section 2 has pre-embedded steel reinforcement connecting sleeves 10, and the longitudinal reinforcement of the upper and lower cast-in-place sections extends into the sleeves to achieve continuous connection. The connecting hole 4 has pre-embedded sleeves to facilitate the installation of tie bolts 7. The precast section 2 also serves as a rigid internal support and tie rod support for the formwork of the upper and lower cast-in-place sections.

[0036] During construction: The factory prefabricates the middle prefabricated section 2 (including the outer side connecting hole 4 sleeve, the upper and lower mating surface sleeve 10, the side connector 8, the mating surface keyway 11, and the side buffer pad 12) and the non-removable outer formwork 6 (inner surface keyway, outer surface tie hole 4); when building the wall, the cavity between the upper and lower cast-in-place sections is reserved, and toothed joints 9 and tie bars are left at the corresponding heights of the upper and lower cast-in-place sections according to the specifications; the prefabricated section 2 is hoisted into place, and the connector 8 passes through the buffer pad 12 and connects with the tie bars; the non-removable outer formwork 6 is installed on the outer side of the upper and lower cast-in-place sections, and the connection with the outer side of the prefabricated section 2 is a continuous outer skin. The tie bolts 7 pass through the prefabricated section connecting hole 4 at the height of the prefabricated section and through the tie hole 4 of the non-removable outer formwork at the height of the cast-in-place section and are tightened; concrete is poured and overlapped with the inner surface keyway 11 of the non-removable outer formwork 6, and the mating surface grout is poured; after curing, the non-removable outer formwork 6 is left as the outer skin of the column and does not need to be removed. This invention solves the problem of synergistic coordination between eliminating the need for wall penetration formwork, eliminating the need for formwork removal, preventing damage to aerated concrete blocks, and improving overall integrity by combining a precast load-bearing section in the middle, an external formwork that does not need to be dismantled, an elastic buffer side connection, and top and bottom cast-in-place concrete.

[0037] Some of the data in the above formulas are numerical calculations with dimensions removed, and the contents not described in detail in this specification are all prior art known to those skilled in the art.

[0038] The above embodiments are only used to illustrate the technical methods of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical methods of the present invention without departing from the spirit and scope of the technical methods of the present invention.

Claims

1. A precast-cast-in-place composite structural column, characterized in that, Along the height of the structural column, it includes the lower cast-in-place section (3), the middle precast section (2), and the upper cast-in-place section (1). The two outer sides of the prefabricated section (2) in the middle are respectively pre-embedded with connection holes (4) for horizontal insertion of tie bolts. The lower cast-in-place section (3) and the upper cast-in-place section (1) are constructed on the construction site with formwork erected. The outer side of the lower cast-in-place section (3) is supported by a precast concrete outer formwork (6) that does not need to be removed. The tie bolts (7) pass through the connection holes (4) embedded in the outer side of the middle precast section (2) at the height of the precast section and through the tie holes (4) reserved on the precast outer formwork (6) at the height of the cast-in-place section to fasten the formwork on both sides. The tie bolts (7) do not contact the aerated block masonry wall (5). The toothed joint (9) is formed by leaving aerated block masonry within the height range corresponding to the lower cast-in-place section (3) and the upper cast-in-place section (1), and filling it with cast-in-place concrete to form a toothed joint. The masonry is laid flat within the height range corresponding to the middle precast section (2). At least one side of the prefabricated middle section (2) is fixedly connected to the aerated block masonry wall (5) by a pre-embedded connector (8), and an elastic buffer pad (12) is sandwiched between the prefabricated middle section (2) and the aerated block masonry wall (5). The joint surfaces of the middle precast section (2) with the lower cast-in-place section (3) and the upper cast-in-place section (1) are provided with shear keyways (11) and filled with high-strength grout. The longitudinal steel bars of the upper and lower cast-in-place sections are continuously connected by steel bar connecting sleeves (10) embedded in the middle precast section (2).

2. The precast-cast-in-place composite structural column according to claim 1, characterized in that, The non-removable outer formwork (6) is a factory-prefabricated concrete thin plate with shear keyway (11) or rough surface on its inner surface, which is superimposed with the cast-in-place concrete of the upper cast-in-place section (1) and the lower cast-in-place section (3) to form an integral whole. The outer surface of the non-removable outer mold (6) is pre-embedded with a sleeve or nut for a tie hole (4). The tie bolt (7) is matched with the sleeve or nut. After casting, the non-removable outer mold (6) remains on the structural column as the outer skin of the column and does not need to be removed.

3. A precast-cast-in-place composite structural column according to claim 2, characterized in that, The non-removable outer formwork (6) and the middle prefabricated section (2) are connected on the outer side by tongue and groove, pre-embedded connectors or grouting material, so that the outer skin of the column is continuous.

4. A precast-cast-in-place composite structural column according to claim 1, characterized in that, The connecting hole (4) is pre-embedded with a metal sleeve or a pre-embedded nut. The tie bolt (7) is engaged with the sleeve or nut. After demolding, the hole is located on the precast section (2).

5. A precast-cast-in-place composite structural column according to claim 1, characterized in that, The joint surface between the middle precast section (2) and the lower cast-in-place section (1) and the upper cast-in-place section (3) is a rough surface or is provided with shear keyway (11), and high-strength non-shrink grout is injected at the joint.

6. A precast-cast-in-place composite structural column according to claim 1, characterized in that, The steel bar connecting sleeve (10) is a straight thread sleeve or a grouting sleeve, and the longitudinal steel bars of the lower cast-in-place section (1) and the upper cast-in-place section (3) extend into the sleeve and connect with it.

7. A precast-cast-in-place composite structural column according to claim 1, characterized in that, The elastic buffer layer (12) is a closed-cell elastomer layer pre-applied to the side of the middle prefabricated section (2) in the factory. The material is selected from rubber, EVA, EPS foam or polyurethane, and the thickness is 5mm.

8. A precast-cast-in-place composite structural column according to claim 1, characterized in that, The elastic buffer pad (12) has through holes for the pre-embedded connector (8) to pass through. The connector (8) passes through the buffer pad (12) and is welded or mechanically connected to the tie bar in the aerated block masonry wall (5).

9. A precast-cast-in-place composite structural column according to claim 1, characterized in that, The side of the prefabricated section (2) in the middle is provided with an interlocking groove. The aerated block is embedded in the groove for masonry, and an elastic buffer pad (12) is sandwiched between the inner wall of the groove and the block, forming a dual connection of mechanical interlocking and elastic buffering.

10. A construction method for a precast-cast-in-place composite structural column, wherein the method is carried out according to any one of claims 1-9, characterized in that, Includes the following steps: S1. In the factory prefabrication of the middle prefabrication section (2), sleeves or nuts for connecting holes (4) are pre-embedded on its two outer sides, steel bar connecting sleeves (10) and side connecting parts (8) are pre-embedded on the upper and lower joint surfaces, the joint surfaces are made into rough surfaces or keyways, and elastic buffer pads (12) are pre-attached on the side surfaces in the factory; at the same time, the factory prefabricates the non-removable outer mold (6), with shear keyways (11) or rough surfaces on its inner surface and sleeves for tie holes (4) pre-embedded on its outer surface; S2. Construct aerated block masonry wall (5), leave a cavity between the lower cast-in-place section (3) and the upper cast-in-place section (1) at the position of the structural column, and leave toothed joints (9) and tie bars at the corresponding heights of the upper and lower cast-in-place sections according to the specifications. S3. Hoist the middle precast section (2) into place, adjust the verticality and elevation, and connect and fix the connector (8) through the elastic buffer pad layer (12) and the wall tie bar so that the precast section (2) and the masonry (5) are connected as a whole and there is an elastic buffer gap between them. S4. Install the non-removable outer formwork (6) on the two outer sides of the lower cast-in-place section (3) and the upper cast-in-place section (1) so that the non-removable outer formwork (6) is connected to the outer side of the middle precast section (2) as a continuous outer skin. The tie bolts (7) pass through the connection hole (4) of the precast section (2) at the height of the precast section and through the tie hole (4) of the non-removable outer formwork (6) at the height of the cast-in-place section and are tightened. The tie bolts (7) do not contact the aerated block masonry wall (5). S5. Pour concrete into the cavity of the cast-in-place section. The concrete overlaps with the keyway (11) on the inner surface of the non-removable outer formwork (6). High-strength grout is injected at the joint surface and compacted by vibration. S6. After the concrete reaches its strength, the outer formwork (6) is left on the column as the outer skin of the column without removal. The connecting hole (4) is located on the precast section (2) or the outer formwork (6) without removal. The wall does not need to be patched.

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