Prefabricated reinforced concrete frame column column in the node construction method

Abstract

The application discloses a kind of fabricated reinforced concrete frame column column in assembly node construction method, belong to the technical field of fabricated building, method includes: hoisting, positioning to prefabricated upper column and prefabricated lower column;Under the support of adjustable lateral support unit, upper and lower steel pipes are welded, sleeve grouting connection is carried out to upper and lower steel bars;Column in assembly node shaping formwork is installed on the outside of upper and lower steel bars;Pouring concrete into column in assembly node shaping formwork, upper and lower steel pipes, form reinforced concrete frame column;Curing concrete, when concrete final setting, in the early age of concrete, on the current layer reinforced concrete frame column, upper layer construction is carried out.Column in assembly node is arranged in the position where column bending moment is smaller, the bearing capacity of column assembly node early age is improved by using the confinement effect of steel pipe concrete, and the template support system with stiffness is applied to transfer construction load to prefabricated component, which greatly improves the early age load bearing capacity and realizes rapid assembly.

Description

Technical Field

[0001] This invention belongs to the field of prefabricated building technology, and more specifically, relates to a construction method for prefabricated joints in prefabricated reinforced concrete frame columns. Background Technology

[0002] Prefabricated buildings refer to buildings assembled on-site using prefabricated components manufactured in a factory. They offer advantages such as saving construction time, reducing construction costs, and minimizing construction waste. Furthermore, the components can be reused, making them more environmentally friendly than traditional concrete structures. During the construction phase of reinforced concrete structures, beams, columns, and floor slabs need to withstand construction loads of varying stress levels before the concrete reaches maturity. These stress levels are closely related to the construction method and speed. In the context of rapid construction, the load-bearing capacity of early-age concrete, especially very early-age concrete, and the timing of formwork removal have become core issues affecting structural safety. Even slight negligence can easily lead to major safety accidents.

[0003] The assembly and connection method of vertical components is a major factor affecting the assembly and construction speed, and improving the construction speed of vertical components is the main means to achieve rapid assembly and construction of projects. The stress conditions at the assembly joint locations and the early-age bearing capacity of the assembly joints are the core contents for achieving the goal of rapid construction of prefabricated concrete frame columns, and are also the most significant differences between concrete structures and steel structures in terms of assembly and construction.

[0004] To enhance the load-bearing capacity, ductility, and seismic performance of vertical structural member assembly joints, steel-concrete composite tubes are commonly used to improve their stress resistance. Patent CN209482588U discloses a rapidly assembleable, internally-built steel-box confined concrete column with advantages such as high load-bearing capacity, good ductility, and superior seismic performance. However, the curing of the concrete at the connection joint requires a significant amount of time, necessitating waiting for the concrete strength to reach the required load-bearing capacity before proceeding to the next stage of construction, thus failing to achieve the goal of rapid assembly. Patent CN108149844A discloses a self-positioning prefabricated steel-concrete composite tube column joint and its construction method. While this connection method reduces the pouring and curing time of the concrete inside the steel tube, it results in insufficient integrity between the upper and lower columns, reduced ductility and seismic performance. Furthermore, it requires waiting for the cement-based grout to reach the required load-bearing capacity before proceeding to the next construction step, again failing to achieve the goal of rapid assembly. Summary of the Invention

[0005] To address the shortcomings and improvement needs of existing technologies, this invention provides a construction method for prefabricated reinforced concrete frame column assembly nodes, aiming to provide a column assembly node with more robust support and higher assembly efficiency, as well as its construction method.

[0006] To achieve the above objectives, according to one aspect of the present invention, a construction method for assembly nodes in prefabricated reinforced concrete frame columns is provided, comprising: S1, hoisting and positioning a prefabricated upper column and a prefabricated lower column; the prefabricated upper column includes an upper steel pipe and upper reinforcing bars surrounding the outside of the upper steel pipe, and the prefabricated lower column includes a lower steel pipe and lower reinforcing bars surrounding the outside of the lower steel pipe, wherein the assembly connection position of the prefabricated upper column and the prefabricated lower column is set within a predetermined range in the middle of the floor height; S2, arranging adjustable lateral support units, wherein the adjustable lateral support units... With the support of the element, the upper steel pipe and the lower steel pipe are welded together, and the upper steel bar and the lower steel bar are connected by sleeve grouting; S3, the column assembly node shaping template is installed on the outside of the upper steel bar and the lower steel bar; S4, concrete is poured into the column assembly node shaping template, the upper steel pipe and the lower steel pipe to form a reinforced concrete frame column; S5, the concrete is cured, and when the concrete has finally set, during the early age of the concrete, the upper layer precast reinforced concrete frame column is constructed on the current layer reinforced concrete frame column.

[0007] Furthermore, the column assembly node formwork comprises: an inner steel plate, transverse reinforcing ribs, longitudinal reinforcing ribs, and tie bolts; the tie bolts are used to connect the column assembly node formwork, and the inner steel plate, transverse reinforcing ribs, and longitudinal reinforcing ribs are used to increase the rigidity of the column assembly node formwork; the adjustable lateral support unit comprises: an upper inclined support, a lower inclined support, an adjustable top support, and an adjustable bottom support; the upper inclined support and the lower inclined support are cross-connected, the adjustable top support is connected to one end of the upper inclined support, the adjustable bottom support is connected to one end of the lower inclined support, and the other ends of the upper and lower inclined supports are used to support the sides of the precast component; the column assembly node formwork and the adjustable lateral support unit are used to transfer external loads to the precast component.

[0008] Furthermore, the early age period is defined as 1-3 days after concrete pouring.

[0009] Furthermore, the outer surface of the welded end of the lower steel pipe is provided with multiple ear plates, and S2 further includes: welding the ear plates and the upper steel pipe to reinforce the connection between the upper steel pipe and the lower steel pipe.

[0010] Furthermore, the number of ear plates is four, and the positions of the ear plates are staggered from the positions of the lower reinforcing bars.

[0011] Furthermore, a high-strength grouting material mold is installed on the outside of the upper and lower reinforcing bars, and the side of the high-strength grouting material mold is provided with grouting holes and grout discharge holes.

[0012] Furthermore, the inner side of the high-strength grouting material mold is roughened.

[0013] Furthermore, the column surface of the reinforced concrete frame column is a rough surface.

[0014] According to another aspect of the present invention, an assembly node in a prefabricated reinforced concrete frame column is provided, characterized in that it is assembled using the prefabricated reinforced concrete frame column assembly node construction method described above.

[0015] In summary, the above-described technical solutions conceived in this invention can achieve the following beneficial effects:

[0016] (1) A construction method for assembly nodes in prefabricated reinforced concrete frame columns is provided. By setting the assembly connection positions of the prefabricated upper and lower columns within a certain range in the middle of the story height, the assembly node of the frame column is located in the column with less stress. By embedding a steel pipe in the core of the assembly node section to confine the concrete core column, the requirements of the early-age concrete column assembly node for axial compression, bending and shear bearing capacity under construction conditions can be met. This reduces the construction waiting time, greatly shortens the construction cycle, and enables rapid assembly.

[0017] (2) The upper layer construction is carried out in the early age after the concrete has set, so that the concrete at the joint is stressed in the early age. Under the constraint effect of the formwork and steel pipe, the concrete particles are more compact, the solubility of cement is increased, and the hydration reaction of concrete is increased, so that the concrete has a higher load-bearing capacity in the later stage, which is more conducive to the long-term load-bearing capacity of the assembled joint. In addition, all the longitudinal reinforcement in the assembled joint area is connected, and the upper and lower steel pipe concrete are cast in place together, which further improves the load-bearing performance of the assembled joint.

[0018] (3) Install the prefabricated column assembly node template and adjustable lateral support unit on the outside of the prefabricated component. Through the lateral constraint of the template, the bearing capacity of the column assembly node section can be improved simultaneously. The prefabricated column and prefabricated beam are connected into a spatial force system by using the template and adjustable lateral support unit. The force transmission path is clear. Except for the frame column assembly node, the prefabricated component is fully utilized to transmit the load on the force transmission path, which greatly reduces the load on the assembly node and makes it meet the early age construction requirements. Attached Figure Description

[0019] Figure 1 A flowchart of the construction method for assembly nodes in prefabricated reinforced concrete frame columns provided in this embodiment of the invention;

[0020] Figure 2 This is a structural schematic diagram of the assembly node in a prefabricated reinforced concrete frame column provided in an embodiment of the present invention;

[0021] Figure 3 This is a detailed structural diagram of the lower column of the assembled joint in the prefabricated reinforced concrete frame column provided in an embodiment of the present invention;

[0022] Figure 4 This is a top view of the lower column of an assembled joint in a prefabricated reinforced concrete frame column provided in an embodiment of the present invention;

[0023] Figure 5 A schematic diagram of a standard template for a column assembly node with lateral constraint function provided in an embodiment of the present invention;

[0024] Figure 6 This is a detailed drawing of the template for the column assembly node with lateral constraint function provided in an embodiment of the present invention.

[0025] Figure 7 This is a schematic diagram of the assembly template for the column assembly node with lateral constraint function provided in an embodiment of the present invention.

[0026] Figure 8 A graph showing the relationship between the loading age and the bearing capacity improvement rate of steel-concrete composite pipes provided for embodiments of the present invention.

[0027] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0028] 1 is a precast column, 2 is a precast beam, 3 is a precast slab, 4 is the bottom reinforcement, 5 is the bottom steel pipe, 6 is the ear plate, 7 is the high-strength grouting material mold, 8 is the concrete inside the steel pipe, 9 is the high-strength grouting material, 10 is the concrete outside the steel pipe, 11 is an adjustable lateral support unit, 12 is the precast formwork for the assembly node in the column, 13 is the poured concrete, 14 is the steel plate inside the precast formwork, 15 is the tie bolt, 16 is the transverse reinforcement back rib, and 17 is the longitudinal reinforcement back rib. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0030] In this invention, the terms "first," "second," etc. (if present) in the invention and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0031] Figure 1 A flowchart illustrating the construction method for assembled joints in prefabricated reinforced concrete frame columns provided in this embodiment of the invention. (See also...) Figure 1 , combined Figures 2-8 The construction method of the assembly node in the prefabricated reinforced concrete frame column in this embodiment is described in detail. The construction method includes operation S1-operation S5.

[0032] Operation S1 is used to hoist and position the precast upper column and the precast lower column. The precast upper column includes an upper steel pipe and upper reinforcing bars surrounding the outside of the upper steel pipe. The precast lower column includes a lower steel pipe and lower reinforcing bars surrounding the outside of the lower steel pipe. The assembly connection position of the precast upper column and the precast lower column is set within a set interval in the middle of the floor height.

[0033] The components required for assembling precast column 1 are transported to the site, and the precast upper and lower columns are hoisted and positioned to ensure vertical alignment. Specifically, the upper and lower steel pipes are aligned, and the upper and lower reinforcing bars are aligned one by one.

[0034] In this embodiment, the set interval can be set according to specific actual needs. By setting the assembly connection position of the precast upper column and the precast lower column within the set interval in the middle of the floor height, it is ensured that the frame column assembly node is located in the middle part of the column where the stress is less. In this embodiment, the frame column assembly node can be set in the middle part of the column where the stress is less, based on the specific floor height in the construction scenario, while ensuring ease of construction.

[0035] Operate S2 to arrange the adjustable lateral support unit. Under the support of the adjustable lateral support unit, weld the upper and lower steel pipes and connect the upper and lower reinforcing bars with sleeve grouting.

[0036] An adjustable lateral support unit 11 is arranged. Under the support of the adjustable lateral support unit, an upper steel pipe and a lower steel pipe are welded. The upper steel bar is aligned with the lower steel bar 4 with the high-strength grouting material mold 7, and high-strength grouting material 9 is injected into the grouting hole.

[0037] According to an embodiment of the present invention, the adjustable lateral support unit includes: an upper inclined support, a lower inclined support, an adjustable top support, and an adjustable bottom support; the upper inclined support and the lower inclined support are cross-connected, the adjustable top support is connected to one end of the upper inclined support, the adjustable bottom support is connected to one end of the lower inclined support, and the other ends of the upper and lower inclined supports are used to support the side of the precast component, such as... Figure 5 and Figure 6 As shown, Figure 5 The image shows 13, which has already been poured.

[0038] Preferably, the outer surface of the welded end of the lower steel pipe 5 is provided with a plurality of ear plates 6. Operation S2 further includes: welding the ear plates and the upper steel pipe to reinforce the connection between the upper and lower steel pipes.

[0039] Preferably, there are four ear plates, and the positions of the ear plates are staggered from the positions of the lower reinforcing bars to facilitate welding.

[0040] Preferably, the inner side of the high-strength grouting material mold is a rough surface.

[0041] Operate S3 to install the column assembly node formwork on the outside of the upper and lower reinforcing bars.

[0042] According to an embodiment of the present invention, the prefabricated template 12 for the column assembly node includes: an inner steel plate 14, transverse reinforcing back ribs 16, longitudinal reinforcing back ribs 17, and tie bolts 15. The tie bolts are used to connect the prefabricated template for the column assembly node. The inner steel plate, transverse reinforcing back ribs, and longitudinal reinforcing back ribs are used to increase the rigidity of the prefabricated template for the column assembly node. Adjustable lateral support units are supported on the prefabricated components, and their height can be adjusted according to the floor height.

[0043] In this embodiment, the size of the assembly node template can be adjusted according to different assembly nodes. All components used in this assembly node can be prefabricated in the factory, reused, and are easy to operate, suitable for different scenarios. By using the prefabricated template of the column assembly node and the adjustable lateral support unit, the prefabricated column 1, prefabricated beam 2 and prefabricated slab 3 are connected into a spatial force-bearing system. The force transmission path is clear, and except for the frame column assembly node, the rest of the force transmission path makes full use of the prefabricated components to transfer the load.

[0044] By using prefabricated formwork and lateral supports in the column assembly nodes, external loads are transferred to the prefabricated components, making full use of the prefabricated components to transfer loads and greatly reducing the load on the core nodes.

[0045] Operate S4 to pour concrete into the pre-formed template, upper steel pipe, and lower steel pipe of the column assembly node to form a reinforced concrete frame column.

[0046] The structure of the precast reinforced concrete frame columns is as follows: Figure 2 As shown, the top view is as follows Figure 4 As shown; the specific structure of the lower column of the precast reinforced concrete frame column is as follows. Figure 3 As shown, the column surface of the reinforced concrete frame column is rough.

[0047] Operate S5 to cure the concrete. After the concrete has set, during the early age of the concrete, construct the upper-level precast reinforced concrete frame columns on the current-level reinforced concrete frame columns.

[0048] According to an embodiment of the present invention, the early age period is 1-3 days after concrete pouring. The final construction results in a building structure comprising multiple layers of precast reinforced concrete frame columns, as shown below. Figure 7 As shown.

[0049] See Figure 8The graph showing the relationship between the loading age and the bearing capacity improvement rate of concrete-filled steel tubes (CFST) specimens demonstrates that early loading followed by curing is beneficial to the later-stage ultimate bearing capacity of CFST specimens. The increase in the later-stage ultimate bearing capacity of CFST specimens is negatively correlated with the loading age; the earlier the loading age, the greater the increase in the later-stage ultimate bearing capacity. Based on this finding, in this embodiment of the invention, the concrete poured inside the steel tube is subjected to stress at an early age, which not only does not reduce the later-stage bearing capacity but also improves the performance of the assembly joint.

[0050] This invention also provides an assembly joint in a prefabricated reinforced concrete frame column, employing, as shown in... Figures 1-8 The prefabricated reinforced concrete frame column is assembled using the assembly node construction method shown.

[0051] The prefabricated joint in the precast reinforced concrete frame column includes a precast upper column, a precast lower column, and cast-in-place concrete. The precast upper column includes an upper steel pipe and upper reinforcing bars; the precast lower column includes a lower steel pipe and lower reinforcing bars; the cast-in-place concrete includes concrete 10 on the outside of the steel pipe and concrete 8 on the inside of the steel pipe. The upper and lower steel pipes are welded together, with four ear plates reinforcing the outside of the steel pipes, and cast-in-place concrete on the inside. The upper reinforcing bars surround the upper steel pipe, and the lower reinforcing bars surround the lower steel pipe; the upper and lower reinforcing bars are connected by high-strength grout. The concrete on the outside of the steel pipes is poured around the upper and lower steel pipes and wraps around the upper and lower reinforcing bars.

[0052] The prefabricated reinforced concrete frame column assembly node construction method provided in this invention adopts a composite column scheme with a steel tube concrete core column set in the core of the frame column section to improve the early-age axial compression bearing capacity of the prefabricated reinforced concrete column. At the same time, the tensile and compressive bearing capacity of the longitudinal reinforcement around the frame column provides the flexural bearing capacity of the section. The shear bearing capacity is provided by the auxiliary prefabricated node formwork to meet the requirements of the early-age bearing capacity of the prefabricated node column. The early-age bearing capacity of the prefabricated node can be adjusted by changing the cross-sectional size of the core column, the constraint effect, the strength of the infill concrete, etc., so as to meet the requirements of different construction speeds and achieve a construction speed close to that of prefabricated steel structures.

[0053] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A construction method for assembled joints in prefabricated reinforced concrete frame columns, characterized in that, include: S1, hoisting and positioning the precast upper column and the precast lower column; the precast upper column includes an upper steel pipe and an upper reinforcing bar surrounding the outside of the upper steel pipe, the precast lower column includes a lower steel pipe and a lower reinforcing bar surrounding the outside of the lower steel pipe, and the assembly connection position of the precast upper column and the precast lower column is set within a set interval in the middle of the floor height. S2, Arrange an adjustable lateral support unit, and under the support of the adjustable lateral support unit, weld the upper steel pipe and the lower steel pipe, and connect the upper reinforcing bar and the lower reinforcing bar with sleeve grouting; S3, install the node shaping formwork in the column outside the upper and lower reinforcing bars; S4, pour concrete into the preformed template of the column assembly node, the upper steel pipe and the lower steel pipe to form a reinforced concrete frame column; S5, the concrete is cured. After the concrete has set, during the early age of the concrete, the upper-level precast reinforced concrete frame column is constructed on the current-level reinforced concrete frame column. The prefabricated template for the column assembly node includes: an inner steel plate, a transverse stiffening back rib, a longitudinal stiffening back rib, and tie bolts; the tie bolts are used to connect the prefabricated template for the column assembly node, and the inner steel plate, the transverse stiffening back rib, and the longitudinal stiffening back rib are used to increase the rigidity of the prefabricated template for the column assembly node; The adjustable lateral support unit includes: an upper inclined support, a lower inclined support, an adjustable top support, and an adjustable bottom support; the upper inclined support and the lower inclined support are cross-connected, the adjustable top support is connected to one end of the upper inclined support, the adjustable bottom support is connected to one end of the lower inclined support, and the other ends of the upper inclined support and the other ends of the lower inclined support are used to support the side of the precast component; The prefabricated template for the column assembly node and the adjustable lateral support unit are used to transfer external loads to the prefabricated components.

2. The construction method for assembled joints in prefabricated reinforced concrete frame columns as described in claim 1, characterized in that, The early age period is defined as 1-3 days after concrete pouring.

3. The construction method for assembled joints in prefabricated reinforced concrete frame columns as described in claim 1, characterized in that, The outer surface of the welded end of the lower steel pipe is provided with multiple ear plates. S2 further includes: welding the ear plates and the upper steel pipe to reinforce the connection between the upper steel pipe and the lower steel pipe.

4. The construction method for assembled joints in prefabricated reinforced concrete frame columns as described in claim 3, characterized in that, The number of ear plates is four, and the positions of the ear plates are staggered from the positions of the lower reinforcing bars.

5. The construction method for assembled joints in prefabricated reinforced concrete frame columns as described in claim 1, characterized in that, A high-strength grouting material mold is installed on the outside of the upper and lower reinforcing bars, and the side of the high-strength grouting material mold is provided with grouting holes and grout discharge holes.

6. The construction method for assembled joints in prefabricated reinforced concrete frame columns as described in claim 5, characterized in that, The inner side of the high-strength grouting material mold is rough.

7. The construction method for assembled joints in prefabricated reinforced concrete frame columns as described in any one of claims 1-6, characterized in that, The column surface of the reinforced concrete frame column is rough.

8. An assembly joint in a prefabricated reinforced concrete frame column, characterized in that, It is assembled using the assembly node construction method in the prefabricated reinforced concrete frame column as described in any one of claims 1-7.

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