Construction method of precast concrete unit outer hanging inner concave window wall plate support

Abstract

The application relates to the technical field of assembled building, and provides a construction method of a precast concrete unit outer-hung inner-concave window wall plate support, a precast concrete unit outer-hung inner-concave window wall plate deepening design, embedded part processing and manufacturing, steel bar binding and embedded part installation, connecting part and ball foot bolt welding and installation, outer-hung wall plate hoisting, bottom ball foot bolt installation, high-strength bolt initial tightening, standard high alignment and position adjustment, and bolt final tightening. The construction method has the characteristics of precast concrete inner-concave window modeling and structure requirements, reasonable stress combination and high installation efficiency.

Description

Technical Field

[0001] This invention belongs to the field of prefabricated building technology, specifically relating to a construction method for connecting precast concrete external recessed window wall panels. Background Technology

[0002] Traditional construction techniques for external wall panels, such as direct welding or bolting on the sides, are only suitable for flat wall panels and cannot be directly applied to recessed window wall panels. Recessed window wall panels have uneven stress distribution and are prone to eccentric stress. Traditional load-bearing points are generally supported by four points on the side, and conventional processes such as sleeve grouting are used for the lower support points. Sleeve grouting requires later grouting, and it takes time for the concrete to reach its strength. In addition, it is not suitable for recessed window wall panels due to the influence of shape or construction efficiency.

[0003] The space for recessed windows is limited, and there is no place to place conventional brackets / supports. Traditional construction requires additional supports on the inside for secondary installation, such as welding, bolting, and sealing the cavity, which leads to complicated procedures, increased costs, and damage to the shape. Summary of the Invention

[0004] This invention aims to provide a construction method for precast concrete unit external recessed window wall panel supports. This support system construction method combines the structural requirements of precast concrete recessed windows with the characteristics of reasonable stress combination and high installation efficiency. It abandons the traditional thinking of "building the structure first and then adding the support," directly utilizing the cavity created by the recessed window's architectural shape as the installation space for the support and corbel, achieving the triple goals of "preserving the architectural shape, ensuring reliable structural stress, and improving construction efficiency."

[0005] The specific technical solution of the present invention is as follows: A construction method for a precast concrete unit external recessed window wall panel support, the construction steps of which are as follows:

[0006] S1, Detailed design of precast concrete unit external recessed window wall panel, and processing and fabrication of embedded parts;

[0007] S2, external wall panel processing and manufacturing, pre-embedded bottom fixed hinge node pre-embedded part ball bolt sleeve, top sliding node pre-embedded part L2, and lifting ring;

[0008] S3, on-site steel bar binding and connection base embedded parts installation. During the construction of the floor structure, the beam and slab steel bars are bound. Additional stirrups and cantilever lugs are set at the self-weight support points of the external wall panels. YM1 embedded parts are set on the left side of the cantilever lugs, and YM2 embedded parts are set on the upper side of the cantilever lugs.

[0009] S4, Connector installation: The top sliding node connector includes L3 connector and L1 connector. L3 connector is welded to the YM1 embedded part on the left side of the cantilever ear. L1 connector is stacked with the L3 connector of the top sliding node. The two are connected by high-strength bolts. The bottom sliding node L4 connector and the ball foot bolt base are welded to the YM2 embedded part on the upper side of the cantilever ear.

[0010] S5, external recessed window wall panels are hoisted using lifting rings;

[0011] S6, insert one end of the ball bolt into the ball bolt sleeve of the outer wall panel, and insert the other end into the ball bolt connection base on the lug to realize the bottom fixed hinge node connection;

[0012] S7, high-strength bolts are initially tightened, the top sliding node L1 connector is bolted to the top sliding node embedded part L2, and the bottom sliding node L4 connector is fixed to the bottom of the outer wall panel by bolts, thus realizing the initial connection between the bottom sliding node and the top sliding node.

[0013] S8, Elevation correction and position adjustment;

[0014] S9, tighten the bolts to complete the installation of the external wall panel.

[0015] Furthermore, in the construction method of the precast concrete unit external recessed window wall panel support, in S2, the top sliding node embedded part L2 is a steel plate, which is closely attached to the inner side of the external wall panel. One end is welded to the anchor bar of the external wall panel, and the other end extends out of the external wall panel and is provided with two round holes.

[0016] Furthermore, in the construction method of the precast concrete unit external recessed window wall panel support, in S3, the additional stirrups are six in number, the type of additional stirrups is the same as the stirrups of the structural beam, and the spacing is 50mm; the YM1 / 2 embedded parts are steel plates, each with 3*3 anchor bars and cantilever bars welded together, and the concrete is poured and cured in one go.

[0017] Furthermore, in the construction method of the precast concrete unit external recessed window wall panel support, in step S4, the top sliding node connector includes L3 and L1, both of which are vertically bent steel plates. The vertical surface of the L3 connector is welded to the embedded part YM1 on the left side of the cantilever ear, and two round holes are provided on the horizontal surface. The vertical surface of the L1 connector has two elongated holes, which are connected to the embedded part L2 of the external wall panel by high-strength bolts. The horizontal surface has two round holes, which are stacked on top of the horizontal surface of the L3 connector and connected by high-strength bolts.

[0018] Furthermore, in the construction method of the precast concrete unit external recessed window wall panel support, in step S4, the bottom sliding node L4 connector is a vertically bent steel plate with two elongated holes on the vertical surface.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1) Integrated design concept of form and structure

[0021] Abandoning the traditional thinking of "building the structure first and then adding the support", the cavity created by the recessed window architectural shape itself is directly used as the support installation space, achieving the triple goal of "not destroying the architectural shape + reliable structural stress + improved construction efficiency".

[0022] 2) Dedicated load-bearing system for irregularly shaped exterior wall panels

[0023] In response to the uneven stress distribution and tendency to cause eccentric stress in recessed window wall panels, a custom 490×400mm cantilever lug with 6 additional reinforced stirrups is designed.

[0024] Using M30 seated ball bolts as the main load-bearing nodes can reliably transmit vertical loads and release small rotational stresses, thus avoiding rigid failure of the nodes.

[0025] It forms a system of "lower ball foot bearing + upper bolt adjustment + 6-point coordinated force bearing", which is more suitable for irregular wall panels than the conventional 2-4 point support;

[0026] 3) Synergistic process of "flexible adjustment + rigid force"

[0027] The use of elongated holes enables flexible adjustment during installation, solving the problems of limited space and high installation precision requirements in recessed windows.

[0028] After the bolts are finally tightened, a rigid load-bearing system is formed, ensuring structural safety during the service life. Attached Figure Description

[0029] Figure 1 Rear perspective view of the precast concrete unit with recessed window wall panel of the present invention;

[0030] Figure 2 A top view of the precast concrete unit with an externally mounted recessed window wall panel according to the present invention.

[0031] Figure 3 Cross-sectional view of the window frame of the precast concrete unit with external recessed window of the present invention;

[0032] Figure 4 Cross-sectional view of the fabrication node of the precast concrete unit external wall panel of this invention;

[0033] Figure 5 A diagram showing the composition of the bottom fixed hinge node of this invention;

[0034] Figure 6 Diagram of the bottom sliding node composition of this invention;

[0035] Figure 7Diagram of the top sliding node composition of this invention;

[0036] Figure 8 The top sliding node L1 connector of the present invention and its 1-1 and 2-2 sectional views;

[0037] Figure 9 The bottom sliding node L4 connector of the present invention and its 6-6 and 7-7 sectional views;

[0038] Figure 10 The pre-embedded component of the top sliding node L2 of the present invention and its 3-3 sectional view;

[0039] Figure 11 The top sliding node L3 connector of the present invention and its 4-4 and 5-5 sectional views;

[0040] Figure 12 Schematic diagram of additional stirrups at the support point of the external wall panel of this invention. Detailed Implementation

[0041] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of the present invention will become clearer from the following description and claims. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the present invention.

[0042] Example:

[0043] A precast concrete unit external recessed window wall panel support includes an external recessed window wall panel (hereinafter referred to as the external wall panel) 1, and several sets of connection nodes set at the bottom and top of the external wall panel. All nodes consist of three parts: embedded parts embedded in the external wall panel, embedded parts of the connection base fixed to the main structure, and adjustable connecting parts connecting the two. The connection nodes include bottom nodes and top nodes.

[0044] The bottom connection node includes a bottom fixed hinge node 3 and a bottom sliding node 5. This invention uses two bottom fixed hinge nodes and two bottom sliding nodes. Figure 1 Rear perspective view of the precast concrete unit with recessed window wall panel of this invention. Figure 2 The invention relates to a precast concrete unit with an externally mounted recessed window wall panel, shown in the bottom view. The bottom fixed hinge joint is mainly used to bear the vertical load generated by the self-weight of the wall panel and to provide the main shear resistance and limiting constraints in the plane of the wall panel; the bottom sliding joint is mainly used to cooperate in bearing the vertical load and to allow the wall panel to slide along its length as designed.

[0045] The number of top nodes is the same as the number of bottom nodes. This invention includes two top sliding nodes 4, which are mainly used to provide support against wind loads and out-of-plane seismic forces, and allow the wall panel to slip within the plane as designed to accommodate the inter-story displacement of the main structure.

[0046] The single external wall panel 1 is connected to the main structural beam 2 through two bottom fixed hinge nodes 3, two bottom sliding nodes 5 and two top sliding nodes 4, forming a stable support system. Figure 1 Rear perspective view of the precast concrete unit with recessed window wall panel of this invention. Figure 2 A bottom view of the precast concrete unit with an external recessed window wall panel of this invention. Figure 3 Cross-sectional view of the precast concrete unit external recessed window frame of the present invention, and Figure 4 This invention provides a cross-sectional view of the fabrication details of precast concrete unit external wall panels. Figure 3 7 is an externally mounted recessed window frame.

[0047] Bottom fixed hinge node 3 is the main load-bearing and shear constraint point, including bottom fixed hinge embedded part, connecting base, and bottom fixed hinge connecting part. The bottom fixed hinge embedded part is a ball foot bolt mounting sleeve prefabricated at the bottom of the external wall panel.

[0048] A cantilever lug 3-2 is installed at the self-weight support point of the external wall panel on the main structural beam, serving as a node connection base. The cantilever lug is a C35 reinforced concrete structure, 490×400mm, with six additional stirrups. The type of additional stirrups is the same as the stirrups of the structural beam, with a spacing of 50mm. YM1 / 2 embedded parts, which are steel plates, are installed inside the cantilever lug. YM1 embedded part 3-4 is located on the left side of the cantilever lug, and YM2 embedded part 3-1 is located on the upper side of the cantilever lug. The concrete is poured and cured in one go. The combined design of the cantilever lug and the additional stirrups enhances the bending resistance and anchoring performance of the support. The bottom fixed hinge connection is an M30 seated ball bolt 3-3. The seated ball bolt 3-3 includes a mounting base 33-1, a ball bolt 33-2, and a ball bolt sleeve 33-3. The ball bolt sleeve is embedded in the bottom of the external wall panel, and the ball bolt mounting base is welded and fixed to the YM2 embedded part 3-1 inside the cantilever lug 3-2. During installation, after the external wall panel is initially hoisted into place, one end of the ball-foot screw 33-2 is inserted into the ball-foot bolt sleeve 33-3, and the other end is positioned on the mounting base 33-1. This node transmits most of the vertical reaction force and constrains the translational motion of the bottom plane of the external wall panel. For example... Figure 5 As shown, Figure 5 A diagram showing the composition of the bottom fixed hinge node of this invention.

[0049] The bottom sliding node 5 assists in bearing vertical loads and allows the external wall panel to undergo the designed allowable temperature expansion and contraction displacement along its length. The bottom sliding node includes the bottom sliding node L4 connector 5-2 and the YM2 embedded part 3-1 in the cantilever lug 3-2. The bottom sliding node L4 connector 5-2 is a steel plate bent at a right angle, with two elongated holes 5-2-1 on the vertical surface and two circular holes on the horizontal surface, such as... Figure 9 As shown, Figure 9 The invention relates to the bottom sliding node L4 connector and its sectional views 6-6 and 7-7. The bottom sliding node L4 connector 5-2 is welded to the YM2 embedded part 3-1 on the lug 3-2, as shown below. Figure 6 As shown, Figure 6 This is a diagram of the bottom sliding node of the present invention. An M24 (grade 10.9) bearing-type high-strength bolt 5-3 passes through the oblong hole 5-2-1 and is inserted into the bottom of the outer wall panel. The oblong hole provides controllable sliding capability and excellent deformation adaptability: during installation, it allows for flexible position adjustment, solving the problems of limited space in recessed windows and high installation precision requirements; during use, it allows the outer wall panel to slide controllably along the design direction when temperature changes, shrinkage, and inter-layer displacement of the main structure occur, thereby effectively releasing constrained internal forces. The length of the oblong hole is 110mm, determined based on the elastic inter-layer displacement angle of the main structure under earthquakes of design intensity, relevant dimensions of the wall panel, and installation tolerances, to ensure sufficient deformation capacity of the node; the length of the oblong hole is scientifically calculated to ensure effective operation of the node and structural safety under large deformations.

[0050] The top sliding node 4 is crucial for resisting out-of-plane loads and releasing in-plane deformation. The top of the external wall panel has a pre-embedded part 4-1 for the top sliding node L2, as shown below. Figure 10 As shown, Figure 10 The invention relates to the pre-embedded part of the top sliding node L2 and its 3-3 sectional view; the pre-embedded part 4-1 of the top sliding node L2 is a Q355B steel plate with a round hole, the lower section is vertically attached to and welded to the anchor bar at the top of the outer wall panel, and the upper section extends out of the top of the outer wall panel, the round hole is located in the upper section of the steel plate.

[0051] like Figure 8 As shown, Figure 8 The L1 connector at the top of this invention and its 1-1 and 2-2 sectional views. The L1 connector 4-3 is a steel plate bent at a right angle. The vertical surface of the steel plate has two parallel elongated holes, and the horizontal surface has two circular holes.

[0052] like Figure 11 As shown, Figure 11 The invention relates to the top sliding node L3 connector and its 4-4 and 5-5 sectional views. The L3 connector 4-4 is a steel plate bent at a right angle. The horizontal surface of the steel plate has two circular holes for bolt fixing connection.

[0053] L1 connector 4-3 and L3 connector 4-4 are stacked together and connected by M24 (10.9 grade) bearing high-strength bolts 4-3-1 to constrain translation within the plane and achieve the connection between the top of the external wall panel and the main structural beam.

[0054] like Figure 7 As shown, Figure 7 This is a diagram of the top sliding node of the present invention. A YM1 embedded part 3-4 is provided on the left side of the C35 reinforced concrete cantilever 3-2 on the main structural beam. The external wall panel is connected to the cantilever via an L1 connector 4-3 and an L3 connector 4-4. The vertical surface of the L1 connector 4-3 rests against the top of the external wall panel, and its elongated hole is fixedly connected to the circular hole of the top sliding node L2 embedded part 4-1 by high-strength bolts. The vertical surface of the L3 connector 4-4 is welded to the YM1 embedded part 3-4 of the cantilever. The horizontal circular hole of the L1 connector 4-3 is aligned vertically with the horizontal circular hole of the L3 connector 4-4 and fixedly connected by high-strength bolts. The high-strength bolts are M24 (10.9 grade) bearing-type high-strength bolts. During fixing, modified ultra-high molecular weight polyethylene gaskets 6 are used to achieve small displacement release, avoiding rigid damage to the node. The elongated hole allows for flexible adjustment of the position of the external wall panel during installation, and during use, when the external wall panel undergoes temperature changes, shrinkage, or displacement between the main structural layers, it can generate controllable sliding along the design direction, thereby effectively releasing the constraint internal force.

[0055] Modified ultra-high molecular weight polyethylene sliding pads 6 are installed between the contact surfaces of all high-strength bolts to reduce friction, achieve small displacement release, and avoid joint rigidity failure.

[0056] The length L of the oblong hole is calculated using the formula L≥2*Δ*H+d+ΔL, where Δ is the elastic inter-story drift angle of the main structure under the design intensity earthquake, H is the height of the external wall panel, d is the bolt diameter, and ΔL is the installation tolerance. This node resists wind and out-of-plane seismic forces, while allowing the wall panel to slide in-plane to release deformation stress.

[0057] Under sustained conditions such as wind load and self-weight, the load is distributed through each node according to its function. During earthquakes or temperature deformation, the "controllable sliding mechanism" in the top sliding node 4 and the bottom sliding node 5 is activated, allowing the wall panel to slide controllably relative to the main structure along the elongated hole, dissipating energy and releasing force, achieving "adapting to deformation through sliding" and ensuring overall safety.

[0058] The construction method for the precast concrete unit external recessed window wall panel support is as follows:

[0059] Step 1: Detailed design and fabrication of precast concrete unit external recessed window wall panels (hereinafter referred to as external wall panels): Using BIM modeling and other methods, node collisions are simulated in advance, construction feasibility and support stress design are considered, and the precast concrete unit external recessed window wall panels are detailed in advance. The cavity formed by the upper and lower shapes of the recessed window is used to set up the installation support. The external wall panels are manufactured in the factory. According to the detailed design drawings, the embedded parts of the structural stage are fabricated, including the top sliding node embedded parts L2, YM1, YM2, L3 connector, L4 connector, and L1 connector; the ball bolts are standard parts and are used directly.

[0060] Step 2: Fabrication of the external wall panel, including the pre-embedded ball bolt sleeve of the bottom fixed hinge node, the pre-embedded part L2 of the top sliding node, and the lifting ring; the lifting ring is a ∅20 round steel lifting ring, which is cast at the same time as the external wall panel and is used for hoisting the external wall panel.

[0061] Step 3: Binding of floor beam and slab reinforcement and installation of embedded parts for connection base. During floor structure construction, the beam and slab reinforcement is bound. At the self-weight support point of the external wall panel, 3-5 additional stirrups (six in total) are installed. The stirrup type is the same as the structural beam stirrups, and the stirrup spacing is 50mm. Figure 12 As shown. A cantilever is provided at the self-weight support point of the external wall panel, extending outward by 490mm and with a height of 400mm. The YM1 / 2 embedded part is welded to the cantilever reinforcement, and the concrete is poured and cured in one go. The combination design of the cantilever and additional stirrups enhances the bending resistance and anchorage performance of the support.

[0062] Step 4: Welding and installation of the connector and ball-foot bolt base. After the precast concrete exterior wall panel arrives on site, measure and mark the position of the connector. Weld the vertical surface of the L3 connector to the YM1 embedded part on the left side of the cantilever lug. Align the horizontal round hole of the L1 connector with the horizontal round hole of the L3 connector at the top sliding node. The two are connected by bolts. Weld the bottom sliding node L4 connector and the ball-foot bolt base to the YM2 embedded part on the upper side of the cantilever lug. The weld height is 8mm. The ball-foot bolts are M30 seated ball-foot bolts. The L1 connector and L3 connector are bolted together and tightened. The bolts are M24 (10.9 grade) bearing-type high-strength bolts.

[0063] Step 5, External wall panel hoisting: The external wall panels are hoisted to the corresponding positions on the floor using a crane connected to ∅20 round steel lifting rings for installation;

[0064] Step 6, Bottom ball anchor bolt installation: Insert one end of the ball anchor bolt of the bottom M30 seated ball anchor bolt into the ball anchor bolt sleeve of the outer wall panel for fixation, and insert the other end of the ball anchor bolt into the ball anchor bolt connection base on the lug. The seated ball anchor bolt is located directly below the outer wall panel and has the function of transmitting most of the vertical reaction force and restraining the movement of the bottom plane of the wall panel.

[0065] Step 7, Initial tightening of high-strength bolts: The top sliding node L1 connector and the top sliding node embedded part L2 are initially connected by bolts, and the bottom sliding node L4 connector is directly bolted to the bottom of the outer wall panel to achieve the initial connection between the bottom sliding node and the top sliding node; the bolts are M24 (10.9 grade) bearing type high-strength bolts;

[0066] Step 8, Elevation Correction and Position Adjustment: Adjust the elevation and position using the elongated holes on the top sliding node L1 connector and the bottom sliding node L4 connector. The elongated hole size is 110mm.

[0067] Step 9, Final Bolt Tightening: Tighten all bolts to ensure the external wall panel is under load, and the support installation is complete; through the combined action of the 6 load-bearing points, welded bolts and seated supports, the synergistic function of "flexible adjustment + rigid load-bearing" is achieved.

[0068] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents. The foregoing description is merely a description of preferred embodiments of the invention and is not intended to limit the scope of the invention in any way. Any changes or modifications made by those skilled in the art based on the foregoing disclosure shall fall within the scope of the claims.

Claims

1. A construction method for a precast concrete unit external recessed window wall panel support, characterized in that, Construction steps: S1, Detailed design of precast concrete unit external recessed window wall panel, and processing and fabrication of embedded parts; S2, external wall panel processing and manufacturing, pre-embedded bottom fixed hinge node pre-embedded part ball foot bolt sleeve, top sliding node pre-embedded part L2, and lifting ring; S3, on-site steel bar binding and installation of embedded parts for connecting base. During the construction of the floor structure, the steel bars of the beams and slabs are bound. A cantilever is set at the self-weight support point of the external wall panel. Additional stirrups are added inside the cantilever. YM1 embedded part is set on the left side of the cantilever and YM2 embedded part is set on the upper side of the cantilever. S4, L3 connectors, L4, L1, and ball-foot bolts are installed on the base. The top sliding node connectors include L3 and L1. The L3 connector is welded to the YM1 embedded part on the left side of the cantilever lug. The L1 connector is stacked with the top sliding node L3 connector and the two are connected by bolts. The bottom sliding node L4 connector and the ball-foot bolt base are welded to the YM2 embedded part on the upper side of the cantilever lug. S5, external recessed window wall panels are hoisted using lifting rings; S6, one end of the ball foot screw is inserted into the ball foot bolt sleeve of the external wall panel for fixation, and the other end of the ball foot is inserted into the ball foot bolt on the lug to connect to the base, so as to realize the bottom fixed hinge node connection; S7, initial bolt tightening: the top sliding node L1 connector is bolted to the top sliding node embedded part L2, and the bottom sliding node L4 connector is fixed to the bottom of the outer wall panel by bolts, thus realizing the initial connection between the bottom sliding node and the top sliding node. S8, Elevation correction and position adjustment; S9, tighten the bolts to complete the installation of the external wall panel.

2. The construction method for a precast concrete unit external recessed window wall panel support as described in claim 1, characterized in that, In S2, the top sliding node embedded part L2 is a steel plate, the lower section of which is vertically attached to and welded to the anchor bar at the top of the outer wall panel, and the upper section extends out of the top of the outer wall panel. The round hole is located in the upper section of the steel plate.

3. The construction method for a precast concrete unit external recessed window wall panel support as described in claim 1, characterized in that, In S3, there are six additional stirrups, the same type as the stirrups in the structural beam, and the spacing is 50mm; the YM1 / 2 embedded part is a steel plate, and the concrete is poured and cured in one go.

4. The construction method for a precast concrete unit external recessed window wall panel support as described in claim 1, characterized in that, In S4, the top sliding node connector includes L3 and L1, both of which are vertically bent steel plates. The L3 connector has two round holes on its horizontal surface. The L1 connector has two parallel elongated holes on its vertical surface and two round holes on its horizontal surface. During installation, the L1 connector is placed against the top of the outer wall panel, and the elongated holes are fixedly connected to the round holes of the top sliding node L2 embedded part by high-strength bolts. The vertical surface of the L3 connector is welded to the YM1 embedded part of the cantilever ear, and the horizontal round holes of the L1 connector are aligned vertically with the horizontal round holes of the L3 connector and fixedly connected by high-strength bolts.

5. The construction method for a precast concrete unit external recessed window wall panel support as described in claim 1, characterized in that, In S4, the bottom sliding node L4 connector is a vertically bent steel plate with two elongated holes on the vertical surface; during installation, bolts pass through the elongated holes of the L4 connector and are fixed to the bottom of the outer wall panel.

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