Outer wall unhooking type fully-prefabricated stair connecting joint and construction method thereof

Abstract

The invention relates to an outer wall unhooking type fully-prefabricated stair connecting joint and a construction method thereof.The outer wall unhooking type fully-prefabricated stair connecting joint comprises fully-prefabricated stair plates and stair beams, each fully-prefabricated stair plate comprises a stair section and platform plates located at the two ends of the stair section, the platform plates and the stair section are integrally formed, through bolt holes are formed in the platform plates at the two ends, and screws are welded to the top faces of the stair beams; the platform plates at the two ends of the fully-prefabricated stair plate are placed at the tops of the stair beams on the corresponding sides respectively, screws on the stair beams penetrate through bolt holes in the platform plates and are fixed through nuts, the platform plates and the outer wall are not fixedly connected, gaps between the platform plates and the outer wall are filled with rock wool layers, and the outer portions of the rock wool layers are subjected to blocking and sealing treatment. A facing layer is arranged on the top face of the fully-prefabricated stair board. The fully-prefabricated stair plates are connected with the pre-welded screws at the tops of the stair beams in a sleeving mode, wet operation is avoided, the fully-prefabricated stair plates and the outer wall are in a disengagement type design, the continuity of a heat preservation layer of the outer wall face cannot be damaged, a heat conduction path between the stair and the outer wall cannot be cut off, and stress transmission between the stair and the outer wall is reduced.

Description

Technical Field

[0001] This invention relates to the field of prefabricated steel structure buildings, specifically to an external wall detachable fully prefabricated staircase connection node and its construction method. Background Technology

[0002] In steel structure prefabricated building construction, prefabricated components are increasingly used for assembly. Compared to on-site concrete pouring, this significantly improves construction progress. Prefabricated stairs are a common type of prefabricated component used in high-rise buildings. Stairs typically consist of flight paths and platform slabs connecting to both ends of the flight paths. Most existing prefabricated stairs only use prefabricated flight paths. When assembling these on-site, the platform slabs are usually connected to the building's exterior walls, and then the prefabricated flight paths are assembled and connected to the platform slabs and stair beams. For ultra-low energy buildings, the design requires the insulation layer of the exterior walls to be continuous and not interrupted by the connection to the stairs. Therefore, existing prefabricated stairs typically require insulation layers on both the upper and lower surfaces of the flight paths and platform slabs during assembly to ensure the continuity of the insulation layer after the stairs are connected to the exterior walls, avoiding the formation of thermal bridges at the connection points.

[0003] The existing connection methods described above involve complex construction procedures, slow construction progress, high cost of insulation materials used in stairwells, and a risk of cracking and falling off at the connection between the platform slab and the exterior wall. Summary of the Invention

[0004] In view of the shortcomings of the existing prefabricated staircase connection methods, the present invention discloses an external wall detachable fully prefabricated staircase connection node that will not damage the continuous insulation layer of the external wall.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A prefabricated staircase connection node with detachable external wall includes a prefabricated stair slab and a stair beam. The prefabricated stair slab includes a stair section and platform slabs at both ends of the stair section. The platform slabs are integrally formed with the stair section. Through bolt holes are opened on both ends of the platform slabs. The top surface of the stair beams is welded with bolts. The platform slabs at both ends of the prefabricated stair slabs are respectively placed on the top of the stair beams on the corresponding sides. The bolts on the stair beams pass through the bolt holes on the platform slabs and are fixed with nuts. The platform slabs are not fixedly connected to the external wall. The gap between the two is filled with a rock wool layer. The rock wool layer is sealed. A finishing layer is provided on the top surface of the prefabricated stair slabs.

[0006] Furthermore, after the platform plate is fixed to the ladder beam, the bolt holes are first filled with grout, and the top of the grout is filled with sealing mortar.

[0007] Furthermore, a cement mortar leveling layer is provided on the top of the ladder beam, and the platform plate is placed on the cement mortar leveling layer.

[0008] Furthermore, a PE rod is embedded in the outer periphery of the rock wool layer, and sealant is applied to the outside of the PE rod.

[0009] The construction method for the above-mentioned external wall detachable prefabricated staircase connection node shall be carried out according to the following steps: Step 1): According to the design drawings, complete the construction of the exterior walls, stair beams and stair columns, and weld bolts on the top surface of the stair beams; Step 2): Lay a cement mortar leveling layer on top of the ladder beam; Step 3): Hoist the prefabricated stair slab to the installation position, ensuring that the platform slabs at both ends of the prefabricated stair slab correspond to the stair beams at the required installation positions; Step 4): Lower the fully prefabricated stair slab, insert the bolt holes on the platform slab into the threaded rods on the stair beams, and tighten them with nuts to secure them; Step 5): After completing step 4), first fill the bolt holes with grout, and then fill the surrounding gaps with sealing mortar. Step 6): First, fill the gap between the platform board and the exterior wall with a layer of rock wool, then embed a PE rod on the outside of the rock wool layer, and finally apply sealant to the outside of the PE rod. Step 7): Apply the finishing layer to the top surface of the precast stair slab.

[0010] This invention employs a pre-welded threaded connection between fully prefabricated stair slabs and the top of the stair beams, resulting in simple and quick assembly. No wet work is required on-site. The prefabricated stair slabs are detached from the exterior wall, with no direct fixed connection, allowing for simultaneous installation of the staircase and exterior wall insulation system. This avoids the overlapping issues of exterior wall insulation construction and staircase installation common in traditional methods, shortening the overall construction period. More importantly, it does not disrupt the continuity of the exterior wall insulation layer. Furthermore, the detached design of the staircase from the exterior wall cuts off the heat conduction path between the staircase and the exterior wall, reducing stress transfer (such as temperature deformation and structural settlement) and preventing insulation failure and reduced airtightness caused by joint cracking. Attached Figure Description

[0011] Figure 1 This is a three-dimensional structural diagram of the fully prefabricated stair slab in the embodiment; Figure 2 This is a schematic diagram of the installation structure of the fully prefabricated stair slab in the embodiment; Figure 3 for Figure 2 Enlarged view of point A in the middle.

[0012] Figure label: 1. Staircase; 2. Platform slab; 3. Bolt holes; 4. Stair beams; 5. Exterior wall; 6. Floor slab; 7. Bolt; 8. Cement mortar leveling layer; 9. Grouting material; 10. Sealing mortar; 11. Finishing layer; 12. Rock wool layer; 13. PE rod; 14. Sealant. Detailed Implementation

[0013] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0014] This embodiment discloses an external wall detachable prefabricated staircase connection node, wherein the staircase is assembled from multiple prefabricated PC staircase panels, and the structure of the prefabricated staircase panels is as follows: Figure 1 As shown, the middle section of the fully prefabricated stair slab is a stair section 1 with treads, and the two ends of the stair section 1 are platform slabs 2. The platform slabs 2 and the stair section 1 are integrally formed. Bolt holes 3 penetrating the thickness direction of the platform slabs 2 are prefabricated in the factory. The stair beams 4 are prefabricated in the factory. In this embodiment, the stair beams 4 are PEC beams. The bolts 7 are pre-welded to the top surface of the stair beams 4 in the factory.

[0015] The installation structure of the prefabricated stair slab described above in this embodiment is as follows: Figure 2 and Figure 3 As shown, the platform slabs 2 at both ends of each precast stair slab are placed on top of the corresponding side stair beams 4. Before placing the precast stair slabs, a cement mortar leveling layer 8 can be laid on top of the stair beams 4 to level the installation surface. Then, the bolts 7 on the stair beams 4 are passed through the bolt holes 3 on the platform slabs 2 and tightened with nuts. After fixing, the bolt holes 3 are filled with grout 9, and the surrounding gaps are filled and sealed with sealing mortar 10. The precast stair slabs do not need to be directly fixed to the exterior wall 5. A gap is left between the platform slabs 2 at the ends of the precast stair slabs and the exterior wall 5 on the corresponding side. This gap is first filled with a rock wool layer 12 for thermal insulation and soundproofing. Then, PE rods 13 are embedded in the gaps outside the rock wool layer 12 to provide expansion and contraction buffering. Finally, sealant 14 is applied to the outer ring of the PE rods 13 for waterproof sealing. After the stair slabs are installed and the sealing joints are cured, floor tiles or other materials can be laid on the top surface of the precast stair slabs as a finishing layer 11.

[0016] The construction method for the above-mentioned external wall detachable prefabricated staircase connection node shall be carried out according to the following steps: Step 1): According to the design drawings, complete the installation of the main structural beams and columns, ladder beam 4 and ladder columns, and weld the screw rod 7 on the top surface of ladder beam 4.

[0017] Specifically, the main structural beams, columns, and stair beams are positioned according to the design drawings, and then mechanically hoisted into place, temporarily fixed with embedded parts or bolts. The planar position, verticality, and elevation of the components are corrected, and after acceptance, the joint connections (such as welding and grouting) are completed to form a stable support system.

[0018] Step 2): Construction and installation of cast-in-place concrete insulated formwork exterior wall 5: Hoist the insulated formwork wall components according to the wall layout drawing, and reliably fix them to the main structure through connectors to ensure that the verticality and flatness of the wall meet the specifications. Complete the joint treatment between the formwork walls, and simultaneously reserve the connection node space with the stairs and steel beams, and complete the connection construction between the floor slab 6 and the exterior wall 5.

[0019] Step 3): Lay a cement mortar leveling layer 8 on the top of the ladder beam 4: Clean the debris on the top surface of the ladder beam 4, lay a 1:1 cement mortar leveling layer 8 on the ladder beam 4 according to the design elevation, smooth and polish it with a scraper, and cure it until it reaches the required strength.

[0020] Step 4): Hoisting of the fully prefabricated PC stair slab: Check the appearance of the fully prefabricated PC stair slab components and the integrity of the embedded parts. Use lifting equipment to hoist the stair slab above the stair beam 4 and make preliminary adjustments to align it with the stair beam 4 and the reserved nodes of the platform slab.

[0021] Step 5): Align the pre-drilled bolt holes 3 on the PC stair platform slab with the threaded rods 7 on the stair beam 4 and install the seals: Precisely insert the bolt holes 3 into the 1M16, C-grade threaded rods 7 on the stair beam 4. After adjusting the elevation and level of the stair slab, tighten the nuts and threaded rods 7 for fixation. Then, fill the joints of the threaded rods 7 with C40 grade CGM grouting material 9, and seal the surrounding gaps with sealing mortar 10.

[0022] Step 6): Sealing the gap between the prefabricated stair slab and the exterior wall 5: Clean the gap between the prefabricated stair slab and the exterior wall 5, first fill it with rock wool layer 12 to make it solid for thermal insulation and sound insulation, embed PE rod 13 on the outside for expansion and contraction buffer, and finally apply sealant 14 to seal and waterproof.

[0023] Step 7): After the stairs and sealing nodes have been cured, clean the base layer of the stair treads and lay the finishing layer such as floor tiles according to the design requirements to complete the surface cleaning and finished product protection.

[0024] The present invention has the following beneficial effects: (1) High precision in factory prefabrication, and "zero wet operation" on site; All core components of the fully prefabricated staircase (stair flights, platforms, and beams) are factory-finished, requiring only hoisting and joint connections on site. Compared to cast-in-place staircases, this reduces on-site wet work by more than 80%, eliminates the need for extensive formwork, and simplifies the construction process. The fully prefabricated staircase also serves as a construction access point, greatly facilitating construction.

[0025] (2) High construction efficiency, shortening the construction period of energy-saving systems; The fully prefabricated staircase eliminates the need for on-site wet work. Its design, which separates it from the exterior wall, allows for simultaneous construction with the main structure and exterior wall insulation system (eliminating the need to wait for the exterior wall to be completed before installing the staircase). This avoids the problem of "overlapping impacts between exterior wall insulation construction and staircase installation" in traditional processes, shortening the overall construction period by 20%-30% and ensuring that the construction rhythm of ultra-low energy consumption systems (such as insulation and airtightness) is not disturbed.

[0026] (3) 100% cut off linear thermal bridges with the exterior wall; When traditional staircases are directly connected to the exterior wall, the staircase (concrete / metal) easily becomes a "thermal bridge" (heat is rapidly transferred through the component). This invention's "detached design," through rock wool filling, PE rods, and sealant, completely cuts off the heat conduction path between the staircase and the exterior wall, reducing heat loss from the building envelope by 15%-20%, reducing the use of insulation materials, and significantly reducing on-site construction procedures.

[0027] (4) The insulation shell is truly "continuous and complete"; Exterior wall insulation can be applied in one continuous layer to the top, eliminating the need to cut off the insulation at stairwell openings, landings, or stair beams to leave "fireproof isolation strips" or "insulation terminations." This creates a continuous, uninterrupted insulation layer for the entire building, simplifying the design, construction, and acceptance processes.

[0028] (5) Reduce post-maintenance costs: The decoupled design reduces stress transfer between the staircase and the exterior wall (such as temperature deformation and structural settlement), avoiding problems such as insulation failure and reduced air tightness caused by joint cracking; at the same time, the fully prefabricated components are more durable, and the maintenance costs caused by thermal bridging and leakage in the later stage are reduced by more than 80%, which is in line with the goal of "long life and low maintenance" of ultra-low energy buildings.

[0029] Although embodiments of the 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.

Claims

1. A prefabricated staircase connection node with detachable hook-on mechanism for exterior walls, characterized in that: The system includes fully prefabricated stair slabs and stair beams. The fully prefabricated stair slabs consist of stair sections and platform slabs at both ends of the stair sections. The platform slabs are integrally formed with the stair sections, and through bolt holes are opened on both ends of the platform slabs. The top surface of the stair beams is welded with bolts. The platform slabs at both ends of the fully prefabricated stair slabs rest on the top of the stair beams on the corresponding sides, and the bolts on the stair beams pass through the bolt holes on the platform slabs and are fixed with nuts. The platform slabs are not fixedly connected to the exterior wall. The gap between the two is filled with a rock wool layer, and the outside of the rock wool layer is sealed. A finishing layer is installed on the top surface of the fully prefabricated stair slabs.

2. The external wall detachable prefabricated staircase connection node according to claim 1, characterized in that: After the platform plate is fixed to the ladder beam, the bolt holes are first filled with grout, and the top of the grout is filled with sealing mortar.

3. The external wall detachable prefabricated staircase connection node according to claim 1, characterized in that: A cement mortar leveling layer is provided on the top of the ladder beam, and the platform slab is placed on the cement mortar leveling layer.

4. The external wall detachable prefabricated staircase connection node according to claim 1, characterized in that: PE rods are embedded in the outer periphery of the rock wool layer, and sealant is applied to the outside of the PE rods.

5. The construction method of the external wall detachable prefabricated staircase connection node as described in any one of claims 1-4, characterized in that, Includes the following steps: Step 1): According to the design drawings, complete the construction of the exterior walls, stair beams and stair columns, and weld bolts on the top surface of the stair beams; Step 2): Lay a cement mortar leveling layer on top of the ladder beam; Step 3): Hoist the precast stair slab to the installation position, ensuring that the platform slabs at both ends of the precast stair slab correspond to the stair beams at the required installation positions; Step 4): Lower the fully prefabricated stair slab, insert the bolt holes on the platform slab into the threaded rods on the stair beams, and tighten them with nuts to secure them; Step 5): After completing step 4), first fill the bolt holes with grout, and then fill the surrounding gaps with sealing mortar. Step 6): First, fill the gap between the platform board and the exterior wall with a layer of rock wool, then embed a PE rod on the outside of the rock wool layer, and finally apply sealant to the outside of the PE rod. Step 7): Apply the finishing layer to the top surface of the precast stair slab.

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