Cast-in-situ stair formwork system and construction method

Abstract

This invention relates to a cast-in-place staircase formwork system and construction method, comprising the following steps: a staircase formwork system without shear walls, a staircase formwork system with shear walls, and a bottom formwork support system; the staircase formwork system without shear walls includes a bottom formwork, side formwork, reinforcing wooden wedges, tie rods, triangular base blocks, reinforced side formwork, and bidirectional tie rods. The beneficial effects of this invention are: the tie rods connect the formwork of each step into a whole, improving the stability of the step formwork during concrete pouring; the installation of reinforced side formwork and quick-release locking pins on the outside of the side formwork, after being tightened, can hold the side formwork in place, further preventing lateral deformation during concrete pouring; the clever use of pre-reserved bolt holes in the shear wall to install brackets and unidirectional tie rods suspends and fixes the step formwork, reinforcing the side formwork to prevent lateral displacement during pouring; it is applicable to staircase formwork construction of different heights and sizes, ensuring the stability and reliability of the entire staircase formwork system.

Description

Technical Field

[0001] This invention belongs to the field of building construction, and in particular relates to a cast-in-place staircase formwork system and construction method. Background Technology

[0002] Staircases are an important structural element in building construction, serving as one of the most common vertical passageways in various building types. Although elevators are becoming increasingly prevalent in modern society, traditional staircases still hold a vital position in many emerging building structures due to their safety and convenience, meeting requirements for traffic flow, evacuation, and fire prevention. In structural analysis, slab staircases are typically analyzed as bending members, exhibiting not only excellent bending performance but also convenience, speed, and high safety, making them the most common vertical transportation route in the current building construction field.

[0003] A staircase consists of continuous flights of steps, landings, and cladding components. Compared to beam-slab-column structures, staircases have more complex designs, and the speed of construction significantly restricts the acceptance of sub-sections and the scheduling of subsequent processes. For cast-in-place staircases, problems such as skewed, sunken, or displaced step formwork, and inconsistent step formwork dimensions are prone to occur during construction. This makes the cast-in-place staircase steps highly susceptible to cross-sectional deformation and dimensional deviations exceeding the allowable values ​​specified in the standards, affecting the construction of subsequent processes. Therefore, the system stability and ease of installation and dismantling of the cast-in-place staircase formwork are key influencing factors, determining the probability of problems such as chipped edges, unevenness, and deformation, thus affecting the overall quality of the cast-in-place staircase. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a cast-in-place staircase formwork system and construction method.

[0005] This cast-in-place staircase formwork system includes a staircase formwork system without shear walls, a staircase formwork system with shear walls, and a bottom formwork support system; the staircase formwork system without shear walls includes a bottom formwork, side formwork, reinforcing wooden wedges, tie rods, triangular base blocks, reinforced side formwork, and bidirectional tie rods;

[0006] In a shear wall-free staircase formwork system, the bottom formwork is placed between the upper and lower floor slabs; the side formwork is symmetrically placed on both sides of the bottom formwork, with several slots evenly distributed at the top; the tread formwork and continuous rectangular timber are vertically placed in the slots of the side formwork; the reinforcing wooden wedges are attached to the continuous rectangular timber and secured in the slots; the tie plate is placed in the middle of the tread formwork, and the triangular base block is embedded below the tie plate of the lower floor slab; the reinforced side formwork is symmetrically placed on the outside of the side formwork and is connected and fixed by bidirectional tie rods; the two ends of the bidirectional tie rods are equipped with quick-release locking pins.

[0007] When shear walls are present, pre-drilled bolt holes are provided on the shear walls, and the staircase formwork system with shear walls is fixed to the shear walls through the pre-drilled bolt holes;

[0008] The bottom formwork support system is used to support stair formwork systems without shear walls or stair formwork systems with shear walls.

[0009] Preferably, the shear wall staircase formwork system includes a shear wall, horizontal supports, vertical supports, bottom formwork, side formwork, step formwork, continuous square timber, reinforcing wooden wedges, tie rods, and one-way tie rods. In the shear wall staircase formwork system, the horizontal supports are fixed to the pre-drilled bolt holes in the shear wall by bolts. The upper end of the vertical supports is welded to the horizontal supports, and the lower end is suspended from the step formwork and continuous square timber by bolts. One end of the one-way tie rod is anchored to the pre-drilled bolt hole in the shear wall by a quick-release nut, and the other end is fixed to the outside of the side formwork by a quick-release locking pin.

[0010] Preferably, the bottom width of the slot is the same as the thickness of the step template, the vertical side height is the same as the height of the step template, and the inclined side is perpendicular to the side wall of the side template.

[0011] Preferably, the lower end of the step template is at the same elevation as the upper end of the step template of the adjacent lower step; the tie plate is fixed to each step template with iron nails, and the lowermost end of the tie plate rests against the surface of the lower floor slab.

[0012] Preferably, the bottom formwork support system includes triangular braces, back braces, and square timber. The triangular braces include two main sleeve rods; the two ends of the main sleeve rods are respectively connected to an upper screw and a lower screw via threads; a handle is welded in the middle of the main sleeve rod; a top support is provided at the top of the upper screw; a base is hinged to the bottom of the lower screw via a pin, and the base is anchored to the ground by anchor bolts; the angle of the main sleeve rods is adjusted by the pin, and the length of the upper and lower screws is adjusted by the handle; the back braces are evenly distributed below the bottom formwork along the length of the staircase; the square timber is evenly distributed between the back braces and the top support along the width of the staircase.

[0013] Preferably, a steel reinforcement cage is provided between the bottom template and the step template.

[0014] The construction method for this cast-in-place staircase formwork system includes the following steps:

[0015] Step 1: Erect the bottom formwork between the upper and lower floor slabs;

[0016] Step 2: Install the bottom formwork support system, using several triangular braces to support the bottom formwork;

[0017] Step 3: Install side formwork and tie the reinforcing steel frame;

[0018] Step 4: Use the slots on the side formwork to construct the step formwork and continuous square timber;

[0019] Step 5: Reinforce the stair tread template; Install tie rods along each stair tread template from top to bottom, and embed the triangular base blocks under the tie rods of the lower floor slab;

[0020] Step 6: Reinforce the side template; tighten and secure the side template by rotating the quick-release locking pin.

[0021] Preferably, the bottom formwork support system includes triangular braces, which adjust the angle of the main sleeve rod via pins and adjust the length of both ends of the main sleeve rod via handles. In step two, back braces are set below the bottom formwork along the length of the staircase, and square timber is set below the back braces along the width of the staircase. According to the design position and size of the staircase, several triangular braces are installed. The inclination angle of the main sleeve rod is adjusted and then fixed. The handle is rotated to simultaneously adjust the length of the upper and lower screws at both ends of the main sleeve rod until the square timber is supported.

[0022] As a preferred option, in the absence of shear walls, in step four, each step template is installed sequentially into the slot on the side template and extends outward a certain distance; then, a full-length rectangular timber is laid across the side template and attached to the outside of the step template, and finally, a reinforcing wooden wedge is inserted into the slot to secure it; in step six, the reinforcing side template and the two-way tie rod are installed sequentially, and the side templates on both sides of the staircase are pulled and fixed by rotating the quick-release locking pin.

[0023] As a preferred option, when there is a shear wall, in step four, the horizontal support, vertical support, step template, and continuous square timber are installed in sequence; one end of the step template and the continuous square timber is installed in the groove on the side template, and the other end is installed below the vertical support. Finally, the reinforcing wooden wedge is inserted into the groove and tightened to complete the process; in step six, the unidirectional tie rod is installed using the screw holes reserved for shear wall construction. One end of the tie rod is inserted through the screw hole and anchored with a quick-release nut, and the other end is tightened and fixed to the side template on the outside of the staircase by rotating the quick-release locking pin.

[0024] The beneficial effects of this invention are:

[0025] 1) This invention develops a shear wall-free stair formwork system, which connects the formwork of each step into a whole by tie plates, thereby improving the stability of the step formwork during concrete pouring; by installing reinforced side formwork and quick-release locking pins on the outside of the side formwork, the side formwork can be held in place after being tightened by tie plates, further preventing lateral deformation during concrete pouring.

[0026] 2) This invention has developed a staircase formwork system with shear walls. It cleverly utilizes the pre-reserved screw holes in the shear wall to install brackets and unidirectional tie rods. The former is used to suspend and fix the step formwork, and the latter is used to reinforce the side formwork to prevent lateral displacement during the pouring process.

[0027] 3) This invention developed a bottom formwork support system. By using triangular braces with structures such as swivel handles and pins, it can be applied to the construction of stair formwork for different heights and sizes, ensuring the stability and reliability of the entire stair formwork system. Attached Figure Description

[0028] Figure 1 This is a side view of the shear wall-free staircase formwork system and bottom formwork support system in this invention.

[0029] Figure 2 This is a top view of the shear wall-free staircase formwork system in this invention.

[0030] Figure 3 yes Figure 1 Detailed view of area A in the middle.

[0031] Figure 4 yes Figure 3 Decomposition diagram of each structure.

[0032] Figure 5 This is a schematic diagram of the quick-release locking pin in this invention.

[0033] Figure 6 This is a schematic diagram of the shear wall staircase formwork system in this invention.

[0034] Figure 7 This is a schematic diagram of the cast-in-place staircase steel reinforcement cage in this invention.

[0035] In the diagram: 1. Bottom formwork; 2. Side formwork; 3. Step formwork; 4. Continuous square timber; 5. Reinforcing wooden wedge; 6. Tie strip; 7. Triangular base block; 8. Reinforced side formwork; 9. Two-way tie rod; 10. Shear wall; 11. Horizontal support; 12. Vertical support; 13. One-way tie rod; 14. Triangular diagonal brace; 141. Main sleeve rod; 142. Upper screw rod; 143. Lower screw rod; 144. Handle; 145. Top support; 146. Base; 147. Pin; 148. Anchor bolt; 15. Back rib; 16. Square timber; 17. Upper floor slab; 18. Lower floor slab; 19. Slot; 20. Quick-release locking pin; 21. Bolt; 22. Screw hole; 23. Quick-release nut; 24. Reinforcing steel cage. Detailed Implementation

[0036] The present invention will be further described below with reference to embodiments. The description of the embodiments below is only for the purpose of helping to understand the present invention. It should be noted that those skilled in the art can make several modifications to the present invention without departing from the principle of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0037] Example 1

[0038] As one embodiment, this cast-in-place staircase formwork system is characterized by including a shear wall-free staircase formwork system and a bottom formwork support system.

[0039] The shear-free wall staircase formwork system includes a bottom formwork 1, side formwork 2, step formwork 3, continuous rectangular timber 4, reinforcing wooden wedges 5, tie rods 6, triangular base blocks 7, reinforced side formwork 8, and bidirectional tie rods 9. The bottom formwork 1 is positioned between the upper floor slab 17 and the lower floor slab 18. The side formwork 2 is symmetrically positioned on both sides of the bottom formwork 1, with several evenly distributed slots 19 cut into its upper end. The step formwork 3 and the continuous rectangular timber 4 are vertically positioned within the slots 19 of the side formwork 2. The reinforcing wooden wedges 5 are tightly secured to the continuous rectangular timber 4 within the slots 19. The tie rods 6 are positioned in the middle of the step formwork 3, with their lowest end abutting against the surface of the lower floor slab 18. The triangular base blocks 7 are embedded below the tie rods 6 of the lower floor slab 18. The reinforced side formwork 8 is symmetrically positioned on the outside of the side formwork 2 and is connected and fixed by the bidirectional tie rods 9. The bidirectional tie rods 9 have quick-release locking pins 20 symmetrically positioned at both ends.

[0040] The bottom formwork support system includes triangular braces 14, back braces 15, and square timber 16. The triangular braces 14 include a main sleeve rod 141, an upper screw rod 142, a lower screw rod 143, a handle 144, a top support 145, and a base 146. The upper screw rod 142 and lower screw rod 143 are threadedly embedded at both ends of the main sleeve rod 141. The handle 144 is welded to the middle of the main sleeve rod 141. The top support 145 is located at the top of the upper screw rod 142. The base 146 is hinged to the bottom of the lower screw rod 143 via a pin 147 and anchored to the ground via anchor bolts 148. The back braces 15 are evenly distributed along the length of the staircase below the bottom formwork 1. The square timber 16 are evenly distributed along the width of the staircase between the back braces 15 and the top support 145.

[0041] The bottom width of the slot 19 is the same as the thickness of the step template 3, the height of the vertical side is the same as the height of the step template 3, and the inclined side is perpendicular to the side wall of the side template 2. The lower end of the step template 3 is at the same elevation as the upper end of the adjacent lower step template 3.

[0042] The tie plate 6 is fixed to each step template 3 with nails, connecting all step templates 3 together from top to bottom. The quick-release locking pin 20 can be flexibly installed and removed from the one-way tie rod 13 by rotation.

[0043] The angle of the main sleeve 141 can be adjusted arbitrarily by means of the pin 147, and the length of the upper screw 142 and the lower screw 143 can be adjusted arbitrarily by means of the handle 144.

[0044] A steel reinforcement cage 24 is also provided between the bottom formwork 1 and the step formwork 3.

[0045] Example 2

[0046] As another embodiment, this embodiment proposes, based on embodiment one, that when a shear wall 10 is present, this cast-in-place staircase formwork system includes a shear wall staircase formwork system.

[0047] The shear wall staircase formwork system includes a shear wall 10, horizontal supports 11, vertical supports 12, bottom formwork 1, side formwork 2, step formwork 3, continuous square timber 4, reinforcing wooden wedges 5, tie rods 6, and one-way tie rods 13. The horizontal supports 11 are fixed to the pre-drilled bolt holes 22 in the shear wall 10 using bolts 21. The upper end of the vertical supports 12 is welded to the horizontal supports 11, and the lower end suspends the step formwork 3 and the continuous square timber 4 using bolts 21. One end of the one-way tie rod 13 is anchored to the pre-drilled bolt hole 22 in the shear wall 10 using a quick-release nut 23, and the other end is fixed to the outside of the side formwork 2 using a quick-release locking pin 20.

[0048] The quick-release locking pin 20 and quick-release nut 23 can be flexibly installed and removed from the one-way tie rod 13 by rotation.

[0049] It should be noted that the parts in this embodiment that are the same as or similar to those in Embodiment 1 can be referred to each other, and will not be repeated in this application.

[0050] Example 3

[0051] As another embodiment, this embodiment three proposes a construction method for cast-in-place staircase formwork without shear walls, based on embodiment one.

[0052] Step 1: Formwork fabrication. Based on the tread dimensions of the standard floor staircase in the design drawings, determine the dimensions of the "V"-shaped groove 19 of the side formwork 2, and fabricate the bottom formwork 1 and side formwork 2 according to the layout drawing. The formwork material used in this invention is preferably fir wood.

[0053] Install the bottom formwork. Erect the bottom formwork 1 at an angle between the upper floor slab 17 and the lower floor slab 18.

[0054] Step 2: Install the bottom formwork support system. Place 50mm×100mm timber as back braces 15 at equal intervals along the length of the staircase below the bottom formwork 1. Then, place 50mm×30mm square timber 16 at equal intervals along the width of the staircase below the back braces 15. According to the staircase design location and dimensions, install two triangular braces 14 along the length and width of the staircase respectively. Anchor the base 146 to the ground using anchor bolts 148. Adjust the inclination angle of the main sleeve rod 141 to the appropriate position and tighten the pin 147. Rotate the handle 144 to simultaneously adjust the lengths of the upper screw rod 142 and the lower screw rod 143 until the top support 145 tightens the square timber 16.

[0055] Step 3: Install side formwork 2 symmetrically on both sides of the bottom formwork 1, and then tie the reinforcing steel cage 24 inside the formwork, as shown. Figure 7 As shown.

[0056] Step 4: Install the step templates. Install each step template 3 sequentially into the slot 19 on the side template 2, extending it outwards a certain distance; then, place a full-length square timber 4 across the side template 2 and tightly against the outside of the step template 3; finally, insert the reinforcing wooden wedge 5 into the slot 19 and tighten it to complete the process. Apply a layer of release agent evenly to the inner surfaces of the bottom template 1, side template 2, and step template 3.

[0057] Step 5: Reinforce the step template. Install tie plates 6 from top to bottom along each step template 3 until they abut against the lower floor slab 18. Use nails to fix the tie plates 6 to the top of the step template 3. Embed the triangular base block 7 under the tie plate 6 of the lower floor slab 18 to support the lowest step template 3.

[0058] Step Six: Reinforce the side formwork. Install the reinforcing side formwork 8 and the bidirectional tie rod 9 in sequence: After passing the bidirectional tie rod 9 through the side formwork 2 and the reinforcing side formwork 8, install the quick-release locking pins 20 symmetrically, rotate the quick-release locking pins 20 to pull the side formwork 2, and ensure that it remains vertical during the subsequent concrete pouring process.

[0059] Example 4

[0060] As another embodiment, this embodiment four provides a construction method for cast-in-place staircase formwork support when there is a shear wall 10, based on embodiments two and three.

[0061] Step 1: Process the templates. Based on the tread dimensions of the standard floor staircase in the design drawings, determine the dimensions of the slot 19 of the side template 2, and process the bottom template 1 and the side template 2 according to the layout drawing.

[0062] Install the bottom formwork. Erect the bottom formwork 1 at an angle between the upper floor slab 17 and the lower floor slab 18.

[0063] Step 2: Install the bottom formwork support system. Distribute the back braces 15 at equal intervals along the length of the staircase below the bottom formwork 1, and then distribute the square timber 16 at equal intervals along the width of the staircase below the back braces 15. According to the staircase design location and dimensions, install several triangular braces 14: Anchor the base 146 to the ground using anchor bolts 148, adjust the inclination angle of the main sleeve rod 141 to the appropriate position, and tighten the pin 147; rotate the handle 144 to simultaneously adjust the lengths of the upper screw rod 142 and the lower screw rod 143 until the top support 145 firmly presses against the square timber 16.

[0064] Step 3: Install side formwork 2 on the bottom formwork 1 on the side away from the shear wall, and tie the steel reinforcement cage 24 inside the formwork.

[0065] Step 4: Install the step template. Install the horizontal support 11, vertical support 12, step template 3, and continuous square timber 4 in sequence. One end of the step template 3 and the continuous square timber 4 are installed in the groove 19 on the side template 2, and the other end is installed below the vertical support 12. Finally, insert the reinforcing wooden wedges 5 into the grooves 19 and tighten them. Apply a layer of release agent evenly to the inner surface of the bottom template 1, side template 2, and step template 3.

[0066] Step 5: Reinforce the step template. Install tie rods 6 from top to bottom along each step template 3, and secure them with nails.

[0067] Step Six: Reinforce the side formwork. Install one-way tie rods 13 using the threaded holes 22 reserved during the construction of the shear wall 10. After passing one end through the threaded hole 22, anchor it with a quick-release nut 23. Tighten and fix the other end to the side formwork 2 on the outside of the staircase by rotating the quick-release locking pin 20.

[0068] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

Claims

1. A cast-in-place staircase formwork system, characterized in that: It includes a stair formwork system without shear walls, a stair formwork system with shear walls, and a bottom formwork support system; the stair formwork system without shear walls includes a bottom formwork, side formwork, reinforcing wooden wedges, tie rods, triangular base blocks, reinforced side formwork, and bidirectional tie rods; In a shear wall-free staircase formwork system, the bottom formwork is placed between the upper and lower floor slabs; the side formwork is symmetrically placed on both sides of the bottom formwork, with several slots evenly distributed at the top; the tread formwork and continuous rectangular timber are vertically placed in the slots of the side formwork; reinforcing wooden wedges are attached to the continuous rectangular timber and secured in the slots; tie plates are placed in the middle of the tread formwork, and triangular base blocks are embedded below the tie plates of the lower floor slab; reinforced side formwork is symmetrically placed on the outside of the side formwork and is connected and fixed by bidirectional tie rods; quick-release locking pins are provided at both ends of the bidirectional tie rods; When shear walls are present, pre-drilled bolt holes are provided on the shear walls, and the staircase formwork system with shear walls is fixed to the shear walls through the pre-drilled bolt holes; The bottom formwork support system is used to support stair formwork systems without shear walls or stair formwork systems with shear walls; The lower end of the step template is at the same elevation as the upper end of the step template of the adjacent lower step; the tie plate is fixed to each step template with iron nails, and the lowermost end of the tie plate rests against the surface of the lower floor slab.

2. The cast-in-place staircase formwork system according to claim 1, characterized in that: The shear wall staircase formwork system includes a shear wall, horizontal supports, vertical supports, bottom formwork, side formwork, step formwork, continuous square timber, reinforcing wooden wedges, tie rods, and one-way tie rods. In the shear wall staircase formwork system, the horizontal supports are fixed to the pre-drilled bolt holes in the shear wall by bolts. The upper end of the vertical supports is welded to the horizontal supports, and the lower end suspends the step formwork and continuous square timber by bolts. One end of the one-way tie rod is anchored to the pre-drilled bolt hole in the shear wall by a quick-release nut, and the other end is fixed to the outside of the side formwork by a quick-release locking pin.

3. The cast-in-place staircase formwork system according to claim 1, characterized in that: The bottom width of the slot is the same as the thickness of the step template, the vertical side height is the same as the height of the step template, and the inclined side is perpendicular to the side wall of the side template.

4. The cast-in-place staircase formwork system according to claim 1, characterized in that: The bottom formwork support system includes triangular braces, back braces, and square timber. The triangular braces include two main sleeve rods; the two ends of the main sleeve rods are respectively connected to an upper screw and a lower screw via threads; a handle is welded in the middle of the main sleeve rod; a top support is provided at the top of the upper screw; a base is hinged to the bottom of the lower screw via a pin, and the base is anchored to the ground by anchor bolts; the angle of the main sleeve rods is adjusted by the pin, and the length of the upper and lower screws is adjusted by the handle; the back braces are evenly distributed below the bottom formwork along the length of the staircase; the square timber is evenly distributed between the back braces and the top support along the width of the staircase.

5. The cast-in-place staircase formwork system according to claim 1, characterized in that: A steel reinforcement cage is also provided between the bottom formwork and the step formwork.

6. The construction method of the cast-in-place staircase formwork system as described in any one of claims 1-5, characterized in that, Includes the following steps: Step 1: Erect the bottom formwork between the upper and lower floor slabs; Step 2: Install the bottom formwork support system, using several triangular diagonal braces to support the bottom formwork; Step 3: Install side formwork and tie the reinforcing steel frame; Step 4: Use the slots on the side formwork to construct the step formwork and continuous square timber; Step 5: Reinforce the stair tread template; Install tie rods along each stair tread template from top to bottom, and embed the triangular base blocks under the tie rods of the lower floor slab; Step 6: Reinforce the side template; tighten and secure the side template by rotating the quick-release locking pin.

7. The construction method of the cast-in-place staircase formwork system according to claim 6, characterized in that: The bottom formwork support system includes triangular braces. The angle of the main sleeve rod is adjusted by a pin, and the length of both ends of the main sleeve rod is adjusted by a handle. In step two, a back brace is set below the bottom formwork along the length of the staircase, and square timber is set below the back brace along the width of the staircase. According to the design position and size of the staircase, several triangular braces are installed. The inclination angle of the main sleeve rod is adjusted and then fixed. The handle is rotated to simultaneously adjust the length of the upper and lower screws at both ends of the main sleeve rod until the square timber is supported.

8. The construction method of the cast-in-place staircase formwork system according to claim 6, characterized in that: In the absence of shear walls, in step four, each step template is installed sequentially into the slot on the side template and extends outward a certain distance; then, a full-length square timber is laid across the side template and attached to the outside of the step template, and finally, the reinforcing wooden wedge is inserted into the slot to secure it; in step six, the reinforcing side template and the two-way tie rod are installed sequentially, and the side templates on both sides of the staircase are pulled and fixed by rotating the quick-release locking pin.

9. The construction method of the cast-in-place staircase formwork system according to claim 6, characterized in that: When there is a shear wall, in step four, install the horizontal support, vertical support, step formwork, and continuous square timber in sequence; one end of the step formwork and continuous square timber is installed in the groove on the side formwork, and the other end is installed below the vertical support. Finally, insert the reinforcing wooden wedge into the groove and tighten it to complete the process; in step six, install the one-way tie rod using the screw holes reserved in the shear wall construction, insert one end of the tie rod through the screw hole and anchor it with a quick-release nut, and tighten and fix the other end to the side formwork on the outside of the staircase by rotating the quick-release locking pin.

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