Floor protection grommet capable of quickly marking position of reinforcing steel

Abstract

This utility model discloses a floor slab protective layer spacer ring for quickly marking the position of reinforcing bars. It is made of rigid plastic tubing cut into a hollow ring with two arc-shaped notches at the center of the top. In use, the spacer ring is placed on the top surface of the floor slab formwork before the reinforcing bars are tied. The arc-shaped notches support and restrain the lower outer reinforcing bars of the floor slab, and the height from the bottom of the arc-shaped notches to the bottom surface of the spacer ring is the thickness of the reinforcing bar protective layer. Due to the difference in material and color between plastic and concrete, after the concrete curing and demolding, the bottom surface of the spacer ring will be visible on the bottom of the slab, with its center corresponding to the position of the reinforcing bars. This helps to avoid the reinforcing bars when drilling holes for ceiling installation and electrical work during later decoration. This spacer ring is readily available, easy to process, highly efficient, low-cost, and provides good marking results, making it suitable for cast-in-place concrete slab construction and worthy of promotion.

Description

Technical Field

[0001] This utility model belongs to the field of building engineering technology and relates to the support and position marking of the steel reinforcement protective layer of cast-in-place concrete floor slabs. Background Technology

[0002] In the construction of cast-in-place concrete slabs, the thickness of the concrete cover for reinforcing bars directly determines the structural durability and load-bearing capacity. Spacers, as the core component controlling this thickness, are crucial in terms of performance and functional suitability. Currently, the mainstream methods used in engineering are precast mortar spacers, concrete spacers, and ordinary plastic spacers. Mortar spacers, due to insufficient strength and inadequate curing, are prone to cracking under vibration and impact, leading to rebar displacement or even exposure. Concrete spacers, although having higher strength, are made of the same material as the slab concrete and are completely integrated into the structure after molding, lacking obvious identifiable features. Ordinary plastic spacers are mostly simple block or column-shaped, lacking an effective fixing structure, and are easily displaced during construction due to trampling and vibration, causing deviations in the concrete cover thickness.

[0003] A more prominent problem lies in the later operation and maintenance phase: when drilling holes for decoration and electromechanical installation of the ceiling, it is necessary to accurately avoid the reinforcing bars under the floor slab to prevent structural damage. Existing positioning methods have significant limitations—manual pre-marking is easily blurred and ineffective due to construction disturbances; rebar detectors are not only expensive but also affected by the thickness of the floor slab and the density of the concrete, making them extremely inefficient for large-scale construction. Traditional spacers, due to their material characteristics or structural design, cannot form identifiable rebar location marks after formwork removal, leading to frequent accidental contact with rebar during drilling operations, requiring rework, repair, or even reinforcement, which increases costs and delays the construction period.

[0004] In summary, existing spacers can only meet the requirements for controlling the thickness of the protective layer. They generally suffer from defects such as being easily damaged, easily displaced, and lacking marking functions. They are difficult to balance the stability during the construction phase with the identifiability during the operation and maintenance phase. There is an urgent need for a low-cost device that combines precise control of the protective layer with intuitive marking of the rebar position. Utility Model Content

[0005] This utility model discloses a floor slab protective layer gasket that can quickly mark the position of reinforcing bars, aiming to solve the problems of existing gaskets being easily damaged, easily displaced, and lacking the function of marking the position of reinforcing bars, and to achieve the dual requirements of accurate control of protective layer thickness and subsequent reinforcing bar positioning.

[0006] The main body of this gasket is a hollow ring, cut and processed from commonly used rigid plastic pipes in construction (such as PVC, PE, and ABS pipes). The material is readily available and inexpensive, requiring no complex production equipment; it can be manufactured simply through conventional cutting, resulting in high processing efficiency. The ring's structural design focuses on practicality: two symmetrical arc-shaped cuts about the ring's axis are located at the center of the top. The arc of these cuts matches the outer diameter of the lower outer layer of the floor slab's reinforcing steel bars, providing stable support and effectively constraining the bars to prevent displacement caused by trampling or vibration during construction, thus ensuring the accuracy of the protective layer thickness. Simultaneously, the height from the bottom of the arc-shaped cuts to the bottom surface of the gasket is pre-set to the design thickness of the floor slab's reinforcing steel protective layer, eliminating the need for additional measurement and adjustment during installation and simplifying the construction process.

[0007] When using this product, the spacer ring is placed directly on the top surface of the floor slab formwork before the floor slab reinforcement is tied. After the concrete is poured and cured and the formwork is removed, the bottom of the spacer ring will be clearly visible on the bottom of the slab due to the significant difference in material and color between the plastic and concrete. At this time, the center position of the visible spacer ring precisely corresponds to the position of the lower layer of reinforcement in the floor slab, providing a visual mark for subsequent electromechanical installation and ceiling drilling operations. Workers can quickly avoid the reinforcement positions by recognizing the spacer ring marks on the bottom of the slab, effectively avoiding rework and structural damage caused by accidentally hitting the reinforcement during drilling, thus balancing convenience during the construction phase and safety during the operation and maintenance phase. Attached Figure Description

[0008] The present invention will be further described below with reference to the accompanying drawings and specific embodiments: Figure 1 This is a three-dimensional view of the floor slab protective layer gasket ring of this utility model. Figure 2 A 3D view of the floor slab protective layer gasket after the floor slab reinforcement is tied. Figure 3 Side view of the floor slab protective layer gasket after the floor slab reinforcement is tied.

[0009] The main components of the device shown in the figure include: a hollow ring (1), with two arc-shaped cutouts (11) and (12) reserved at the center of its top, as shown in the figure. Figure 1 As shown; it also involves the top surface of the formwork (2), the outer reinforcement of the lower layer of the floor slab (31), and the inner reinforcement of the lower layer of the floor slab (32), as shown. Figure 2 As shown.

[0010] Before binding the floor slab reinforcement (31) and (32), place the pad ring (1) on the top surface (2) of the floor slab formwork. The arc cuts (11) and (12) are used to support and constrain the lower outer reinforcement (31) of the floor slab. The height from the bottom of the arc cuts (11) and (12) to the bottom surface of the pad ring (1) is the thickness of the reinforcement protective layer.

[0011] like Figure 3 As shown, the diameters of the arc cuts (11) and (12) are slightly larger than the floor slab reinforcement (31) by 1-2 mm to facilitate the embedding and restraint of the reinforcement (31). Detailed Implementation

[0012] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the following description, in conjunction with specific illustrations, further elaborates on this utility model.

[0013] It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the implementation conditions of this utility model. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationships, or adjustments to the size, without affecting the effects and purposes that this utility model can produce, should still fall within the scope of the technical content disclosed in this utility model. Furthermore, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are only for clarity of description and are not intended to limit the scope of implementation of this utility model. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of implementation of this utility model. The utility model will now be described in detail with reference to the embodiments and accompanying drawings.

[0014] During the ring fabrication stage, two core parameters need to be clearly defined: first, the design thickness of the concrete cover for the floor slab reinforcement (e.g., 15mm, 20mm); and second, the outer diameter of the outermost reinforcement of the lower layer of the floor slab (e.g., Φ8, Φ10). Using commonly used rigid plastic pipes (PVC, PE, or ABS pipes) as the raw material, the total height of the ring is calculated based on these parameters: Total ring height = Design thickness of the concrete cover for the reinforcement + Circular cut depth (the cut depth is typically 5-8mm, ensuring the reinforcement does not fall out after embedding). For example, when the concrete cover thickness is 15mm, the total ring height can be set to 22mm (including a 7mm cut depth). After cutting the plastic pipe into hollow rings of a set total height using a pipe cutter, two symmetrical arc cuts about the ring axis are machined at the center of the top surface of the ring using a drill bit. The arc of the cuts must be adapted to the outer diameter of the reinforcing bar (1-2mm larger than the outer diameter of the reinforcing bar to facilitate the embedding of the reinforcing bar), and the depth of the cuts must be strictly controlled to ensure that the vertical distance from the bottom of the arc cut to the bottom surface of the pad ring is exactly equal to the design thickness of the reinforcing bar protective layer after processing. This step must be checked piece by piece with calipers to avoid dimensional deviations.

[0015] During on-site construction, the spacer rings must be installed before the floor slab reinforcement is tied. First, clean the top surface of the floor slab formwork to ensure it is flat. Then, according to the reinforcement layout plan (e.g., 200mm x 200mm spacing), place spacer rings directly below the preset positions of the lower outer reinforcement bars. The placement density should be controlled at 2-3 rings per square meter to ensure stable support for the reinforcement bars. After all the spacer rings are in place, tie the lower layer of floor slab reinforcement bars. Slowly insert the lower outer reinforcement bars into the arc-shaped cuts of the spacer rings. At this time, the bottom surface of the reinforcement bar will be in close contact with the bottom of the arc-shaped cut, while the bottom surface of the spacer ring will be in contact with the top surface of the formwork. The distance from the bottom surface of the reinforcement bar to the top surface of the formwork (i.e., the protective layer thickness) is exactly equal to the height from the bottom of the arc-shaped cut to the bottom surface of the spacer ring, achieving precise control of the protective layer thickness. At the same time, the sidewall of the arc-shaped cut will form a lateral constraint on the reinforcement bars. Even if there are external forces such as personnel stepping on the reinforcement bars or concrete vibration during subsequent construction, the reinforcement bars will not easily deviate from the preset positions, avoiding deviations in the protective layer thickness.

[0016] In the concrete construction and subsequent application stages, the floor slab concrete is poured according to standard procedures and cured to standard. The formwork is removed after the concrete reaches the required strength. After demolding, it is visible that due to the difference in material and color between the rigid plastic pipe and the concrete, a clear annular development mark is formed on the bottom of the floor slab on the bottom surface of the spacer ring. The center of the development mark corresponds perfectly to the axis of the lower layer of reinforcing steel in the floor slab. During subsequent drilling for electromechanical installation and ceiling installation, construction workers can directly use the annular development mark on the bottom of the slab to quickly locate the reinforcing steel position. Drilling points can be planned in the unreinforced areas between the development marks, precisely avoiding the reinforcing steel and preventing rework due to accidental drilling. The entire implementation process requires no special equipment, and processing and installation are convenient. This solves the problems of easy displacement and lack of marking associated with traditional spacers, and through precise cut size design, ensures that the protective layer thickness meets the specifications. Example

[0017] This embodiment focuses on the construction of a 120mm thick C30 industrial floor slab reinforced concrete structure. The following procedure is followed to implement the application of floor slab protective layer spacers that can quickly mark the position of the reinforcing bars.

[0018] First, the gasket rings are processed. A DN50 rigid PE pipe with a wall thickness of 3.7mm is selected and cut into hollow rings with a height of 26mm using a pipe cutter. Since the requirement of "ring height - cut depth = protective layer thickness" must be met, subtracting the 6mm cut depth from the 26mm ring height yields the design value of a 20mm rebar protective layer. Then, using an arc-shaped mold for positioning, two symmetrical arc cuts are processed at the center of the top surface of the ring: the cut diameter is set to 14mm (2mm larger than the outer diameter of a Φ12mm rebar, facilitating rebar embedding and preventing loosening), and the cut depth is strictly controlled to 6mm. After processing, each piece is inspected with calipers to ensure that the vertical distance from the bottom of the cut to the bottom surface of the ring is precisely 20mm, with an error not exceeding ±1mm, ensuring the accuracy of the protective layer thickness.

[0019] During the on-site construction phase, the top surface of the steel formwork for the three-story industrial floor slab is first cleaned to remove welding slag and debris, ensuring the flatness of the formwork. According to the rebar layout plan (Φ12mm@200 bidirectional rebar), a spacer ring is placed directly below each rebar intersection, with a density of 3 rings per square meter (the industrial floor slab has a large load, so the spacers are placed more densely to enhance support stability). After all the spacers are in place, the lower layer of Φ12mm rebar is tied, embedding the rebar into a 14mm cut. At this point, the bottom surface of the rebar is flush with the bottom of the cut, and the bottom surface of the ring is tightly against the top surface of the formwork. The distance from the bottom surface of the rebar to the top surface of the formwork is exactly 20mm of protective layer thickness, and the sidewall of the cut provides lateral restraint to the rebar, resisting external forces generated by construction workers stepping on it and concrete vibration, preventing rebar displacement.

[0020] When pouring C30 concrete, a flat vibrator is used to vibrate along the direction perpendicular to the reinforcing bars to avoid direct impact on the spacer rings. After 28 days of standard curing, the formwork is removed, and a clear annular development is visible on the bottom of the DN50 spacer ring at the bottom of the floor slab (due to the difference in material and color between PE and C30 concrete). Later, when drilling holes for electromechanical installation in the ceiling, construction personnel identify the position of the Φ12mm reinforcing bars by recognizing the developed annular ring (the center of the development corresponds to the reinforcing bar axis), and plan the drilling points within the annular gaps (within a 200mm interval) to precisely avoid the reinforcing bars, meeting the operation and maintenance needs of the industrial floor slab.

[0021] This gasket offers significant advantages: It is made from readily available, common rigid plastic pipes suitable for typical construction site environments, requiring no special procurement; its processing is simple and efficient, requiring only standard tools; it allows for precise control of the protective layer thickness and also restrains rebar to prevent displacement, improving construction efficiency; it is cost-effective, requiring minimal materials and incurring no additional waste; and its marking effect is intuitive and reliable, with clear visibility after demolding. Suitable for cast-in-place concrete slab construction, it offers high overall value and is worthy of widespread adoption.

[0022] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A floor slab protective layer gasket for quickly marking the location of reinforcing bars, characterized in that: It includes a hollow ring formed by cutting and processing rigid plastic pipes; the center of the top of the hollow ring has two arc-shaped cuts, which are used to support and constrain the outer reinforcement of the lower layer of the floor slab; the spacer ring is used to be placed on the top surface of the floor slab formwork before the floor slab reinforcement is tied, and the height from the bottom of the arc-shaped cut to the bottom surface of the hollow ring is equal to the design thickness of the concrete cover of the floor slab reinforcement; due to the difference in material and color between plastic and concrete, the bottom surface of the hollow ring can be seen on the bottom of the floor slab after the floor slab concrete is cured and demolded.

2. The washer ring according to claim 1, characterized in that: The rigid plastic pipe can be made of PVC, PE, or ABS, which facilitates on-site cutting and processing.

3. The washer ring according to claim 1, characterized in that: The two circular arc cuts are symmetrically arranged about the axis of the hollow ring, and the curvature of the circular arc cuts is adapted to the outer diameter of the outer steel bars of the lower layer of the floor slab.

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