Method for improving strain lag influence of floor support reinforcing rib

Abstract

The invention relates to the technical field of floor support reinforcement, in particular to a method for improving the strain lag influence of floor support reinforcing ribs, which comprises the following steps of: chiseling off a floor protective layer in a reinforcing area at a plate support, and paving a plurality of reinforcing ribs on the reinforcing area of the plate support without the floor protective layer, the end parts of the reinforcing ribs are embedded into the floor drill holes by adopting anchoring embedded steel bar glue; a supporting rod is arranged between every two adjacent reinforcing ribs, the two reinforcing ribs are transversely clamped into a broken line shape through a clamping tool, the reinforcing ribs are forced to be bent from straight to generate tensile strain, the reinforcing ribs are bound after prestress application is completed, structural interface glue is brushed on a floor slab protection layer, a C30 fine aggregate concrete laminated layer with the thickness being 40 mm is poured, and the floor slab protection layer is vibrated compactly. The clamping tool is used for transversely clamping the two reinforcing ribs into a broken line shape, the reinforcing ribs are forced to be bent from straight to generate tensile strain, the influence of strain lag of the reinforcing ribs is eliminated or reduced, and therefore the effect of the reinforcing part is fully exerted, and the safety reserve of the bearing capacity of the floor support is improved.

Description

Technical Field

[0001] The invention relates to the technical field of floor support reinforcement, and in particular to a method for improving the strain hysteresis effect of floor support reinforcement bars. Background Art

[0002] Reinforced concrete slabs need to be reinforced due to an increase in live loads caused by changes in their functional use, or quality accidents in design and construction. Article 6.1.3-5 of the "General Code for Appraisal and Reinforcement of Existing Buildings" GB55021-2021 stipulates: When verifying the bearing capacity of structures and components, the influence of strain lag and the degree to which the reinforced part works together with the original structure should be taken into account. In Article 5.2.3 of the "Code for Design of Reinforcement of Concrete Structures" GB50367-2013, when verifying the bending bearing capacity of the section, in order to consider the influence of strain lag, the "newly added steel bar strength utilization coefficient αs", that is, the strength reduction coefficient, is used to reflect the influence of strain lag on the reduction in the strength of the reinforcement bars. However, this method does not give a corresponding strength reduction coefficient based on the actual lag strain size, but instead uniformly takes a value of 0.9. When the hysteresis strain is large, whether it is reasonable to use a strength reduction factor of 0.9 remains to be discussed. Especially when the load on the structure cannot be removed during the reinforcement process, the adverse effects of the secondary force will become more obvious, and the hysteresis strain of the reinforcement bars will become more prominent. At this time, it may not be safe to use the "newly added steel bar strength utilization factor αs" of 0.9.

[0003] Therefore, it is necessary to provide a method to improve the strain lag effect of the floor support reinforcement bars to solve the above technical problems. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a method for improving the strain hysteresis effect of floor support reinforcement bars.

[0005] The present invention provides a method for improving the strain hysteresis effect of the reinforcement bars of floor slab supports, and the specific steps are as follows:

[0006] S1. Chisel off the protective layer of the floor slab in the reinforced area of ​​the slab support, remove the floating dust and debris, and then rinse with water;

[0007] S2. Lay multiple reinforcing bars on the slab support reinforcement area where the floor slab protective layer is removed, and implant the ends of the reinforcing bars into the drilled holes of the floor slab using anchoring glue;

[0008] S3. A support rod is arranged between two adjacent reinforcing bars, and the two reinforcing bars are clamped together into a broken line shape by a clamping tool, so as to force the reinforcing bars to change from straight to curved and produce tensile strain, and the reinforcing bars are tied after the prestressing is completed;

[0009] S4. After binding, apply structural interface glue on the floor protection layer, pour a 40mm thick C30 fine stone concrete overlay layer, and vibrate it to make it dense.

[0010] By installing reinforcing bars on the floor support, and using a clamping tool to clamp two reinforcing bars together in a broken line shape, the reinforcing bars are forced to change from straight to curved to produce tensile strain, eliminating or reducing the influence of strain hysteresis of the reinforcing bars, so as to give full play to the role of the reinforcement part, improve the safety reserve of the bearing capacity of the floor support, and improve the degree of coordinated force and joint work between the reinforcement part and the original component, and use a clamping tool to clamp two reinforcing bars together in a broken line shape, forcing the reinforcing bars to change from straight to curved to produce tensile strain, thereby establishing prestress in the reinforcing bars. Prestressing can effectively control the cracking of the concrete of the floor support, reduce the width and number of cracks, and improve the overall crack resistance of the floor support.

[0011] Preferably, in said S1, the thickness of the floor slab protective layer removed in the reinforced area at the support is 15 mm.

[0012] Preferably, before laying the reinforcing bars in S2, the actual size needs to be verified on site, and then the reinforcing bars to be laid are cut and manufactured, and the reinforcing bars need to be straightened before cutting.

[0013] Preferably, the support rod in S3 is selected from angle steel or coarse steel bar, and the clamping tool is a "Π" type buckle.

[0014] Preferably, the support rod and buckle used in S3 are cut by a cutting machine so that their ends are flat and the size is accurate.

[0015] Preferably, after the concrete superimposed layer in S4 is vibrated and compacted, a leveling layer is constructed on the top of the concrete superimposed layer.

[0016] Compared with the related art, the method for improving the strain hysteresis effect of the reinforcement bars of the floor support provided by the present invention has the following beneficial effects:

[0017] 1. The present invention generates tensile strain by tensioning the reinforcement bars of the floor support, thereby eliminating or reducing the influence of the strain hysteresis of the reinforcement bars, thereby giving full play to the role of the reinforcement part, improving the safety reserve of the bearing capacity of the floor support, and improving the degree of coordinated force and joint work between the reinforcement part and the original component. In addition, it can effectively make up for the deficiency that when the load acting on the floor cannot be unloaded during the reinforcement process, the strength reduction coefficient is uniformly taken as 0.9 during the bearing capacity verification, instead of giving the corresponding strength reduction coefficient according to the actual hysteresis strain size;

[0018] 2. The present invention uses a clamping tool to clamp two reinforcing bars together in a folded line shape, forcing the reinforcing bars to change from straight to curved to generate tensile strain, thereby establishing prestress in the reinforcing bars. The prestress can effectively control the cracking of the concrete of the floor support, reduce the width and number of cracks, and improve the overall crack resistance of the floor support;

[0019] 3. The present invention adopts a reinforcement method that uses a new plate surface overlap layer and tensions the reinforcing bars to eliminate or reduce the strain lag effect of the reinforcing bars by using plate surface supports. Compared with the reinforcement method of gluing steel plates and the reinforcement method of gluing fiber composite materials, the present invention is convenient to construct, has a simple reinforcement process, and significantly reduces costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic flow chart of a preferred embodiment of a method for improving the strain hysteresis effect of reinforcement bars of floor slab supports provided by the present invention;

[0021] Figure 2 for Figure 1 The schematic diagram of the tensioning structure of the reinforcement bars at the mid-span supports of the slab using the method for improving the strain hysteresis effect of the reinforcement bars at the floor supports is shown;

[0022] Figure 3 for Figure 1 The schematic diagram of the tensioning structure of the side span reinforcement bars using the method of improving the strain lag effect of the reinforcement bars at the floor supports is shown. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0024] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0026] In the description of the embodiments of the present invention, it should be noted that if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the product of the invention is usually placed when in use. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, if the terms "first", "second", "third", etc. appear, they are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0027] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components must be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0028] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] The following is a detailed description of the specific implementation of a method for improving the strain hysteresis effect of floor support reinforcement bars in conjunction with a specific embodiment.

[0030] refer to Figure 1 The present invention provides a method for improving the strain hysteresis effect of the reinforcement bars of floor supports, and the specific steps are as follows:

[0031] S1. Chisel off the protective layer of the floor slab in the reinforced area of ​​the slab support, remove the floating dust and debris, and then rinse with water;

[0032] S2. Lay multiple reinforcing bars on the slab support reinforcement area where the floor slab protective layer is removed, and implant the ends of the reinforcing bars into the drilled holes of the floor slab using anchoring glue;

[0033] S3. A support rod is arranged between two adjacent reinforcing bars, and the two reinforcing bars are clamped together into a broken line shape by a clamping tool, so as to force the reinforcing bars to change from straight to curved and produce tensile strain, and the reinforcing bars are tied after the prestressing is completed;

[0034] S4. After binding, apply structural interface glue on the floor protection layer, pour a 40mm thick C30 fine stone concrete overlay layer, and vibrate it to make it dense.

[0035] It should be noted that: by installing reinforcing bars on the floor support, and using a clamping tool to clamp two reinforcing bars together in a broken line shape, the reinforcing bars are forced to change from straight to curved to produce tensile strain, eliminating or reducing the influence of strain hysteresis of the reinforcing bars, so as to give full play to the role of the reinforced part, improve the safety reserve of the bearing capacity of the floor support, and improve the degree of coordinated force and joint work between the reinforced part and the original component, and use a clamping tool to clamp two reinforcing bars together in a broken line shape in a broken line shape, forcing the reinforcing bars to change from straight to curved to produce tensile strain, thereby establishing prestress in the reinforcing bars. Prestress can effectively control the cracking of the concrete of the floor support, reduce the width and number of cracks, and improve the overall crack resistance of the floor support. The reinforcement of the board surface support adopts a reinforcement method of adding a new board surface superposition layer and tensioning the reinforcing bars to eliminate or reduce the influence of strain hysteresis of the reinforcing bars. Compared with the reinforcement method of gluing steel plates and gluing fiber composite materials, the present invention is convenient to construct, has a simple reinforcement process, and significantly reduces costs.

[0036] In an embodiment of the present invention, the thickness of the floor slab protective layer removed from the reinforced area at the support in S1 is 15 mm.

[0037] It should be noted that by reducing the thickness of the floor slab protective layer to 15mm, the thickness of the chiseled layer can be reduced without affecting the connection between the reinforcement bars and the floor slab protective layer. During subsequent repairs, the original floor decoration load should not be increased as much as possible.

[0038] In an embodiment of the present invention, before laying the reinforcing bars in S2, the actual size needs to be verified on site, and then the reinforcing bars to be laid are cut and manufactured, and the reinforcing bars need to be straightened before cutting.

[0039] It should be noted that by straightening the reinforcement bars, subsequent bending operations can be facilitated and the replacement can be subjected to tensile strain.

[0040] In an embodiment of the present invention, the support rod in S3 is selected from angle steel or thick steel bar, and the clamping tool is a "Π" type buckle.

[0041] In the embodiment of the present invention, the support rod and the buckle used in S3 are cut by a cutting machine so that the ends thereof are flat and the size is accurate.

[0042] It should be noted that: by using a cutting machine to cut the support rods and buckles, the ends of the support rods and buckles are flat and accurate in size, so that the support rods can be used to support two adjacent reinforcement bars, and the buckles can apply force evenly, so that the reinforcement bars are changed from straight to curved to produce tensile strain;

[0043] In an embodiment of the present invention, after the concrete superimposed layer in S4 is vibrated and compacted, a leveling layer is constructed on the top of the concrete superimposed layer.

[0044] It should be noted that by constructing a leveling layer on top of the concrete overlay layer, it is possible to prevent subsequent construction operations from being affected by unevenness or slopes.

[0045] Construction method of leveling layer: The leveling layer should be provided with partition joints, the spacing between the joints should not be greater than 6mm, and the allowable deviation of the surface flatness of the leveling layer is 5mm.

[0046] Before laying the leveling layer, clean the insulation layer and keep it moist. When laying, follow the procedure of far first, near later, and from high to low. When using cement mortar for leveling, it should be calendered twice after the water is absorbed and fully cured. After laying the leveling layer for 12 hours, sprinkle water for curing for 7 to 10 days.

[0047] The working principle of the method for improving the strain hysteresis effect of the reinforcement bars of the floor support provided by the present invention is as follows:

[0048] By tensioning the floor support reinforcement bars to generate tensile strain, the influence of the strain hysteresis of the reinforcement bars is eliminated or reduced, thereby giving full play to the role of the reinforcement part, improving the safety reserve of the bearing capacity of the floor support, and improving the degree of coordinated force and joint work between the reinforcement part and the original component. It can also effectively make up for the deficiency that when the load acting on the floor cannot be removed during the reinforcement process, the strength reduction coefficient is uniformly taken as 0.9 when the bearing capacity is verified, instead of giving the corresponding strength reduction coefficient according to the actual hysteresis strain size. By using the plate support reinforcement, a reinforcement method of adding a new plate surface overlap layer and tensioning the reinforcement bars to eliminate or reduce the influence of the strain hysteresis of the reinforcement bars is adopted. Compared with the steel plate bonding reinforcement method and the fiber composite material bonding reinforcement method, the present invention is convenient in construction, simple in reinforcement process, and significantly reduces costs.

[0049] The circuits and controls involved in the present invention are all prior art and will not be described in detail here.

[0050] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for improving the strain hysteresis effect of floor support reinforcement bars, characterized in that: The specific steps are as follows: S1, chiseling off the protective layer of the floor slab in the reinforced area of ​​the slab support, removing floating dust and debris, and then washing with water; S2. Lay multiple reinforcing bars on the slab support reinforcement area where the floor slab protective layer is removed, and implant the ends of the reinforcing bars into the drilled holes of the floor slab using anchoring glue; S3. A support rod is arranged between two adjacent reinforcing bars, and the two reinforcing bars are clamped together into a broken line shape by a clamping tool, so as to force the reinforcing bars to change from straight to curved and produce tensile strain, and the reinforcing bars are tied after the prestressing is completed; S4. After binding, apply structural interface glue on the floor protection layer, pour a 40mm thick C30 fine stone concrete overlay layer, and vibrate it to make it dense.

2. A method for improving the strain hysteresis effect of floor support reinforcement bars according to claim 1, characterized in that: In the S1, the thickness of the floor slab protective layer removed in the reinforced area at the support is 15 mm.

3. A method for improving the strain hysteresis effect of floor support reinforcement bars according to claim 1, characterized in that: Before laying the reinforcing bars in S2, the actual size needs to be verified on site, and then the reinforcing bars to be laid are cut and produced, and the reinforcing bars need to be straightened before cutting.

4. The method for improving the strain hysteresis effect of the floor support reinforcement bars according to claim 1, characterized in that: The support rod in S3 is selected from angle steel or thick steel bar, and the clamping tool is a "Π" type buckle.

5. A method for improving the strain hysteresis effect of floor support reinforcement bars according to claim 4, characterized in that: The support rods and buckles used in S3 are cut by a cutting machine to make their ends flat and accurate in size.

6. A method for improving the strain hysteresis effect of floor support reinforcement bars according to claim 5, characterized in that: After the concrete superimposed layer in S4 is vibrated and compacted, a leveling layer is constructed on the top of the concrete superimposed layer.

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