Reinforced concrete beam and slab with fireproofing layer and method for manufacturing the same
By installing wire mesh on the surface of reinforced concrete beams and slabs and anchoring it into the supports, the problem of concrete protective layer falling off under fire was solved, the load-bearing capacity was maintained and the fire resistance limit was extended, and the construction cost was reduced.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-06-05
- Publication Date
- 2026-03-24
AI Technical Summary
Existing technologies are prone to concrete cover loss in reinforced concrete beams and slabs under fire, leading to reduced load-bearing capacity and collapse risk. Furthermore, existing fire-retardant coatings and polypropylene fiber solutions suffer from high costs and poor durability.
A wire mesh is installed on the surface of reinforced concrete beams and slabs and connected to the internal concrete through anchor wires. The wire mesh is anchored into the support to form a reliable connection between the wire mesh and the concrete, thereby fixing the concrete protective layer, slowing down the heating rate, and preventing it from falling off.
It effectively prevents the concrete protective layer from falling off, slows down the decline in load-bearing capacity under fire, extends the fire resistance limit, reduces high-temperature damage, and creates conditions for post-fire repair. At the same time, it has low construction cost and does not affect the durability of concrete.
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Figure CN116876684B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the field of disaster prevention and mitigation of building horizontal components, and particularly relates to a reinforced concrete beam and slab with fire-induced spalling prevention and a manufacturing method thereof. BACKGROUND
[0002] Under the action of fire, the concrete cover of reinforced concrete beams and slabs falls off in large areas, the steel bars and internal concrete rapidly heat up, the mechanical properties of the materials deteriorate, and the load-carrying capacity of the horizontal components decreases or even collapses. Therefore, it is very important to take measures to prevent the concrete cover of horizontal components from falling off under fire.
[0003] The existing technologies for reducing the degree of concrete spalling of reinforced concrete beams and slabs under fire include spraying fireproof paint on the surface of the components and adding polypropylene fibers to the concrete.
[0004] Spraying fireproof paint on the surface of the components can slow down the transfer of temperature to the concrete, thereby reducing the degree of spalling of the concrete cover. However, the construction cost of fireproof paint is relatively high, the performance of fireproof paint may deteriorate in the long-term service, the durability of fireproof paint may be inferior to that of concrete in the whole life cycle of the concrete structure, and in addition, there may be problems such as hollowing and spalling between the fireproof paint and the surface of the components during the service.
[0005] Adding polypropylene fibers to the concrete can make the water vapor generated inside the concrete at high temperatures more easily discharged from the concrete, so the pore pressure of the internal pores of the concrete with polypropylene fibers is smaller than that without polypropylene fibers, thereby reducing the damage to the concrete caused by high pore pressure and reducing the degree of spalling of the concrete under fire. However, under the action of fire, the pores formed by the melting of polypropylene fibers have an adverse effect on the durability of the concrete after the fire. SUMMARY
[0006] In order to at least solve one of the problems in the prior art, the present application provides a reinforced concrete beam and slab with fire-induced spalling prevention and a manufacturing method thereof, which prevents the spalling of the concrete cover of the reinforced concrete beam and slab under fire by arranging a steel mesh on the surface of the reinforced concrete beam and slab, thereby reducing the heating rate of the steel bars and internal concrete under fire, which can slow down the attenuation of the load-carrying capacity of the components under fire and prolong the fire resistance limit of the components, and can also reduce the high-temperature damage to the steel bars and internal concrete, thereby creating favorable conditions for post-fire repair and reinforcement.
[0007] In order to achieve the object of the present application, the present application provides a reinforced concrete beam and slab with fire-induced spalling prevention, which comprises a reinforced concrete beam with fire-induced spalling prevention and a reinforced concrete slab with fire-induced spalling prevention,
[0008] The reinforced concrete slab with the fireproof layer falling inhibition function comprises a reinforced concrete slab, a surface steel mesh of the slab and an anchoring wire of the slab, the surface steel mesh of the slab is laid close to a bottom formwork of the reinforced concrete slab, and end portions of the surface steel mesh of the slab are anchored into a beam support;
[0009] The reinforced concrete beam with the fireproof layer falling inhibition function comprises a reinforced concrete beam, a surface steel mesh of the beam and an anchoring wire of the beam, the surface steel mesh of the beam is laid close to a bottom formwork of the reinforced concrete beam and inside a side formwork of the reinforced concrete beam, and end portions of the surface steel mesh of the beam are anchored into a column support;
[0010] The anchoring wire of the slab and the anchoring wire of the beam are asymmetrically folded metal wires, which are respectively fixed at grid intersection points of the surface steel mesh of the slab and the surface steel mesh of the beam, and the metal wires are respectively extended into internal concrete of the reinforced concrete slab and the reinforced concrete beam, and end portions of the extended metal wires are bent into hooks.
[0011] Further, if a plurality of rows of the anchoring wire of the slab and the anchoring wire of the beam are arranged, adjacent rows are staggered.
[0012] Further, diameters of the steel wires of the surface steel mesh of the slab and the surface steel mesh of the beam are 1-5 mm, strengths of the steel wires are 300-600 MPa, and grid sizes of the steel meshes are 20-50 mm.
[0013] Further, diameters of the anchoring wire of the slab and the anchoring wire of the beam are 1-2 mm, and arrangement intervals are 100-500 mm.
[0014] Further, a length l1 of the surface steel mesh of the slab anchored into the beam support is greater than or equal to 5d1 and at least 0.5 times a width of the beam support, and d1 is a maximum diameter of the steel wire of the surface steel mesh of the slab.
[0015] Further, a length of the anchoring wire of the slab anchored into the reinforced concrete slab is at least 0.5 times a thickness of the reinforced concrete slab.
[0016] Further, a length l2 of the surface steel mesh of the beam anchored into the column support is greater than or equal to 5d2+0.5h c , d2 is a maximum diameter of the steel wire of the surface steel mesh of the beam, and h c is a width of the column support.
[0017] Further, a length of the anchoring wire of the beam anchored into the reinforced concrete beam is at least 50 mm+d, and d is a maximum diameter of a longitudinal reinforcement of the reinforced concrete beam.
[0018] The application also provides a manufacturing method of the reinforced concrete slab with the fireproof protection layer, comprising the following steps:
[0019] (1) laying the prefabricated steel mesh closely on the upper surface of the bottom formwork of the reinforced concrete slab;
[0020] (2) binding the bidirectional double-layer steel bars arranged in the reinforced concrete slab;
[0021] (3) binding the anchoring wire at the grid intersection of the steel mesh, and bending the end of the protruding part of the anchoring wire into a hook;
[0022] (4) pouring the concrete of the reinforced concrete slab and curing.
[0023] The application also provides a manufacturing method of the reinforced concrete beam with the fireproof protection layer, comprising the following steps:
[0024] (1) laying the prefabricated steel mesh closely on the upper surface of the bottom formwork of the reinforced concrete beam and the inner surface of the side formwork of the reinforced concrete beam;
[0025] (2) binding the steel cage arranged in the reinforced concrete beam;
[0026] (3) binding the anchoring wire at the grid intersection of the steel mesh, and bending the end of the protruding part of the anchoring wire into a hook;
[0027] (4) pouring the concrete of the reinforced concrete beam and curing.
[0028] The principle of the application is as follows:
[0029] The steel mesh is laid closely on the formwork and connected reliably with the internal concrete of the reinforced concrete beam and slab through the anchoring wire, and the steel mesh of the reinforced concrete beam and slab is anchored into the column support and beam support respectively. When calculating the normal temperature bearing capacity of the beam and slab, the load shared by the steel mesh is ignored and taken as a safety reserve; at high temperature, the steel mesh can fix the possible falling concrete protection layer, effectively prevent the falling of the concrete protection layer, protect the steel bars and internal concrete, reduce the temperature rising rate of the steel bars and internal concrete under fire, slow down the decay of the bearing capacity of the component under fire, and prolong the fire resistance limit of the component; meanwhile, the temperature rising rate of the steel bars and internal concrete under fire is reduced, the high temperature damage of the steel bars and internal concrete is reduced, and favorable conditions are created for the post-fire repair and reinforcement.
[0030] Compared with the prior art, the application has at least the following beneficial effects:
[0031] (1) The reinforced concrete beam and slab provided by the application can slow down the attenuation of the load bearing capacity of the component under fire and prolong the fire resistance limit of the component;
[0032] (2) The reinforced concrete beam and slab provided by the application can reduce the high-temperature damage of the steel bars and the internal concrete, and create favorable conditions for post-fire repair and reinforcement;
[0033] (3) The reinforced concrete beam and slab can be used as a safety reserve of the load bearing capacity at normal temperature.
[0034] (4) The construction cost is low. The application only uses steel wire mesh and anchoring wires, the raw material prices are low, and the construction steps are simple, so the labor cost and the mechanical use cost are low.
[0035] The following will be further described in detail in combination with the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS
[0036] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description only constitute some embodiments of the application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor, wherein:
[0037] Figure 1 It is a front view of the steel wire mesh and anchoring wire of the reinforced concrete slab in the embodiment of the application.
[0038] Figure 2 It is a top view of the steel wire mesh and anchoring wire of the reinforced concrete slab in the embodiment of the application.
[0039] Figure 3 It is a front view of the steel wire mesh and anchoring wire of the bottom surface of the reinforced concrete beam in the embodiment of the application.
[0040] Figure 4 It is a front view of the steel wire mesh and anchoring wire of the side surface of the reinforced concrete beam in the embodiment of the application.
[0041] Figure 5 It is a sectional view of the reinforced concrete beam in the embodiment of the application.
[0042] In the drawings, 1 is a reinforced concrete slab, 2 is a surface steel wire mesh of the slab, 3 is an anchoring wire of the slab, 4 is a reinforced concrete beam, 5 is a surface steel wire mesh of the beam, and 6 is an anchoring wire of the beam. DETAILED DESCRIPTION
[0043] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort are within the protection scope of the present application. If the directions and sequences such as "upper", "lower", "front", "rear", "left", "right" and the like are mentioned in the following embodiments, they are only for reference to the directions of the drawings, and therefore, the directions are used for illustration but not for limitation of the present application. In addition, the terms "have", "contain" and the like are intended to cover a non-exclusive range.
[0044] Please refer to Figures 1 to 5 The present application provides a reinforced concrete beam and slab with fireproof protection layer, comprising a reinforced concrete slab 1, a surface steel mesh 2 of the slab, anchoring wires 3 of the slab, a reinforced concrete beam 4, a surface steel mesh 5 of the beam, and anchoring wires 6 of the beam. The surface steel mesh 2 of the slab is laid on the bottom formwork of the reinforced concrete slab 1, and the end of the surface steel mesh 2 is anchored into the beam support. The surface steel mesh 5 of the beam is laid on the bottom formwork of the reinforced concrete beam 4 and the inner side of the side formwork of the reinforced concrete beam 4, and the end of the surface steel mesh 5 is anchored into the column support. The anchoring wires 3 of the slab and the anchoring wires 6 of the beam are asymmetrically folded metal wires, which are respectively fixed at the grid intersection points of the surface steel mesh 2 of the slab and the surface steel mesh 5 of the beam. The protruding parts of the metal wires are respectively inserted into the internal concrete of the reinforced concrete slab 1 and the reinforced concrete beam 4, and the ends of the protruding parts of the metal wires are bent into hooks.
[0045] Preferably, if multiple rows of the anchoring wires 3 of the slab and the anchoring wires 6 of the beam are provided, the adjacent rows are staggered.
[0046] During construction, only the steel mesh and the anchoring wires are added to the ordinary reinforced concrete beam and slab, and the cost of the new materials is low and the construction is simple.
[0047] Please refer to Figure 1 , Figure 2 The manufacturing process of the reinforced concrete slab with fireproof protection layer comprises the following steps:
[0048] (1) In some embodiments of the present application, the diameter of the steel wire of the surface steel mesh 2 of the slab is 1-5 mm, the strength of the steel wire is 300-600 MPa, and the grid size of the steel mesh is 20-50 mm. For example, Figure 1As shown, the prefabricated surface steel mesh 2 of the plate is tightly laid on the upper surface of the bottom formwork of the reinforced concrete slab 1, the surface steel mesh 2 of the plate is anchored into the beam support, so that the beam support can provide sufficient constraint for the surface steel mesh 2 of the plate, the length l15d1 of the surface steel mesh 2 of the plate anchored into the beam support is at least 0.5 times the width of the beam support, and d1 is the maximum diameter of the steel wire of the surface steel mesh 2 of the plate;
[0049] (2) The two-way double-layered steel bars of the reinforced concrete slab 1 are bound and arranged.
[0050] (3) The anchoring wire 3 of the plate is asymmetrically folded metal wire, in some embodiments of the present application, the diameter of the metal wire is 1-2 mm, and the arrangement interval is 100-500 mm. As shown, Figure 2 The anchoring wire 3 of the plate is bound and arranged at the grid intersection of the surface steel mesh 2 of the plate; in order to make the surface steel mesh 2 of the plate bear force uniformly, the anchoring wire 3 of the plate is provided with multiple rows, and each row is staggered. Specifically, when arranging the anchoring wire 3 of the plate, the anchoring wire 3 of the plate is bound and arranged at the grid intersection of the surface steel mesh 2 of the plate by using the method of binding steel bars with wire, then the part of the anchoring wire 3 of the plate protruding into the reinforced concrete slab 1 is bent into a hook and anchored into the reinforced concrete slab. In some embodiments of the present application, the anchoring wire 3 of the plate is anchored into the reinforced concrete slab 1 to a height of at least 0.5 times the thickness of the plate;
[0051] (4) Pouring concrete for the reinforced concrete slab 1 and curing.
[0052] As shown, Figure 1 The anchoring wire 3 of the plate is used to connect the surface steel mesh 2 of the plate and the concrete inside the reinforced concrete slab 1, so that when the reinforced concrete slab 1 is on fire and the concrete protective layer is about to fall off, the concrete protective layer of the reinforced concrete slab 1 will be fixed by the surface steel mesh 2 of the plate due to the reliable connection between the surface steel mesh 2 of the plate and the inside of the reinforced concrete slab 1 through the anchoring wire 3 of the plate, thereby avoiding the falling off of the concrete protective layer.
[0053] Referring to Figure 3 , Figure 4 , Figure 5 , a manufacturing process of a reinforced concrete beam for inhibiting the fire-induced falling off of the protective layer includes the following steps:
[0054] (1) In some embodiments of the present application, the diameter of the steel wire of the surface steel mesh 5 of the beam is 1-5 mm, the strength of the steel wire is 300-600 MPa, and the grid size of the steel mesh is 20-50 mm. As shown, Figure 3 , Figure 5As shown, the precast surface wire mesh 5 of the beam is laid tightly onto the upper surface of the bottom formwork and the inner surface of the side formwork of the reinforced concrete beam 4. The surface wire mesh 5 is anchored into the column support so that the column support can provide sufficient restraint for the surface wire mesh 5. The length l2 of the surface wire mesh 5 anchored into the column support is ≥ 5d2 + 0.5h. c d2 is the maximum diameter of the wires in the surface wire mesh 5 of the beam; h c The width of the column support;
[0055] (2) Tie and arrange the steel cage of reinforced concrete beam 4;
[0056] (3) The anchor wire 6 of the beam is an asymmetrically folded metal wire. In some embodiments of the present invention, the diameter of the metal wire is 1-2 mm. For example... Figure 4 As shown, the anchor wires 6 of the beam are tied to the grid intersections of the steel wire mesh 5 on the beam surface during arrangement. Specifically, when arranging the anchor wires 6 of the beam, the anchor wires 6 are tied to the grid intersections of the steel wire mesh 5 on the beam surface using the method of tying reinforcing bars with wire. Then, the extended portion of the anchor wires 6 extends into the interior of the reinforced concrete beam 4, and the end of the extended portion of the anchor wires 6 is bent into a hook. In some embodiments of the present invention, the length of the anchor wires 6 anchored into the reinforced concrete beam 4 is at least 50 mmd, where d is the maximum diameter of the longitudinal reinforcement of the reinforced concrete beam 4.
[0057] (4) Pour concrete for reinforced concrete beam 4 and cure it.
[0058] like Figure 3 , Figure 4 , Figure 5 As shown, the bottom and sides of the reinforced concrete beam 4 are provided with surface wire mesh. The anchor wires 6 of the beam connect the surface wire mesh 5 of the beam to the concrete inside the reinforced concrete beam 4. In this way, when the reinforced concrete beam 4 is exposed to fire and the concrete protective layer is about to fall off, the surface wire mesh 5 of the beam is reliably connected to the inside of the reinforced concrete beam 4 through the anchor wires 6, and the concrete protective layer of the reinforced concrete beam 4 will be fixed by the surface wire mesh 5 of the beam, thereby preventing the concrete protective layer from falling off.
[0059] The solution provided by the foregoing embodiments of the present invention can prevent the concrete protective layer of beams and slabs from falling off under fire, thereby reducing the rate of temperature rise of steel bars and internal concrete under fire. First, it can slow down the attenuation of the load-bearing capacity of components under fire and extend the fire resistance limit of components; second, it can reduce the high-temperature damage to steel bars and internal concrete, creating favorable conditions for post-fire repair and reinforcement.
[0060] The foregoing embodiments of the present application have the advantages that the prior art does not have, including: (1) low construction cost (including raw material price, labor cost, etc.); (2) no adverse effect on the durability of concrete; (3) can be used as a safety reserve of the bearing capacity of reinforced concrete beams and slabs at room temperature.
[0061] In the foregoing embodiments, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can be seen in the relevant description of other embodiments.
[0062] The foregoing description of the disclosed embodiments enables a person skilled in the art to carry out or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the generic principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A reinforced concrete beam or slab that inhibits fire-induced peeling of the protective layer, characterized in that, This includes reinforced concrete beams and reinforced concrete slabs designed to prevent fire-induced spalling of the protective layer. The reinforced concrete slab that suppresses the detachment of the protective layer in a fire includes a reinforced concrete slab (1), a surface wire mesh (2) of the slab, and anchor wires (3) of the slab. The surface wire mesh (2) of the slab is laid tightly on the bottom formwork of the reinforced concrete slab (1). The ends of the surface wire mesh (2) of the slab are anchored into the beam support. The surface wire mesh (2) of the slab is used to prevent the concrete protective layer of the reinforced concrete slab from detaching in a fire. The reinforced concrete beam that suppresses the detachment of the protective layer in a fire includes a reinforced concrete beam (4), a surface wire mesh (5) of the beam, and anchor wires (6) of the beam. The surface wire mesh (5) of the beam is laid tightly on the bottom formwork of the reinforced concrete beam (4) and the inside of the side formwork of the reinforced concrete beam (4). The ends of the surface wire mesh (5) of the beam are anchored into the column supports. The surface wire mesh (5) of the beam is used to prevent the concrete protective layer of the reinforced concrete beam from detaching in a fire. The anchor wires (3) of the slab and the anchor wires (6) of the beam are asymmetrically folded metal wires, which are respectively tied and fixed at the grid intersection of the surface wire mesh (2) of the slab and the surface wire mesh (5) of the beam. The extended parts of the metal wires extend into the concrete inside the reinforced concrete slab (1) and the reinforced concrete beam (4), and the ends of the extended parts of the metal wires are bent into hooks.
2. A reinforced concrete beam or slab for suppressing fire-induced detachment of the protective layer according to claim 1, characterized in that, The anchor wires (3) of the plate and the anchor wires (6) of the beam are arranged in multiple rows, with adjacent rows staggered.
3. A reinforced concrete beam or slab for suppressing fire-induced detachment of the protective layer according to claim 1, characterized in that, The wire diameter of the steel wire mesh (2) on the surface of the plate and the steel wire mesh (5) on the surface of the beam is 1~5mm, the wire strength is 300~600MPa, and the mesh size of the steel wire mesh is 20~50mm.
4. A reinforced concrete beam or slab for suppressing fire-induced detachment of the protective layer according to claim 1, characterized in that, The diameter of the anchor wire (3) of the plate and the anchor wire (6) of the beam is 1~2mm, and the spacing between them is 100~500mm.
5. A reinforced concrete beam or slab for suppressing fire-induced detachment of the protective layer according to claim 1, characterized in that, The length of the steel wire mesh on the surface of the plate (2) anchored into the beam support And it should be at least 0.5 times the width of the beam support. The maximum diameter of the wire in the surface wire mesh (2) of the plate.
6. A reinforced concrete beam or slab for suppressing fire-induced detachment of the protective layer according to claim 1, characterized in that, The anchor wire (3) of the slab is anchored into the reinforced concrete slab (1) at a height of at least 0.5 times the thickness of the reinforced concrete slab (1).
7. A reinforced concrete beam or slab for suppressing fire-induced detachment of the protective layer according to claim 1, characterized in that, The length of the steel wire mesh on the surface of the beam (5) anchored into the column support , The maximum diameter of the wire in the surface wire mesh (5) of the beam is given. The width of the column support.
8. A reinforced concrete beam or slab for suppressing fire-induced peeling of the protective layer according to claim 1, characterized in that, The anchoring wire (6) of the beam is anchored into the reinforced concrete beam (4) for a length of at least 50 mm. , The maximum diameter of the longitudinal reinforcement of the reinforced concrete beam (4) is given.
9. A method for manufacturing a reinforced concrete slab that inhibits fire-induced peeling of the protective layer, characterized in that, Includes the following steps: (1) Lay the precast steel wire mesh (2) tightly onto the upper surface of the bottom formwork of the reinforced concrete slab (1); (2) Tie and arrange the two-way double-layer reinforcement of the reinforced concrete slab (1); (3) Tie the anchor wire (3) of the plate to the grid intersection of the steel wire mesh (2) on the surface of the plate, extend the part of the anchor wire (3) of the plate into the plate along the thickness direction of the reinforced concrete plate (1), and then bend the end of the part of the anchor wire (3) of the plate into a hook. (4) Pour concrete into the reinforced concrete slab (1) and cure it.
10. A method for manufacturing a reinforced concrete beam that inhibits fire-induced detachment of the protective layer, characterized in that, Includes the following steps: (1) The surface wire mesh (5) of the precast beam is laid tightly onto the upper surface of the bottom formwork of the reinforced concrete beam (4) and the inner surface of the side formwork of the reinforced concrete beam (4); (2) Tie and arrange the steel cage of the reinforced concrete beam (4); (3) Tie the anchor wire (6) of the beam to the grid intersection of the steel wire mesh (5) on the surface of the beam, extend the long part of the anchor wire (6) into the reinforced concrete beam (4), and then bend the end of the long part of the anchor wire (6) into a hook. (4) Pour concrete for the reinforced concrete beam (4) and cure it.
Citation Information
Patent Citations
Building cast-in-place template lined with steel wire mesh
CN209538664U