A reinforced concrete beam
By using concave shaped steel plate reinforcement structure on the side surface of the reinforced concrete beam, combined with fasteners and adhesive layers, the problems of poor reinforcement effect and self-weight in the prior art are solved, and higher bending and shear resistance are achieved Force performance and lower self-weight.
Patent Information
- Application Number
- CN202110271232.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-03-12
- Publication Date
- 2024-12-06
- Estimated Expiration
- 2041-03-12
AI Technical Summary
In the prior art methods for reinforced reinforced concrete beams, there is a lack of research on the shape, coverage position and connection structure of the steel plate, resulting in poor reinforcement effect and large self-weight, making it difficult to effectively withstand bending moments and shear forces.
The concave shaped structure of steel plates is optimized by combining the bonding layer and stretching to reduce self-weight and improve bending and shear resistance by connecting the fastener and through holes on the side surface of the reinforced concrete beam. Force performance.
The bearing capacity of reinforced concrete beams is significantly improved, the range of concrete tensile damage is reduced, the stress strength is increased, and the self-weight after reinforcement is reduced, and the bending and shear resistance is optimized.
Smart Images
Figure CN112854811B_ABST
Abstract
Description
Technical Field
[0001] The invention mainly relates to a reinforced concrete beam reinforced by a beam side-attached steel plate method, in particular to the shape and connection structure of the side-attached steel plate, and belongs to the field of building structures. Background Art
[0002] The method of attaching steel plates to the sides of beams is a method for reinforcing reinforced concrete beams. After reinforcement, the reinforced concrete beams have significant changes in the force-displacement relationship, stress, concrete damage, etc. However, there is currently a lack of research on the shape, covering position, and connection structure of the reinforcing steel plates. Usually, the steel plates are used to cover the entire surface of the reinforced concrete beam for reinforcement. Summary of the invention
[0003] In order to solve the above problems, the present invention aims to provide a reinforced concrete beam reinforced by a method of attaching steel plates to the sides of the beam. While using steel plates to reinforce the reinforced concrete beam, the structural shape of the reinforced steel plates is optimized, which can effectively and reasonably withstand bending moments and shear forces, while reducing the deadweight of the steel plate reinforced beam.
[0004] In order to achieve the above object, the present invention adopts the following technical solutions:
[0005] A reinforced concrete beam, wherein steel plates are connected to the outer sides of two opposite side surfaces of the reinforced concrete beam, the length and height of the steel plates are equal to the length and height of the reinforced concrete beam, and the length edge of the steel plate is aligned with the length edge of the reinforced concrete beam, the height edge of the steel plate is aligned with the height edge of the reinforced concrete beam, and a first notch is opened on the upper edge of the steel plate, so that the steel plate is concave in shape.
[0006] Furthermore, the two steel plates are tightly attached to the side surface of the reinforced concrete beam via connecting fasteners.
[0007] Furthermore, the connecting fasteners are multiple rods penetrating two opposite side surfaces of the reinforced concrete beam, and locking structures are provided at both ends of the rods.
[0008] Furthermore, the above scheme also includes a through hole, which is composed of a first through hole penetrating two opposite side surfaces of the reinforced concrete beam and a second through hole penetrating the thickness direction of the steel plate, and the second through hole does not intersect with the first notch;
[0009] The two steel plates are pressed against the side surface of the reinforced concrete beam by connecting fasteners inserted into the first through hole and the second through hole at the same time.
[0010] Preferably, an adhesive layer, such as glue, is coated between the steel plate and the side surface of the reinforced concrete beam to improve the connection performance between the steel plate and the side surface of the reinforced concrete beam so that the two can form a whole.
[0011] Furthermore, the above scheme also includes at least one tie rod, which is parallel to the length direction of the reinforced concrete beam, and is located in the area between the first notch and the lower edge of the steel plate, and both ends of the tie rod are fixedly connected to the connecting fasteners.
[0012] Preferably, the lengths of the tie bars are different, but their shortest length is greater than the length of the first notch.
[0013] Furthermore, the above scheme also includes a second notch, a plurality of the second notches are arranged in parallel and at intervals on the steel plate, and the second notches are located on both sides of the first notch.
[0014] Furthermore, the reinforced concrete beam includes longitudinal main force bars arranged along the length direction of the reinforced concrete beam, and stirrups arranged at intervals along the longitudinal main force bars.
[0015] Furthermore, the above scheme also includes a second notch, and a plurality of the second notches are arranged in parallel and at intervals on the steel plate, the second notches are located on both sides of the first notch, and the spacing between two adjacent second notches is equal to the spacing between adjacent stirrups.
[0016] Preferably, the height of the second notch is smaller than the height of the first notch.
[0017] Preferably, the steel plate is a steel plate of unequal thickness, and the thickness at the location where the bending moment and shear force of the reinforced concrete beam are maximum is greater than the thickness at other locations.
[0018] In particular, the reinforced concrete beam is a beam of uniform cross-section, and steel plates are connected to the outer sides of two opposite side surfaces of the reinforced concrete beam. The length and height of the steel plates are equal to the length and height of the reinforced concrete beam, and the length edge of the steel plate is aligned with the length edge of the reinforced concrete beam, and the height edge of the steel plate is aligned with the height edge of the reinforced concrete beam. A first notch is opened on the upper edge of the steel plate, so that the steel plate is concave in shape, and the distance from the left end of the first notch to the left end of the reinforced concrete beam is equal to the distance from the right end of the first notch to the right end of the reinforced concrete beam.
[0019] The side steel plate reinforcement structure of the present invention solves the problem of later reinforcement of reinforced concrete beams. By adding steel plates to the side surfaces of the beams, the bending and shear resistance of the beams when bearing loads are changed. By opening notches at different positions of the steel plates, the cross-sectional shape of the beams is changed while reducing weight, and in particular, corresponding adjustments are made to the positions with maximum bending moment and maximum shear force.
[0020] Since reinforced concrete beams are prone to cracking and damage at the bottom of the bend, in addition to strengthening the steel plate itself, tension bars are added at the corresponding positions to improve the bending resistance.
[0021] It should be noted that the direction of the first notch in the present invention is made on the premise that the upper end face of the reinforced concrete beam bears the load. The specific direction of the first notch is determined according to the position of the load. Its purpose is to reduce the weight while ensuring that the steel bars at the reinforced concrete beam that bears the largest bending moment are reinforced by the steel plate, and the places without stirrups in the reinforced concrete beam are also reinforced by the steel plate.
[0022] Compared with the prior art, the side-attached steel plate reinforced reinforced concrete beam of the present invention has the following characteristics:
[0023] (1) The reinforcement effect is good and the bearing capacity of reinforced concrete beams is significantly improved. Compared with ordinary reinforced concrete beams, the tensile damage range of reinforced concrete beams reinforced with side steel plates is smaller.
[0024] (2) According to the stress characteristics of the reinforced concrete beam, a first notch is opened on the side steel plate so that the side steel plate does not completely cover the side surface of the reinforced concrete beam, thereby reducing the self-weight of the reinforced structure and giving full play to the bending moment resistance performance of the steel plate below the first notch.
[0025] (3) Side-bonded steel plates can significantly increase the stress strength of reinforced concrete beams.
[0026] (4) When a simply supported beam is subjected to concentrated force at a symmetrical point, the bending moment on the beam is large in the middle and small at both ends. At this time, the bending moment is mainly resisted by the longitudinal steel bars at the bottom of the reinforced concrete beam. Therefore, the steel plate is designed to have a first notch (concave shape), which optimizes the bending capacity while avoiding material waste and reducing the self-weight of the beam after reinforcement; the shear force on the beam is large at both ends and small in the middle. The shear force is resisted by the stirrups. The steel plate between the second notches plays a role in resisting the shear force. The second notch avoids material waste and reduces the self-weight of the beam. Even if the simply supported beam is subjected to an asymmetric load, the positions of the first notch and the second notch can be set according to the same concept, and the corresponding tension bars can be used.
[0027] (5) Holes are opened at both ends of the connecting fasteners to fix the connecting reinforcements, and reinforcements of different lengths are set. For example, when there are two reinforcements, steel bars are used as reinforcements to connect the two connecting fasteners with a smaller spacing, and steel bars are also used as reinforcements to connect the two connecting fasteners with a larger spacing. The function of the two reinforcements is to resist the bending moment and control and slow down the cracking of the concrete at the bottom of the beam. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Figure 1 This is a schematic diagram of the structure of an ordinary reinforced concrete beam without side steel plate reinforcement;
[0029] Figure 2 This is a schematic diagram of a reinforced concrete beam structure reinforced with side-attached steel plates;
[0030] Figure 3 This is a schematic diagram of a reinforced concrete beam structure that is reinforced with side-attached steel plates and connected to the steel plates on both sides by connectors. The connection holes of the connectors are drawn in the figure;
[0031] Figure 4 A schematic diagram of the reinforced concrete beam structure with side-attached steel plates is drawn for the connection parts;
[0032] Figure 5 for Figure 1 AA section diagram in;
[0033] Figure 6 for Figure 2 , Figure 3 and Figure 4 BB cross-section diagram in;
[0034] Figure 7 for Figure 2 , Figure 3 and Figure 4 Schematic diagram of CC cross section;
[0035] Figure 8 for Figure 3 and Figure 4 DD cross-section diagram in;
[0036] Fig. 9 This is the concrete tensile damage analysis diagram of an ordinary reinforced concrete beam without side steel plate reinforcement after loading;
[0037] Fig.10 This is a diagram showing the tensile damage analysis of concrete after loading of a reinforced concrete beam reinforced with side-attached steel plates. DETAILED DESCRIPTION
[0038] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments, but it should not be understood that the scope of the subject matter described in the present invention is limited to the following embodiments. Without departing from the above-mentioned technical ideas of the present invention, various modifications, substitutions and changes made according to the common technical knowledge and customary means in the field are included in the scope of the present invention.
[0039] like Figure 1 The figure shows an existing unreinforced ordinary reinforced concrete beam (RCB). Its internal reinforcement is as follows Figure 4 As shown in the AA section.
[0040] like Figures 2 to 8As shown, the reinforced concrete beam (SSRCB) reinforced with a side-plated steel plate 1 is shown in this embodiment. The following uses a rectangular beam of equal cross-section as an example. According to the principle that when a simply supported beam is subjected to concentrated force at three equal points, the bending moment of the beam is large in the middle and small at both ends, and the shear force is large at both ends and zero in the middle (in a pure bending state), the steel plate 1 of the reinforced concrete beam reinforced with a side-plated steel plate 1 is designed to be groove-shaped. Specifically: on the basis of an ordinary reinforced concrete beam, the method of sticking the steel plate 1 on both sides of the longitudinal section of the beam is adopted. The two ends of the steel plate 1 are designed to be spread along the longitudinal surface of the beam, and the height is flush with the height of the beam. The middle of the steel plate 1 is designed to cover only along the bottom of the beam, and the height is 1 / 3 of the height of the beam.
[0041] Specifically, the reinforced concrete beam is a rectangular beam of uniform cross-section, and the reinforced concrete beam includes longitudinal main force bars arranged along the length direction of the reinforced concrete beam, and stirrups arranged at intervals along the longitudinal main force bars. The outer sides of the two opposite side surfaces of the reinforced concrete beam are connected with steel plates 1, and the length and height of the steel plate 1 are equal to the length and height of the reinforced concrete beam, and the length edge of the steel plate 1 is aligned with the length edge of the reinforced concrete beam, and the height edge of the steel plate 1 is aligned with the height edge of the reinforced concrete beam. A first notch 2 is opened on the upper edge of the steel plate 1, so that the steel plate 1 is in a concave shape, and the length of the first notch 2 is equal to one-third of the length of the reinforced concrete beam, and the height of the first notch 2 is equal to two-thirds of the height of the reinforced concrete beam, and the left end and the right end of the first notch 2 are respectively located at the three equal division points in the length direction of the reinforced concrete beam, that is, the distance from the left end of the first notch 2 to the left end of the reinforced concrete beam is equal to 1 / 3 of the length of the reinforced concrete beam, and similarly, the distance from the right end of the first notch 2 to the right end of the reinforced concrete beam is equal to 1 / 3 of the length of the reinforced concrete beam, and the height of the steel plate 1 below the first notch 2 is 1 / 3 of the height of the reinforced concrete beam.
[0042] like Fig. 9 and Fig.10 As shown in the figure, the numerical simulation of the damage analysis of the reinforced concrete beam without and with the side steel plate 1 is performed. By comparison, it can be seen that compared with the unreinforced ordinary reinforced concrete beam RCB, the reinforced concrete beam SSRCB reinforced with the side steel plate 1 has a smaller concrete damage range than the unreinforced ordinary reinforced concrete beam in general, especially the degree of damage to the mid-span concrete upward and the degree of damage spreading to both sides are much smaller than those of the unreinforced ordinary reinforced concrete beam, which further illustrates that the side steel plate 1 has a good effect on reducing concrete damage.
[0043] Furthermore, the reinforced concrete beam also includes second notches 3 spaced apart on the surface of the steel plate 1, the second notches 3 are located on both sides of the first notch 2, and the spacing between two adjacent second notches 3 is equal to the spacing between adjacent stirrups. The height of the second notch 3 is less than the height of the first notch 2. The reinforced concrete beam is also provided with through holes 4 and connecting fasteners, the through holes 4 are composed of a first through hole penetrating two opposite side surfaces of the reinforced concrete beam and a second through hole penetrating the thickness direction of the steel plate 1, and the second through hole does not intersect with the first notch 2 and the second notch 3; after the connecting fastener passes through the first through hole and the second through hole at the same time, the steel plate 1 is pressed against the two opposite side surfaces of the reinforced concrete beam, as shown in FIG. Figure 3 , Figure 4 , Figure 7 and Figure 8 , by inserting a connecting fastener into the through hole 4 to connect and tighten the steel plates 1 on both sides, the connecting fastener is a rod with threads and through holes at both ends, and the steel plates 1 are tightened by locking nuts, such as Figure 4 In the area between the lower portion of the first notch 2 of the steel plate 1 and the lower edge of the steel plate 1, two tie bars 5 of different lengths are provided, and the two ends of the tie bars 5 are respectively connected to the through holes of the connecting fasteners. Figure 4 The through holes 4 at the upper edge of the middle steel plate 1 are only used for inserting connecting fasteners.
Claims
1. A reinforced concrete beam, characterized in that: The outer sides of the two opposite side surfaces of the reinforced concrete beam are connected with steel plates (1), the length and height of the steel plates (1) are equal to the length and height of the reinforced concrete beam, and the length edge of the steel plates (1) is aligned with the length edge of the reinforced concrete beam, and the height edge of the steel plates (1) is aligned with the height edge of the reinforced concrete beam. The upper edge of the steel plate (1) is provided with a first notch (2), so that the steel plate (1) is in a concave shape, the length of the first notch (2) is equal to one third of the length of the reinforced concrete beam, the height of the first notch (2) is equal to two thirds of the height of the reinforced concrete beam, and the left end and the right end of the first notch (2) are respectively located at the points of three equal divisions in the length direction of the reinforced concrete beam; the two steel plates (1) are tightly attached to the side surfaces of the reinforced concrete beam by connecting fasteners, and the connecting fasteners are a plurality of rods penetrating the two opposite side surfaces of the reinforced concrete beam, and locking structures are arranged at both ends of the rods; It also includes through holes (4), the through holes (4) consisting of a first through hole penetrating two opposite side surfaces of the reinforced concrete beam and a second through hole penetrating the thickness direction of the steel plate (1), and the second through hole does not intersect with the first notch (2); the two steel plates (1) are pressed against the side surface of the reinforced concrete beam by connecting fasteners inserted simultaneously into the first through hole and the second through hole; It also includes at least one tie rod (5), the tie rod (5) being parallel to the length direction of the reinforced concrete beam, and the tie rod (5) being located in the area between the first notch (2) and the lower edge of the steel plate (1), and the two ends of the tie rod (5) being fixedly connected to the connecting fasteners; It also comprises a second notch (3), a plurality of the second notches (3) are arranged in parallel and at intervals on the steel plate (1), and the second notches (3) are located on both sides of the first notch (2).
2. A reinforced concrete beam according to claim 1, characterized in that: The reinforced concrete beam comprises longitudinal main force bars arranged along the length direction of the reinforced concrete beam, and stirrups arranged at intervals along the longitudinal main force bars.
3. A reinforced concrete beam according to claim 2, characterized in that: The distance between two adjacent second notches (3) is equal to the distance between adjacent stirrups.
4. A reinforced concrete beam according to claim 3, characterized in that: The height of the second notch (3) is smaller than the height of the first notch (2).
5. A reinforced concrete beam according to claim 1, characterized in that: The reinforced concrete beam is a beam of uniform cross-section.