Hollow slab beam prestressed tendon durability protection structure

Abstract

The utility model relates to a hollow slab beam prestressed tendon durability protection structure which comprises a beam body, a plurality of prestressed tendons are embedded in the beam body, a sleeve is arranged at the bottom of the beam body and outside at least one prestressed tendon in a sleeved mode, a notch is formed in the end of the beam body and close to a bottom plate of the beam body, and the notch is filled with a plugging block. The plugging block is used for plugging the sleeve orifice and the end part of the prestressed tendon; the construction method has the advantages that during construction, the gaps reserved in the ends of the beam body are not poured temporarily, after the hollow slab beam is formed, the sleeves and the prestressed tendons at the gaps are cut off, then a formwork is built at the gaps, repairing materials are injected into the gaps, the plugging blocks are formed after solidification, the plugging blocks are poured into the gaps of the hollow slab beam by filling the large plugging blocks, and the hollow slab beam is formed. The method replaces a thin plugging material coating or non-plugging mode, so that the pipe orifice of the sleeve and the exposed prestressed tendon can be effectively plugged, rainwater is prevented from entering the sleeve to cause corrosion of the prestressed tendon, the durability of the hollow slab beam is improved, and the service life of the hollow slab beam is prolonged.

Description

TECHNICAL FIELD

[0001] The utility model belongs to hollow slab beam technical field, more particularly, relate to a kind of hollow slab beam prestressed tendon durability protection structure. BACKGROUND

[0002] With the rapid improvement of prefabricated building component production process, prefabricated building component occupies a larger and larger proportion in various fields of capital construction, especially in the field of bridge, the technology of prefabricated building component is very mature, and prestressed hollow slab beam bridge is widely used in bridge construction due to its simple structure, easy standardization production and construction, convenient transportation and lifting and other advantages.

[0003] Pre-tensioning prestressed hollow slab beam is widely used in bridge engineering, and the process includes material preparation, bottom mold and reinforcement skeleton installation, prestressed tendon tensioning, installation of side mold and end mold, concrete pouring, tensioning and subsequent maintenance inspection. However, in order to meet the stress and construction requirements, the prestressed tendon (steel strand) in the bottom plate of the pre-tensioning prestressed concrete hollow slab beam is not bonded with the concrete in the entire length of the bottom plate, and part of the prestressed tendon (steel strand) is not bonded with the concrete within a certain length range from the beam end. Generally, the method of realizing unbonding is to cover the end of the prestressed tendon (steel strand) with a PVC pipe, which isolates the prestressed tendon (steel strand) within a certain length range from the concrete, thereby realizing the effect of unbonding. This method of covering the end of the prestressed tendon (steel strand) with a PVC pipe has defects, and the PVC pipe is often exposed at the beam end. During the use stage of the hollow slab beam, after the water seepage in the bridge area reaches the beam end, the water will enter the PVC pipe, thereby corroding the prestressed tendon (steel strand).

[0004] In actual construction, workers will apply a thin layer of sealing material to the end of the hollow slab beam, but the sealing material is easy to peel off under the sun and wind. Even worse, no sealing protection and durability protection measures are taken for the exposed prestressed tendon (steel strand) and PVC pipe at the end of the hollow slab beam. In the long-term use process, not only is the exposed prestressed tendon (steel strand) prone to rust, but also rainwater can corrode the prestressed tendon (steel strand) in the pipe through the opening of the PVC pipe, causing the prestressed tendon (steel strand) in the pipe to rust. Even worse, rainwater can enter the hollow slab beam through the exposed prestressed tendon (steel strand) and PVC pipe, causing the prestressed tendon (steel strand) in the hollow slab beam to rust and the concrete to crack, and in severe cases, the prestressed tendon (steel strand) can break, greatly affecting the safety and durability of the bridge structure, and even affecting the overall safety and service life of the bridge, which needs to be improved. UTILITY MODEL CONTENTS

[0005] The purpose of this invention is to provide a durable protective structure for the prestressed tendons of hollow slab beams. After the hollow slab beam is poured, sealing blocks are filled into the pre-reserved gaps at the ends of the hollow slab beam. The sealing blocks are used to seal and protect the openings of the sleeves and the exposed prestressed tendons at the beam ends. This helps to prevent rainwater from entering the sleeves and causing corrosion of the prestressed tendons, thereby improving the durability of the hollow slab beam, extending its service life, and reducing the impact on bridge safety.

[0006] To achieve the above-mentioned technical objectives, the technical solution of this utility model is as follows:

[0007] A durable protective structure for prestressed tendons in a hollow slab beam includes a beam body with several prestressed tendons embedded within it. At the bottom of the beam body, at least one of the prestressed tendons is fitted with a sleeve. A notch is provided at the end of the beam body near its base plate, and the notch is filled with a sealing block. The sealing block is used to seal the opening of the sleeve and the end of the prestressed tendon. The sealing block is formed by casting repair material, and the width of the sealing block is 3cm to 5cm, and the height of the sealing block is 9cm to 10cm.

[0008] During the concrete pouring stage of the hollow slab beam, the pre-reserved gap at the end of the beam is not poured yet. After the hollow slab beam concrete is poured and reaches the design strength, the sleeve at the gap, the prestressing tendons inside the sleeve, and the exposed prestressing tendons are cut off. Then, a formwork is erected at the gap, and repair material is injected into the area enclosed by the formwork, i.e., the space at the gap. After solidification, a sealing block is formed. By filling the pre-reserved gap at the end of the hollow slab beam with a larger sealing block, instead of applying a thin layer of sealing material or not sealing at all, the sleeve opening and all the ends of the prestressing tendons at the beam end can be stably sealed. This can seal the exposed prestressing tendons and the prestressing tendons inside the PVC pipe, preventing rainwater from entering the sleeve and causing corrosion of the prestressing tendons. This is beneficial to improving the durability of the hollow slab beam and thus extending its service life.

[0009] Specifically, the notch penetrates both sides of the bottom of the beam end; there are several notches, and each notch corresponds to a prestressing tendon and a sleeve opening.

[0010] Here, the notch can be horizontally penetrating to both sides of the bottom of the beam end, or it can not penetrate to both sides of the bottom of the beam end. Alternatively, multiple notches can be reserved for the sleeve and exposed prestressing tendons. In actual processes, to simplify the process, a horizontally continuous notch that penetrates to both sides of the bottom of the beam end is generally used.

[0011] Specifically, the sealing block has protrusions used to seal the casing opening and the ends of the prestressing tendons. During the injection of repair material, some of the material enters the casing, forming protrusions, while some fills the gap between the exposed prestressing tendons and the notch sidewall, forming protrusions, thereby further improving the sealing effect.

[0012] In one specific implementation, the notch has a protrusion on its sidewall and the sealing block has a groove for inserting the protrusion; and / or the notch has a receiving hole on its sidewall and the sealing block has a filling block that fills the receiving hole.

[0013] When the repair material is injected, it fills the receiving hole to form a filler block. When the repair material encounters the protrusion on the side wall of the gap, the protrusion inserts into the repair material, so that the sealing block forms a groove, thereby increasing the connection stability between the sealing block and the hollow slab beam.

[0014] This invention involves pre-leaving a notch at the end of a hollow slab beam and then filling the notch with a sealing block, thereby sealing the sleeve and the exposed ends of the prestressing tendons, preventing corrosion, improving the durability of the hollow slab beam, and avoiding shortening its lifespan. Attached Figure Description

[0015] Figure 1 This is a structural cross-sectional view of a durable protective structure for prestressed tendons in a hollow slab beam according to an embodiment of this utility model.

[0016] Figure 2 This is a schematic diagram of the structure of the sleeve, the prestressing tendons inside the sleeve, and the exposed prestressing tendons in the embodiments of this utility model.

[0017] Figure 3 This is a structural cross-sectional view from another angle of a durable protective structure for prestressed tendons in a hollow slab beam according to an embodiment of this utility model.

[0018] Explanation of reference numerals in the attached drawings: 1. Beam; 2. Prestressed tendon; 3. Sleeve; 4. Notch; 5. Sealing block; 6. Protrusion. Detailed Implementation

[0019] Reference Figure 1 and Figure 2 A durable protective structure for prestressed tendons in a hollow slab beam includes a beam body 1, in which several prestressed tendons 2 are pre-embedded. At the bottom of the beam body 1, some of the prestressed tendons 2 are covered with sleeves 3, and some of the prestressed tendons 2 are exposed at the ends of the beam body 1. The ends of the beam body 1 and near the bottom of the beam have notches 4.

[0020] Specifically, the notch 4 extends laterally through both sides of the bottom of the beam end, or it may not extend through both sides of the bottom of the beam end. In this embodiment, the notch 4 is horizontally continuous and extends through both sides of the bottom of the beam end.

[0021] Reference Figure 2 and Figure 3 The notch 4 is filled with a sealing block 5, which is used to seal the opening of the sleeve 3, the prestressed tendons 2 inside the sleeve 3, and the exposed ends of the prestressed tendons 2. The sealing block 5 has a protrusion 6, which is also used to seal the opening of the sleeve 3, the prestressed tendons 2 inside the sleeve 3, and the exposed ends of the prestressed tendons 2. The width of the sealing block 5 is 3-5 cm, and the height of the sealing block 5 is 9-10 cm. The sealing block 5 is formed by casting repair material. In this embodiment, the repair material can be concrete, cement-based grout, or structural adhesive, etc., as building repair materials.

[0022] In other embodiments, there are several gaps 4, each gap 4 corresponding to an exposed prestressed tendon 2 and sleeve 3, and each gap 4 is filled with a sealing block 5.

[0023] The sidewall of notch 4 has a protrusion, and the sealing block 5 has a groove for inserting the protrusion; the sidewall of notch 4 is provided with receiving holes, and the sealing block 5 is provided with a filling block for filling the receiving holes. In actual process, in order to improve the connection stability between the sealing block 5 and the hollow slab beam, when filling the repair material, the sidewall of notch 4 is roughened to form multiple receiving holes. When the repair material is injected, the repair material fills the receiving holes and forms a filling block after solidification.

[0024] In other embodiments, the sidewall of the notch 4 has a protrusion, and the sealing block 5 has a groove for the protrusion to be inserted; if the sidewall of the notch 4 is relatively rough after the hollow slab beam is formed, it is possible to choose not to roughen it and directly inject the repair material. When the repair material encounters the protrusion, a groove is formed on the sealing block 5.

[0025] Alternatively, a receiving hole may be provided on the side wall of the notch 4, and a filling block may be provided on the sealing block 5, which fills the receiving hole; if the side wall of the notch 4 is relatively smooth after the hollow slab beam is formed, then the side wall of the notch 4 needs to be roughened.

[0026] The above are all preferred embodiments of this utility model, and are not intended to limit the scope of protection of this utility model. Therefore, all equivalent changes made to the structure, shape and principle of this utility model should be covered within the scope of protection of this utility model.

Claims

1. A durable protective structure for prestressed tendons in a hollow slab beam, comprising a beam body (1), wherein a plurality of prestressed tendons (2) are pre-embedded within the beam body (1), and at the bottom of the beam body (1), at least one of the prestressed tendons (2) is fitted with a sleeve (3), characterized in that: The beam (1) has a notch (4) at its end and near its bottom plate. The notch (4) is filled with a sealing block (5). The sealing block (5) is used to seal the opening of the sleeve (3) and the end of the prestressed tendon (2).

2. The durability protection structure for prestressed tendons of hollow slab beams according to claim 1, characterized in that: The notch (4) penetrates both sides of the beam (1).

3. The durability protection structure for prestressed tendons of hollow slab beams according to claim 1, characterized in that: There are several gaps (4), and each gap (4) corresponds to a prestressed tendon (2) and a sleeve (3) opening.

4. The durability protection structure for prestressed tendons of hollow slab beams according to claim 1, characterized in that: The sealing block (5) has a protrusion (6) for sealing the opening of the sleeve (3) and the end of the prestressed tendon (2).

5. The durability protection structure for prestressed tendons of hollow slab beams according to claim 1, characterized in that: The notch (4) has a protrusion on its side wall, and the sealing block (5) has a groove for inserting the protrusion. And / or the sidewall of the notch (4) is provided with a receiving hole, and the sealing block (5) has a filling block that fills the receiving hole.

6. The durability protection structure for prestressed tendons of hollow slab beams according to claim 1, characterized in that: The width of the sealing block (5) is 3-5 cm.

7. The durability protection structure for prestressed tendons of hollow slab beams according to claim 1, characterized in that: The height of the sealing block (5) is 9-10 cm.

8. The durability protection structure for prestressed tendons of hollow slab beams according to claim 1, characterized in that: The sealing block (5) is a sealing block (5) formed by pouring repair material.

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