Double-layer anti-corrosion pre-stressed anchor rod with double-layer sleeve

Abstract

The invention provides a double-layer anti-corrosion pre-stressed anchor rod with a double-layer sleeve. The double-layer plastic sleeve is arranged on the periphery of an anchor rod body. The inner layer is a corrugated sleeve, cement paste solidification bodies are filled between the inner layer corrugated sleeve and the anchor rod body, the outer layer plastic sleeve is formed by connecting an outer layer corrugated sleeve section and an outer layer light pipe section through a first heat shrinkage sleeve, the outer layer corrugated sleeve section is located on the front side and corresponds to the anchoring section, and the outer layer light pipe section is located on the rear side and corresponds to the free section. The device can be applied to the pre-stressed anchor rod, double-layer corrosion prevention of the pre-stressed anchor rod is achieved, the prefabricated double-layer corrosion prevention anchor rod can be protected from being damaged in the transportation and installation process through multiple protection effects, and it can be achieved and guaranteed that the anchor rod can be located in a reasonable position in an anchor rod hole and is stably fixed to a hole opening; and the building quality of the anchor rod is ensured and improved. The method can be implemented on site or prefabricated in a factory, the crack width requirement does not need to be controlled, and the reliability is higher.

Description

Technical Field

[0001] This invention relates to a double-layer anti-corrosion prestressed anchor rod with a double-layer sleeve, which is mainly suitable for underground engineering, foundation pit engineering, retaining wall engineering and slope engineering in cases of temporary reinforcement or permanent reinforcement in medium or strong corrosive strata. Background Technology

[0002] Prestressed anchors are rigid rod-shaped components that actively bear tensile forces. They are fixed to the ground through drilling, and prestress is applied during installation to stabilize the reinforced body and limit its deformation. A prestressed anchor consists of an anchor head, a free section, an anchoring section, and accessories. With the development of anchoring technology, the requirements for the reliability and durability of anchors are becoming increasingly stringent and sophisticated. Permanent structures, in particular, require permanently protected anchors. For anchors in corrosive strata, special design is needed to ensure their durability. Anchors buried in the ground are susceptible to corrosion when the soil or groundwater is corrosive. Corrosion of the anchor body is the greatest threat to its lifespan. Accidents of anchor failure due to corrosion caused by improper design and construction of anti-corrosion protection structures occur frequently both domestically and internationally. Summary of the Invention

[0003] The purpose of this invention is to provide a double-layer anti-corrosion prestressed anchor rod with a double-layer sleeve, thereby improving the corrosion resistance of the prestressed anchor rod. The technical solution adopted by this invention is as follows: A double-layer anti-corrosion prestressed anchor bolt with double-layer sleeve, comprising an anchor bolt body, wherein the anchor bolt body includes an anchoring section and a free section, characterized in that... A double-layered plastic sleeve is installed around the anchor bolt body. The inner layer is a corrugated sleeve, and the space between the inner corrugated sleeve and the anchor bolt body is filled with cement grout. The outer plastic sleeve consists of an outer corrugated sleeve section and an outer smooth sleeve section connected by a first heat-shrink sleeve. The outer corrugated sleeve section is located at the front, corresponding to the anchoring section, and the outer smooth sleeve section is located at the rear, corresponding to the free section. A centering bracket is installed between the outer plastic sleeve and the anchor bolt hole wall, and the space is filled with cement grout. A corrosion-resistant cap is installed at the rear end of the outer corrugated sleeve section. A sealing ring is installed between the anti-corrosion cap and the outer corrugated sleeve section. A second heat-shrinkable sleeve is also fitted over the connection between the anti-corrosion cap and the outer corrugated sleeve section. An extension sleeve is installed on the rear side of the pressure plate. The extension sleeve passes through the hole in the concrete base and is inserted into the anchor bolt hole. The front end of the outer smooth pipe section is inserted into the extension sleeve and a sealing ring is installed between the two. The part of the anchor bolt body that extends out of the outer smooth pipe section is protected by the pressure plate, the extension sleeve and the concrete inside. The pressure plate and the anchor bolt hole opening are sealed by an epoxy resin pad. The anchor head includes a nut, a bearing plate, an epoxy resin pad, and a concrete base. The prestressed anchor rod has its inner end anchoring force determined by the bonding force between the section corresponding to the outer corrugated sleeve and the anchor hole wall. After tensioning, the front end of the anchor rod is connected and fixed to the anchor hole opening using a nut, a bearing plate, an epoxy resin pad, and a concrete base. An anchor head plastic cap is also installed at the anchor head. The anchor head plastic cap covers the end of the anchor rod body, the nut and the nut washer of the anchor head, and is filled with rust inhibitor to achieve the sealing of the integrity of the anchor rod body.

[0004] Based on the above technical solutions, the present invention may also employ the following further technical solutions, or combine these further technical solutions: The nut washer includes a hemispherical washer, and the opening of the pressure plate fits the shape of the hemispherical washer; an epoxy resin pad is provided at the bottom of the pressure plate, which, together with the concrete base, achieves spatial sealing to prevent the intrusion of external corrosive substances; the double-layer anti-corrosion prestressed anchor rod is also provided with a guide sleeve, which extends from the through hole on the concrete base to the opening of the anchor rod hole.

[0005] The anchor head components of the anchor rods are all coated with galvanized or epoxy anti-corrosion coatings, providing an additional layer of anti-corrosion for the anchor head and the front rod body.

[0006] The anchor rod body is composed of several rod segments connected together, and adjacent rod segments are connected by connectors, which allows the anchor rod to be further lengthened.

[0007] The outer plastic sleeve is fitted with a grouting pipe and a return grouting pipe between it and the wall of the anchor bolt hole. The space between the inner corrugated sleeve and the anchor bolt body, or the space connected to it, is also connected to a return grouting pipe and a grouting inlet pipe.

[0008] The pressure plate, hemispherical gasket, guide tube, and extension sleeve are galvanized or epoxy coated for corrosion protection. The concrete base structure can be designed with different inclination angles. The bottom of the concrete base is a concrete pad or sprayed concrete layer. The pressure plate is fitted with the concrete base surface and the epoxy resin coating. The pressure plate and hemispherical gasket are provided with openings for the grouting pipe and return grouting pipe to pass through.

[0009] The space between the outer plastic sleeve and the anchor rod body is filled with cement grout solidified by pre-grouting in the factory or injecting it on site to form a double-layer plastic sleeve and anchor rod body prefabricated body.

[0010] An isolation frame is installed between the inner corrugated sleeve and the anchor rod body, and between the inner corrugated plastic sleeve and the outer plastic sleeve. Cement grout is used to fill the space between the two layers of plastic sleeves. A common grout return pipe is installed in the space between the two layers of plastic sleeves and in the space between the inner corrugated sleeve and the anchor rod body. The front end of the outer smooth pipe section is longer than the inner corrugated sleeve, and the inlet of the common grout return pipe is located within the portion of the outer plastic sleeve that is longer than the inner corrugated sleeve.

[0011] Because of the technical solution of this invention, it can be applied to prestressed anchor bolts, achieving double-layer corrosion protection. For prefabricated double-layer corrosion-resistant anchor bolts, it provides multiple layers of protection to prevent damage during transportation and installation. It also ensures that the anchor bolt is positioned appropriately within the anchor hole and is stably fixed to the hole opening, thus guaranteeing and improving the construction quality of the anchor bolt. This invention can be implemented on-site or prefabricated in a factory, eliminating the need to control crack width requirements and resulting in higher reliability. Attached Figure Description

[0012] Figure 1 This is a structural schematic diagram of an embodiment of the present invention.

[0013] Figure 2 This is a schematic diagram of the AA cross-sectional structure of an embodiment of the present invention. Detailed Implementation

[0014] The present invention will be further described below with reference to the accompanying drawings.

[0015] like Figure 1 As shown, the double-layer anti-corrosion prestressed anchor rod with double-layer sleeve provided by the present invention includes an anchor rod body, the anchor rod body includes an anchoring section and a tensioning section, and the anchor head includes a nut 304, a bearing plate 305, an epoxy resin pad 203 and a concrete base 201.

[0016] A double-layer plastic sleeve is provided around the anchor rod body; the inner layer is a corrugated sleeve, and the space between the inner corrugated sleeve 505 and the anchor rod body is filled with cement grout solidified material 202. An isolation frame 603 is fitted on the anchor rod body to ensure the thickness of the cement grout solidified material, and to provide support and centering; the outer plastic sleeve is composed of an outer corrugated sleeve section 509 and an outer smooth sleeve section 506 connected by a first heat shrink sleeve 511. The outer corrugated sleeve section 509 is located on the front side, and the anchor rod body is located on the outer corrugated sleeve. The section within pipe segment 509 is the anchoring section, while the outer smooth pipe segment 506 is located at the rear. The section of the anchor rod within the range of the outer smooth pipe segment 506 is the free section. A centering bracket 601 is installed between the outer plastic sleeve and the wall of the anchor rod hole 102, and cement grout solidified material 204 is used to fill the gap. This ensures the thickness of the cement grout outside the sleeve, providing support and centering functions, preventing displacement of the anchor rod structure during grouting, which would lead to unevenness in the anti-corrosion protection structure, and improving the anti-corrosion protection effect and overall mechanical properties. The corrugated plastic sleeve not only has anti-corrosion function but also provides sufficient anchoring friction. The smooth plastic sleeve has anti-corrosion function and allows the free section rod to slide freely during tensioning. An anti-corrosion cap 508 is provided at the rear end of the outer corrugated sleeve segment 509, and a sealing ring 507 is installed between the anti-corrosion cap 508 and the outer corrugated sleeve segment 509. A second heat-shrinkable sleeve 510 is also fitted over the connection between the anti-corrosion cap 508 and the outer corrugated sleeve segment 509. A centering bracket 602 is installed between the inner corrugated sleeve 505 and the outer plastic sleeve, and the space is filled with cement grout solidified material 205. If prefabricated, the outer plastic sleeve also protects the integrity of the internal anti-corrosion structure.

[0017] The centering bracket 601 and the isolation frames 602 and 603 each include a main ring and uniformly toothed support protrusions of equal height evenly arranged on the main ring along the circumferential direction. The main rings of the centering bracket 601 and the isolation frames 602 and 603 are respectively matched with the diameters of the outer plastic sleeve, the inner plastic corrugated sleeve and the anchor rod.

[0018] An extension sleeve 802 is provided on the rear side of the pressure plate 305. The extension sleeve 802 passes through the hole on the concrete base 201 and is inserted into the anchor bolt hole 102. The front end of the outer light tube section 509 is inserted into the extension sleeve 802 and a sealing ring 502 is provided between the two. The part of the anchor bolt body that extends out of the outer light tube section is protected by the extension sleeve 802 and the concrete inside. The pressure plate 305 and the opening of the anchor bolt hole are sealed by an epoxy resin pad 203.

[0019] The prestressed anchor rod has its inner end anchoring force determined by the bonding force between the section corresponding to the outer corrugated sleeve section 509 and the wall of the anchor rod hole. After the anchor rod body is tensioned, its front end is connected and fixed to the anchor rod hole opening by a nut 304, a bearing plate 305, an epoxy resin pad 203, and a concrete base 201. An anchor head plastic cap 900 is also provided at the anchor head location. The anchor head plastic cap 900 covers the end of the anchor rod body, the nut 304, and the nut washer 303 of the anchor head, and is filled with rust inhibitor 901 to achieve a seal that maintains the integrity of the anchor rod body. The plastic cap 900 can be filled with rust inhibitor 901 through the opening 902. An epoxy resin pad 203 at the anchor head location seals the space between the pressure plate 305 and the concrete base 201, which can be cast in an inclined shape.

[0020] The nut washer 303 can be a hemispherical washer, and the opening 3051 of the pressure plate 305 fits the shape of the hemispherical washer; the bottom of the pressure plate 305 is provided with an epoxy resin pad 203, which, together with the concrete base 201, achieves spatial sealing and prevents external corrosive substances from entering.

[0021] The concrete base structure 201 can be designed with different inclination angles to compensate for the inclination angle of the anchor bolt hole axis, so as to cope with anchor bolts with different inclinations and make the anchor bolts more stable in a reasonable position. The bearing plate 305 and the hemispherical washer are provided with openings for the grouting pipe or return grouting pipe to pass through.

[0022] All anchor head metal components, including nut 304, bearing plate 305, and nut washer 303, are galvanized or epoxy coated at the factory. A guide tube 801 is also installed at the orifice section to guide the prestressed anchor bolt.

[0023] The anchor rod body is composed of two rod sections 301 and 302 connected together (or it can be a single or multiple rod sections connected together). Adjacent rod sections are connected by connector 701, which allows the anchor rod to be further lengthened. Connector 701 is a metal connecting sleeve. The connecting ends of the two rod sections 301 and 302 are threaded 702 and threaded to the connector 701.

[0024] Grouting between the outer plastic sleeve and the anchor hole wall is achieved through the grout inlet pipe 402 and the grout return pipe 403. The grout inlet pipe 402 and the grout return pipe 403 pass through the openings on the pressure plate 305 and enter the space between the outer plastic sleeve and the anchor hole wall. The outlet of the grout inlet pipe 402 is located at the inner end of the anchor hole, and the inlet of the grout return pipe 403 is close to the outer end of the anchor hole.

[0025] The space between the inner corrugated sleeve 505 and the anchor rod body, and the space connected to it, are connected by a grout inlet pipe 401 and a grout return pipe 404. In this embodiment, the grout inlet pipe 401 extends along the surface of the inner corrugated sleeve 505 to the space between the anchor rod body, the inner end of the inner corrugated sleeve 505, and the anti-corrosion cap 508. The grout inlet pipe 401 serves as a common grouting pipe for the space between the inner corrugated sleeve 505 and the anchor rod body, and for the space between the inner corrugated sleeve 505 and the outer plastic sleeve. The grout return pipe 404 serves as a common grout return pipe for the space between the inner corrugated sleeve 505 and the anchor rod body, and for the space between the inner corrugated sleeve 505 and the outer plastic sleeve. The front end of the plastic smooth tube section 506 in the outer plastic sleeve is longer than the inner corrugated sleeve 505, and the inlet of the grout return pipe 404 is located within the portion of the plastic smooth tube section 506 that is longer than the inner corrugated sleeve 505. For grouting the space between the outer plastic sleeve and the anchor hole 102, this embodiment uses on-site grouting; for grouting the space between the outer plastic sleeve and the anchor rod body, it can be either on-site grouting or factory grouting.

[0026] The hemispherical washer is provided with through holes for the slurry inlet pipe 401 and the slurry return pipe 404.

[0027] The double-layer corrosion protection is achieved through an inner corrugated sleeve 505, an outer plastic sleeve, and a closed structure at both ends and the middle, combined with the isolation frame in the anchor rod and the anti-corrosion kit at the center right angle and anchor head.

[0028] The implementation steps of this embodiment are as follows: the anchor rod is transported to the site. After drilling and cleaning are completed on site, the cushion layer 101, concrete base 201 and epoxy resin cushion layer 305 are poured. The anchor rod structure (excluding cement grout) is installed and placed into the anchor rod hole 102. Pure cement grout is injected through the grout inlet pipe 401 and air is released through the internal grout return pipe 404. Grouting is stopped after the upper end of the internal grout return pipe 404 has stabilized and returned grout.

[0029] Similarly, pure cement slurry is injected through the slurry inlet pipe 402 and air is released through the slurry return pipe 403. Grouting is stopped once the slurry returns steadily from the upper end of the external slurry return pipe 403.

[0030] Once the grout reaches the specified strength, prestress is applied, and the anchor head is locked by tightening the nut 304. Finally, the anchor head is sealed with the anchor head plastic cap 900 and rust inhibitor 901.

[0031] The grout inlet and return pipes described in this embodiment and the accompanying drawings correspond to the case where the anchor bolt hole is a downward-facing hole. For upward-facing holes, the functions of the grout inlet and return pipes are reversed accordingly, that is, the grout inlet pipe of the downward-facing hole becomes the grout return pipe of the upward-facing hole, and the grout return pipe of the downward-facing hole becomes the grout inlet pipe of the upward-facing hole.

[0032] The above description is merely a specific implementation example of the invention. The technical features of the invention are not limited thereto. Any changes or modifications made by those skilled in the art within the scope of the invention are covered by the protection scope of the invention.

Claims

1. A double-layer anticorrosion prestressed anchor rod with double-layer sleeve, comprising an anchor rod body, the anchor rod body comprising an anchoring segment and a free segment, characterized in that, the anchor head part comprises a nut, a pressure plate, an epoxy resin pad and a concrete base; a double-layer plastic sleeve is arranged on the periphery of the anchor rod body; the inner layer is a corrugated sleeve, the space between the inner layer corrugated sleeve and the anchor rod body is filled with cement slurry solidification body, the outer layer plastic sleeve is composed of an outer layer corrugated sleeve segment and an outer layer smooth pipe segment connected through a first heat shrink sleeve, the outer layer corrugated sleeve segment is located at the front side and corresponds to the anchoring segment, the outer layer smooth pipe segment is located at the rear side and corresponds to the free segment, a centering support is arranged between the outer layer plastic sleeve and the anchor rod hole wall, and the space is filled with cement slurry solidification body; an anticorrosion cap is arranged at the rear end of the outer layer corrugated sleeve segment, a sealing ring is arranged between the anticorrosion cap and the outer layer corrugated sleeve segment, and a second heat shrink sleeve is further sleeved outside the connection part of the anticorrosion cap and the outer layer corrugated sleeve segment; an extension sleeve is arranged at the rear side of the pressure plate, the extension sleeve is inserted into the anchor rod hole through a hole on the concrete base, the front end of the outer layer smooth pipe segment is inserted into the extension sleeve, and a sealing ring is arranged between the two, the part of the anchor rod body that extends out of the outer layer smooth pipe segment is protected by the pressure plate, the extension sleeve and the concrete, and the space between the pressure plate and the anchor rod hole is closed by the epoxy resin pad; the bonding force between the segment corresponding to the outer layer corrugated sleeve segment of the prestressed anchor rod and the anchor rod hole wall is the inner end anchoring force, after the anchor rod body is tensioned, the front end is connected and fixed with the anchor rod hole orifice by the nut, the pressure plate, the epoxy resin pad and the concrete base the anchor head part is further provided with an anchor head plastic cap, the anchor head plastic cap covers the anchor rod body end part, the nut and the nut gasket outside the anchor head, the inside is filled with rust inhibitor, and the integrity of the anchor rod body is closed.

2. The double corrosion protection prestressed anchor rod with double sleeve according to claim 1, characterized in that, the nut gasket comprises a hemispherical gasket, the pressure plate is provided with an opening matched with the shape of the hemispherical gasket; the bottom of the pressure plate is provided with an epoxy resin pad, which is used together with the concrete base to realize space closure and avoid the intrusion of external corrosive substances; the double-layer anticorrosion prestressed anchor rod is further provided with a guide sleeve, the guide sleeve extends from the through hole on the concrete base to the orifice of the anchor rod hole.

3. The double corrosion protection prestressed anchor rod with double sleeve according to claim 1, characterized in that, The anchor head components of the anchor rod are all provided with a zinc plating or epoxy anticorrosion coating, which additionally provides the anchor head and the front rod body with an anticorrosion layer.

4. The double corrosion protection prestressed anchor rod with double sleeve as claimed in claim 1, wherein, The anchor rod body is composed of a plurality of rod body segments connected by connectors, so that the anchor rod can be further lengthened.

5. The double corrosion protection prestressed anchor rod with double sleeve as claimed in claim 1, wherein, A grouting pipe and a back grouting pipe are arranged between the outer layer plastic sleeve and the anchor rod hole wall, and a back grouting pipe and a grouting pipe are further connected to the space between the inner layer corrugated sleeve and the anchor rod body or the space connected thereto.

6. The double corrosion protection prestressed anchor rod with double sleeve as claimed in claim 2, characterized in that: The pressure plate, the hemispherical gasket, the guide pipe and the extension sleeve are provided with a zinc plating or epoxy coating for anticorrosion, the concrete base structure can be designed to have different inclination angles, the bottom of the concrete base is a concrete pad or a shotcrete layer, the pressure plate is matched with the surface of the concrete base and the epoxy resin coating; the pressure plate and the hemispherical gasket are provided with openings for the grouting pipe and the back grouting pipe to pass through.

7. The double corrosion protection prestressed anchor rod with double sleeve as claimed in claim 1, wherein, The space between the outer layer plastic sleeve and the anchor rod body is filled with cement slurry solidification body by factory pre-filling or on-site grouting to form a double-layer plastic sleeve and an anchor rod body prefabricated body.

8. The double corrosion protection prestressed anchor rod with double sleeve as claimed in claim 1, wherein, The isolation frame is arranged between the inner corrugated sleeve and the anchor rod body and between the inner corrugated plastic sleeve and the outer plastic sleeve, and the space between the two plastic corrugated sleeves is filled with cement slurry solidification body; the space between the two plastic corrugated sleeves and the space between the inner corrugated sleeve and the anchor rod body are provided with a common slurry return pipe; the front end of the outer light pipe section is longer than the inner corrugated sleeve, and the inlet of the common slurry return pipe is located in the part of the outer plastic sleeve which is longer than the inner corrugated sleeve.

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