Concrete T-beam reinforcing structure based on UHPC (Ultra High Performance Concrete) and prestressed steel strands and construction method

Abstract

The invention relates to a concrete T-beam reinforcing structure based on UHPC and prestressed steel strands and a construction method, and the construction method comprises the steps that a prefabricated part is manufactured, the prefabricated part is designed into a main body section and an extension section, and a strand channel is reserved in the main body section; an anchoring ring is installed at the web position of the beam, a hoisting steel strand penetrates through the anchoring ring and a first ring of the prefabricated part, the prefabricated part is hoisted to the bottom position of the T-beam, and the hoisting steel strand is bound to the first ring to fix the prefabricated part; extending sections at the two ends of the prefabricated part are stretched to be erected above the T-beam pier, and a second circular ring and an anchoring circular ring are bound through a steel strand; the prestressed steel strand penetrates through the prefabricated part through the strand channel, the two ends of the prestressed steel strand are anchored to the T-beam through the prestressed steel strand anchoring device, and the prestressed steel strand is tensioned; the hoisting steel strand is released, the anchoring ring is dismantled, UHPC is poured in the prefabricated part, when a UHPC pouring layer is formed through hardening, the prefabricated part is dismantled, and T-beam reinforcement is completed.

Description

Technical Field

[0001] This invention relates to the field of bridge reinforcement technology, specifically to a reinforced concrete T-beam structure and construction method based on UHPC and prestressed steel strands. Background Technology

[0002] As the main bridge type in service, concrete T-beams are generally plagued by problems such as concrete carbonation and spalling, cracking, and steel corrosion. In order to meet the increasing traffic demand, it is essential to maintain and reinforce concrete T-beams.

[0003] Among the commonly used reinforcement techniques for concrete T-beam bridges, the concrete section enlargement method is a traditional approach. This method increases the structural load-bearing capacity and stiffness by increasing the cross-sectional dimensions of the member (e.g., increasing the beam's height, width, or compression zone area) and adding new reinforcing steel. However, this method also has significant drawbacks. The added concrete and steel significantly increase the member's self-weight, potentially leading to additional loads on the substructure. Furthermore, it requires multiple steps, including surface preparation of the original structure (roughening, cleaning, and rebar installation), formwork erection, rebar tying, concrete pouring, and curing, resulting in a long overall construction period. Currently, the reinforcement effect remains relatively poor.

[0004] Existing technologies, such as the one proposed in CN109972538A, involve a steel plate internally filled concrete bridge structure and construction technology. This technology integrates the reinforcing steel plate with the bridge beam through bottom and side anchor bars and filler material, forming a composite structure that integrates the reinforcing steel plate and concrete. This significantly improves the load-bearing capacity and stiffness of the structure. However, the above structure and construction scheme still have the following drawbacks:

[0005] (1) Although using ordinary concrete as filler can increase the cross-sectional size, there are still defects such as increased reinforcement layer thickness but insufficient reinforcement strength, low reinforcement efficiency and significant increase in bridge self-weight, which affect the reinforcement effect of the bridge.

[0006] (2) Using steel plates as templates, the reinforced structure designed with steel templates is heavy and inconvenient to transport and install. At the same time, steel plates still need to be drilled and reinforced to enhance the bonding ability between steel plates and concrete. The construction process is complicated, the construction time is long, and the construction efficiency is affected.

[0007] (3) As a reinforcement structure, steel plates are prone to corrosion, which affects the durability of the reinforcement structure and reduces the service safety of the reinforcement structure.

[0008] (4) The above-disclosed construction plan requires the erection of scaffolding to facilitate construction. The erection of scaffolding will occupy the space under the T-beam bridge, resulting in insufficient clearance under the T-beam bridge and affecting normal traffic. If the T-beam bridge is located in a complex terrain area, such as crossing a river, a canyon, or other complex terrain, the difficulty of erecting scaffolding will increase significantly, seriously affecting construction efficiency. Summary of the Invention

[0009] The primary objective of this application is to address at least one of the aforementioned problems by providing a reinforced concrete T-beam structure and construction method based on UHPC and prestressed steel strands.

[0010] To achieve the primary objective of this application, the following technical solution is adopted:

[0011] A reinforced concrete T-beam structure based on UHPC and prestressed steel strands, provided for one of the purposes of this application, comprises:

[0012] Precast components, prestressed steel strands, and UHPC casting layers;

[0013] The prefabricated component includes a main body section and an extension section sleeved on the outer surface of the main body section. The main body section forms a U-shaped groove with a bottom plate and a side plate, and the extension section forms a U-shaped groove with a bottom plate and a side plate. The main body section has a plurality of stranded wire channels arranged parallel to the length direction of the prefabricated component on the inner surface of the side plate. The main body section has a first ring arranged on the center line along the height direction of the side plate.

[0014] The prestressed steel strand is disposed within the strand channel;

[0015] The UHPC casting layer is disposed in the gap between the precast component and the T-beam body.

[0016] In an optional embodiment, the extension section includes a second ring disposed on the extension section close to the first ring along the height direction of the side plate.

[0017] In an optional embodiment, the extension section includes a baffle disposed at the end of the extension section away from the main body section, and the baffle has a through hole adapted to the stranded wire channel.

[0018] In an optional embodiment, a limiting groove for limiting the prestressed steel strand is provided at the top of the side wall of the strand channel.

[0019] In an optional embodiment, the precast component further includes a prestressed steel strand anchoring device for fixing both ends of the prestressed steel strand to the T-beam body.

[0020] In an optional embodiment, the prefabricated component is made of GFRP.

[0021] In an optional embodiment, the top of the side plate of the extension section is provided with a edging portion extending into the U-shaped groove, and the lower surface of the edging portion abuts against the top of the side plate of the main body section.

[0022] On the other hand, a construction method for a concrete T-beam reinforcement structure based on UHPC and prestressed steel strands, provided to meet one of the purposes of this application, uses the concrete T-beam reinforcement structure based on UHPC and prestressed steel strands as provided in the first aspect to reinforce the main body of the T-beam. The construction method includes:

[0023] Precast components are manufactured, and the precast components are designed as the middle part of the main section and the extendable part of the extension section. The strand channels through which the prestressed steel strands pass are pre-processed on the inner wall of the side plate of the main section.

[0024] Drill holes in the web of the T-beam above the pier to install anchoring rings. Pass the hoisting steel strands through the anchoring rings in the web of the beam and the first ring of the precast component. The lifting unit hoists the precast component to the bottom of the T-beam using the hoisting steel strands. The hoisting steel strands are then tied to the first ring to fix the precast component.

[0025] The extension sections at both ends of the precast component are stretched and erected above the T-beam pier. The baffle is pasted to the ends of the two extension sections. The second ring is bound to the anchoring ring by steel strands. The prestressed steel strands are passed through the precast component through the strand channel. The two ends of the prestressed steel strands are anchored to the T-beam by the prestressed steel strand anchoring device. The prestressed steel strands are tensioned to complete the first reinforcement.

[0026] After the first reinforcement, the hoisting steel strands used for temporary hoisting are released and the anchoring rings at the beam web are removed. UHPC is poured in the gap between the precast component and the T-beam body for the second reinforcement. When the UHPC hardens to form the UHPC pouring layer, the precast component is removed to complete the reinforcement.

[0027] In an optional embodiment, the prefabricated component is made of GFRP and is designed as a U-shaped channel plate with a bottom plate and side plates.

[0028] In an optional embodiment, the hoisting steel strand is passed through the anchoring ring at the web of the beam and the first ring of the precast component. The lifting unit hoists the precast component to the bottom of the T-beam using the hoisting steel strand, and the hoisting steel strand is bound to the first ring to fix the precast component, including:

[0029] The hoisting steel strands are passed through the anchoring rings at the web of the beam, the first ring of the precast component, and the second ring of the precast component. The hoisting unit then hoists the precast component to the bottom of the T-beam using the hoisting steel strands, and binds the hoisting steel strands to the first and second rings to fix the precast component.

[0030] The technical solution of this application has many advantages, including but not limited to the following aspects:

[0031] This application firstly approves the use of precast components as reinforcement templates, which makes the process of pouring UHPC more convenient and efficient, reduces on-site formwork erection and rebar tying, thereby achieving rapid prefabricated construction, shortening construction time, simplifying on-site procedures, and has good application prospects and economic benefits.

[0032] Secondly, the material of the precast components is GFRP, a glass fiber reinforced plastic, which gives the precast components the advantages of being lightweight and high-strength. This reduces the self-weight of the reinforced structure during the reinforcement process, reduces the difficulty of hoisting, and eliminates the need for large mechanical assistance, making it easy to transport and install quickly.

[0033] Furthermore, using UHPC for bridge reinforcement results in a smaller increase in the bridge's self-weight and thickness, leading to better overall stress performance and bending resistance after reinforcement, thus solving the problem of poor reinforcement strength in the past.

[0034] Furthermore, the concrete T-beams are reinforced a second time using prestressed steel strands and UHPC, resulting in a more robust reinforcement. Precast components are hoisted and temporarily fixed using anchoring rings located on the beam web. Since the anchoring rings are located above the piers, the weight of the precast components is transferred to the anchoring rings via the steel strands during hoisting and temporary fixing, and then to the piers, preventing the reinforced section of the bridge from bearing weight. After the prestressed steel strand reinforcement is completed, the precast components are suspended on the prestressed steel strands. The weight of the precast components and the subsequent weight of the poured UHPC are transferred to the prestressed anchoring devices at both ends via the prestressed steel strands, and then to the piers. Before the UHPC hardens, the reinforced section of the bridge will not bear weight.

[0035] Furthermore, the construction method based on the precast component reinforcement structure in this application does not require the erection of scaffolding, does not occupy the space under the bridge or on the bridge deck, avoids the problem of insufficient clearance under the bridge due to space occupation, ensures the normal passage of vehicles and pedestrians, and reduces interference with traffic operations. At the same time, for bridges that cross rivers, canyons or have complex terrain under the bridge, not erecting scaffolding can completely avoid the difficulties of scaffolding erection caused by complex terrain, greatly reduce the complexity of construction, and enhance the adaptability and feasibility of construction in complex environments.

[0036] Finally, the old concrete T-beams are reinforced using prestressed steel strands, reducing the cumbersome process of rebar installation on the concrete T-beams. At the same time, UHPC can protect the prestressed steel strands from corrosion. The combination of prestressed steel strands and UHPC gives the cured overall reinforced structure superior bending and crack resistance, significantly improving its load-bearing capacity compared to other reinforcement measures. Construction is also simpler, making it more applicable in engineering practice. It reduces on-site formwork erection and rebar tying, enabling prefabricated construction, shortening construction time, simplifying on-site procedures, and resulting in good economic benefits. Attached Figure Description

[0037] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0038] Figure 1 This is a schematic diagram of the unstretched state of the concrete T-beam reinforcement structure based on UHPC and prestressed steel strands in this application.

[0039] Figure 2 for Figure 1 A schematic diagram of the extension state of a reinforced concrete T-beam structure based on UHPC and prestressed steel strands;

[0040] Figure 3 This is an extended front view of an exemplary prefabricated component in this application;

[0041] Figure 4 This is a schematic cross-sectional view of an exemplary prefabricated component in this application;

[0042] Figure 5 This is a top view of an exemplary prefabricated component in this application after it has been extended.

[0043] Figure 6 This is a schematic diagram of the structure of an exemplary baffle in this application;

[0044] Figure 7 This is a schematic diagram of an exemplary anchoring ring in this application;

[0045] Figure 8 This is a schematic diagram of an exemplary precast component in this application after it has been extended at the bottom of a T-beam;

[0046] Figure 9 This is a schematic diagram of the installation of a baffle on a precast component after it has extended from the bottom of a T-beam, as exemplified in this application.

[0047] Figure 10 This is a schematic diagram of the concrete T-beam reinforcement structure based on UHPC and prestressed steel strands, as exemplified in this application, after tensioning the prestressed steel strands and casting the UHPC.

[0048] Figure 11This is a schematic diagram of an exemplary reinforced T-beam structure in this application.

[0049] Figure 12 This is a schematic diagram of the construction method for the reinforced concrete T-beam structure based on UHPC and prestressed steel strands in this application.

[0050] Figure 13 for Figure 4 A cross-sectional schematic diagram of a prefabricated component according to another embodiment.

[0051] Figure label:

[0052] 100. T-beam main body; 101. Bridge pier;

[0053] 1000. Precast components; 1001. Base slab; 1002. Side slabs;

[0054] 1100. Main body section;

[0055] 1200, extension section; 1201, baffle; 1202, through hole; 1203, edging section;

[0056] 1300, stranded wire channel; 1301, limiting groove;

[0057] 1400, First Ring;

[0058] 1500, the second ring;

[0059] 1600. Prestressed steel strand anchoring device;

[0060] 2000, Prestressed steel strand;

[0061] 3000, UHPC casting layer;

[0062] 4000, Anchoring Ring;

[0063] 5000, hoisting steel strand. Detailed Implementation

[0064] The technical solution of this application is applicable to the field of bridge reinforcement technology, and is particularly applicable to the reinforcement of T-beams. In this context, concrete T-beams, as the main bridge type in service, suffer from various problems such as concrete carbonization spalling, cracking, and steel corrosion due to factors such as imperfect early design theory, construction quality defects, and untimely operation and maintenance. In order to meet the increasing traffic volume, it is necessary to maintain and reinforce concrete T-beams.

[0065] Among the commonly used reinforcement techniques for concrete T-beam bridges, the concrete section enlargement method is a traditional approach. This method increases the structural load-bearing capacity and stiffness by increasing the cross-sectional dimensions of the member (e.g., increasing the beam's height, width, or compression zone area) and adding new reinforcing steel. However, this method also has significant drawbacks. The added concrete and steel significantly increase the member's self-weight, potentially leading to additional loads on the substructure. Furthermore, it requires multiple steps, including surface preparation of the original structure (roughening, cleaning, and rebar installation), formwork erection, rebar tying, concrete pouring, and curing, resulting in a long overall construction period. Currently, the reinforcement effect remains relatively poor.

[0066] Existing technologies, such as the one proposed in CN109972538A, involve a steel plate internally filled concrete bridge structure and construction technology. This technology integrates the reinforcing steel plate with the bridge beam through bottom and side anchor bars and filler material, forming a composite structure that integrates the reinforcing steel plate and concrete. This significantly improves the load-bearing capacity and stiffness of the structure. However, the above structure and construction scheme still have the following drawbacks:

[0067] Although using ordinary concrete as filler can increase the cross-sectional size, it still has the drawbacks of insufficient reinforcement strength and a significant increase in the bridge's self-weight, thus affecting the quality of bridge reinforcement.

[0068] Using steel plates as templates results in a heavy self-weight of the reinforced structure, which is inconvenient for transportation and installation. At the same time, the steel plates still need to be drilled and reinforced with steel bars for reinforcement, making the construction process complicated, time-consuming and affecting construction efficiency.

[0069] The aforementioned construction plan requires the erection of scaffolding to facilitate construction. However, erecting scaffolding will occupy the space under the T-beam bridge, resulting in insufficient clearance under the T-beam bridge and affecting normal traffic. If the T-beam bridge is located in a complex terrain area, such as crossing a river, a canyon, or other complex terrain, the difficulty of erecting scaffolding will increase significantly, seriously affecting construction efficiency.

[0070] To address the problems of insufficient strength of the filler and the heavy self-weight and complex procedures of the reinforced structure, resulting in unsatisfactory reinforcement effects, the technical solution provided by the embodiments of this application has the following general idea:

[0071] Concrete T-beams were reinforced using UHPC and prestressed steel strands. The UHPC was used to fix the prestressed steel strands to the existing concrete T-beams. Compared to previous reinforcement methods using ordinary concrete, this method results in a smaller increase in the bridge's self-weight and thickness, and provides better overall load-bearing capacity and bending resistance. It also addresses the problem of poor reinforcement strength in previous methods. GFRP (glass fiber reinforced plastic) was chosen as the material for the precast components. The precast components are designed as U-shaped channel plates, which act as construction templates, making the UHPC pouring process more convenient and efficient. Furthermore, the precast components are lightweight and high-strength, easy to hoist, require no large machinery, and are convenient to transport and install, reducing the self-weight of the reinforced structure during the reinforcement process. In this method, precast components are supported by anchoring rings and prestressed steel strands. During hoisting and temporary fixing, the weight of the precast components is transferred to the anchoring rings via the steel strands, and then to the bridge piers. This prevents the reinforced ends of the concrete T-beams from bearing weight during the reinforcement process, reducing the load on the bridge. After the prestressed steel strand reinforcement is completed, the precast components are suspended on the prestressed steel strands. The weight of the precast components and the subsequent weight of the poured UHPC are also transferred to the prestressed anchoring devices located at both ends above the bridge piers via the prestressed steel strands, thus transferring stress to the bridge piers and reducing the load on the bridge during the reinforcement process. This method is quite applicable in engineering practice, reducing on-site formwork and rebar tying, enabling prefabricated construction, shortening construction time, simplifying on-site procedures, and providing good economic benefits.

[0072] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0073] The specific embodiments described below can be combined with each other, and the same or similar concepts or processes will not be described again in some embodiments. The embodiments of this application will be described below with reference to the accompanying drawings.

[0074] See Figures 1 to 11 This application discloses a reinforced concrete T-beam structure based on UHPC and prestressed steel strands, comprising:

[0075] The precast component 1000, prestressed steel strand 2000, and UHPC casting layer 3000 are included. The size design of the precast component 1000 can be adjusted according to the actual reinforcement project requirements, as long as the UHPC casting layer and prestressed strand have the required bending and crack resistance and bearing capacity after reinforcement.

[0076] The precast component 1000 includes a main body section 1100 and an extension section 1200 fitted onto the outer surface of the main body section 1100. The main body section 1100 forms a U-shaped groove with a base plate 1001 and a side plate 1002, and the extension section 1200 also forms a U-shaped groove with a base plate 1001 and a side plate 1002. The number of extension sections 1200 is at least one. If located at the end of a bridge, only one stretchable extension section can be provided at one end of the main body section 1100. Section 1200 can meet the reinforcement project at the end of the bridge. Typically, a precast component 1000 consists of a main section 1100 and two extension sections 1200 respectively set at both ends of the main section 1100. The main section 1100 and the extension section 1200 of the precast component 1000 are enclosed by a U-shaped groove through the bottom plate 1001 and the side plate 1002. More UHPC can be poured through the U-shaped groove of the main section 1100 and the extension section 1200, thereby increasing the reinforcement area of ​​the UHPC.

[0077] Furthermore, the prefabricated component 1000 is a telescopic structure, wherein the main section 1100 and the extension section 1200 can form a telescopic structure through interference fit, pulley connection or slide rail connection, etc. This application does not make specific limitations. Through the telescopic structural design, the use of storage space can be reduced during transportation and construction, the space utilization rate of transportation space or construction storage area can be improved, and transportation, warehousing and construction applications can be facilitated.

[0078] Furthermore, the precast component 1000 can be used as a template for reinforcing structures, making the process of pouring UHPC more convenient and efficient. It can effectively reduce on-site formwork erection, rebar tying and other procedures, enabling rapid assembly construction, shortening construction time, simplifying on-site procedures, and achieving good economic benefits.

[0079] The main body section 1100 has several stranded wire channels 1300 arranged parallel to the length of the precast component 1000 on the inner surface of the side plate 1002. The main body section 1100 has a first ring 1400 arranged on the center line of the height direction of the side plate 1002. The inner walls of the left and right side plates 1002 of the main body section 1100 are reserved with channels for installing prestressed steel strands, which facilitates the subsequent installation of prestressed steel strands. The arrangement of the first ring 1400 facilitates the hoisting and fixing of the precast component 1000 to the bottom of the T-beam by hoisting the steel strands during construction, thereby realizing rapid assembly construction, shortening construction time, simplifying on-site procedures, and having good economic benefits.

[0080] The prestressed steel strand 2000 is installed within the strand channel 1300. During construction, the prestressed steel strand 2000 effectively prevents the weight of the precast components and the cast-in-place UHPC from applying stress to the T-beams, instead transferring it directly to the piers, thus reducing the impact of the reinforcement process on the T-beams. Furthermore, the prestressed steel strand 2000 can work in conjunction with the UHPC for reinforcement. During construction, the prestressed steel strand 2000 simply needs to be threaded into the strand channel 1300, making construction simple and quick while ensuring the reinforcement effect of the bridge.

[0081] The UHPC casting layer 3000 is formed by casting UHPC into the gap between the precast component 1000 and the T-beam body 100 and hardening it.

[0082] It should be noted that UHPC is a cement-based composite material with excellent performance. Through optimized material composition and processing, it exhibits outstanding performance in terms of strength, durability, and construction flexibility. UHPC has extremely high compressive and flexural strength, typically two to three times that of traditional concrete, enabling it to withstand greater loads and deformations. In this application, UHPC is used to reinforce T-beams, resulting in a minimal increase in the bridge's self-weight and thickness. The overall stress performance and bending resistance are improved after reinforcement, solving the problem of poor strength effects in previous reinforcement methods.

[0083] In an optional embodiment, the extension section 1200 includes a second ring 1500, which is disposed on the extension section 1200 close to the first ring 1400 along the height direction of the side plate 1002. The addition of the second ring 1500 allows for the hoisting of the precast component 1000 during construction via the first ring 1400, the second ring 1500, and the anchoring ring 4000, ensuring the stability and safety of the hoisting of the precast component 1000. Especially when fixing the hoisting steel strands, the steel strands can be tightly bound to the intermediate main section 1100, the first ring 1500, and the two second rings 1500 of the extension section 1200, preventing the precast component 1000 from falling off and ensuring construction safety.

[0084] In an optional embodiment, the extension section 1200 includes a baffle 1201, which is located at the end of the extension section 1200 away from the main body section 1100. The baffle 1201 has a through hole 1202 adapted to the stranded wire channel 1300. During construction, AB glue or other adhesive substances can be used to install the baffle 1201 at the end of the extension section 1200, wherein the cross-sectional shape of the baffle 1201 is adapted to the cross-sectional shape of the extension section 1200, and the baffle 1201 has a pre-drilled through hole for the prestressed steel strand 2000 to pass through, so as to facilitate the subsequent anchoring of the prestressed steel strand 2000 to the T-beam by the prestressed steel strand anchoring device 1600.

[0085] In an optional embodiment, a limiting groove 1301 for limiting the prestressed steel strand 2000 is provided at the top of the side wall of the strand channel 1300; as an example, such as Figure 4 As shown, the cross-section of the strand channel 1300 can be a right-angled trapezoidal structure, and a limiting groove 1301 is set at the bottom corner of the right-angled trapezoidal structure. The limiting groove 1301 at the bottom corner opens upwards and gradually narrows upwards, allowing the prestressed steel strand 2000 passing through the strand channel 1300 to be confined within the channel. Especially during construction, when the prestressed steel strand 2000 is tensioned, it will abut against the groove wall of the limiting groove 1301, ensuring that the prestressed steel strand 2000 does not wobble and guaranteeing the tensioning effect. This results in the subsequent hardening of the UHPC casting layer 3000 and the overall reinforcement structure of the prestressed steel strand 2000 exhibiting superior bending and crack resistance.

[0086] In another preferred embodiment, such as Figure 13 As shown, the cross-section of the stranded wire channel 1300 can be an L-shaped structure, wherein the inner wall of the limiting groove 1301 at the top position of the L-shaped structure is a smoothly transitioned curved surface. Compared with the above-mentioned exemplary right-angled trapezoidal structure, the curved surface that abuts the prestressed steel strand 2000 can reduce the stress effect. It is understood that the cross-section of the stranded wire channel 1300 is not limited in this application, as long as the stranded wire channel 1300 is provided with a limiting groove 1301 to limit the prestressed steel strand 2000. Preferably, the inner wall of the limiting groove 1301 is curved, which can effectively reduce the influence of stress.

[0087] In an optional embodiment, the precast component 1000 further includes a prestressed steel strand anchoring device 1600 for fixing both ends of the prestressed steel strand 2000 to the T-beam body 100. The prestressed steel strand anchoring device 1600 can fix the prestressed steel strand 2000 to the T-beam and tension the prestressed steel strand 2000, resulting in superior bending and crack resistance of the subsequently hardened UHPC casting layer 3000 and the overall reinforced structure of the prestressed steel strand 2000.

[0088] In an optional embodiment, the precast component 1000 is made of GFRP. Compared to the existing reinforcement method that uses steel plates as templates, the precast component 1000 proposed in this application is made of GFRP, a glass fiber reinforced plastic, which gives the precast component 1000 the advantages of being lightweight and high-strength. It is easy to hoist during actual construction and does not require the assistance of large machinery, facilitating transportation and installation, and reducing the self-weight of the reinforced structure during the reinforcement process. It should be noted that GFRP (Glass Fiber Reinforced Plastic)... GFRP (Glass Fiber Reinforced Plastic), also known as UHPC, is a composite material composed of glass fibers and resin. As a material for making precast component formwork, GFRP achieves significant weight reduction due to its low density, being only 1 / 3 to 1 / 4 the density of steel formwork. This greatly reduces the suspension load and construction difficulty of precast components during reinforcement. Its tensile strength and elastic modulus can stably withstand the load of uncured UHPC, and its fatigue and impact resistance can cope with repeated stress during construction. Furthermore, GFRP's excellent corrosion resistance allows it to withstand the alkaline environment of UHPC, ultraviolet radiation from outdoor construction, and other factors. The impact of rainwater erosion means that frequent maintenance is not required. GFRP is easy to process into complex shapes, has a smooth surface that does not easily adhere to UHPC, and has an outstanding overall cost-effectiveness. It balances the lightweight, mechanical properties, construction adaptability and economy of concrete T-beam reinforcement structures, making it the preferred material for precast components in bridge bottom reinforcement scenarios. It is understood that, in addition to GFRP (glass fiber reinforced plastic) as the material for precast component 1000 as specified in this embodiment, other composite materials with high strength, corrosion resistance and low self-weight can also be used as the material for precast component 1000.

[0089] In an optional embodiment, the top of the side plate 1002 of the extension section 1200 is provided with a edging portion 1203 extending into the U-shaped groove, and the lower surface of the edging portion 1203 abuts against the top of the side plate 1002 of the main body section 1100. The edging portion 1203 further prevents the extension section 1200 from detaching from the main body section 1100. Since the prefabricated component 1000 is designed with a U-shaped groove, the edging portion 1203 effectively prevents the extension section 1200, which is fitted onto the outer surface of the main body section 1100, from detaching from the main body section 1100, especially preventing separation of the main body section 1100 and the extension section 1200 in the prefabricated component 1000 during transportation.

[0090] The unique technical advantage of this application lies in the fact that, firstly, using precast components as reinforcement templates makes the process of pouring UHPC more convenient and efficient, reducing on-site formwork erection, rebar tying, and other procedures, thereby achieving rapid prefabricated construction, shortening construction time, simplifying on-site procedures, and having good application prospects and economic benefits.

[0091] Secondly, the precast components are made of GFRP, which gives them the advantages of being lightweight and high-strength. This reduces the self-weight of the reinforced structure during the reinforcement process, lowers the difficulty of hoisting, and eliminates the need for large machinery, making them easy to transport and install quickly.

[0092] Furthermore, using UHPC for bridge reinforcement results in a smaller increase in the bridge's self-weight and thickness, leading to better overall stress performance and bending resistance after reinforcement, thus solving the problem of poor reinforcement strength in the past.

[0093] Furthermore, the T-beams are reinforced a second time using prestressed steel strands and UHPC, resulting in a more robust reinforcement. During the reinforcement process, because the prestressed steel strands support the precast components, the weight of the precast components and the poured UHPC are not applied to the T-beams, but are transferred to the piers, so that the T-beams are not subjected to the external forces generated during the reinforcement process.

[0094] Furthermore, the construction method based on the precast component reinforcement structure in this application does not require the erection of scaffolding, does not occupy the space under the bridge or on the bridge deck, avoids the problem of insufficient clearance under the bridge due to space occupation, ensures the normal passage of vehicles and pedestrians, and reduces interference with traffic operations. At the same time, for bridges that cross rivers, canyons or have complex terrain under the bridge, not erecting scaffolding can completely avoid the difficulties of scaffolding erection caused by complex terrain, greatly reduce the complexity of construction, and enhance the adaptability and feasibility of construction in complex environments.

[0095] Finally, the old concrete T-beams are reinforced using prestressed steel strands, reducing the cumbersome process of rebar installation on the concrete T-beams. At the same time, UHPC can protect the prestressed steel strands from corrosion. The combination of prestressed steel strands and UHPC gives the cured overall reinforced structure superior bending and crack resistance, significantly improving its load-bearing capacity compared to other reinforcement measures. Construction is also simpler, making it more applicable in engineering practice. It reduces on-site formwork erection and rebar tying, enabling prefabricated construction, shortening construction time, simplifying on-site procedures, and resulting in good economic benefits.

[0096] Please see Figure 12 According to one aspect of this application, a construction method for a reinforced concrete T-beam structure based on UHPC and prestressed steel strands is provided. The construction method uses the reinforced concrete T-beam structure based on UHPC and prestressed steel strands provided above to reinforce the main body of the T-beam. The construction method includes the following steps:

[0097] S1. Fabricate precast components, designing the precast components as the middle part of the main section and the extendable part of the extension section, and pre-reserving the strand channels through which the prestressed steel strands pass on the inner wall of the side plate of the main section.

[0098] S2. Drill holes in the web of the T-beam above the pier to install anchoring rings. Pass the hoisting steel strands through the anchoring rings in the web of the beam and the first ring of the precast component. The lifting unit hoists the precast component to the bottom of the T-beam using the hoisting steel strands. Tie the hoisting steel strands to the first ring to fix the precast component.

[0099] S3. The extension sections at both ends of the precast component are stretched and erected above the T-beam pier. The baffle is pasted to the ends of the two extension sections. The second ring is bound to the anchoring ring through the steel strand. The prestressed steel strand is passed through the precast component through the strand channel. The two ends of the prestressed steel strand are anchored to the T-beam using the prestressed steel strand anchoring device. The prestressed steel strand is tensioned to complete the first reinforcement.

[0100] S4. After the first reinforcement, release the hoisting steel strands used for temporary hoisting and remove the anchoring rings at the beam web position. Pour UHPC in the gap between the precast component and the T-beam body for the second reinforcement. When the UHPC hardens to form the UHPC pouring layer, remove the precast component to complete the reinforcement.

[0101] It should be noted that UHPC is a cement-based composite material with excellent performance. Through optimized material composition and processing, it exhibits outstanding performance in terms of strength, durability, and construction flexibility. UHPC has extremely high compressive and flexural strength, typically two to three times that of traditional concrete, enabling it to withstand greater loads and deformations. In this application, UHPC is used to reinforce T-beams, resulting in a minimal increase in the bridge's self-weight and thickness. The overall stress performance and bending resistance are improved after reinforcement, solving the problem of poor strength effects in previous reinforcement methods.

[0102] Based on any embodiment of the construction method of this application, in the construction method of this application, the precast component is made of GFRP as the material, wherein GFRP is a glass fiber reinforced plastic, and the precast component is designed as a U-shaped channel plate with a bottom plate and side plates. Compared with the reinforcement method of using steel plates as templates in the prior art, the precast component 1000 proposed in this application is made of GFRP, which makes the precast component 1000 lightweight and high-strength. It is easy to hoist in the actual construction process and does not require the assistance of large machinery, which facilitates transportation and installation. It can reduce the self-weight of the reinforcement structure during the reinforcement process. GFRP, also known as glass fiber reinforced plastic, is a composite material composed of glass fiber and resin. As a material for making precast component templates, GFRP achieves significant weight reduction due to its low density characteristics. Its density is only 1 / 3-1 / 4 of that of steel templates, which greatly reduces the suspension load and construction difficulty of the precast component during the reinforcement process. Its tensile strength and elastic modulus can stably withstand the load of UHPC when it is not hardened, and it is resistant to fatigue and GFRP's impact resistance can withstand repeated stress during construction; at the same time, its excellent corrosion resistance allows it to resist the effects of the alkaline environment of UHPC, ultraviolet radiation during open-air construction, and rainwater erosion, requiring no frequent maintenance; GFRP is easy to process into complex shapes, has a smooth surface that does not easily adhere to UHPC, and has a relatively outstanding overall cost-effectiveness, balancing the lightweight, mechanical properties, construction adaptability, and economy of concrete T-beam reinforcement structures. It is the preferred material for precast components in bridge bottom reinforcement scenarios. It is understood that, in addition to GFRP as the material for precast component 1000 as specified in this embodiment, other composite materials with high strength, corrosion resistance, and low self-weight can also be used as the material for precast component 1000.

[0103] Based on any embodiment of the construction method of this application, in the construction method of this application, passing the hoisting steel strand through the anchoring ring at the beam web position and the first ring of the precast component, the lifting unit hoists the precast component to the bottom position of the T-beam using the hoisting steel strand, and binding the hoisting steel strand to the first ring to fix the precast component, can be replaced by: passing the hoisting steel strand through the anchoring ring at the beam web position, the first ring of the precast component, and the second ring of the precast component, the lifting unit hoists the precast component to the bottom position of the T-beam using the hoisting steel strand, and binding the hoisting steel strand to the first ring. The precast components are fixed on the second ring; the addition of the second ring 1500 allows for the hoisting of the precast components 1000 during construction through the first ring 1400, the second ring 1500, and the anchoring ring 4000, ensuring the stability and safety of the hoisting of the precast components 1000 during construction. In particular, when fixing the hoisting steel strands, the steel strands can be bound to the middle main section 1100 and the first ring 1500 and the two second rings 1500 of the extension section 1200 to prevent the precast components 1000 from falling off and ensure construction safety.

[0104] In this embodiment, UHPC and prestressed steel strands are used to reinforce the old concrete T-beam. UHPC is used to fix the prestressed steel strands to the old concrete T-beam. Compared with the previous reinforcement method using ordinary concrete, it results in a smaller increase in the bridge's self-weight and thickness. The overall stress performance and bending resistance of the reinforced bridge are better, solving the problem of poor reinforcement strength in the past. During the reinforcement process, because the precast components are tensioned by steel strands, the weight of the precast components and the cast-in-place UHPC are not applied to the T-beam, but are transferred to the pier. This ensures that the original T-beam is not subjected to the external forces generated during reinforcement. The prestressed steel strands can reinforce the old concrete T-beam, avoiding the cumbersome process of rebar installation. At the same time, UHPC not only reinforces the T-beam, but also protects the prestressed steel strands from corrosion. The combination of the two results in a solidified overall structure with superior bending and crack resistance, significantly improved load-bearing capacity compared to other reinforcement measures, and simpler construction. It is more applicable in actual engineering, reducing on-site formwork and rebar tying, enabling prefabricated construction, shortening construction time, simplifying on-site procedures, and providing good economic benefits.

Claims

1. A reinforced concrete T-beam structure based on UHPC and prestressed steel strands, characterized in that, include: Precast components (1000), prestressed steel strands (2000), and UHPC cast-in-place layer (3000); The prefabricated component (1000) includes a main body section (1100) and an extension section (1200) sleeved on the outer surface of the main body section (1100). The main body section (1100) forms a U-shaped groove with a base plate (1001) and a side plate (1002). The extension section (1200) forms a U-shaped groove with a base plate (1001) and a side plate (1002). The main body section (1100) has a plurality of stranded wire channels (1300) arranged parallel to the length direction of the prefabricated component (1000) on the inner surface of the side plate (1002). The main body section (1100) has a first ring (1400) arranged on the center line of the height direction of the side plate (1002). The prestressed steel strand (2000) is disposed within the strand channel (1300); The UHPC casting layer (3000) is disposed in the gap between the precast component (1000) and the T-beam body (100).

2. The reinforced concrete T-beam structure based on UHPC and prestressed steel strands according to claim 1, characterized in that, The extension section (1200) includes a second ring (1500), which is disposed on the extension section (1200) close to the first ring (1400) along the height direction of the side plate (1002).

3. The reinforced concrete T-beam structure based on UHPC and prestressed steel strands according to claim 1, characterized in that, The extension section (1200) includes a baffle (1201), which is located at the end of the extension section (1200) away from the main body section (1100). The baffle (1201) has a through hole (1202) adapted to the stranded wire channel (1300).

4. The reinforced concrete T-beam structure based on UHPC and prestressed steel strands according to claim 1, characterized in that, A limiting groove (1301) for limiting the prestressed steel strand (2000) is provided at the top of the side wall of the strand channel (1300).

5. The reinforced concrete T-beam structure based on UHPC and prestressed steel strands according to claim 1, characterized in that, The precast component (1000) also includes a prestressed steel strand anchoring device (1600) for fixing the two ends of the prestressed steel strand (2000) to the T-beam body (100) respectively.

6. The reinforced concrete T-beam structure based on UHPC and prestressed steel strands according to claim 1, characterized in that, The prefabricated component (1000) is made of GFRP.

7. The reinforced concrete T-beam structure based on UHPC and prestressed steel strands according to claim 1, characterized in that, The side plate (1002) of the extension section (1200) is provided with a edging portion (1203) extending into the U-shaped groove at the top, and the lower surface of the edging portion (1203) abuts against the top of the side plate (1002) of the main body section (1100).

8. A construction method for a reinforced concrete T-beam structure based on UHPC and prestressed steel strands, characterized in that, The construction method employs a concrete T-beam reinforcement structure based on UHPC and prestressed steel strands as described in any one of claims 1-7 to reinforce the main body of the T-beam. The construction method includes: Precast components are manufactured, and the precast components are designed as the middle part of the main section and the extendable part of the extension section. The strand channels through which the prestressed steel strands pass are pre-processed on the inner wall of the side plate of the main section. Drill holes in the web of the T-beam above the pier to install anchoring rings. Pass the hoisting steel strands through the anchoring rings in the web of the beam and the first ring of the precast component. The lifting unit hoists the precast component to the bottom of the T-beam using the hoisting steel strands. The hoisting steel strands are then tied to the first ring to fix the precast component. The extension sections at both ends of the precast component are stretched and erected above the T-beam pier. The baffle is pasted to the ends of the two extension sections. The second ring is bound to the anchoring ring by steel strands. The prestressed steel strands are passed through the precast component through the strand channel. The two ends of the prestressed steel strands are anchored to the T-beam by the prestressed steel strand anchoring device. The prestressed steel strands are tensioned to complete the first reinforcement. After the first reinforcement, the hoisting steel strands used for temporary hoisting are released and the anchoring rings at the beam web are removed. UHPC is poured in the gap between the precast component and the T-beam body for the second reinforcement. When the UHPC hardens to form the UHPC pouring layer, the precast component is removed to complete the reinforcement.

9. The construction method for the reinforced concrete T-beam structure based on UHPC and prestressed steel strands according to claim 8, characterized in that, The prefabricated components are made of GFRP and are designed as U-shaped channel plates with a bottom plate and side plates.

10. The construction method for the reinforced concrete T-beam structure based on UHPC and prestressed steel strands according to claim 8, characterized in that, The hoisting steel strand is passed through the anchoring ring at the web of the beam and the first ring of the precast component. The lifting unit uses the hoisting steel strand to hoist the precast component to the bottom of the T-beam. The hoisting steel strand is then tied to the first ring to secure the precast component. This includes: The hoisting steel strands are passed through the anchoring rings at the web of the beam, the first ring of the precast component, and the second ring of the precast component. The hoisting unit then hoists the precast component to the bottom of the T-beam using the hoisting steel strands, and binds the hoisting steel strands to the first and second rings to fix the precast component.

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