Concrete crane beam with RPC (reactive powder concrete) reinforced end

Abstract

The utility model discloses a concrete crane beam with RPC (reactive powder concrete) reinforced ends. The concrete crane beam comprises a concrete crane beam main body and an RPC reinforced area, rPC is poured in the 1 / 4 span range of the end of the concrete crane beam body, reactive powder concrete doped with reinforcing materials such as steel fibers is poured in an RPC reinforcing area, a triangular slope interface matched with shearing force distribution of the end is naturally formed by means of the low fluidity of the reactive powder concrete, and hook-shaped short ribs are pre-embedded in the interface. Therefore, the bonding performance of a new and old concrete interface is improved. According to the utility model, the RPC arrangement at the end part is optimized and is matched with the shearing force distribution at the end part, so that the shearing resistance of the end part is improved, the consumption of high-strength concrete is reduced, the utilization rate of material performance is maximized, and both economical efficiency and high efficiency are realized.

Description

Technical Field

[0001] This utility model relates to the field of industrial building structure technology, specifically to a concrete crane beam with end RPC reinforcement. Background Technology

[0002] Crane beams, as key load-bearing components in industrial plants, logistics warehouses, and other buildings, are subjected to repeated loads from moving cranes over long periods. Due to shear concentration, their end areas are prone to diagonal cracks, shear failure, and interface delamination, severely impacting structural safety and durability. Traditional crane beams are typically designed with ordinary concrete. To meet shear resistance requirements, the cross-sectional height needs to be increased, resulting in a bulky structure, material waste, and reduced building clearance. Furthermore, ordinary concrete has low tensile strength and poor fatigue resistance; under repeated dynamic loads from cranes, diagonal cracks at the beam ends propagate rapidly, and the reinforcing steel is prone to corrosion, typically resulting in a service life of less than 30 years. Existing technologies often address these issues by increasing the overall beam cross-section, adding haunches, or encasing it in steel plates, but these methods suffer from drawbacks such as complex construction, high costs, and large space requirements. In recent years, high-strength concrete, due to its superior mechanical properties and durability, has been increasingly used in bridge and building projects; however, its high overall beam cost limits its widespread adoption. Therefore, there is an urgent need for a local reinforcement technology that balances performance and economy, which can achieve a balance between lightweight structure, long service life and ease of construction by precisely strengthening the high shear zone at the end of the crane beam. Summary of the Invention

[0003] Purpose of the utility model: This utility model overcomes the shortcomings of the prior art by utilizing material properties and geometric shape to adapt to the end shear stress distribution, achieving precise reinforcement in the area of ​​maximum shear force, and proposing a lightweight, low-cost, and highly durable crane beam structure.

[0004] The technical solution adopted in this utility model is: a concrete crane beam with RPC reinforcement at the end, including a concrete crane beam body, short bars, a new and old concrete interface, longitudinal bars and stirrups;

[0005] The main body of the concrete crane beam is divided into an RPC reinforced area and an ordinary concrete area, and longitudinal bars and stirrups are provided inside the main body of the concrete crane beam.

[0006] The main body of the concrete crane beam is a plain concrete area in the middle, and an RPC reinforced area is poured within 1 / 4 of the span at its ends;

[0007] The contact point between the RPC reinforced area and the ordinary concrete area is the interface between the old and new concrete. The interface between the old and new concrete has a triangular slope, and the slope direction matches the shear force envelope diagram at the beam end. Short bars with hooks are evenly embedded along the interface between the old and new concrete.

[0008] Preferably, the ratio of the triangular slope of the new and old concrete interface is 1:2 to 1:3, and the bottom of the triangular slope of the new and old concrete interface extends to 1 / 4 span from the support.

[0009] Preferably, the RPC reinforced region is active powder concrete with a reinforcing material, which is steel fiber.

[0010] Preferably, the short reinforcement bars penetrate vertically through the interface between the old and new concrete, are symmetrically distributed on both sides of the interface, and the lengths of the upper and lower ends of the short reinforcement bars are equally divided by the interface between the old and new concrete.

[0011] Preferably, the short bars are fixed to the longitudinal bars or stirrups that intersect with the interface between the old and new concrete by binding or welding.

[0012] The beneficial effects of this utility model are:

[0013] 1. Using RPC with steel fiber or other reinforcing materials at the ends can significantly improve the mechanical properties of the ends, such as shear resistance and fatigue life.

[0014] 2. By locally reinforcing the ends with high-strength materials, it is possible to reduce the cross-sectional dimensions and the structural weight.

[0015] 3. Local reinforcement measures are implemented only at the ends, and the triangular slope interface matches the shear force distribution at the beam end, maximizing material utilization and achieving both economy and efficiency.

[0016] 4. By pre-embedding short bars at the interface between new and old concrete, and by utilizing the "burr effect" formed by the exposed steel fiber interface, the bonding performance between the new and old concrete interfaces is improved.

[0017] 5. The slope is naturally formed by utilizing the low fluidity of high-strength concrete, making construction convenient. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the RPC-reinforced concrete crane beam at the end of this utility model.

[0019] Figure 2 This is a schematic diagram of the RPC reinforcement area structure of the end-reinforced concrete crane beam of this utility model.

[0020] Figure 3 This is a schematic diagram of the interface structure of the RPC-reinforced concrete crane beam at the end of this utility model.

[0021] Reference numerals: 1. RPC reinforced area; 2. Ordinary concrete area; 3. Short reinforcement; 4. Interface between old and new concrete; 5. Longitudinal reinforcement; 6. Stirrups. Detailed Implementation

[0022] The entire technical solution will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0023] Please see Figure 1-3 A concrete crane beam with RPC reinforcement at the ends includes a concrete crane beam body, short bars 3, a new and old concrete interface 4, longitudinal bars 5, and stirrups 6.

[0024] The main body of the concrete crane beam is divided into an RPC reinforced area 1 and an ordinary concrete area 2. The main body of the concrete crane beam is provided with longitudinal bars 5 and stirrups 6.

[0025] The main body of the concrete crane beam is a regular concrete area 2 in the middle, and an RPC reinforced area 1 is poured within 1 / 4 of the span at its ends;

[0026] The contact point between the RPC reinforced area 1 and the ordinary concrete area 2 is the new and old concrete interface 4. The new and old concrete interface 4 has a triangular slope, and the slope direction matches the shear force envelope diagram at the beam end. Short bars 3 with hooks are evenly embedded along the new and old concrete interface 4.

[0027] The ratio of the triangular slope of the new and old concrete interface 4 is 1:2 to 1:3, and the bottom of the triangular slope of the new and old concrete interface 4 extends to 1 / 4 of the span from the support; the RPC reinforced area 1 is active powder concrete with reinforcing material; the reinforcing material is steel fiber; the short bars 3 penetrate vertically through the new and old concrete interface 4, are symmetrically distributed on both sides of the new and old concrete interface 4, and the lengths of the upper and lower ends of the short bars 3 are equally divided by the new and old concrete interface 4; the short bars 3 are fixed to the longitudinal bars 5 or stirrups 6 that intersect with the new and old concrete interface 4 by binding or welding.

[0028] This invention features lightweight, high strength, and cost-effectiveness. While improving end shear resistance, it also ensures the bond performance at the interface between new and old concrete. (See [link to related documentation]). Figure 1-3 This includes the following steps:

[0029] Step 1: Tie the steel reinforcement cage.

[0030] Step 2: Based on the design cross-sectional dimensions and the slope parameters of the new and old concrete interface 4, accurately locate the direction of the new and old concrete interface 4, and then fix the short bars 3 by binding or welding on the longitudinal bars 5 or stirrups 6 that intersect with the new and old concrete interface 4.

[0031] Step 3: Complete the mold setting and apply release agent.

[0032] Step 4: Pour the RPC reinforcement area 1 at the end.

[0033] Step 5: After the RPC reinforced area 1 at the end has initially set, pour the ordinary concrete area 2 in the middle.

[0034] Step 6: Remove the formwork one day after the overall specimen is poured, and use indoor curing conditions in winter for 28 days.

[0035] The embodiments of this utility model have been described in detail above with reference to the accompanying drawings. It should be noted that for those skilled in the art, several modifications, equivalent substitutions, and improvements can be made without departing from the principles of this utility model, and these modifications, equivalent substitutions, and improvements should also be considered within the protection scope of this utility model.

Claims

1. A concrete crane beam with RPC reinforcement at the ends, characterized in that: This includes the main body of the concrete crane beam, short bars, the interface between new and old concrete, longitudinal bars, and stirrups; The main body of the concrete crane beam is divided into an RPC reinforced area and an ordinary concrete area, and longitudinal bars and stirrups are provided inside the main body of the concrete crane beam. The main body of the concrete crane beam is a plain concrete area in the middle, and an RPC reinforced area is poured within 1 / 4 of the span at its ends; The contact point between the RPC reinforced area and the ordinary concrete area is the interface between the old and new concrete. The interface between the old and new concrete has a triangular slope, and the slope direction matches the shear force envelope diagram at the beam end. Short bars with hooks are evenly embedded along the interface between the old and new concrete.

2. The concrete crane beam with end RPC reinforcement according to claim 1, characterized in that: The ratio of the triangular slope of the interface between the old and new concrete is 1:2 to 1:3, and the bottom of the triangular slope of the interface between the old and new concrete extends to 1 / 4 span from the support.

3. A concrete crane beam with end RPC reinforcement according to claim 2, characterized in that: The short reinforcement bars penetrate vertically through the interface between the old and new concrete, are symmetrically distributed on both sides of the interface, and the lengths of the upper and lower ends of the short reinforcement bars are equally divided by the interface between the old and new concrete.

4. The end-reinforced RPC concrete crane beam according to claim 3, characterized in that: The short bars are fixed to the longitudinal bars or stirrups that intersect with the interface between the old and new concrete by binding or welding.

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