A load-bearing support for fire resistance test of engineering components under high temperature environment

Abstract

This utility model relates to the field of testing equipment, and more particularly to a load-bearing support for fire resistance testing of engineering components under high-temperature conditions. It consists of two rows of columns, two upper longitudinal beams, and a lower crossbeam. The ends of the upper longitudinal beams have connecting structures extending towards the columns and connecting to the top of the columns. The upper longitudinal beams, columns, and lower crossbeams form an H-shaped foundation load-bearing unit from the left and right sides. The front and rear rows of columns are laterally connected to the lower crossbeams, and the upper longitudinal beams are fixed to the top of the columns, forming a spatial rigid frame system. The upper longitudinal beams evenly transfer the specimen load to the columns, while the lower crossbeams enhance the rigidity of the support, evenly distributing the load, optimizing the transfer path, avoiding local stress concentration, improving lateral and overturning resistance, and ensuring stable load-bearing capacity under high temperatures. Simultaneously, the upper longitudinal beams only support the specimen on both sides, avoiding obstruction and reducing resistance to hot airflow, ensuring uniform heating of the specimen from all directions, and allowing the test data to more accurately reflect the actual fire resistance performance.

Description

Technical Field

[0001] This utility model relates to the field of testing equipment, and in particular to a load-bearing support for fire resistance testing of engineering components under high temperature conditions. Background Technology

[0002] In the field of civil engineering, accurately assessing the fire resistance limit and high-temperature mechanical properties of engineering components (such as beams, slabs, and columns) is crucial for structural fire safety design and calculation of evacuation time. Standard fire resistance tests are typically conducted in dedicated high-temperature furnaces, where temperatures can reach over 1100°C. However, existing support technologies still have significant shortcomings, directly affecting the reliability and safety of test results.

[0003] Currently, the mainstream testing method still uses refractory brick stacks to directly support the specimens. When multiple sets of specimens need to be tested simultaneously, several independent brick stacks need to be densely stacked inside the furnace. Due to the large heat capacity and high volume ratio of the brick stacks themselves, they severely hinder the smooth flow of high-temperature hot air and the uniform radiation of heat, resulting in a highly uneven temperature field distribution inside the furnace. The heating state of different areas of the same specimen or different specimens varies significantly, directly causing distortion in the measurement of temperature data, deformation data, and refractory limit, and failing to truly reflect the actual refractory performance of the components.

[0004] Furthermore, refractory brick stacks are formed by mortar or simple stacking, resulting in extremely weak overall structural integrity and resistance to lateral forces. When supporting heavy specimens (such as large beams or columns) or when specimens undergo significant deformation (such as bending or expansion) at high temperatures, the brick stacks are prone to instability, tilting, or even overturning due to horizontal thrust or eccentric loads, leading to test interruptions, equipment damage, or safety accidents.

[0005] To overcome the drawbacks of refractory brick stacks, some experiments used ordinary steel support structures. While these supports are easy to install and reusable, the strength and modulus of elasticity of the steel decrease sharply at temperatures above 400-500℃. When supporting heavy specimens or subjected to prolonged high temperatures, the load-bearing beams and support columns of the steel support are prone to excessive bending deformation or even buckling instability. This deformation of the support itself interferes with the acquisition of accurate deformation data of the specimen, and also alters the boundary constraints of the specimen, ultimately distorting the experimental results. Secondly, to maintain stability, ordinary steel supports are usually designed with upper transverse connecting beams. These beams inevitably obstruct the surface of the specimen, hindering the normal transfer of temperature from the furnace to the specimen, resulting in uneven heating of the specimen and weakening the validity of the experiment. Utility Model Content

[0006] The present invention aims to overcome the defects of the prior art, such as low stability of refractory brick stack structure, poor uniformity of thermal field, and significant deformation and instability of ordinary steel frame at high temperature, which also hinders temperature transfer and causes uneven heating of the specimen.

[0007] The technical solution adopted by this utility model is to provide a load-bearing support for fire resistance testing of engineering components under high temperature environment, including columns, upper longitudinal beams and lower crossbeams. The columns are arranged in pairs, forming two rows at the front and rear of the support. The upper longitudinal beams are respectively connected to the tops of the front row of columns and the rear row of columns, and their ends are provided with connecting structures extending towards the columns. The top of the columns is fixedly connected to the connecting structures of the corresponding upper longitudinal beams. The lower crossbeams are connected between the two rows of columns. The upper longitudinal beams, columns and lower crossbeams together form the H-shaped basic load-bearing units on the left and right sides.

[0008] The upper longitudinal beam is horizontally connected to the front and rear columns and the lower crossbeam, and the connecting structure at the end of the upper longitudinal beam is fixedly connected to the top of the column, forming an H-shaped spatial rigid frame system. The upper longitudinal beam evenly distributes the specimen load to the front and rear columns, while the lower crossbeam enhances the overall rigidity of the support by horizontally connecting the columns. When the specimen itself is heavy and the upper longitudinal beam is deformed or subjected to horizontal thrust at high temperatures, the support can evenly distribute the load, optimize the load transfer path, avoid local stress concentration, suppress column tilting or overturning, and improve the overall lateral and overturning resistance of the support, ensuring that the support maintains stable load-bearing capacity at high temperatures. At the same time, the upper longitudinal beam, as a direct load-bearing component, only forms support on both sides of the specimen, avoiding the obstruction of the specimen by the transverse connecting beam at the top of the traditional steel support, reducing the obstruction of hot airflow, and allowing the high-temperature hot airflow in the furnace to smoothly radiate to the entire specimen, ensuring that the specimen is heated evenly in all directions, so that the temperature and deformation data measured in the test more accurately reflect the actual fire resistance performance of the component.

[0009] Furthermore, the equal cross-sectional areas of the columns, upper longitudinal beams, and lower cross beams ensure a more balanced stress level across the components, preventing localized stress concentration and enhancing the overall stability of the support frame.

[0010] The uprights and lower crossbeams utilize a hollow structure, which reduces the weight of the support while ensuring bending and compressive strength, facilitating movement and transportation. Meanwhile, the upper longitudinal beams employ a solid structure, enabling them to withstand larger bending moments and shear forces. When transferring specimen loads, the solid structure, with the same cross-sectional area, exhibits a larger bending section modulus, effectively resisting bending deformation caused by the weight or deformation of the specimen at high temperatures, thus preventing distortion of test results due to deformation of the support itself.

[0011] Furthermore, the columns and lower crossbeams are constructed from hollow steel pipes, which not only reduces material usage while ensuring strength but also lowers the overall weight and heat capacity of the support structure. This reduces the heat absorbed by the structure itself at high temperatures, thereby mitigating the risk of deformation due to thermal expansion or stress, enhancing overall lateral force resistance, and improving the stability of the overall structure under high-temperature conditions. Simultaneously, the upper longitudinal beams and their connecting structures are constructed from steel pipes with internally poured concrete filling. Concrete has good thermal stability, and the internal concrete supports the steel pipes, delaying the strength decline of the steel pipes at high temperatures. The constraint effect of the steel pipes on the concrete enhances the overall compressive and bending resistance. The combination of these two materials provides superior high-temperature load-bearing capacity, stiffness, and stability compared to single materials. In addition, the steel-concrete composite structure of the upper longitudinal beam connecting structure is fixedly connected to the hollow steel pipe structure at the top of the columns, forming a stiffness-matched transition node. The steel-concrete section extends to the fixed connection node area and participates in the load-bearing, significantly improving the bending stiffness and load-bearing capacity of the connection node. This effectively transfers the performance of the steel-concrete composite to the entire support structure, avoiding the risk of deformation in locally weak points of the support structure when bearing heavy components or under high-temperature conditions.

[0012] Furthermore, the outer surfaces of the upper longitudinal beams, columns, and lower crossbeams are wrapped with refractory fiber insulation layers to prevent the high temperature inside the furnace from being directly transmitted to the support structure, reduce the surface and internal temperature of the support steel, delay the degradation of the mechanical properties of the material at high temperatures, reduce the deformation of the support caused by material softening, and ensure that the support maintains stable load-bearing capacity and structural stiffness during high-temperature testing.

[0013] Furthermore, the load-bearing support can be constructed by modularly and continuously splicing multiple basic load-bearing units. The scale of the support can be flexibly expanded according to the test requirements, such as supporting 2 or 3 sets of specimens at the same time. This avoids the thermal interference and structural weaknesses caused by multiple independent brick stack arrays in traditional methods, and improves test efficiency while ensuring thermal uniformity. At the same time, the length of the longitudinal beam on the spliced ​​support extends continuously from one side of the support to the other side. The basic load-bearing units are connected by the connecting structure of the longitudinal beam and share the central column to form a continuous and stable frame system. This avoids local instability caused by splicing multiple independent units, improves the overall lateral force resistance and overturning resistance during multi-specimen testing, and ensures test safety.

[0014] Preferably, the load-bearing support is composed of two basic load-bearing units arranged in a row and continuously spliced ​​from left to right, with the lateral length extended. The ratio of the longitudinal dimension to the lateral dimension is 1:2. The length of the upper longitudinal beam extends continuously from the left side of the support to the right side along the row direction. The two basic load-bearing units are connected by a central column through the connection structure of the upper longitudinal beam to accommodate multiple specimens of shorter length for testing.

[0015] In another preferred embodiment, the load-bearing support is composed of multiple basic load-bearing units continuously spliced ​​together in a column direction to extend the longitudinal width. The upper longitudinal beam extends continuously from the left to the right along the row direction and is arranged from the front to the back along the column direction. The basic load-bearing units are connected collaboratively by sharing the middle column and the upper longitudinal beam to accommodate test specimens with longer lengths.

[0016] In the third preferred embodiment, the load-bearing support is composed of multiple basic load-bearing units arranged in a longitudinal and transverse matrix, which are expanded in both length and width. The longitudinal beams on the support extend continuously from the left side to the right side of the support along the row direction and are arranged from the front to the back side along the column direction. The multiple basic load-bearing units arranged laterally are connected by a central column through the connection structure of the upper longitudinal beams, and the multiple basic load-bearing units arranged longitudinally are connected by a central column and upper longitudinal beams to accommodate test specimens with larger areas.

[0017] In the fourth preferred embodiment, the load-bearing support is composed of multiple basic load-bearing units continuously spliced ​​together in an L-shaped arrangement to accommodate irregularly shaped specimens for testing.

[0018] Compared with existing technologies, the beneficial effects of this utility model are as follows: An H-shaped foundation load-bearing unit, formed by the coordinated connection of front and rear columns, upper longitudinal beams, and lower transverse beams, creates a spatial rigid frame system. Combined with hollow steel pipe columns and lower transverse beams, a steel-concrete composite upper longitudinal beam, and a fixed connection design between the steel-concrete upper longitudinal beam and the top of the hollow steel pipe columns, the overall rigidity and lateral force resistance of the load-bearing support are improved. Even when supporting heavy specimens or experiencing prolonged high temperatures, the support can control its deformation within a minimal range through uniform load distribution and optimized high-temperature material performance. This avoids the instability of brick stacks and the bending and buckling problems caused by high-temperature softening in traditional steel supports, ensuring stable boundary constraints on the specimens during testing and reliable data acquisition.

[0019] The upper longitudinal beam adopts an open support design that connects only on both sides of the specimen, completely eliminating the obstruction of the top of the specimen by the transverse connecting beams at the top of the traditional steel support. Combined with the hot airflow channel formed by the modular arrangement of the foundation load-bearing units, the high-temperature hot airflow in the furnace can radiate smoothly along the length and width of the specimen, avoiding the "heat shielding" effect caused by the dense stacking of refractory bricks. Whether testing a single specimen or multiple specimens, uniform heating can be achieved on the top, sides, and different positions of the specimen, significantly improving the accuracy of temperature data, deformation data, and fire resistance limit measurements, truly reflecting the actual fire resistance performance of the component.

[0020] The basic load-bearing unit is supported laterally by the lower crossbeam and the columns, and combined with the high-temperature protection of the overall component by the refractory fiber insulation layer, a highly stable load-bearing system is formed. Even if the specimen undergoes significant deformation or horizontal thrust at high temperatures, the support can evenly distribute the load through the spatial rigid frame effect, avoiding tilting, overturning, or specimen falling caused by local stress concentration. This fundamentally solves the safety risks caused by the poor structural stability of traditional brick stacks and ensures the safety of the experiment.

[0021] The modular design of the basic load-bearing unit allows it to be used independently or combined into rows, columns, matrices, L-shapes, etc., enabling the support to flexibly adapt to different test requirements. It can be used for fine testing of single specimens, or for large-scale testing of multiple specimens by splicing 2 to 3 sets of units. At the same time, the combination of hollow steel pipes and steel-concrete composite materials reduces the self-weight of the support, making it easy to install, transport, and reuse, further reducing test costs. Attached Figure Description

[0022] Figure 1 This is a perspective view of Embodiment 1 of the present invention.

[0023] Figure 2 This is a front view of Embodiment 1 of this utility model.

[0024] Figure 3 This is a top view of Embodiment 1 of the present invention.

[0025] Figure 4 This is a side view of Embodiment 1 of the present invention.

[0026] Figure 5 This is a schematic diagram of the cross-sectional structure of the column and the lower beam.

[0027] Figure 6 This is a schematic diagram of the cross-sectional layer structure of the upper longitudinal beam and its connecting structures.

[0028] Figure 7 This is a perspective view of Embodiment 2 of the present invention.

[0029] Figure 8 This is a front view of Embodiment 2 of the present invention.

[0030] Figure 9 This is a top view of Embodiment 2 of the present invention.

[0031] Figure 10 This is a perspective view of Embodiment 3 of the present invention.

[0032] Figure 11 This is a side view of Embodiment 3 of the present invention.

[0033] Figure 12 This is a top view of Embodiment 3 of the present invention.

[0034] Figure 13 This is a perspective view of Embodiment 4 of the present invention.

[0035] Figure 14 This is a front view of Embodiment 4 of the present invention.

[0036] Figure 15 This is a side view of Embodiment 4 of the present invention.

[0037] Figure 16 This is a top view of Embodiment 4 of the present invention.

[0038] Figure 17 This is a perspective view of Embodiment 5 of the present invention.

[0039] Figure 18 This is a top view of Embodiment 5 of the present invention.

[0040] Explanation of reference numerals in the attached drawings: Column 110, Upper longitudinal beam 120, Connecting structure 121, Lower crossbeam 130, Steel pipe 200, Concrete 300, Fire-resistant fiber insulation layer 400. Detailed Implementation

[0041] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this invention. To better illustrate the following embodiments, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0042] Example 1

[0043] like Figure 1 As shown, this embodiment 1 provides a load-bearing support for fire resistance testing of engineering components under high-temperature conditions, including a column 110, an upper longitudinal beam 120, and a lower transverse beam 130. Combined with... Figure 2 and Figure 3 As shown, the upper longitudinal beam 120 supports the specimen, and four columns 110 stand on the ground at their bottom ends, arranged in two rows at the front and back of the support. Two upper longitudinal beams 120 are connected to the tops of the two front and two rear columns 110 respectively. A lower crossbeam 130 connects the left and right rows of columns 110. A connecting structure 121 is provided at the end of the upper longitudinal beam 120, extending towards the top of the columns 110. The tops of the four columns 110 are connected to the connecting structures 121 at the ends of the corresponding two upper longitudinal beams 120. Further integration... Figure 4 As shown, the upper longitudinal beam 120, the column 110 and the lower horizontal beam 130 together form an H-shaped foundation load-bearing unit from the left and right sides.

[0044] like Figure 5 and Figure 6As shown, the cross-sectional shape of the column 110, the upper longitudinal beam 120, and the lower cross beam 130 are all square, and their areas are equal. The column 110 and the lower cross beam 130 are hollow structures, specifically composed of hollow steel pipes 200, while the upper longitudinal beam 120 and its connecting structure 121 are solid structures, specifically composed of steel pipes 200 with an inner cavity filled with concrete 300. A fire-resistant fiber insulation layer 400 is wrapped around the outer surface of the upper longitudinal beam 120, the column 110, and the lower cross beam 130.

[0045] Example 2

[0046] like Figure 7 , Figure 8 and Figure 9 As shown, this embodiment 2 provides another load-bearing support for fire resistance testing of engineering components under high temperature conditions. Specifically, the upper longitudinal beam 120 extends continuously from the left to the right along the row direction, forming two basic load-bearing units in the row arrangement direction. The ratio of the longitudinal dimension to the transverse dimension is 1:2, and the two basic load-bearing units share a middle column. It includes six columns 110 arranged in two rows at the front and back of the support. The two upper longitudinal beams 120 are respectively connected to the tops of the three columns 110 in the front row and the three columns 110 in the back row. The upper longitudinal beams 120 are provided with connecting structures 121 in the middle and at the ends. The tops of the six columns 110 are connected to the connecting structures 121 in the middle and at the ends of the corresponding two upper longitudinal beams 120. The lower crossbeam 130 is connected between the three rows of columns 110 in the left, middle and right.

[0047] Example 3

[0048] like Figure 10 , Figure 11 and Figure 12 As shown, this embodiment 3 provides a load-bearing support for fire resistance testing of engineering components under high temperature conditions. Specifically, the basic load-bearing units are arranged in rows, with two units in total. The upper longitudinal beams 120 still extend from the left to the right along the row direction and are arranged from the front to the rear along the column direction. It includes six columns 110 arranged in three rows in the front, middle, and rear of the support. The three upper longitudinal beams 120 are respectively connected to the top of the two columns 110 in the front row, the two columns 110 in the middle row, and the two columns 110 in the rear row. The ends of the upper longitudinal beams 120 are provided with connecting structures 121. The tops of the six columns 110 are connected to the connecting structures 121 at the ends of the corresponding two upper longitudinal beams 120. The lower crossbeams 130 are connected between the three rows of columns 110.

[0049] Example 4

[0050] like Figure 13 , Figure 14 , Figure 15 and Figure 16As shown, this embodiment 4 provides a load-bearing support for fire resistance testing of engineering components under high temperature conditions. Specifically, the basic load-bearing units are arranged in a longitudinal and transverse matrix pattern. The upper longitudinal beams 120 extend from the left to the right along the row direction and are arranged from the front to the rear along the column direction. It includes nine columns 110 arranged in three rows at the front, middle, and rear of the support. The three upper longitudinal beams 120 are respectively connected to the top of the three columns 110 in the front row, the three columns 110 in the middle, and the three columns 110 in the three rows. The upper longitudinal beams 120 are provided with connecting structures 121 in the middle and at the ends. The tops of the nine columns 110 are connected to the connecting structures 121 in the middle and at the ends of the corresponding three upper longitudinal beams 120. The lower transverse beams 130 are connected between the columns 110 in the front, middle, and rear rows.

[0051] Example 5

[0052] like Figure 17 and Figure 18 As shown, this embodiment 5 provides a load-bearing support for fire resistance testing of engineering components under high temperature conditions. Specifically, the basic load-bearing unit is arranged in an L-shaped direction, and the upper longitudinal beam 120 extends from the left to the right along the row direction. It includes six columns 110 arranged in the front and middle rows of the support, and two columns 110 arranged in the rear row of the support. The three upper longitudinal beams 120 are respectively connected to the top of the three columns 110 in the front row, the three columns 110 in the middle row, and the two columns 110 in the three rows. The two upper longitudinal beams 120 in the front and middle rows are provided with connecting structures 121 in the middle and at the ends. The single upper longitudinal beam 120 in the rear row is provided with a connecting structure 121 at the end. The tops of the eight columns 110 are connected to the connecting structures 121 in the middle and at the ends of the corresponding three upper longitudinal beams 120. The lower crossbeam 130 is connected between the three rows of columns 110 in the front, middle, and rear rows.

[0053] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the technical solution of this utility model, and are not intended to limit the specific implementation of this utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the claims of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A load-bearing support for fire resistance testing of engineering components under high temperature conditions, comprising a plurality of columns (110) arranged in pairs in front and back rows of the support, two upper longitudinal beams (120) respectively connected to the tops of the columns (110) in the front row and the columns (110) in the back row, and a lower crossbeam (130) connected between the two rows of columns (110), characterized in that, The upper longitudinal beam (120) is provided with a connecting structure (121) extending to the column (110) on the lower side. The top of each column (110) is connected to the connecting structure (121) of the corresponding upper longitudinal beam (120). The upper longitudinal beam (120), column (110) and lower crossbeam (130) together form an H-shaped foundation load-bearing unit from the left and right sides.

2. The load-bearing bracket according to claim 1, characterized in that, The column (110) and lower crossbeam (130) are hollow structures, while the upper longitudinal beam (120) is a solid structure. The cross-sectional areas of the column (110), upper longitudinal beam (120), and lower crossbeam (130) are equal.

3. The load-bearing bracket according to claim 2, characterized in that, The column (110) and lower crossbeam (130) are made of hollow steel pipe (200), and the upper longitudinal beam (120) is made of steel pipe (200) with an inner cavity filled with concrete (300).

4. The load-bearing bracket according to claim 3, characterized in that, The outer surfaces of the upper longitudinal beam (120), column (110) and lower crossbeam (130) are covered with a fire-resistant fiber insulation layer (400).

5. The load-bearing bracket according to any one of claims 1 to 4, characterized in that, The load-bearing support includes one or more continuously spliced ​​basic load-bearing units, and the upper longitudinal beam (120) extends continuously from one side to the other side.

6. The load-bearing bracket according to claim 5, characterized in that, The basic load-bearing units are arranged in rows, and the upper longitudinal beam (120) extends continuously from the left to the right along the row direction.

7. The load-bearing bracket according to claim 6, characterized in that, The number of basic load-bearing units is 2 to 3, and the ratio of the longitudinal dimension to the transverse dimension of the bracket is 1:2 to 1:

3.

8. The load-bearing bracket according to claim 5, characterized in that, The basic load-bearing units are arranged in columns, and the upper longitudinal beam (120) extends continuously from the left to the right along the row direction.

9. The load-bearing bracket according to claim 5, characterized in that, The basic load-bearing units are arranged in a longitudinal and transverse matrix. The upper longitudinal beam (120) extends continuously from the left to the right along the row direction, or the upper longitudinal beam (120) extends continuously from the front to the rear along the column direction.

10. The load-bearing bracket according to claim 5, characterized in that, The basic load-bearing units are arranged in an L-shape, and the upper longitudinal beam (120) extends continuously from the left to the right along the row direction, and / or the upper longitudinal beam (120) extends continuously from the front to the rear along the column direction.

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