A fire resistance test mechanism for in-plane restrained reinforced concrete slab-column joint structure

Abstract

The present invention relates to a fire resistance test mechanism for a reinforced concrete slab-column node structure with in-plane constraints, comprising a slab-column node structure, a fire test furnace, and an in-plane constraint device; the fire test furnace comprises a furnace body with an upper end opening; the slab-column node structure covers the upper end of the furnace body; the in-plane constraint device acts on the edge of the slab-column node structure to provide constraints for the slab-column node structure. The fire resistance test mechanism for a reinforced concrete slab-column node structure with in-plane constraints of the present invention studies the fire resistance of the reinforced concrete slab-column node structure under in-plane constraints to approximately consider the constraint influence of adjacent components in the structure, thereby studying the influence of the slab surface freely tilting up and down under the in-plane constraints on the fire resistance of the reinforced concrete slab-column node, and at the same time can guide the fire resistance design of the reinforced concrete slab-column node structure according to the test to improve the corresponding fire resistance.

Description

Technical Field

[0001] The invention relates to the technical field of disaster prevention and reduction of building structures, and in particular to a fire resistance testing mechanism for an in-plane constrained reinforced concrete slab-column node structure. Background Art

[0002] As people's living needs grow, their demand for building space becomes higher and higher. The frequency of fire has ranked first among various disasters, causing significant losses to human life and property every year.

[0003] After a building is exposed to high temperatures caused by a fire, its columns, beams, floor slabs and other components will be affected to varying degrees, causing the stability, safety and durability of the entire building structure to decrease. Therefore, studying how to improve the fire resistance of building structures and components and reduce post-disaster losses through the fire resistance of existing structures and reasonable design has become an important research topic in the current field of fire research.

[0004] When a building fire occurs, the concrete slab-column structure, as a direct fire-affected component, plays a key role in preventing the spread of fire, effectively bearing the floor load, and preventing the catastrophic collapse of the building. Therefore, studying the fire resistance of reinforced concrete slab-column structures under in-plane constraints and conducting reasonable fire resistance design are of great significance for safe operation and development.

[0005] At present, most tests on slab-column joints do not consider the influence of the constraints of adjacent components in the structure, and the internal forces and deformations obtained are quite different from the actual fire conditions. Therefore, studying the fire resistance of reinforced concrete slab-column joint structures under in-plane constraints to approximately consider the constraints of adjacent components in the structure is of great significance for understanding the actual fire performance of reinforced concrete slab-column joint structures and promoting the fire resistance performance-based design of reinforced concrete slab-column joint structures. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a fire resistance test mechanism for an in-plane constrained reinforced concrete slab-column node structure, which studies the fire resistance performance of the reinforced concrete slab-column node structure under in-plane constraint conditions, so as to approximately consider the constraint influence of adjacent components in the structure, thereby studying the influence of the free up and down tilting of the slab surface under the action of the in-plane constraint on the fire resistance performance of the reinforced concrete slab-column node. At the same time, the fire resistance design of the reinforced concrete slab-column node structure can be guided according to the test to improve the corresponding fire resistance performance.

[0007] The technical solution adopted by the present invention to solve its technical problems is: a fire resistance test mechanism for an in-plane constrained reinforced concrete slab-column node structure, comprising a slab-column node structure, a fire test furnace, and an in-plane constraint device; the fire test furnace comprises a furnace body with an opening at the upper end; the slab-column node structure covers the upper end of the furnace body; the in-plane constraint device acts on the edge of the slab-column node structure to provide constraints for the slab-column node structure.

[0008] Furthermore, the in-plane restraint device includes a first fixing portion and a second fixing portion; the first fixing portion is used to be fixedly connected to the edge of the plate-column node structure; and the second fixing portion is used to provide an external fixing point for the first fixing portion.

[0009] Furthermore, the second fixing part includes multiple support columns and multiple reaction beams; the support columns are in a fixed state; the reaction beam is installed and fixed between two adjacent support columns; the reaction beam is horizontally arranged and located near the edge of the plate-column node structure, which is used to provide an external fixing point, and one end of the first fixing part is fixedly connected to the edge of the plate-column node structure, and the other end is installed and connected to the reaction beam.

[0010] Furthermore, a slide rail is installed on the reaction beam; a support is provided at one end of the first fixing portion; a pulley assembly is installed on the support; and the pulley assembly is assembled in the slide rail.

[0011] Furthermore, the first fixing part includes a tension and compression sensor and a connecting piece; one end of the tension and compression sensor is hinged to the support, and the other end is connected to one end of the connecting piece; the other end of the connecting piece is fixedly connected to the edge of the plate-column node structure.

[0012] Furthermore, a load weight is provided on the top surface of the plate-column node structure, and a flexible refractory layer is provided between the upper end surface of the furnace body and the plate-column node structure to ensure close contact between the plate-column node structure and the furnace body.

[0013] Furthermore, the fire test furnace also includes an oil supply pipeline surrounding the furnace body and a plurality of ignition nozzles installed on the outer wall of the furnace body. The oil supply pipeline forms a loop with the external oil tank. A fan is provided at each ignition nozzle, and an oil pump connected to the oil supply pipeline is provided at each fan.

[0014] Furthermore, the fire test furnace also includes a water circulation pipeline and at least one smoke exhaust duct; the furnace body has a furnace bottom; the smoke exhaust duct is arranged below the furnace bottom, and the furnace bottom is also provided with at least one smoke exhaust port; the smoke exhaust duct is connected to the interior of the furnace body through the smoke exhaust port; the water circulation pipeline is installed on the outside of each smoke exhaust duct.

[0015] Furthermore, the fire test furnace also includes a data acquisition device, which includes one or a combination of several of a temperature sensor, a displacement sensor and a force sensor; there are multiple temperature sensors, among which at least one temperature sensor is arranged inside the furnace body, and at least one temperature sensor is pre-buried in the column node structure; the force sensor includes at least a tension and compression sensor.

[0016] Furthermore, the test mechanism also includes a control system, which is electrically connected to the data acquisition device, the oil pump, the ignition nozzle, and the fan respectively; the control system is configured to receive signal data from the data acquisition device, and is also configured to output control signals to the oil pump, the ignition nozzle, and the fan.

[0017] Advantages of the present invention: The fire resistance test mechanism of the in-plane constrained reinforced concrete slab-column node structure of the present invention approximately considers the interaction between adjacent components of the structure in a fire by applying horizontal constraints to the boundary of the reinforced concrete slab through a pulley, considers the influence of the constraint effect of adjacent components in the structure, and thus can deeply understand the influence law of the actual fire performance of the reinforced concrete slab-column node structure; the temperature in the furnace can be monitored in real time and can be adjusted at any time, so that the temperature in the furnace can well meet the required standard heating curve or other related heating lines. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic top view of a fire resistance test mechanism for an in-plane restrained reinforced concrete slab-column node structure according to an embodiment;

[0019] Figure 2 A schematic diagram of an in-plane restraint device of an in-plane restraint reinforced concrete slab-column joint structure fire resistance test mechanism according to an embodiment;

[0020] Figure 3 It is a schematic diagram of the internal structure of the facade of an in-plane restrained reinforced concrete slab-column node structure fire resistance test mechanism of an embodiment;

[0021] Figure 4 The figure is a schematic diagram of the internal structure of a plane of a fire resistance test mechanism for an in-plane constrained reinforced concrete slab-column node structure according to an embodiment. DETAILED DESCRIPTION

[0022] In order to deepen the understanding of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. The embodiments are only used to explain the present invention and do not limit the protection scope of the present invention. Example

[0023] like Figures 1 to 4As shown, this embodiment provides an in-plane constrained reinforced concrete slab-column node structure fire resistance test mechanism, including a slab-column node structure 9, a fire test furnace, and an in-plane constraint device; wherein the slab-column node structure 9 is a reinforced concrete slab-column node structure, which is composed of a slab surface and a column, and is made of reinforced concrete; a furnace body 14 is arranged below the reinforced concrete slab-column node structure 9, and in order to ensure that the reinforced concrete slab-column node structure 9 is in close contact with the furnace body, a flexible refractory layer 10 is filled between the furnace body 14 and the slab-column node structure 9, and the flexible refractory material 10 is made of refractory fiber cotton; a load weight 8 is arranged on the slab surface of the reinforced concrete slab-column node structure 9, and the edge of the slab surface of the reinforced concrete slab-column node structure 9 is connected to the in-plane constraint device; a fire viewing hole 13 is arranged on the side wall of the furnace body.

[0024] In the fire resistance test mechanism of the in-plane restrained reinforced concrete slab-column node structure of the present embodiment, the in-plane restraint device includes a support column 1, a reaction beam 2, a slide rail 3, a pulley 4, a tension and compression sensor 5, a grooved connector 6, and a hinge support 7. A total of four support columns 1 are provided, which are respectively vertically arranged at the four corners of the fire test furnace, and their bottom ends are fixedly connected to the ground, and their upper parts are respectively fixedly connected to the horizontally arranged reaction beams 2; at least two grooved connectors 6 are symmetrically arranged on the plate edge at the relative position of the reinforced concrete slab-column node structure 9, such as Figure 1 As shown, the four sides of the plate-column node structure are provided with in-plane constraints. In the actual test design, the corresponding number of in-plane constraint devices can be provided according to the requirements; the grooved connector 6 is a channel steel structure near the side section of the plate, and its groove size matches the plate thickness size. The grooved connector at the other end is bolted to the tension and compression sensor 5 along the length direction of the connector, and one end of the tension and compression sensor 5 is connected to the pulley assembly 4 through the support 7, and the pulley assembly is installed on the slide rail 3, and the slide rail 3 is fixedly connected to the reaction beam 2; the support 7 adopts a universal hinge support. There are 4 reaction beams, which are fixedly connected to the support column 1 and form an overall frame structure.

[0025] In a fire resistance test mechanism for an in-plane constrained reinforced concrete slab-column node structure of the present embodiment, the fire test furnace includes a furnace bottom 15, an oil supply pipeline 12, a water circulation pipeline 20, a smoke exhaust duct 16, a thermocouple 11, an ignition nozzle 19, an automatic ignition computer control system 21 and a line pipeline 17. The thermocouple 11 is arranged on the inner wall of the furnace near the ignition nozzle 19. The oil supply pipeline 12 surrounding the furnace body forms a loop with an external oil tank 23. Each ignition nozzle 19 is provided with a fan 18, and each fan 18 is provided with an oil pump connected to the oil supply pipeline 12. The smoke exhaust duct 16 is provided with a heat exchanger 17, and the heat exchanger 17 is provided with a heat exchanger 17. The duct is arranged underground, and at least one smoke exhaust port 22 is arranged at the bottom of the furnace; the smoke exhaust duct 16 is connected with the interior of the furnace body 14 through the smoke exhaust port 22, and the smoke generated during the test is discharged to the outside through the external smoke exhaust duct, each smoke exhaust duct corresponds to a water pipe of a water circulation pipeline, and the automatic ignition computer control system is connected to the ignition nozzle; the automatic ignition computer control system 21 is in the furnace temperature control room next to the test furnace, and all the wires arranged in the furnace body are connected to the main control box in the control room through the line pipe 17, and finally the automatic ignition control is realized by the computer.

[0026] In a fire resistance test mechanism for an in-plane constrained reinforced concrete slab-column node structure of the present embodiment, the data acquisition system includes one or a combination of several of a temperature sensor, a displacement sensor and a force sensor; the data acquisition system can be divided into a concrete temperature and steel temperature acquisition system, a displacement acquisition system, and a boundary constraint data acquisition system for the slab-column node structure; the concrete temperature and steel temperature acquisition system includes thermocouples arranged in the reinforced concrete slab and the column, the embedded thermocouples are connected to the data acquisition instrument through wires, the data acquisition instrument is connected to a computer, the displacement acquisition system includes a displacement sensor, the displacement sensor is connected to the data acquisition instrument, and the boundary constraint acquisition system includes a reverse tension and compression sensor, and is connected to the data acquisition instrument.

[0027] In the embodiment of the present invention, a fire resistance test mechanism for an in-plane restrained reinforced concrete slab-column node structure is used. When in use, a prefabricated reinforced concrete slab-column node structure is placed on a furnace body, and the gap between the two is filled with refractory fiber cotton, and then a load weight is placed on the plate surface of the slab-column node structure; then, a corresponding surface restraint device is installed. After the installation is completed, the oil pump is controlled by the control system to extract oil from an external oil tank and transport it to the ignition nozzle, and the wind is sent to the ignition nozzle by the fan, and then the ignition nozzle is controlled to ignite and then sprayed into the furnace body, wherein an armored K-type thermocouple is arranged at a position near the ignition nozzle on the inner wall of the furnace body. Through the measurement and feedback of this thermocouple, the control system controls the temperature in the furnace to rise according to the set heating curve. At the same time, through other data acquisition systems, relevant test data are collected, and the internal situation can be observed through the fire viewing hole; after the test is completed, the collected data can be analyzed. Since horizontal constraints are added to the plate surface of the slab-column node structure, the interaction between adjacent plate surfaces and columns of the slab-column node structure in a real fire can be approximately considered through this constraint method, and then the real fire resistance performance of the slab-column node structure can be deeply analyzed.

[0028] The above embodiments should not limit the present invention in any way, and any technical solutions obtained by equivalent replacement or equivalent conversion shall fall within the protection scope of the present invention.

Claims

1. A fire resistance test mechanism for in-plane restrained reinforced concrete slab-column joint structure, characterized by: It comprises a plate-column node structure, a fire test furnace, and an in-plane restraint device; the fire test furnace comprises a furnace body with an upper end opening; the plate-column node structure covers the upper end of the furnace body; the in-plane restraint device acts on the edge of the plate-column node structure to provide restraint for the plate-column node structure; The in-plane restraint device comprises a first fixing portion and a second fixing portion; the first fixing portion is used to be fixedly connected to the edge of the plate-column node structure; the second fixing portion is used to provide an external fixing point for the first fixing portion; The second fixing part includes a plurality of support columns and a plurality of reaction beams; the support columns are in a fixed state; the reaction beam is installed and fixed between two adjacent support columns; the reaction beam is horizontally arranged and located near the edge of the plate-column node structure, and is used to provide an external fixing point, and one end of the first fixing part is fixedly connected to the edge of the plate-column node structure, and the other end is installed and connected to the reaction beam; A slide rail is installed on the reaction beam; a support is provided at one end of the first fixing portion; a pulley assembly is installed on the support; and the pulley assembly is assembled in the slide rail; The first fixing part includes a tension and compression sensor and a connecting piece; one end of the tension and compression sensor is hinged to the support, and the other end is connected to one end of the connecting piece; the other end of the connecting piece is fixedly connected to the edge of the plate-column node structure; the connecting piece is a groove-type connecting piece.

2. The fire resistance test mechanism for in-plane restrained reinforced concrete slab-column joint structure according to claim 1, characterized in that: A load weight is also arranged on the top surface of the plate-column node structure, and a flexible refractory layer is also arranged between the upper end surface of the furnace body and the plate-column node structure to make the plate-column node structure in close contact with the furnace body.

3. The fire resistance test mechanism for in-plane restrained reinforced concrete slab-column joint structure according to claim 2, characterized in that: The fire test furnace also includes an oil supply pipeline surrounding the furnace body and a plurality of ignition nozzles mounted on the outer wall of the furnace body. The oil supply pipeline forms a loop with an external oil tank. A fan is provided at each ignition nozzle, and an oil pump connected to the oil supply pipeline is provided at each fan.

4. The fire resistance test mechanism for in-plane restrained reinforced concrete slab-column joint structure according to claim 3, characterized in that: The fire test furnace also includes a water circulation pipeline and at least one smoke exhaust duct; the furnace body has a furnace bottom; the smoke exhaust duct is arranged below the furnace bottom, and the furnace bottom is also provided with at least one smoke exhaust port; the smoke exhaust duct is connected to the interior of the furnace body through the smoke exhaust port; the water circulation pipeline is installed on the outside of each smoke exhaust duct.

5. The fire resistance test mechanism for in-plane restrained reinforced concrete slab-column joint structure according to claim 4, characterized in that: The fire test furnace also includes a data acquisition device, which includes one or a combination of several of a temperature sensor, a displacement sensor and a force sensor; there are multiple temperature sensors, among which at least one temperature sensor is arranged inside the furnace body, and at least one temperature sensor is pre-buried in the column node structure; the force sensor includes at least a tension and compression sensor.

6. The fire resistance test mechanism for in-plane restrained reinforced concrete slab-column joint structure according to claim 5, characterized in that: The test mechanism also includes a control system, which is electrically connected to the data acquisition device, the oil pump, the ignition nozzle, and the fan respectively; the control system is configured to receive signal data from the data acquisition device, and is also configured to output control signals to the oil pump, the ignition nozzle, and the fan.

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