A field test system for concrete T-beams after fire high temperature
By loading and measuring the concrete T-beams in the field after a fire, the problem of assessing internal damage to concrete bridge structures under high temperatures after a fire was solved, and a scientific reinforcement solution was provided to ensure structural safety and performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHINA STATE RAILWAY GRP CO LTD
- Filing Date
- 2025-05-22
- Publication Date
- 2026-06-09
AI Technical Summary
Existing technologies cannot effectively monitor and test the temperature field and damage inside railway concrete bridge structures under high temperatures during fires, making it difficult to assess the structural safety and durability after a fire.
A field testing system for concrete T-beams after high-temperature fire is provided, including a loading device and a measuring device, for evaluating the performance of damaged concrete T-beams before reinforcement. The system is loaded by a locomotive, a heavy-duty train or concrete blocks, and measures parameters such as maximum crack size, maximum displacement and deformation using multiple measuring points.
It enables performance evaluation of concrete T-beams after a fire, provides scientific reinforcement solutions, ensures structural safety and performance, and is suitable for field testing of railway bridges.
Smart Images
Figure CN224341365U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of road and bridge testing technology, and in particular to a field testing system for concrete T-beams after high temperatures following a fire. Background Technology
[0002] Railways are a major public infrastructure and lifeline project related to national security, economic lifeline, and people's livelihood. By the end of 2023, the total operating mileage of railways in China reached 159,000 kilometers, including 45,000 kilometers of high-speed rail. The number of railway bridges has also increased rapidly with the extension of railways, reaching a total of 92,000 bridges with a cumulative length of 31,000 kilometers. my country's high-speed rail lines are mostly constructed using a "bridge-instead-of-road" approach. Bridges account for an average of about 50% of the mileage of existing high-speed rail lines, reaching as high as 91% in some areas. Commonly used prestressed concrete simply supported beam bridges account for 94% of the total bridge mileage.
[0003] As the scope of railway construction and operation gradually expands, and the "eight vertical and eight horizontal" high-speed rail network is about to take shape, railway bridge operations face a complex environment, with various types of major disasters having a significant impact, among which fire is a major one. Prestressed concrete railway bridges, during their long service life, are highly likely to encounter extreme fire loads, leading to severe structural damage or even collapse, posing a serious threat to line operation and personal safety. This represents a significant challenge for prestressed concrete railway bridges in operation.
[0004] In recent years, fires have frequently occurred along railway bridges, which have seriously affected the structure of railway concrete bridges. Under the high temperature of the fire, the structure has suffered damage such as concrete spalling, concrete hollowing and cracking, exposed steel bars and exposed steel strands.
[0005] Under the high temperature of a fire, the strength, stiffness, and durability of the concrete, steel bars, and steel strands in the railway concrete box girder structure all degrade, resulting in a decline in the overall performance of the box girder structure. This affects the safety and serviceability of the structure, and in severe cases, it can lead to the collapse of the bridge structure. In general, railway concrete box girders will be damaged and need to be reinforced and repaired before they can continue to be used.
[0006] High temperatures from a fire are conducted from the surface of the beam to its interior via heat conduction. The combined effects of various factors result in a highly complex temperature field distribution within the concrete box girder structure. Fire is an accidental and sudden disaster, and under high temperatures, typical damage characteristics such as concrete spalling, exposed rebar, and exposed steel strands can occur. Due to the accidental nature of fires, it is impossible to monitor and test the temperature field and damage of the concrete, rebar, and steel strands inside the structure under the high temperatures of a fire. Therefore, it is necessary to conduct high-temperature fire tests to test the material and structural performance after experiencing high temperatures, in order to scientifically analyze the damage to the concrete beams after experiencing high temperatures, and to provide technical support for assessing the structural safety and durability of concrete beams after being exposed to fire. Summary of the Invention
[0007] This application provides a field testing system for concrete T-beams damaged by high temperatures after a fire, in order to solve the problem in related technologies of how to conduct field tests on damaged concrete T-beams after high temperatures after a fire.
[0008] This application provides a field testing system for concrete T-beams damaged by high temperatures after a fire. The field testing system is used for performance evaluation of the damaged concrete T-beams before reinforcement. The field testing system includes:
[0009] A loading device is provided on the damaged concrete T-beam and loads and unloads the damaged concrete T-beam proportionally within at least one loading cycle.
[0010] A measuring device for measuring and acquiring parameters for performance evaluation of the damaged concrete T-beam during at least one loading cycle.
[0011] In one embodiment of the field testing system for concrete T-beams after high-temperature fire according to this utility model, the parameters for performance evaluation include the maximum crack size of the damaged concrete T-beam during at least one loading cycle, and the maximum displacement and maximum deformation of a portion of the damaged concrete T-beam during at least one loading cycle.
[0012] In one embodiment of the field testing system for concrete T-beams after high-temperature fire according to this utility model, the loading device uses a locomotive, a heavy-duty train, or a concrete block for loading.
[0013] In one embodiment of the field testing system for concrete T-beams after high-temperature fire according to this utility model, the measuring device includes multiple concrete displacement measuring points and multiple concrete strain measuring points.
[0014] In one embodiment of the field testing system for concrete T-beams after high-temperature fire according to this utility model, the measuring device further includes dynamic performance measuring points and / or vibration characteristic measuring points.
[0015] In one embodiment of the field testing system for concrete T-beams after high-temperature fire according to this utility model, the loading device includes three loading cycles, wherein the maximum load is twice the initial load.
[0016] In one embodiment of the field testing system for concrete T-beams after high temperature following a fire, the loading device includes a first loading cycle, a second loading cycle, and a third loading cycle, wherein the load applied in each of the second and third loading cycles is greater than the load applied in each of the first loading cycle.
[0017] In one embodiment of the field testing system for concrete T-beams after high-temperature fire according to this utility model, the loading device includes a first loading cycle, a second loading cycle, and a third loading cycle, wherein the number of loading cycles in the second and third loading cycles is greater than the number of loading cycles in the first loading cycle.
[0018] In one embodiment of the field testing system for concrete T-beams after high-temperature fire according to this utility model, the field testing system further includes a remote control device. The remote control device is connected to the loading device via a signal connection, and the remote control device is used to control the loading device for each loading cycle of the damaged concrete T-beam.
[0019] In one embodiment of the field testing system for concrete T-beams after high-temperature fire according to this utility model, the field testing system further includes a remote control device. The remote control device is connected to the measuring device via a signal connection, and the remote control device is used to control the measuring device to acquire the parameters used for performance evaluation. Attached Figure Description
[0020] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.
[0021] Figure 1 This is a schematic diagram of the loading test of the field test system for concrete T-beams after high temperature from a fire, according to this utility model.
[0022] Figure 2 The loading and testing parameters are for the field testing system of this utility model for concrete T-beams after high temperature from a fire.
[0023] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments.
[0024] Explanation of reference numerals in the attached figures
[0025] 100. Concrete T-beam; 200. Loading device; 300. Measuring device. Detailed Implementation
[0026] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.
[0027] The terms "first," "second," "third," "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in a sequence other than those illustrated or described herein.
[0028] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, such that a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or apparatus.
[0029] Figure 1 This is a schematic diagram of the loading test of the field test system for a concrete T-beam 100 after a fire and high temperature, as described in this utility model. Figure 1 As shown, the field testing system for concrete T-beams 100 damaged by fire and high temperature provided by this utility model is used for performance evaluation of concrete T-beams 100 damaged by fire and high temperature before reinforcement. The field testing system includes a loading device 200 and a measuring device 300.
[0030] The loading device 200 is installed on the damaged concrete T-beam 100 and loads and unloads the damaged concrete T-beam 100 proportionally within at least one loading cycle.
[0031] The measuring device 300 is used to measure and acquire parameters of the damaged concrete T-beam 100 for performance evaluation during at least one loading cycle.
[0032] After the concrete T-beam 100 is subjected to high temperatures from a fire, its structure and function are severely damaged, and further damage could endanger structural safety. Therefore, it is necessary to take reinforcement measures immediately or as soon as possible. Before reinforcing the concrete T-beam 100, the field testing system of this utility model for concrete T-beams 100 after high temperatures from a fire should be used to obtain parameters for evaluating the performance of the concrete T-beam 100, so as to further determine the reinforcement scheme and ensure the safety of subsequent use.
[0033] Figure 1 The diagram illustrates the testing procedures during a field test of a railway concrete T-beam exposed to high temperatures, including concrete displacement and strain measurement points. The number of measurement points can be adjusted according to actual needs. Strain and displacement testing are mandatory items in the field test of this invention. Dynamic performance and vibration characteristic measurement points can also be set according to the structural characteristics of the concrete T-beam 100.
[0034] In one embodiment of the present invention, the parameters for performance evaluation include the maximum crack size of the damaged concrete T-beam 100 during at least one loading cycle, and the maximum displacement and maximum deformation of a portion of the damaged concrete T-beam 100 during at least one loading cycle.
[0035] In one embodiment of this utility model, the loading device 200 uses a locomotive, a heavy-duty train, or a concrete block for loading. In the aforementioned field test, a concrete T-beam 100 that had undergone high temperatures following a fire was used for performance testing. The loading device 200 can be loaded using a locomotive or a heavy-duty train, and its loading efficiency should not be less than 0.8.
[0036] In one embodiment of this utility model, the measuring device 300 includes multiple concrete displacement measuring points and multiple concrete strain measuring points.
[0037] In one embodiment of the present invention, the measuring device 300 further includes a dynamic performance measuring point and a vibration characteristic measuring point.
[0038] Figure 2 The loading and testing parameters of the field testing system for a concrete T-beam 100 after a fire and high temperature are as follows: Figure 2 As shown, in the loading priority process of the field test of the 100-ton railway concrete T-beam after high temperature fire, the load level of the field specimen during the loading process can be divided according to the design load under different load combination conditions. The entire loading process is designed as three cycles. The first cycle is the initial loading cycle. The maximum loading value in the second and third cycles is the maximum value in the test load, which is used to evaluate the stability of the structural state.
[0039] exist Figure 2In this process, obtaining the maximum size of the crack, displacement test, and strain test data are the priority test process data to be completed during the field test loading and acquisition work. If it is inconvenient to observe the crack condition on site, observation can be carried out at the maximum value of each cycle of load.
[0040] In one embodiment of this utility model, the loading device 200 includes three loading cycles, wherein the maximum load is twice the initial load. By setting the maximum load to be greater than the initial load and a multiple of the initial load, the parameters of the concrete T-beam 100 can be accurately tested. This allows technicians to accurately evaluate the performance of the T-beam based on the test parameters, providing support for subsequent reinforcement schemes.
[0041] In one embodiment of the present invention, the loading device 200 includes a first loading cycle, a second loading cycle, and a third loading cycle, wherein the load amount in each of the second loading cycle and the third loading cycle is greater than the load amount in each of the first loading cycle.
[0042] In other embodiments of this utility model, multiple loading cycles can be set, such as a fourth loading cycle and a fifth loading cycle, which can be adjusted by technicians according to the actual situation on site.
[0043] In one embodiment of the field testing system for concrete T-beams 100 after high temperature following a fire, the loading device 200 includes a first loading cycle, a second loading cycle, and a third loading cycle, wherein the number of loading cycles in the second and third loading cycles is greater than the number of loading cycles in the first loading cycle.
[0044] In one embodiment of the field testing system for a concrete T-beam 100 after a fire and high temperature, the field testing system further includes a remote control device. The remote control device is connected to the loading device 200 via a signal connection. The remote control device is used to control the loading device 200 for each loading cycle of the damaged concrete T-beam.
[0045] In one embodiment of the field testing system for concrete T-beams 100 after high-temperature fire according to this utility model, the field testing system further includes a remote control device. The remote control device is connected to the measuring device 300 via a signal connection. The remote control device is used to control the measuring device 300 to acquire the parameters used for performance evaluation.
[0046] By setting up a remote control device, the loading test can be completed in a safe area away from the concrete T-beam 100. The loading device 200 and measuring device 300 can be remotely controlled, and technicians can safely obtain the required test parameters.
[0047] This utility model discloses a field test scheme for the structural performance of a railway concrete T-beam 100 after a fire and high temperature. The scheme includes a loading device 200, a measuring device 300, and a test plan. The test object is a concrete T-beam 100 damaged after a fire and high temperature. The loading device 200 is used to load the damaged concrete T-beam 100, preferably using a locomotive, a heavy-duty train, or a concrete block. The measuring device 300 is used to measure the load and displacement during the field test. The test plan specifies the field test procedure based on the structural characteristics of the railway concrete T-beam.
[0048] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the utility models disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.
[0049] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.
Claims
1. A field testing system for concrete T-beams after high-temperature fire exposure, characterized in that, The field testing system is used for performance evaluation of concrete T-beams damaged by high temperatures after a fire, before reinforcement. The field testing system includes: A loading device is provided on the damaged concrete T-beam and loads and unloads the damaged concrete T-beam proportionally within at least one loading cycle. A measuring device for measuring and acquiring parameters for performance evaluation of the damaged concrete T-beam during at least one loading cycle.
2. The field testing system for concrete T-beams after high-temperature fire exposure as described in claim 1, characterized in that, The parameters used for performance evaluation include: The maximum crack size of the damaged concrete T-beam during at least one loading cycle, the maximum displacement and maximum deformation of a portion of the damaged concrete T-beam during at least one loading cycle.
3. The field testing system for concrete T-beams after high-temperature fire exposure as described in claim 2, characterized in that, The loading device uses a locomotive, a heavy-duty train, or concrete blocks for loading.
4. The field testing system for concrete T-beams after high-temperature fire exposure as described in claim 2, characterized in that, The measuring device includes multiple concrete displacement measuring points and multiple concrete strain measuring points.
5. The field testing system for concrete T-beams after high-temperature fire exposure according to claim 4, characterized in that, The measuring device also includes dynamic performance measuring points and / or vibration characteristic measuring points.
6. The field testing system for concrete T-beams after high-temperature fire exposure according to any one of claims 1-5, characterized in that, The loading device includes three loading cycles, wherein the maximum load is twice the initial load.
7. The field testing system for concrete T-beams after high-temperature fire exposure as described in claim 6, characterized in that, The loading device includes a first loading cycle, a second loading cycle, and a third loading cycle, wherein the load amount in each of the second loading cycle and the third loading cycle is greater than the load amount in each of the first loading cycle.
8. The field testing system for concrete T-beams after high-temperature fire exposure according to claim 6, characterized in that, The loading device includes a first loading cycle, a second loading cycle, and a third loading cycle, wherein the number of loading cycles in the second loading cycle and the third loading cycle is greater than the number of loading cycles in the first loading cycle.
9. The field testing system for concrete T-beams after high-temperature fire exposure according to claim 6, characterized in that, The field testing system also includes a remote control device, which is connected to the loading device via a signal. The remote control device is used to control the loading device for each loading cycle of the damaged concrete T-beam.
10. The field testing system for concrete T-beams after high-temperature fire exposure according to claim 9, characterized in that, The field testing system also includes a remote control device, which is connected to the measuring device via a signal. The remote control device is used to control the measuring device to acquire the parameters used for performance evaluation.