A test method for fatigue temperature rise characteristics of polymer grouting materials

Abstract

The present invention relates to a testing method for fatigue temperature rise characteristics of polymer grouting materials. The testing method for fatigue temperature rise characteristics of polymer grouting materials includes the following steps: making a test piece of polymer grouting materials, fixing a constant temperature device on an electro-hydraulic servo fatigue testing machine through a fixed structure, installing the test piece of polymer grouting materials on the electro-hydraulic servo fatigue testing machine, electrically connecting a probe sensor to a paperless recorder, turning on the constant temperature device, setting different ambient temperatures, performing tensile or compression fatigue performance tests, and recording time-stress-strain data; at the same time, recording the temperature changes at the center and outer surface of the test piece, and collecting time-temperature data. The testing method for fatigue temperature rise characteristics of polymer grouting materials of the present invention has a high degree of automation, which overcomes the difficulties that traditional test methods cannot simulate ambient temperature and cannot monitor the exothermic temperature rise behavior of the test piece during fatigue and the simultaneous monitoring of the internal and surface temperatures of the test piece.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer grouting material testing, and in particular relates to a method for testing fatigue temperature rise characteristics of a polymer grouting material. Background Art

[0002] With the massive construction of transportation infrastructure, my country has entered an era of construction, maintenance and repair. The maintenance and reinforcement of transportation infrastructure requires shorter maintenance time and better mechanical properties. Polymer grouting materials have a short and controllable reaction time, strong injectability, high strength and good durability. They can achieve rapid non-destructive repair and are widely used in the field of maintenance and reinforcement of transportation infrastructure.

[0003] my country has a vast territory, and its transportation infrastructure is in different ambient temperatures. In addition, during the operation and maintenance of transportation infrastructure, it is often subjected to cyclic compression loads or cyclic tension. The response of polymer grouting materials to cyclic loads is relatively complex. Polymer grouting materials are nonlinear viscoelastic materials with poor thermal conductivity. Their mechanical properties are particularly sensitive to temperature, and the exothermic characteristics of the fatigue process will have a certain impact on the original ambient temperature, especially in frozen soil environments. The impact is more significant. At present, the fatigue exothermic temperature rise behavior of polymer grouting materials is unknown, and the influence of ambient temperature on the fatigue exothermic temperature rise of polymer grouting materials is unknown. Therefore, it is necessary to study the fatigue exothermic temperature rise characteristics of polymer grouting materials at different temperatures.

[0004] At present, there is little research on this issue. During the fatigue process, there is a large temperature difference between the inside and outside of the polymer grouting material, and as the size of the test specimen changes, the temperature difference becomes more significant. Therefore, how to provide a test method that is simple to operate and has good simulation effects is an urgent problem that researchers need to solve. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a method for testing fatigue temperature rise characteristics of polymer grouting materials.

[0006] The technical solution of a method for testing fatigue temperature rise characteristics of a polymer grouting material of the present invention is:

[0007] A method for testing fatigue temperature rise characteristics of polymer grouting materials, wherein the devices used in the test include a constant temperature device and an electro-hydraulic servo fatigue testing machine;

[0008] The thermostatic device comprises a thermostatic box, the thermostatic box is provided with a fixing structure for fixing with the electro-hydraulic servo fatigue testing machine, the upper and lower sides of the thermostatic box are provided with coaxially arranged through holes for the power shaft of the electro-hydraulic servo fatigue testing machine to penetrate, the thermostatic box is provided with an infrared temperature sensor, the outer side of the thermostatic device is provided with a paperless recorder, the infrared temperature sensor is electrically connected to the paperless recorder, and the testing method comprises the following steps:

[0009] The polymer grouting material is poured into molds of different shapes and sizes to make polymer grouting material test pieces of different shapes and sizes. During the pouring process, a probe temperature sensor is placed at the center of the pouring mold so that the probe temperature sensor is pre-buried in the polymer grouting material test piece;

[0010] The thermostatic device is fixed on the electro-hydraulic servo fatigue testing machine through a fixing structure, so that the power shaft of the electro-hydraulic servo fatigue testing machine is inserted into the thermostatic box through the perforation;

[0011] Install the polymer grouting material test piece on the electro-hydraulic servo fatigue testing machine, electrically connect the probe sensor to the paperless recorder, turn on the constant temperature device, set different ambient temperatures, turn on the paperless recorder, and when the temperature displayed by the paperless recorder is consistent with the ambient temperature, start the electro-hydraulic servo fatigue testing machine, set the fatigue test parameters according to the test requirements, conduct tensile or compression fatigue performance tests, and record time-stress-strain data; at the same time, record the temperature changes at the center and outer surface of the test piece and collect time-temperature data.

[0012] As a further optimization of the above technical solution, when preparing the polymer grouting material test pieces, two-component polyurethane grouting materials of different masses are evenly mixed in a 1:1 ratio and injected into the mold through a polymer grouting material grouting machine, and polymer grouting materials of different densities are poured. The solidified polymer grouting material is cut into multiple polymer grouting material test pieces on a machine tool.

[0013] As a further optimization of the above technical solution, the upper and lower ends of the polymer grouting material to be tested are mounted on the power shaft of the electro-hydraulic servo fatigue testing machine by a fixture to ensure that the polymer to be tested does not tilt.

[0014] As a further optimization of the above technical solution, during the test, the ambient temperatures simulated by the constant temperature device included -30℃, -20℃, -10℃, 0℃, 10℃, 20℃, and 30℃.

[0015] As a further optimization of the above technical solution, the test parameters of the electro-hydraulic servo fatigue testing machine are: frequency is 10HZ; waveform is a half-sine wave, stress ratio is 0.1; stress levels are 0.9, 0.8, 0.7, and 0.6.

[0016] As a further optimization of the above technical solution, the fixing structure includes upper side fixing holes respectively arranged on the upper side of the constant temperature box and lower side fixing holes respectively arranged on the lower side of the constant temperature box, and the constant temperature box has an infrared temperature sensor socket for inserting the infrared temperature sensor.

[0017] The present invention provides a method for testing fatigue temperature rise characteristics of polymer grouting materials. Compared with the prior art, the present invention has the following beneficial effects:

[0018] The present invention uses a thermostat in combination with an electro-hydraulic servo fatigue testing machine to simulate the cyclic compression and cyclic tensile fatigue performance test of a polymer grouting material to be tested under certain ambient temperature conditions, and collects the exothermic temperature rise characteristics of the polymer grouting material. The probe temperature sensor can detect the internal center temperature of the polymer grouting material to be tested in real time, and the infrared temperature sensor can monitor the temperature change of the outer surface of the polymer grouting material to be tested in real time. During the test, different ambient temperatures are simulated, and polymer grouting materials to be tested are used in different sizes and shapes. According to the test results, the fatigue temperature rise characteristics of the same polymer grouting material to be tested at different ambient temperatures and the fatigue temperature rise characteristics of different polymer grouting materials to be tested at the same ambient temperature can be analyzed. This provides a reference for studying the evolution process of the fatigue exothermic temperature rise characteristics of polymer grouting materials at different ambient temperatures. The thermostat used in the present invention has a simple structure, is easy to use, has high control accuracy, and has good reliability. The test method for fatigue temperature rise characteristics of polymer grouting materials of the present invention has a high degree of automation, and overcomes the difficulties that traditional test methods cannot simulate ambient temperature and cannot monitor the heat release and temperature rise behavior of the test piece during fatigue and simultaneously monitor the internal and surface temperatures of the test piece. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of a constant temperature device in a method for testing fatigue temperature rise characteristics of a polymer grouting material of the present invention;

[0020] Figure 2 It is a schematic structural diagram of a polymer grouting material to be tested after being compressed in the test method of the fatigue temperature rise characteristics of the polymer grouting material of the present invention;

[0021] Figure 3 It is a structural schematic diagram of a polymer grouting material to be tested after being stretched in the test method of the fatigue temperature rise characteristics of the polymer grouting material of the present invention;

[0022] Figure 4 It is a flow chart of a method for testing fatigue temperature rise characteristics of a polymer grouting material of the present invention;

[0023] In the figure: 1. Constant temperature box; 2. Upper side fixing hole; 3. Lower side fixing hole; 4. Through hole; 5. Infrared temperature sensor jack; 6. Infrared temperature sensor; 7. Paperless recorder; 8. Polymer grouting material to be tested piece; 9. Probe temperature sensor. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments:

[0025] The specific embodiment of the test method of the fatigue temperature rise characteristics of the polymer grouting material of the present invention is as follows: Figures 1 to 4 As shown, the devices used in the test include a constant temperature device and an electro-hydraulic servo fatigue testing machine.

[0026] The constant temperature device includes a constant temperature box 1, and the constant temperature box 1 is provided with a fixing structure for fixing with the electro-hydraulic servo fatigue testing machine. The upper and lower sides of the constant temperature box 1 are provided with coaxially arranged through holes 4 for allowing the power shaft of the electro-hydraulic servo fatigue testing machine to penetrate. An infrared temperature sensor is provided in the constant temperature box 1, and a paperless recorder 7 is provided on the outside of the constant temperature device. The infrared temperature sensor 6 is electrically connected to the paperless recorder 7, and the paperless recorder 7 can continuously record the data collected by the infrared temperature sensor. Preferably, the fixing structure includes upper side fixing holes 2 respectively arranged on the upper side of the constant temperature box 1 and lower side fixing holes 3 arranged on the lower side of the constant temperature box 1, and the constant temperature box 1 has an infrared temperature sensor jack 5 for inserting the infrared temperature sensor 6. When the constant temperature box 1 is installed on the electro-hydraulic servo fatigue testing machine through the upper side fixing holes 2 and the lower side fixing holes 3, the power shaft of the electro-hydraulic servo fatigue testing machine penetrates into the constant temperature box 1 through the through hole 4. In order to improve the thermal insulation effect of the constant temperature box 1, a sealant is used to bond the gap between the power shaft and the through hole 4. Preferably, the central axis of the infrared temperature sensor through hole 4 is coaxial with the center of the polymer grouting material test piece 8, the infrared temperature sensor detection angle range covers the entire surface of the test piece, and the infrared temperature sensor can continuously measure the temperature of the irradiated surface.

[0027] The testing method of the fatigue temperature rise characteristics of the polymer grouting material of the present invention comprises the following steps:

[0028] (1) pouring polymer grouting into molds of different shapes and sizes to make polymer grouting material test pieces 8 of different shapes and sizes. During the pouring process, placing a probe temperature sensor 9 at the center of the pouring mold so that the probe temperature sensor 9 is pre-buried in the polymer grouting material test piece 8;

[0029] (2) Fixing the thermostatic device on the electro-hydraulic servo fatigue testing machine through a fixing structure, so that the power shaft of the electro-hydraulic servo fatigue testing machine passes through the through hole 4 and penetrates into the thermostatic box 1;

[0030] (3) Install the polymer grouting material test piece 8 on the electro-hydraulic servo fatigue testing machine, electrically connect the probe sensor to the paperless recorder 7, turn on the constant temperature device, set different ambient temperatures, turn on the paperless recorder 7, and when the temperature displayed by the paperless recorder 7 is consistent with the ambient temperature, start the electro-hydraulic servo fatigue testing machine, set fatigue test parameters according to the test requirements, perform tensile or compressive fatigue performance tests, and record time-stress-strain data; at the same time, record the temperature changes at the center and outer surface of the test piece and collect time-temperature data.

[0031] In this embodiment, two-component polyurethane grouting materials of different masses are uniformly mixed and injected in a ratio of 1:1 through a small polymer grouting material grouting machine, and different densities (0.2g / cm3, 0.3g / cm3, 0.4g / cm3, 0.5g / cm3) of polymer grouting materials are cast through a specific mold (inner diameter D40mm, height H250mm), and cut into 3 polymer grouting material specimens of D40*H80mm on a precision machine tool. At the same time, the probe temperature sensor 9 (temperature measurement range: ±800℃, accuracy ±1%) is pre-embedded in the polymer grouting material compression specimen, ensuring that the probe temperature sensor 9 (temperature measurement range: ±800℃, accuracy ±1%) is placed in the center of the polymer grouting material specimen. During the casting process, the probe sensor (temperature measurement range: ±800℃, accuracy ±1%) probe is cast in the center of the polymer grouting material specimen.

[0032] In this embodiment, the upper and lower ends of the polymer grouting material to be tested piece 8 are mounted on the power shaft of the electro-hydraulic servo fatigue testing machine by means of a clamp to ensure that the polymer to be tested piece does not tilt.

[0033] In this embodiment, during the test, the ambient temperatures simulated by the thermostat include -30°C, -20°C, -10°C, 0°C, 10°C, 20°C, and 30°C. The test parameters of the electro-hydraulic servo fatigue testing machine are: frequency is 10HZ; waveform is half sine wave, stress ratio is 0.1; stress levels are 0.9, 0.8, 0.7, and 0.6.

[0034] The present invention uses a constant temperature device in conjunction with an electro-hydraulic servo fatigue testing machine to simulate the cyclic compression and cyclic tensile fatigue performance test of a polymer grouting material to be tested 8 under certain ambient temperature conditions, and collects the exothermic temperature rise characteristics of the polymer grouting material. The probe temperature sensor 9 can detect the internal center temperature of the polymer grouting material to be tested 8 in real time, and the infrared temperature sensor 6 can monitor the temperature change of the outer surface of the polymer grouting material to be tested 8 in real time. During the test process, different ambient temperatures are simulated, and polymer grouting materials to be tested 8 of different sizes and shapes are used. According to the test results, the fatigue temperature rise characteristics of the same polymer grouting material to be tested 8 at different ambient temperatures and the fatigue temperature rise characteristics of different polymer grouting materials to be tested 8 at the same ambient temperature can be analyzed. This provides a reference for studying the evolution process of the fatigue exothermic temperature rise characteristics of polymer grouting materials at different ambient temperatures. The constant temperature device used in the present invention has a simple structure, is easy to use, has high control accuracy, and has good reliability. The test method for fatigue temperature rise characteristics of polymer grouting materials of the present invention has a high degree of automation, and overcomes the difficulties that traditional test methods cannot simulate ambient temperature and cannot monitor the heat release and temperature rise behavior of the test piece during fatigue and simultaneously monitor the internal and surface temperatures of the test piece.

[0035] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for testing fatigue temperature rise characteristics of polymer grouting materials, characterized in that: The equipment used in the test included a constant temperature device and an electro-hydraulic servo fatigue testing machine; The thermostatic device comprises a thermostatic box, the thermostatic box is provided with a fixing structure for fixing with the electro-hydraulic servo fatigue testing machine, the upper and lower sides of the thermostatic box are provided with coaxially arranged through holes for the power shaft of the electro-hydraulic servo fatigue testing machine to penetrate, the thermostatic box is provided with an infrared temperature sensor, the outer side of the thermostatic device is provided with a paperless recorder, the infrared temperature sensor is electrically connected to the paperless recorder, and the testing method comprises the following steps: The polymer grouting material is poured into molds of different shapes and sizes to make polymer grouting material test pieces of different shapes and sizes. During the pouring process, a probe temperature sensor is placed at the center of the pouring mold so that the probe temperature sensor is pre-buried in the polymer grouting material test piece; The thermostatic device is fixed on the electro-hydraulic servo fatigue testing machine through a fixing structure, so that the power shaft of the electro-hydraulic servo fatigue testing machine is inserted into the thermostatic box through the perforation; Install the polymer grouting material test piece on the electro-hydraulic servo fatigue testing machine, electrically connect the probe sensor to the paperless recorder, turn on the constant temperature device, set different ambient temperatures, turn on the paperless recorder, and when the temperature displayed by the paperless recorder is consistent with the ambient temperature, start the electro-hydraulic servo fatigue testing machine, set the fatigue test parameters according to the test requirements, conduct tensile or compression fatigue performance tests, and record time-stress-strain data; at the same time, record the temperature changes at the center and outer surface of the test piece and collect time-temperature data.

2. The method for testing fatigue temperature rise characteristics of polymer grouting materials according to claim 1, characterized in that: When preparing the polymer grouting material test pieces, two-component polyurethane grouting materials of different masses are uniformly mixed in a 1:1 ratio and injected into a mold through a polymer grouting material grouting machine, and polymer grouting materials of different densities are poured. The cured polymer grouting material is cut into multiple polymer grouting material test pieces on a machine tool.

3. The method for testing fatigue temperature rise characteristics of polymer grouting materials according to claim 2, characterized in that: The upper and lower ends of the polymer grouting material to be tested are mounted on the power shaft of the electro-hydraulic servo fatigue testing machine by means of a clamp to ensure that the polymer to be tested does not tilt.

4. The method for testing fatigue temperature rise characteristics of polymer grouting materials according to claim 1, characterized in that: During the test, the ambient temperatures simulated by the constant temperature device included -30℃, -20℃, -10℃, 0℃, 10℃, 20℃, and 30℃.

5. The method for testing fatigue temperature rise characteristics of polymer grouting materials according to claim 1, characterized in that: The test parameters of the electro-hydraulic servo fatigue testing machine are: frequency is 10HZ; waveform is half sine wave, stress ratio is 0.1; stress levels are 0.9, 0.8, 0.7, and 0.

6.

6. The method for testing fatigue temperature rise characteristics of polymer grouting materials according to claim 1, characterized in that: The fixing structure comprises upper side fixing holes respectively arranged on the upper side of the thermostatic box and lower side fixing holes respectively arranged on the lower side of the thermostatic box. The thermostatic box is provided with an infrared temperature sensor jack for inserting the infrared temperature sensor.

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