Rock heat resistance boiling equipment based on dynamic monitoring and evaluation method thereof

Abstract

The invention discloses rock heat resistance boiling equipment based on dynamic monitoring and an evaluation method thereof. The equipment comprises a water supplementing system, a boiling system and a steam condensation reflux system, the method comprises the following steps that water is injected into a boiling box from a water supplementing box until the water level of the boiling box triggers a liquid level sensor II, and water is injected into the water supplementing box from a water source until the water level of the water supplementing box triggers a liquid level sensor I; the sample basket containing the rock sample is hooked by a lifting hook, so that the sample basket is suspended in the boiling box; water in the water supplementing tank and the boiling tank is heated, and in the whole heating process, water vapor in the boiling tank flows back to the boiling tank after passing through the steam condensation backflow system; in the whole boiling process, the weighing sensor monitors the mass change condition of the rock sample in real time, and after boiling is conducted every 2 h, the sample basket is taken out, photographed and put back until the boiling time reaches 36 h. The invention provides an innovative idea for monitoring the mass loss of the rock sample in real time based on water vapor backflow and buoyancy for the first time.

Description

Technical Field

[0001] The invention belongs to the technical field of rock thermal aging test, and in particular relates to a rock heat resistance boiling device based on dynamic monitoring and an evaluation method thereof. Background Art

[0002] In pavement construction, rock materials are widely used and important. As key materials for base layer construction, large-grained crushed stone, gravel and stone and other rock materials can significantly enhance the bearing capacity of the pavement and fix the roadbed, ensuring the stability and durability of the pavement. In asphalt concrete pavement construction, rock materials such as crushed stone, stone powder and slag are important components for preparing asphalt concrete, which not only enhances the strength and durability of asphalt concrete, but also improves the adhesion and flame retardancy of asphalt concrete. In cement concrete pavement construction, rock materials such as stone, sand and aggregate are essential for locking the shape of cement concrete and enhancing its strength. In addition, long strips of stone play a role in fixing the roadbed and preventing erosion in roadbed protection. Rock materials of various particle sizes and shapes also play a key role in filling cracks and potholes, enhancing the strength and flatness of the pavement in pavement repair. It can be seen that rock materials play an irreplaceable role in pavement construction, and the rational selection and use of rock materials are of great significance to ensuring the quality of the pavement and extending the service life of the pavement.

[0003] During the construction and operation of the road surface, the road surface is subjected to the combined effects of multiple environmental factors such as light, moisture and temperature. Rock materials are exposed to high temperature water immersion or natural environments such as sunlight and rain for a long time. If the heat resistance of the rock material is poor, spots and cracks will gradually appear on its surface. Further decay will cause the surface stone to peel off, and in severe cases, larger cracks and stone fractures will occur. Therefore, before using the rock material, it is necessary to test and evaluate the heat resistance of the rock material, and it can only be used after the test indicators fully meet the standards.

[0004] At present, traditional boiling boxes are usually used to test the heat resistance of rock materials. When conducting boiling tests, a heating furnace is needed to heat the boiling container to boiling, the test time needs to be manually controlled, and boiling water needs to be manually added, which has low work efficiency and high labor costs. Although the existing technology has also developed automated testing equipment, it still has some defects.

[0005] The invention patent with application publication number CN112255261A discloses an aggregate weathering resistance evaluation device for asphalt pavement and its working process. The device includes a container, a sample basket for accommodating materials is arranged inside the container, and a photographing device is arranged outside the container. During the test, the sample is automatically lifted, photographed, and lowered to the initial position at a set time interval. Although this technical solution improves the current situation of poor automation of boiling test instruments, it has the following technical problems: (1) Open the container cover, lift the sample basket, and take photos directly. After opening the cover, a large amount of water vapor comes out of the container, which will affect the photo effect; (2) When taking photos, water vapor comes out directly from the container without a condensation reflux process, resulting in inaccurate evaluation results; (3) The traditional weighing method is used to calculate the mass loss of the sample, without considering the influence of steam reflux on the test results. At the same time, only the mass loss after boiling for 36 hours is measured, which cannot reflect the real-time change of mass loss during the entire boiling process. Summary of the invention

[0006] In order to solve the problems existing in the prior art, the present invention provides a rock heat resistance boiling equipment based on dynamic monitoring, including a box, a water replenishment system, a boiling system, a steam condensation reflux system, a photographing area and a control system; the water replenishment system and the boiling system are arranged inside the box, and the steam condensation reflux system, the photographing area and the control system are arranged outside the box; the water replenishment system, the boiling system and the steam condensation reflux system are connected in sequence to form a water circulation; a water inlet is arranged on one side of the box, and a water outlet is arranged on the other side of the box, the water inlet is connected to the water replenishment system, and the water outlet is connected to the boiling system.

[0007] Preferably, the water replenishment system includes a water replenishment tank, a heating tube I, a temperature sensor I, a liquid level sensor I, a water inlet pipe, a water outlet pipe and an electric valve I; the heating tube I, the temperature sensor I and the liquid level sensor I are arranged inside the water replenishment tank, the water inlet pipe and the water outlet pipe are arranged at the bottom of the water replenishment tank, the water inlet pipe is connected to the water inlet, the water outlet pipe is connected to the boiling system, and the electric valve I is arranged on the water inlet pipe.

[0008] In any of the above schemes, it is preferred that the boiling system includes a boiling box, a heating tube II, a temperature sensor II, a liquid level sensor II, a liquid level sensor III, a water supply pipe, a drain pipe, a steam reflux pipe I, an electric valve II, a sample basket, a hook and a weighing sensor; the boiling box is located lower than the water supply tank in the vertical direction; the heating tube II, the temperature sensor II, the liquid level sensor II and the liquid level sensor III are arranged inside the boiling box, and the liquid level sensor II is located higher than the liquid level sensor III in the vertical direction; the water supply pipe is arranged on one side of the boiling box, and the water supply pipe is connected to the water outlet pipe, the steam reflux pipe I is arranged on the other side of the boiling box, and the steam reflux pipe I passes through the photographing area and is connected to the steam condensation reflux system, the drain pipe is arranged at the bottom of the boiling box, and the drain pipe is connected to the water outlet; the electric valve II is arranged on the water supply pipe, and a manual valve is arranged on the water outlet.

[0009] In any of the above schemes, preferably, the upper end of the hook is connected to the weighing sensor, and the lower end of the hook hooks the sample basket so that the sample basket is suspended inside the boiling box; the weighing sensor is connected to the steam condensation reflux system through a bracket.

[0010] In any of the above schemes, it is preferred that an insulation layer is provided between the outer wall and the inner wall of the boiling box, the inner cavity of the boiling box has a length of 346 mm, a width of 346 mm, and a height of 280 mm; the sample basket has a length of 300 mm, a width of 300 mm, and a height of 150 mm, and a rock sample is placed inside the sample basket; when the rock sample is in block shape, the bottom and side surfaces of the sample basket are frames with cross beams, and when the rock sample is in aggregate shape, the bottom and side surfaces of the sample basket are flat plates with circular holes.

[0011] In any of the above schemes, it is preferred that the steam condensation reflux system includes a steam collecting box, a condenser and a steam reflux pipe II; the steam collecting box is arranged above the boiling box, the bottom open end of the steam collecting box is tightly connected to the top open end of the boiling box, and a box door is arranged on the steam collecting box; the top of the steam collecting box is connected to one end of the condenser through a flange, the other end of the condenser is connected to one end of the steam reflux pipe II through a flange, and the other end of the steam reflux pipe II is connected to the steam reflux pipe I through the photographing area.

[0012] In any of the above solutions, preferably, the weighing sensor and the hook are located inside the steam collection box, and the bracket is fixed on the inner wall of the steam collection box.

[0013] In any of the above schemes, it is preferred that the photographing area includes a water collecting box and a support plate; the support plate is placed at the open end of the water collecting box, and the support plate is a flat plate with a circular hole; the bottom opening of the water collecting box is connected to the steam reflux pipe I, and the side opening of the water collecting box is connected to the steam reflux pipe II.

[0014] In any of the above schemes, it is preferred that the control system includes a control panel, a control module, a power switch, an emergency stop switch, a main equipment switch and a buzzer; the control panel, the power switch, the emergency stop switch, the main equipment switch and the buzzer are arranged on the box body, and the control module is integrated inside the control system; the control module is used to control the heating tube I, the heating tube II, the temperature sensor I, the temperature sensor II, the liquid level sensor I, the liquid level sensor II, the liquid level sensor III, the electric valve I, the electric valve II and the weighing sensor.

[0015] The present invention also provides a method for evaluating the heat resistance of rocks based on dynamic monitoring, using any of the above-mentioned rock heat resistance boiling equipment based on dynamic monitoring, and comprising the following steps in order:

[0016] Step 1: Assemble and connect the various components of the boiling equipment according to the design structure, debug the boiling equipment and check the sealing to ensure that it can be used normally during the boiling process;

[0017] Step 2: Connect the boiling device to the water source and power supply, turn on the main switch of the device and the power switch of the control system, and start the device and the control system;

[0018] Step 3: Open the electric valve Ⅰ and the electric valve Ⅱ, and the water enters the water supply tank through the water inlet and the water inlet pipe in turn, and then enters the boiling tank through the water outlet pipe and the water supply pipe in turn from the water supply tank, until the water level in the boiling tank triggers the liquid level sensor Ⅱ, and then close the electric valve Ⅱ;

[0019] Step 4: Water continues to flow into the water supply tank through the water inlet and the water inlet pipe in sequence until the water level in the water supply tank triggers the liquid level sensor Ⅰ, closing the electric valve Ⅰ;

[0020] Step 5: Open the door of the steam collection box, put the sample basket containing the rock sample into the boiling box, and hook the sample basket with the lower end of the hook. At this time, the sample basket is suspended in the boiling box, and the water in the boiling box covers the sample basket. After the sample basket is stable, close the door of the steam collection box;

[0021] Step 6: Turn on heating tube I to heat the water in the water supply tank. When the water in the water supply tank is heated to 99±1℃, adjust the power of heating tube I to keep the temperature constant and keep it in standby mode. At the same time, turn on heating tube II to heat the water in the boiling tank. During the whole heating process, the water vapor in the boiling tank passes through the steam collecting tank and then enters the condenser, and forms water in the condenser. Then the formed water passes through steam reflux tube II, water collecting tank and steam reflux tube I in sequence and enters the boiling tank.

[0022] Step 7: When the water in the boiling box is heated to 99±1℃, adjust the power of heating tube II to keep the temperature constant. At this time, start recording the boiling time. After the boiling time reaches 2h, open the door of the steam collection box, and quickly take out the sample basket containing the rock sample and place it on the support plate in the photo area. Then quickly close the door of the steam collection box. The water carried out of the sample basket and the rock sample from the boiling box flows into the water collection box through the circular holes on the support plate, and then flows into the boiling box through the steam reflux pipe I. Use a camera to take pictures of the outer surface of the rock sample for subsequent observation of the aging changes on the surface of the rock sample. After the photography is completed, the door of the steam collection box is opened, and the sample basket containing the rock sample is quickly put back into the boiling box, and the sample basket is hooked with the lower end of the hook. At this time, the sample basket is suspended in the boiling box, and the water in the boiling box covers the sample basket. Then the door of the steam collection box is quickly closed, and the rock sample is continued to be boiled; after every 2 hours of boiling time, the above-mentioned operations of taking out the sample basket, taking pictures, and putting the sample basket back are repeated until the boiling time reaches 36 hours, and a total of 18 photos are taken; during the entire boiling process, the weighing sensor monitors the mass change of the rock sample in real time, and then calculates the mass loss rate change of the rock sample in real time;

[0023] Step 8: During the entire boiling process, when the water level in the boiling tank triggers the liquid level sensor III, open the electric valve II. At this time, the water in the water supply tank enters the boiling tank through the outlet pipe and the water supply pipe until the water level in the boiling tank triggers the liquid level sensor II, and then close the electric valve II; open the electric valve I, and the water enters the water supply tank through the water inlet and the water inlet pipe in turn until the water level in the water supply tank triggers the liquid level sensor I, close the electric valve I, and then open the heating tube I to heat the water in the water supply tank. When the water in the water supply tank is heated to 99±1℃, adjust the power of the heating tube I to keep the temperature constant and keep it in standby mode; when the boiling time reaches 36h, the boiling test of the rock sample can be completed;

[0024] Step 9: After the boiling test is completed, turn off the main switch of the equipment and the power switch of the control system, turn off the water source and power supply, open the manual valve on the water outlet, and drain all the water in the boiling tank.

[0025] In step 7, the calculation model of the mass loss rate of the rock sample is: In the formula,

[0026] A i ——mass loss rate of rock sample after boiling for i hours, %;

[0027] m0——the mass of the rock sample before boiling, g;

[0028] m1——mass of the sample basket, g;

[0029] V1——Volume of sample basket, cm 3 ;

[0030] ρ s ——Dry density of rock sample, g / cm 3 ;

[0031] ρ w ——Density of water, g / cm 3 ;

[0032] g——acceleration due to gravity, value is 0.0098N / g;

[0033] F i ——Reading of the weighing sensor after boiling for i hours, N.

[0034] In the present invention, the sample basket and the rock sample are not in contact with the boiling box, but are suspended in the boiling box and are affected by buoyancy, and the buoyancy is related to the water level in the boiling box. The water level needs to completely cover the sample basket, and the weighing sensor displays the reading. If the water level drops, the sample basket is exposed, the buoyancy changes, and the reading of the weighing sensor is also affected, and the weighing result is inaccurate. The present invention designs a steam condensation reflux system. During the entire boiling process, the water vapor in the boiling box is condensed by the condenser to form water, and the water flows back into the boiling box, so that the water level in the boiling box is kept as stable as possible, and the water in the boiling box is always in a boiling state, so that the weighing result is more accurate. The present invention also designs a calculation model for the mass loss rate, which takes into account the influence of water vapor and buoyancy, and is more accurate than the traditional calculation method.

[0035] In the present invention, the water replenishment tank can be designed as a closed box or a box with a cover; after boiling for every 2 hours, the buzzer alarms once to remind you to take photos; the specific positions of the liquid level sensor I, the liquid level sensor II, and the liquid level sensor III can be designed according to the actual test situation; the sample basket can be used to place block rock samples or granular aggregates, and the quantity or quality can be determined according to the actual test situation.

[0036] The rock heat resistance boiling equipment and evaluation method based on dynamic monitoring of the present invention have the following beneficial effects:

[0037] (1) The present invention first proposed an innovative idea of ​​suspending the sample basket and rock sample in a boiling box for boiling test. The influence of water vapor and buoyancy on the measurement results was taken into consideration, and a water vapor condensation reflux system was designed to make the water vapor generated in the boiling box flow back into the boiling box, so that the measurement results are more accurate.

[0038] (2) The present invention proposes for the first time an innovative idea of ​​real-time monitoring of the mass changes of rock samples. During the entire boiling process, a weighing sensor is used to monitor in real time the mass loss changes of rock samples under the action of water vapor reflux and buoyancy. This can evaluate the differences between different stones, while the traditional method can only measure the mass loss of rock samples after boiling for 36 hours.

[0039] (3) The present invention proposes for the first time a buoyancy-based mass loss rate calculation model. As long as the mass and volume of the sample basket, the mass and density of the rock sample before boiling, and the reading of the weighing sensor are known, the mass loss rate of the rock sample after boiling for different times can be calculated, and the calculation result is accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic diagram of the external structure of a preferred embodiment of a rock heat resistance boiling device based on dynamic monitoring according to the present invention;

[0041] Figure 2 for Figure 1 A schematic diagram of the internal structure of the rock heat-resistant boiling equipment in the illustrated embodiment;

[0042] Figure 3 for Figure 1 A front view of the internal structure of the rock heat-resistant boiling device in the embodiment shown;

[0043] Figure 4 for Figure 1 A schematic structural diagram of a water replenishment system in the illustrated embodiment;

[0044] Figure 5 for Figure 1 A schematic diagram of the structure of the boiling system in the illustrated embodiment;

[0045] Figure 6 for Figure 1 A schematic diagram of the structure of the boiling box in the illustrated embodiment;

[0046] Figure 7 for Figure 1 A schematic diagram of the structure of the sample basket in the illustrated embodiment;

[0047] Figure 8 for Figure 1 A schematic structural diagram of a steam condensation reflux system in the illustrated embodiment;

[0048] Fig. 9for Figure 1 A schematic diagram of the structure of the photographing area in the illustrated embodiment;

[0049] Fig.10 for Figure 1 A schematic diagram of a control system in the illustrated embodiment;

[0050] Fig.11 for Figure 1 A schematic diagram of a control module in the illustrated embodiment;

[0051] Fig.12 for Figure 1 The illustrated example shows how the mass loss rate of the rock sample measured in the embodiment changes with boiling time.

[0052] Notes in the figure:

[0053] 1-Box;

[0054] 2-water supply system, 201-water supply tank, 202-heating pipe Ⅰ, 203-temperature sensor Ⅰ, 204-liquid level sensor Ⅰ, 205-water inlet pipe, 206-water outlet pipe, 207-electric valve Ⅰ;

[0055] 3-boiling system, 301-boiling box, 302-heating tube II, 303-temperature sensor II, 304-liquid level sensor II, 305-liquid level sensor III, 306-water supply pipe, 307-drain pipe, 308-steam reflux pipe I, 309-electric valve II, 310-sample basket, 311-hook, 312-weighing sensor, 313-manual valve, 314-bracket;

[0056] 4-steam condensation reflux system, 401-steam collection box, 402-condenser, 403-steam reflux pipe II, 404-box door, 405-flange;

[0057] 5-photographing area, 501-water collection tank, 502-support plate;

[0058] 6-control system, 601-control panel, 602-control module, 603-power switch, 604-emergency stop switch, 605-equipment main switch, 606-buzzer;

[0059] 7- Water inlet;

[0060] 8-Water outlet. DETAILED DESCRIPTION

[0061] In order to further understand the content of the present invention, the present invention will be described in detail below in conjunction with specific embodiments.

[0062] like Figure 1-3As shown, according to a preferred embodiment of the rock heat resistance boiling equipment based on dynamic monitoring of the present invention, it includes a housing 1, a water replenishment system 2, a boiling system 3, a steam condensation reflux system 4, a photographing area 5 and a control system 6; the water replenishment system 2 and the boiling system 3 are arranged inside the housing 1, and the steam condensation reflux system 4, the photographing area 5 and the control system 6 are arranged outside the housing 1; the water replenishment system 2, the boiling system 3 and the steam condensation reflux system 4 are connected in sequence to form a water circulation; a water inlet 7 is arranged on one side of the housing 1, and a water outlet 8 is arranged on the other side of the housing 1, the water inlet 7 is connected to the water replenishment system 2, and the water outlet 8 is connected to the boiling system 3.

[0063] like Figure 4 As shown, the water replenishment system 2 includes a water replenishment tank 201, a heating pipe I 202, a temperature sensor I 203, a liquid level sensor I 204, a water inlet pipe 205, a water outlet pipe 206 and an electric valve I 207; the heating pipe I 202, the temperature sensor I 203 and the liquid level sensor I 204 are arranged inside the water replenishment tank 201, the water inlet pipe 205 and the water outlet pipe 206 are arranged at the bottom of the water replenishment tank 201, the water inlet pipe 205 is connected to the water inlet 7, the water outlet pipe 206 is connected to the boiling system 3, and the electric valve I 207 is arranged on the water inlet pipe 205.

[0064] like Figure 5-7 As shown, the boiling system 3 includes a boiling box 301, a heating pipe II 302, a temperature sensor II 303, a liquid level sensor II 304, a liquid level sensor III 305, a water supply pipe 306, a drain pipe 307, a steam reflux pipe I 308, an electric valve II 309, a sample basket 310, a hook 311 and a weighing sensor 312; the boiling box 301 is located lower than the water supply tank 201 in the vertical direction; the heating pipe II 302, the temperature sensor II 303, the liquid level sensor II 304 and the liquid level sensor III 305 are arranged inside the boiling box 301, and the liquid level sensor II 306 is arranged inside the boiling box 301. The position of 304 in the vertical direction is higher than that of the liquid level sensor III 305; the water supply pipe 306 is arranged on one side of the boiling box 301, and the water supply pipe 306 is connected to the water outlet pipe 206; the steam reflux pipe I 308 is arranged on the other side of the boiling box 301, and the steam reflux pipe I 308 is connected to the steam condensation reflux system 4 through the photographing area 5; the drain pipe 307 is arranged at the bottom of the boiling box 301, and the drain pipe 307 is connected to the water outlet 8; the electric valve II 309 is arranged on the water supply pipe 306, and the water outlet 8 is arranged on the manual valve 313.

[0065] The upper end of the hook 311 is connected to the weighing sensor 312 , and the lower end of the hook 311 hooks the sample basket 310 , so that the sample basket 310 is suspended inside the boiling box 301 ; the weighing sensor 312 is connected to the steam condensation reflux system 4 through a bracket 314 .

[0066] An insulation layer is arranged between the outer wall and the inner wall of the boiling box 301, and the inner cavity of the boiling box 301 has a length of 346 mm, a width of 346 mm, and a height of 280 mm; the sample basket 310 has a length of 300 mm, a width of 300 mm, and a height of 150 mm, and a rock sample is placed inside the sample basket 310; when the rock sample is in block shape, the bottom and side surfaces of the sample basket 310 are frames with crossbeams, and when the rock sample is in aggregate shape, the bottom and side surfaces of the sample basket 310 are flat plates with circular holes.

[0067] like Figure 8 As shown, the steam condensation reflux system 4 includes a steam collecting box 401, a condenser 402 and a steam reflux pipe II 403; the steam collecting box 401 is arranged above the boiling box 301, the bottom open end of the steam collecting box 401 is tightly connected to the top open end of the boiling box 301, and a box door 404 is arranged on the steam collecting box 401; the top of the steam collecting box 401 is connected to one end of the condenser 402 through a flange 405, the other end of the condenser 402 is connected to one end of the steam reflux pipe II 403 through the flange 405, and the other end of the steam reflux pipe II 403 is connected to the steam reflux pipe I 308 through the photographing area 5.

[0068] The weighing sensor 312 and the hook 311 are located inside the steam collection box 401 , and the bracket 314 is fixed on the inner wall of the steam collection box 401 .

[0069] like Fig. 9 As shown, the photographing area 5 includes a water collecting box 501 and a support plate 502; the support plate 502 is placed at the open end of the water collecting box 501, and the support plate 502 is a flat plate with a circular hole; the bottom opening of the water collecting box 501 is connected to the steam reflux pipe I308, and the side opening of the water collecting box 501 is connected to the steam reflux pipe II403.

[0070] like Figure 10-11As shown, the control system 6 includes a control panel 601, a control module 602, a power switch 603, an emergency stop switch 604, a main device switch 605 and a buzzer 606; the control panel 601, the power switch 603, the emergency stop switch 604, the main device switch 605 and the buzzer 606 are arranged on the box body 1, and the control module 2 is integrated inside the control system 6; the control module 2 is used to control the heating tube I 202, the heating tube II 302, the temperature sensor I 203, the temperature sensor II 303, the liquid level sensor I 204, the liquid level sensor II 304, the liquid level sensor III 305, the electric valve I 207, the electric valve II 309 and the weighing sensor 312.

[0071] This embodiment also provides a method for evaluating the heat resistance of rocks based on dynamic monitoring, using the above-mentioned rock heat resistance boiling equipment based on dynamic monitoring, and including the following steps in order:

[0072] Step 1: Assemble and connect the various components of the boiling equipment according to the design structure, debug the boiling equipment and check the sealing to ensure that it can be used normally during the boiling process;

[0073] Step 2: Connect the boiling device to the water source and power supply, turn on the main switch of the device and the power switch of the control system, and start the device and the control system;

[0074] Step 3: Open the electric valve Ⅰ and the electric valve Ⅱ, and the water enters the water supply tank through the water inlet and the water inlet pipe in turn, and then enters the boiling tank through the water outlet pipe and the water supply pipe in turn from the water supply tank, until the water level in the boiling tank triggers the liquid level sensor Ⅱ, and then close the electric valve Ⅱ;

[0075] Step 4: Water continues to flow into the water supply tank through the water inlet and the water inlet pipe in sequence until the water level in the water supply tank triggers the liquid level sensor Ⅰ, closing the electric valve Ⅰ;

[0076] Step 5: Open the door of the steam collection box, put the sample basket containing the rock sample into the boiling box, and hook the sample basket with the lower end of the hook. At this time, the sample basket is suspended in the boiling box, and the water in the boiling box covers the sample basket. After the sample basket is stable, close the door of the steam collection box;

[0077] Step 6: Turn on heating tube I to heat the water in the water supply tank. When the water in the water supply tank is heated to 99±1℃, adjust the power of heating tube I to keep the temperature constant and keep it in standby mode. At the same time, turn on heating tube II to heat the water in the boiling tank. During the whole heating process, the water vapor in the boiling tank passes through the steam collecting tank and then enters the condenser, and forms water in the condenser. Then the formed water passes through steam reflux tube II, water collecting tank and steam reflux tube I in sequence and enters the boiling tank.

[0078] Step 7: When the water in the boiling box is heated to 99±1℃, adjust the power of heating tube II to keep the temperature constant. At this time, start recording the boiling time. After the boiling time reaches 2h, open the door of the steam collection box, and quickly take out the sample basket containing the rock sample and place it on the support plate in the photo area. Then quickly close the door of the steam collection box. The water carried out of the sample basket and the rock sample from the boiling box flows into the water collection box through the circular holes on the support plate, and then flows into the boiling box through the steam reflux pipe I. Use a camera to take pictures of the outer surface of the rock sample for subsequent observation of the aging changes on the surface of the rock sample. After the photography is completed, the door of the steam collection box is opened, and the sample basket containing the rock sample is quickly put back into the boiling box, and the sample basket is hooked with the lower end of the hook. At this time, the sample basket is suspended in the boiling box, and the water in the boiling box covers the sample basket. Then the door of the steam collection box is quickly closed, and the rock sample is continued to be boiled; after every 2 hours of boiling time, the above-mentioned operations of taking out the sample basket, taking pictures, and putting the sample basket back are repeated until the boiling time reaches 36 hours, and a total of 18 photos are taken; during the entire boiling process, the weighing sensor monitors the mass change of the rock sample in real time, and then calculates the mass loss rate change of the rock sample in real time;

[0079] Step 8: During the entire boiling process, when the water level in the boiling tank triggers the liquid level sensor III, open the electric valve II. At this time, the water in the water supply tank enters the boiling tank through the outlet pipe and the water supply pipe until the water level in the boiling tank triggers the liquid level sensor II, and then close the electric valve II; open the electric valve I, and the water enters the water supply tank through the water inlet and the water inlet pipe in turn until the water level in the water supply tank triggers the liquid level sensor I, close the electric valve I, and then open the heating tube I to heat the water in the water supply tank. When the water in the water supply tank is heated to 99±1℃, adjust the power of the heating tube I to keep the temperature constant and keep it in standby mode; when the boiling time reaches 36h, the boiling test of the rock sample can be completed;

[0080] Step 9: After the boiling test is completed, turn off the main switch of the equipment and the power switch of the control system, turn off the water source and power supply, open the manual valve on the water outlet, and drain all the water in the boiling tank.

[0081] In step 7, the calculation model of the mass loss rate of the rock sample is: In the formula,

[0082] A i ——mass loss rate of rock sample after boiling for i hours, %;

[0083] m0——the mass of the rock sample before boiling, g;

[0084] m1——mass of the sample basket, g;

[0085] V1——Volume of sample basket, cm 3 ;

[0086] ρ s ——Dry density of rock sample, g / cm 3 ;

[0087] ρ w ——Density of water, g / cm 3 ;

[0088] g——acceleration due to gravity, value is 0.0098N / g;

[0089] F i ——Reading of the weighing sensor after boiling for i hours, N.

[0090] In this embodiment, the sample basket and the rock sample are not in contact with the boiling box, but are suspended in the boiling box and are affected by buoyancy, which is related to the water level in the boiling box. The water level needs to completely cover the sample basket, and the weighing sensor displays the reading. If the water level drops, the sample basket is exposed, the buoyancy changes, and the weighing sensor reading is also affected, and the weighing result is inaccurate. This embodiment designs a steam condensation reflux system. During the entire boiling process, the water vapor in the boiling box is condensed by the condenser to form water, and the water flows back into the boiling box, so that the water level in the boiling box is kept as stable as possible, and the water in the boiling box is always in a boiling state, so that the weighing result is more accurate. This embodiment also designs a calculation model for the mass loss rate, which takes into account the influence of water vapor and buoyancy, and is more accurate than the traditional calculation method.

[0091] In this embodiment, the water replenishment tank can be designed as a closed box or a box with a cover; the buzzer will sound once every 2 hours of boiling time to remind you to take pictures; the specific positions of liquid level sensor I, liquid level sensor II, and liquid level sensor III can be designed according to actual test conditions; block rock samples or granular aggregates can be placed in the sample basket, and the quantity or quality can be determined according to actual test conditions.

[0092] The rock heat resistance boiling equipment and evaluation method based on dynamic monitoring in this embodiment have the following beneficial effects: (1) For the first time, an innovative idea of ​​suspending the sample basket and the rock sample in the boiling box for boiling test is proposed. Considering the influence of water vapor and buoyancy on the measurement results, a water vapor condensation reflux system is designed to make the water vapor generated in the boiling box flow back into the boiling box, so that the measurement results are more accurate. (2) For the first time, an innovative idea of ​​real-time monitoring of the mass change of the rock sample is proposed. During the whole boiling process, a weighing sensor is used to monitor the mass loss change of the rock sample under the action of water vapor reflux and buoyancy in real time, so as to evaluate the difference of different stones, while the traditional method can only measure the mass loss of the rock sample after boiling for 36 hours. (3) For the first time, a mass loss rate calculation model based on buoyancy is proposed. As long as the mass and volume of the sample basket, the mass and density of the rock sample before boiling, and the reading of the weighing sensor are known, the mass loss rate of the rock sample after different boiling times can be calculated, and the calculation result is accurate.

[0093] In this embodiment, the mass of the sample basket is 2560 g and the volume of the sample basket is 320 cm 3 , the density of water is 1.0g / cm 3 ; Weigh two samples of dry coarse aggregate with a particle size of 9.5-13.2 mm, namely sample 1 and sample 2, and the mass of both samples is 2500 g; according to the "Highway Engineering Acceptance Test Regulations" (JTG 3431), the dry density of coarse aggregate is measured, and the dry density of sample 1 and sample 2 is 2.9 g / cm 3 The rock heat resistance boiling equipment and evaluation method of this embodiment were used to measure the mass loss rate of sample 1 and sample 2 during boiling as a function of boiling time. The results are as follows: Fig.12 shown.

[0094] from Fig.12 It can be seen that the mass loss rates of sample 1 and sample 2 after boiling for 36 hours are 10.61% and 10.85% respectively, and the results are not much different. However, during the entire boiling process, the mass loss rates of sample 1 and sample 2 are significantly different. The mass loss rate of sample 2 increases rapidly in the early stage, and basically tends to be stable after boiling for 14 hours. During the boiling process of 14-36 hours, the change range of the mass loss rate is very small; however, the mass loss rate of sample 1 increases slowly in the early stage, and begins to grow rapidly after boiling for 30 hours. This shows that the long-term heat aging resistance of sample 2 is better, and basically tends to be stable in the later stage of boiling, while the long-term heat aging resistance of sample 1 is poor, and it is still growing rapidly in the later stage of boiling. This embodiment can clearly distinguish the difference in the anti-aging performance of the two samples.

[0095] In the comparative example, the invention patent with application publication number CN112255261A recorded in the background technology, which is named as an aggregate weathering resistance evaluation device for asphalt pavement and its working process, the boiling equipment of the comparative example and the traditional mass loss rate calculation formula can only measure the mass loss rate of the sample after boiling for 36 hours. The traditional mass loss rate calculation formula is Where: S is the mass loss rate of the sample after boiling for 36 hours, %; n0 is the mass of the dry sample before boiling, g; n1 is the mass of the dry sample after boiling for 36 hours, g. Similarly, two dry coarse aggregate samples with a particle size of 9.5-13.2 mm were weighed, and the mass of both samples was 2500g. After boiling for 36 hours, the mass loss rates of the two samples were 8.2% and 8.5% respectively. The analysis is as follows: On the one hand, since the comparative example does not have a water vapor condensation reflux system, the water level in the boiling box is constantly decreasing, and frequent water replenishment is required. The heating tube needs to be frequently opened and closed, resulting in a short effective boiling time and insufficient heating of the sample. Therefore, the mass loss rate of the sample after boiling for 36 hours is low, only about 8%; on the other hand, the comparative example can only test the mass loss rate data after boiling for 36 hours, and cannot distinguish the difference in the anti-aging performance of the two samples.

[0096] Special note: The technical solution of the present invention involves many parameters, and the synergistic effects between the various parameters need to be comprehensively considered to obtain the beneficial effects and significant progress of the present invention. Moreover, the value ranges of the various parameters in the technical solution are obtained after a large number of experiments. For each parameter and the combination of each parameter, the inventor has recorded a large amount of experimental data. Due to space limitations, the specific experimental data will not be disclosed here.

[0097] It is not difficult for those skilled in the art to understand that the rock heat resistance boiling equipment based on dynamic monitoring and the evaluation method thereof of the present invention include any combination of the invention content and the specific implementation method of the above-mentioned invention specification and the various parts shown in the drawings. Due to the limited space and to make the specification concise, the various schemes composed of these combinations are not described one by one. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A rock heat resistance boiling device based on dynamic monitoring, characterized in that: It includes a box, a water replenishment system, a boiling system, a steam condensation reflux system, a photographing area and a control system; the water replenishment system and the boiling system are arranged inside the box, and the steam condensation reflux system, the photographing area and the control system are arranged outside the box; the water replenishment system, the boiling system and the steam condensation reflux system are connected in sequence to form a water circulation; a water inlet is arranged on one side of the box, and a water outlet is arranged on the other side of the box, the water inlet is connected to the water replenishment system, and the water outlet is connected to the boiling system.

2. The rock heat resistance boiling equipment based on dynamic monitoring according to claim 1 is characterized by: The water replenishment system includes a water replenishment tank, a heating pipe I, a temperature sensor I, a liquid level sensor I, a water inlet pipe, a water outlet pipe and an electric valve I; the heating pipe I, the temperature sensor I and the liquid level sensor I are arranged inside the water replenishment tank, the water inlet pipe and the water outlet pipe are arranged at the bottom of the water replenishment tank, the water inlet pipe is connected to the water inlet, the water outlet pipe is connected to the boiling system, and the electric valve I is arranged on the water inlet pipe.

3. The rock heat resistance boiling equipment based on dynamic monitoring according to claim 2 is characterized in that: The boiling system comprises a boiling box, a heating tube II, a temperature sensor II, a liquid level sensor II, a liquid level sensor III, a water supply pipe, a drain pipe, a steam reflux pipe I, an electric valve II, a sample basket, a hook and a weighing sensor; the boiling box is located lower than the water supply tank in the vertical direction; the heating tube II, the temperature sensor II, the liquid level sensor II and the liquid level sensor III are arranged inside the boiling box, and the liquid level sensor II is located higher than the liquid level sensor III in the vertical direction; the water supply pipe is arranged on one side of the boiling box, and the water supply pipe is connected to the water outlet pipe, the steam reflux pipe I is arranged on the other side of the boiling box, and the steam reflux pipe I passes through the photographing area and is connected to the steam condensation reflux system, the drain pipe is arranged at the bottom of the boiling box, and the drain pipe is connected to the water outlet; the electric valve II is arranged on the water supply pipe, and a manual valve is arranged on the water outlet.

4. The rock heat resistance boiling equipment based on dynamic monitoring according to claim 3 is characterized by: The upper end of the hook is connected to the weighing sensor, and the lower end of the hook hooks the sample basket, so that the sample basket is suspended inside the boiling box; the weighing sensor is connected to the steam condensation reflux system through a bracket.

5. The rock heat resistance boiling equipment based on dynamic monitoring according to claim 4 is characterized in that: An insulation layer is arranged between the outer wall and the inner wall of the boiling box, and the inner cavity of the boiling box has a length of 346 mm, a width of 346 mm, and a height of 280 mm; the length of the sample basket is 300 mm, the width is 300 mm, and the height is 150 mm, and the rock sample is placed inside the sample basket; when the rock sample is in block shape, the bottom and side surfaces of the sample basket are frames with cross beams, and when the rock sample is in aggregate shape, the bottom and side surfaces of the sample basket are flat plates with circular holes.

6. The rock heat resistance boiling equipment based on dynamic monitoring according to claim 5 is characterized by: The steam condensation reflux system includes a steam collecting box, a condenser and a steam reflux pipe II; the steam collecting box is arranged above the boiling box, the bottom open end of the steam collecting box is tightly connected to the top open end of the boiling box, and a box door is arranged on the steam collecting box; the top of the steam collecting box is connected to one end of the condenser through a flange, the other end of the condenser is connected to one end of the steam reflux pipe II through a flange, and the other end of the steam reflux pipe II is connected to the steam reflux pipe I through the photographing area.

7. The rock heat resistance boiling equipment based on dynamic monitoring according to claim 6 is characterized by: The weighing sensor and the hook are located inside the steam collection box, and the bracket is fixed on the inner wall of the steam collection box.

8. The rock heat resistance boiling equipment based on dynamic monitoring according to claim 7 is characterized by: The photographing area includes a water collection box and a support plate; the support plate is placed at the open end of the water collection box, and the support plate is a flat plate with a circular hole; the bottom opening of the water collection box is connected to the steam reflux pipe I, and the side opening of the water collection box is connected to the steam reflux pipe II.

9. The rock heat resistance boiling equipment based on dynamic monitoring according to claim 8 is characterized by: The control system includes a control panel, a control module, a power switch, an emergency stop switch, a main equipment switch and a buzzer; the control panel, the power switch, the emergency stop switch, the main equipment switch and the buzzer are arranged on the box, and the control module is integrated inside the control system; the control module is used to control the heating tube I, the heating tube II, the temperature sensor I, the temperature sensor II, the liquid level sensor I, the liquid level sensor II, the liquid level sensor III, the electric valve I, the electric valve II and the weighing sensor.

10. A method for evaluating rock heat resistance based on dynamic monitoring, characterized in that: The rock heat resistance boiling device based on dynamic monitoring according to any one of claims 1 to 9 comprises the following steps in chronological order: Step 1: Assemble and connect the various components of the boiling equipment according to the design structure, debug the boiling equipment and check the sealing to ensure that it can be used normally during the boiling process; Step 2: Connect the boiling device to the water source and power supply, turn on the main switch of the device and the power switch of the control system, and start the device and the control system; Step 3: Open the electric valve Ⅰ and the electric valve Ⅱ, and the water enters the water supply tank through the water inlet and the water inlet pipe in turn, and then enters the boiling tank through the water outlet pipe and the water supply pipe in turn from the water supply tank, until the water level in the boiling tank triggers the liquid level sensor Ⅱ, and then close the electric valve Ⅱ; Step 4: Water continues to flow into the water supply tank through the water inlet and the water inlet pipe in sequence until the water level in the water supply tank triggers the liquid level sensor Ⅰ, closing the electric valve Ⅰ; Step 5: Open the door of the steam collection box, put the sample basket containing the rock sample into the boiling box, and hook the sample basket with the lower end of the hook. At this time, the sample basket is suspended in the boiling box, and the water in the boiling box covers the sample basket. After the sample basket is stable, close the door of the steam collection box; Step 6: Turn on heating tube I to heat the water in the water supply tank. When the water in the water supply tank is heated to 99±1℃, adjust the power of heating tube I to keep the temperature constant and keep it in standby mode. At the same time, turn on heating tube II to heat the water in the boiling tank. During the whole heating process, the water vapor in the boiling tank passes through the steam collecting tank and then enters the condenser, and forms water in the condenser. Then the formed water passes through steam reflux tube II, water collecting tank and steam reflux tube I in sequence and enters the boiling tank. Step 7: When the water in the boiling box is heated to 99±1℃, adjust the power of heating tube II to keep the temperature constant. At this time, start recording the boiling time. After the boiling time reaches 2h, open the door of the steam collection box, and quickly take out the sample basket containing the rock sample and place it on the support plate in the photo area. Then quickly close the door of the steam collection box. The water carried out of the sample basket and the rock sample from the boiling box flows into the water collection box through the circular holes on the support plate, and then flows into the boiling box through the steam reflux pipe I. Use a camera to take pictures of the outer surface of the rock sample for subsequent observation of the aging changes on the surface of the rock sample. After the photography is completed, the door of the steam collection box is opened, and the sample basket containing the rock sample is quickly put back into the boiling box, and the sample basket is hooked with the lower end of the hook. At this time, the sample basket is suspended in the boiling box, and the water in the boiling box covers the sample basket. Then the door of the steam collection box is quickly closed, and the rock sample is continued to be boiled; after every 2 hours of boiling time, the above-mentioned operations of taking out the sample basket, taking pictures, and putting the sample basket back are repeated until the boiling time reaches 36 hours, and a total of 18 photos are taken; during the entire boiling process, the weighing sensor monitors the mass change of the rock sample in real time, and then calculates the mass loss rate change of the rock sample in real time; Step 8: During the entire boiling process, when the water level in the boiling tank triggers the liquid level sensor III, open the electric valve II. At this time, the water in the water supply tank enters the boiling tank through the outlet pipe and the water supply pipe until the water level in the boiling tank triggers the liquid level sensor II, and then close the electric valve II; open the electric valve I, and the water enters the water supply tank through the water inlet and the water inlet pipe in turn until the water level in the water supply tank triggers the liquid level sensor I, close the electric valve I, and then open the heating tube I to heat the water in the water supply tank. When the water in the water supply tank is heated to 99±1℃, adjust the power of the heating tube I to keep the temperature constant and keep it in standby mode; when the boiling time reaches 36h, the boiling test of the rock sample can be completed; Step 9: After the boiling test is completed, turn off the main switch of the equipment and the power switch of the control system, turn off the water source and power supply, open the manual valve on the water outlet, and drain all the water in the boiling tank; In step 7, the calculation model of the mass loss rate of the rock sample is: In the formula, A i ——mass loss rate of rock sample after boiling for i hours, %; m0——the mass of the rock sample before boiling, g; m1——mass of the sample basket, g; V1——Volume of sample basket, cm 3 ; ρ s ——Dry density of rock sample, g / cm 3 ; ρ w ——Density of water, g / cm 3 ; g——acceleration due to gravity, value is 0.0098N / g; F i ——Reading of the weighing sensor after boiling for i hours, N.

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