Device and method for measuring volume shrinkage of resin asphalt

Abstract

The invention provides a device and method for measuring the volume shrinkage rate of resin asphalt, and belongs to the field of road engineering, and the device comprises a silica gel mold, a parallel plate, a resin asphalt sample, a rotational rheometer (DSR), a laser distance measuring sensor, a data acquisition system and a computer. The silica gel mold is used for preparing a resin asphalt DSR sample; the parallel plate is used for containing a resin asphalt sample; the rotational rheometer is used for axial force constraint and displacement measurement of the resin asphalt sample; the laser distance measuring sensor is used for measuring transverse deformation of the resin asphalt sample; and the computer calculates the volume change rate of the resin asphalt sample according to the sample height monitored by the DSR instrument, the radius of the parallel plate and the distance between the sample contour arc monitored by the laser distance measuring sensor and the DSR test plate baseline. According to the invention, rapid and accurate measurement of the volume shrinkage of the resin asphalt cement can be realized under the condition of a small amount of samples.

Description

Technical Field

[0001] The present invention relates to the field of road engineering, and particularly relates to a device and method for measuring the volume shrinkage rate of resin asphalt. Background Art

[0002] As a high-performance road material, resin asphalt has excellent high-temperature stability, low-temperature crack resistance and anti-aging performance compared with ordinary asphalt. However, during the curing process of resin materials (such as epoxy resin, polyurethane, etc.), due to the transformation of the molecular bonding state caused by chemical reactions, that is, the van der Waals interaction distance gradually shortens to the covalent bond length, this process will cause significant volume deformation, further resulting in the generation of residual stress inside, affecting the bonding performance and reliability of resin asphalt as a binder. Therefore, accurately measuring the volume shrinkage rate of resin asphalt is crucial for predicting and controlling the residual stress and strength reliability of resin asphalt binders.

[0003] Currently, the measurement techniques for the volume change during the resin curing reaction mainly include the specific gravity method, mercury dilatometer method, optical method and rheometer method. The existing technologies have the following defects: firstly, although the traditional rheometer method can track the axial shrinkage, it ignores the lateral deformation of the material and cannot be compatible with high-precision in-situ volume measurement; secondly, non-in-situ methods such as mercury dilatometers need to interrupt the curing process and destroy the continuous reaction state of the material, and the obtained data is difficult to reflect the true dynamic shrinkage behavior. Therefore, there is an urgent need to develop a high-precision, multi-parameter combined in-situ measurement technology to synchronously obtain the volume shrinkage rate and curing time evolution data, which is of great significance for the further popularization and application of resin asphalt materials.

[0004] The present invention aims to provide a device and method for measuring the volume shrinkage rate of resin asphalt. This method realizes the combined analysis of axial-lateral deformation during the curing process of resin asphalt through a rotational rheometer and a laser distance sensor, thereby realizing the rapid and accurate in-situ measurement of the volume shrinkage of resin asphalt. Summary of the Invention

[0005] The purpose of the present invention is to propose a device and method for measuring the volume shrinkage rate of resin asphalt, which can accurately measure the volume shrinkage rate of resin asphalt.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is:

[0007] A device for measuring the volume shrinkage rate of resin asphalt, characterized in that it includes a resin asphalt sample, a parallel plate of a rotational rheometer, a laser distance sensor, a rotational rheometer, a data acquisition system and a computer;

[0008] The parallel plate of the rotational rheometer is arranged on the rotational rheometer and is used for holding the resin asphalt sample and applying an axial force;

[0009] The laser distance sensor is placed on one side of the resin asphalt specimen, and its height is level with the resin asphalt specimen, so that the laser is perpendicular to the parallel plate of the rotational rheometer and intersects the center point of the resin asphalt specimen, ensuring that the laser profile is consistent with the cross-sectional profile of the resin asphalt specimen, and is used to measure the distance between the lateral deformation of the resin asphalt specimen and the baseline of the parallel plate of the rotational rheometer at any moment;

[0010] The rotational rheometer is used to control the temperature, axial force and measure the height of the resin asphalt specimen in real time;

[0011] The data acquisition system is respectively connected to the laser distance sensor and the rotational rheometer, and is used to collect the distance between the lateral deformation of the resin asphalt specimen and the baseline of the parallel plate of the rotational rheometer, and the axial height of the resin asphalt specimen;

[0012] The data acquisition system is connected to a computer, and is used to calculate the volume shrinkage rate of the resin asphalt specimen according to the change amount of the distance between the lateral deformation of the resin asphalt specimen and the baseline of the parallel plate of the rotational rheometer and the axial height of the resin asphalt specimen;

[0013] It further includes a Peltier temperature control unit, and the Peltier temperature control unit is connected to the lower plate of the parallel plate of the rotational rheometer, and is used to control the temperature of the resin asphalt specimen during the test.

[0014] As a preferred technical solution of the present invention: the rotational rheometer adopts a force control gap tracking option, and uses 0 ± 0.1 N as the equipment limit of the compression axial force, and the gap control range is 475 - 525 μm.

[0015] As a preferred technical solution of the present invention: the sampling frequency of the laser distance sensor is set to 25 Hz, and the measurement distance is set within the range of 77.5 mm - 92.5 mm from the resin asphalt specimen.

[0016] A method for measuring the volume shrinkage rate of resin asphalt, characterized by comprising the following steps:

[0017] Step 1, uniformly mix the resin asphalt specimen to be measured in proportion and stir evenly;

[0018] Step 2, control the temperature of the lower plate of the parallel plate of the rotational rheometer to the required temperature, evenly apply the resin asphalt specimen on the lower plate of the parallel plate of the rotational rheometer, and lower the upper plate of the parallel plate of the rotational rheometer until the gap reaches the set gap h0, and trim the edge of the resin asphalt specimen;

[0019] Step 3, set up a laser distance sensor, and measure the maximum value S of the distance between the contour arc of the resin asphalt specimen in the initial state and the baseline of the parallel plate of the rotational rheometer through the laser distance sensor (0), measure and calculate the volume V0 of the resin asphalt sample in the initial state;

[0020] Step 4: Start the rheometer software in the computer and record the axial gap h of the resin asphalt sample at different times (t) ;

[0021] Step 5: Measure the maximum value S of the distance between the contour arc of the resin asphalt sample and the baseline of the parallel plate of the rotational rheometer at time t through a laser distance sensor (t) , and calculate the volume V of the resin asphalt sample at time t (t) ;

[0022] Step 6: According to the volume V0 of the resin asphalt sample in the initial state and the volume V of the resin asphalt sample at a certain time t during the curing process (t) , calculate the volume shrinkage rate W of the resin asphalt sample at this time (t) .

[0023] As a preferred technical solution of the present invention: In step 2, the test temperature range of the lower plate of the parallel plate of the rotational rheometer is selected as 20 - 80 °C.

[0024] As a preferred technical solution of the present invention: In step 2, lower the upper plate of the parallel plate of the rotational rheometer through a parallel plate fixture, and select a 25 mm parallel plate for the parallel plate fixture.

[0025] As a preferred technical solution of the present invention: In step 3, assume that the contour geometry of the resin asphalt sample after lateral deformation is a circular arc.

[0026] As a preferred technical solution of the present invention: In step 3, the calculation formula for the volume V0 of the resin asphalt sample in the initial state is as follows:

[0027]

[0028] In the formula, V0 is the volume of the resin asphalt sample at the initial moment; r is the radius of the parallel plate of the rotational rheometer; h0 is the initial gap of the parallel plate of the rotational rheometer; S (0) is the maximum value of the distance between the contour arc of the resin asphalt sample and the baseline of the parallel plate of the rotational rheometer in the initial state.

[0029] As a preferred technical solution of the present invention: In step 5, the volume V of the resin asphalt sample at a certain time t during the curing process (t) The calculation formula is:

[0030]

[0031] In the formula, V (t) is the volume of the resin asphalt sample at time t; r is the radius of the parallel plate of the rotational rheometer; h (t)is the parallel plate gap of the rotational rheometer at time t; S (t) is the maximum value of the distance between the contour arc of the resin asphalt specimen measured by the laser distance sensor and the baseline of the parallel plate of the rotational rheometer at time t.

[0032] As a preferred technical solution of the present invention: in step 6, the calculation formula for the volume shrinkage rate of the resin asphalt specimen at time t is as follows:

[0033]

[0034] In the formula, W (t) is the volume shrinkage rate of the resin asphalt specimen at a certain time t; V0 is the volume of the resin asphalt specimen at the initial time; V (t) is the volume of the resin asphalt specimen at time t.

[0035] Compared with the prior art, the beneficial effects of the present invention are:

[0036] 1. The device for measuring the volume shrinkage rate of resin asphalt provided by the present invention combines the optical method and the rheometer method. By monitoring the axial gap of the sample through a rotational rheometer and combining a laser distance sensor to monitor the lateral deformation of the sample, real-time and high-precision measurement of the volume shrinkage rate of resin asphalt is achieved.

[0037] 2. The method for measuring the volume shrinkage rate of resin asphalt provided by the present invention realizes the combined analysis of axial-lateral deformation by using geometric formulas and outputs the volume shrinkage rate curve in real time; and the measurement of the volume shrinkage rate of resin asphalt at different temperatures can be achieved by adjusting the DSR test temperature.

[0038] 3. The measurement method of the present invention has the advantages of good compatibility, simple operation, low power consumption, etc.; in addition, the device in the present invention uses common equipment in the field of asphalt materials, avoiding the defects of professional and expensive instruments; in addition, the sample tested in the device of the present invention is resin asphalt, but it is also applicable to the volume measurement of other road binder materials with similar curing shrinkage properties, and has a wide range of applications. Description of the Drawings

[0039] Figure 1 is a schematic cross-sectional view of the resin asphalt specimen between the parallel plates of the rotational rheometer in the initial state;

[0040] Figure 2 is a schematic cross-sectional view of the resin asphalt specimen between the parallel plates of the rotational rheometer at a certain time;

[0041] Figure 3 is a schematic view of the device for measuring the volume shrinkage rate of resin asphalt;

[0042] Figure 4 is a schematic view of the method for measuring the volume shrinkage rate of resin asphalt.

[0043] List of reference numerals:

[0044] 1. Parallel plate baseline of rotational rheometer; 2. Resin asphalt sample; 3. Laser line of laser distance sensor; 4. Parallel plate of rotational rheometer; 5. Laser distance measurement sensor; 6. Area A0 between the initial state lateral deformation profile and the test plate baseline; 7. Area A between the lateral deformation profile at this moment and the test plate baseline (t) ; 8. Rotational rheometer; 9. Computer. Detailed implementation manners

[0045] The present invention will be further described in detail below in conjunction with the drawings and specific implementation manners:

[0046] The object of the present invention is to provide a device and method for measuring the volume shrinkage rate of resin asphalt. Its measurement principle is to monitor the axial height change of the sample through the rotational rheometer 8, monitor the lateral deformation of the sample through the laser distance measurement sensor 5, and obtain the volume change rate of resin asphalt after processing the measurement results.

[0047] The present invention is used to study resin asphalt and other materials with similar properties of curing shrinkage deformation. In addition, experiments can be carried out for different curing conditions (temperature, humidity).

[0048] As Figures 1-3 shown, a device for measuring the volume shrinkage rate of resin asphalt proposed by the present invention includes a resin asphalt sample 2, a parallel plate 4 of a rotational rheometer, a laser distance measurement sensor 5, a rotational rheometer 8, a data acquisition system, and a computer 9;

[0049] The parallel plate 4 of the rotational rheometer is arranged on the rotational rheometer 8 and is used for containing the resin asphalt sample 2 and applying an axial force;

[0050] The laser distance measurement sensor 5 is placed on one side of the resin asphalt sample 2, and its height is flush with the resin asphalt sample 2, so that the laser is perpendicular to the parallel plate 4 of the rotational rheometer and intersects the center point of the resin asphalt sample 2 to ensure that the laser profile is consistent with the cross-sectional profile of the resin asphalt sample 2, and is used for measuring the distance between the lateral deformation of the resin asphalt sample 2 at any moment and the parallel plate baseline 1 of the rotational rheometer;

[0051] The rotational rheometer 8 is used for controlling the temperature, axial force, and real-time measuring the height of the resin asphalt sample 2;

[0052] The data acquisition system is respectively connected to the laser distance measurement sensor 5 and the rotational rheometer 8, and is used for collecting the distance between the lateral deformation of the resin asphalt sample 2 and the parallel plate baseline 1 of the rotational rheometer, and the axial height of the resin asphalt sample 2;

[0053] The data acquisition system is connected to a computer 9 and is used to calculate the volume shrinkage rate of the resin asphalt specimen 2 based on the changes in the lateral deformation of the resin asphalt specimen 2 and the distance between the parallel plate baseline 1 of the rotational rheometer, as well as the change in the axial height of the resin asphalt specimen 2.

[0054] It further includes a Peltier temperature control unit, which is connected to the lower plate of the parallel plate 4 of the rotational rheometer and is used to control the temperature of the resin asphalt specimen 2 during the test.

[0055] The rotational rheometer 8 adopts a force control gap tracking option, with a device limit of 0 ± 0.1 N for the compressive axial force, and the gap control range is 475 - 525 μm.

[0056] The sampling frequency of the laser distance sensor 5 is set to 25 Hz, and the measurement distance is set within the range of 77.5 mm - 92.5 mm from the resin asphalt specimen 2.

[0057] As Figure 1 shown, after the laser distance sensor 5 and the resin asphalt specimen 2 are respectively loaded onto the rotational rheometer 8, assuming on one side of the resin asphalt specimen 2, its light should be perpendicular to the parallel plate 4 of the rotational rheometer and pass through the center of the resin asphalt specimen 2, for monitoring the lateral deformation data of the resin asphalt specimen 2. The maximum distance of the lateral deformation of the resin asphalt specimen 2 collected from the rotational rheometer parallel plate baseline 1 is transmitted to the computer 9 through the sensor data line. The computer 9 outputs the volume shrinkage rate of the resin asphalt specimen 2 according to the relevant formula of the resin asphalt volume shrinkage rate calculation method proposed by the present invention.

[0058] The usage method of the above device includes the following steps:

[0059] 1. Connect the test instrument circuit and data line

[0060] Before starting the test, power on the rotational rheometer 8, the laser distance sensor 5, and the computer 9, and the following matters should be confirmed:

[0061] Turn on the gas source system and adjust the air pressure to 0.8 bar;

[0062] Start the Peltier temperature control unit to the preset temperature;

[0063] Turn on the main power of the rotational rheometer 8, wait for the self - test to complete, and complete the software initialization;

[0064] Confirm that the communication between the computer 9 and the rotational rheometer 8 and the laser distance sensor 5 is normal.

[0065] 2. Settings of the rotational rheometer 8 and installation of the parallel plate

[0066] After the rotational rheometer 8 is started, the initialization of the device and the installation of the parallel plates are carried out. The specific operations are as follows: Turn on the power of the main control unit of the rotational rheometer 8; Start the temperature control system (Peltier module) and preheat it to the target test temperature (25°C ± 0.1°C in this embodiment); The rotational rheometer 8 adopts the force control gap tracking option, and uses 0 ± 0.1 N as the equipment limit for the compressive axial force. The gap control range is 475 - 525 μm. The force control gap tracking option can determine the axial gap change by compensating for the axial force caused by the volume change of the material; Install the upper plate of the rotational rheometer parallel plate 4 with a diameter of 25 mm onto the rheometer drive shaft to ensure that the upper plate is firmly installed. Subsequently, install the lower plate of the rotational rheometer parallel plate 4 onto the rheometer temperature control base with a special hex wrench, and confirm that the fixture geometric parameters are loaded correctly on the computer 9.

[0067] 3. Preparation and loading of the resin asphalt sample 2

[0068] Stir each of the two components A and B of the resin asphalt for 30 s, then mix them in proportion into a container and stir for 60 s to make the A and B components evenly mixed. Then place it in an oven at 60°C for 2 h of curing. At this time, the resin asphalt is in a viscous state. Take a small amount of the cured resin asphalt and place it on the lower plate. Then set the scraping gap (520 μm in this embodiment), and then perform scraping to carefully scrape off the resin asphalt sample 2 that overflows significantly; Lower the upper plate further to the initial gap h0 (500 μm in this embodiment) and wait for the test to start.

[0069] 4. Installation of the laser distance sensor 5

[0070] Set up the laser distance sensor 5. The sampling frequency of the laser distance sensor 5 is set to 25 Hz, and the measurement range is set to 77.5 mm to 92.5 mm from the target. As Figure 1 and Figure 2 shown, ensure that the laser line 3 of the laser distance sensor is perpendicular to the rotational rheometer parallel plate 4 and intersects the center point of the resin asphalt sample 2, so that the output profile is equivalent to the cross-sectional profile of the resin asphalt sample 2. Connect the laser distance sensor 5 to the computer 9 and confirm that the measurement data can communicate normally.

[0071] 5. Data acquisition

[0072] After the rotational rheometer 8 and the laser distance sensor 5 are installed, and the resin asphalt sample 2 is scraped and the upper plate of the rotational flow is lowered to the initial gap h0, data acquisition can start. During the entire test process, the axial height of the resin asphalt sample 2 and the maximum distance value of the lateral deformation from the rotational rheometer parallel plate 4 are monitored by the rotational rheometer 8 and the laser distance sensor 5 and transmitted to the computer 9. After the resin asphalt is cured (the curing duration depends on the test temperature), the test terminates and the test ends.

[0073] As Figure 4 shown, a method for measuring the volume shrinkage rate of resin asphalt proposed by the present invention includes the following steps:

[0074] Step 1: Uniformly mix the resin asphalt specimen 2 to be measured in proportion and stir evenly;

[0075] Step 2: Control the temperature of the lower plate of the parallel plate 4 of the rotational rheometer to the required temperature, evenly apply the resin asphalt specimen 2 on the lower plate of the parallel plate 4 of the rotational rheometer, and lower the upper plate of the parallel plate 4 of the rotational rheometer until the gap reaches the set gap h0, and trim the edge of the resin asphalt specimen 2;

[0076] Step 3: Set up a laser distance sensor, and measure the maximum value S of the distance from the contour arc of the resin asphalt specimen 2 to the baseline 1 of the parallel plate of the rotational rheometer in the initial state through the laser distance sensor 5 (0) , measure and calculate the volume V0 of the resin asphalt specimen 2 in the initial state;

[0077] Step 4: Start the rheometer software in the computer 9 and record the axial gap h of the resin asphalt specimen 2 at different times (t) ;

[0078] Step 5: Measure the maximum value S of the distance from the contour arc of the resin asphalt specimen 2 to the baseline 1 of the parallel plate of the rotational rheometer at time t through the laser distance sensor 5 (t) , calculate the volume V of the resin asphalt specimen 2 at time t (t) ;

[0079] Step 6: According to the volume V0 of the resin asphalt specimen 2 in the initial state and the volume V of the resin asphalt specimen 2 at a certain time t during the curing process (t) , calculate the volume shrinkage rate W of the resin asphalt specimen 2 at this time (t) .

[0080] In step 2, the test temperature range of the lower plate of the parallel plate 4 of the rotational rheometer is selected as 20 - 80°C.

[0081] In step 2, lower the upper plate of the parallel plate 4 of the rotational rheometer through a parallel plate fixture, and select a 25 - mm parallel plate for the parallel plate fixture.

[0082] In step 3, assume that the contour geometry of the resin asphalt specimen 2 after lateral deformation is a circular arc.

[0083] In step 3, the calculation formula for the volume V0 of the resin asphalt specimen 2 in the initial state is as follows:

[0084]

[0085] Where, V0 is the volume of the resin asphalt sample 2 at the initial moment; r is the radius of the parallel plate 4 of the rotational rheometer; h0 is the initial gap of the parallel plate 4 of the rotational rheometer; S (0) is the maximum value of the distance between the contour arc of the resin asphalt sample 2 and the baseline 1 of the parallel plate of the rotational rheometer in the initial state.

[0086] In step 5, at a certain moment t during the curing process, the volume V of the resin asphalt sample 2 (t) The calculation formula is:

[0087]

[0088] Where, V (t) is the volume of the resin asphalt sample 2 at the moment t; r is the radius of the parallel plate 4 of the rotational rheometer; h (t) is the gap of the parallel plate 4 of the rotational rheometer at the moment t; S (t) is the maximum value of the distance between the contour arc of the resin asphalt sample 2 and the baseline 1 of the parallel plate of the rotational rheometer measured by the laser distance sensor 5 at the moment t.

[0089] In step 6, the calculation formula for the volume shrinkage rate of the resin asphalt sample 2 at the moment t is as follows:

[0090]

[0091] Where, W (t) is the volume shrinkage rate of the resin asphalt sample 2 at a certain moment t; V0 is the volume of the resin asphalt sample 2 at the initial moment; V (t) is the volume of the resin asphalt sample 2 at the moment t.

[0092] The resin asphalt sample 2 is in a viscous liquid state at the beginning of curing. After the parallel plate descends to the initial height, due to its own gravity, it presents a state of bulging outward horizontally. As Figure 1 shown, at this time, the initial volume of the resin asphalt sample 2 consists of two parts. One part is the volume of the cylinder enclosed by the baseline 1 of the parallel plate of the rotational rheometer on both sides of the parallel plate 4 of the rotational rheometer, and the other part is the volume enclosed by the outer arc and the baseline caused by the horizontal deformation. Assuming that the outer arc caused by the horizontal deformation is a section of arc, according to the calculation formula of the arc area in geometry and the circumference of the circle enclosed by the arc, the corresponding volume can be calculated, and adding these two parts together gives the calculation formula for the initial volume of the resin asphalt sample 2. The calculation formula for the initial volume of the resin asphalt sample 2 is as follows:

[0093]

[0094] Where: V0 is the volume of the resin asphalt sample 2 at the initial moment; r is the radius of the parallel plate; h0 is the initial gap of the parallel plate 4 of the rotational rheometer; S(0) is the maximum distance of the contour arc of the resin asphalt sample 2 from the parallel plate baseline 1 of the rotational rheometer in the initial state.

[0095] Calculate the volume of the resin asphalt sample 2 at a certain moment according to the maximum distance between the lateral deformation contour of the resin asphalt sample 2 and the parallel plate 4 of the rotational rheometer and the axial height.

[0096] During the curing process, the resin asphalt gradually forms strength due to the chemical cross-linking reaction between components. At this time, the lateral deformation generated is different from the initial state and is an inwardly contracting lateral deformation. As Figure 2 shown, the volume of the resin asphalt sample 2 at this time is composed of the volume of the cylinder enclosed by the parallel plate baseline 1 of the rotational rheometer minus the volume enclosed by the arc and the baseline caused by shrinkage. The formula for calculating the volume of the resin asphalt sample 2 at a certain moment during the curing process is as follows:

[0097]

[0098] In the formula, V (t) is the volume of the sample at time t; r is the radius of the parallel plate; h (t) is the gap between the parallel plates 4 of the rotational rheometer at time t; S (t) is the maximum distance of the contour arc of the resin asphalt sample 2 from the parallel plate baseline 1 of the rotational rheometer measured by the laser distance sensor 5 at time t.

[0099] The formula for calculating the volume shrinkage rate of the resin asphalt sample 2 at time t is as follows:

[0100]

[0101] In the formula, W (t) is the volume shrinkage rate of the resin asphalt sample 2 at a certain moment t; V0 is the volume of the resin asphalt sample 2 at the initial moment; V (t) is the volume of the resin asphalt sample 2 at time t.

[0102] The calculation methods of the volume of the resin asphalt sample 2 in the initial state and during the curing process are introduced in detail below.

[0103] Calculation of the test volume in the initial state:

[0104] As Figure 1 shown, the volume form of the resin asphalt sample 2 in the initial state is a cylinder bulging outwards, and its volume is composed of two parts. The first part is the volume of the standard cylinder enclosed by the parallel plate baseline 1 of the rotational rheometer. The formula for calculating this part of the volume is:

[0105] V1 = πr 2 ·h0

[0106] Wherein, r is the radius of the parallel plate; h0 is the initial gap between the parallel plates 4 of the rotational rheometer, which is also the initial height of the resin asphalt sample 2.

[0107] The second part is the volume enclosed by the lateral deformation profile and the baseline 1 of the parallel plates of the rotational rheometer. The calculation principle of this part is as follows:

[0108] Assume that during the initial state and the curing process, the lateral deformation of the resin asphalt sample 2 is an arc. Then, as Figure 1 shown, the deformed cross-sectional area can be approximated as the area of a parabola, and the calculation formula is as follows:

[0109]

[0110] Wherein: A0 is the Figure 1 deformed cross-sectional area shown; h0 is the initial gap between the parallel plates 4 of the rotational rheometer, which is also the initial height of the resin asphalt sample 2, and is measured by the rotational rheometer 8; S (0) is the maximum distance between the sample profile arc and the baseline 1 of the parallel plates of the rotational rheometer in the initial state, and is measured by the laser distance sensor 5.

[0111] Furthermore, it can be assumed that the volume of the annular region enclosed by the lateral deformation profile and the baseline 1 of the parallel plates of the rotational rheometer is unfolded into a "cuboid", and its volume calculation formula is:

[0112] Volume = base area (cross-sectional area A0) × length (annular circumference 2π(r + x s0 ))

[0113] Wherein: A0 is the Figure 1 deformed cross-sectional area shown; r is the radius of the parallel plate; x s0 is the lateral displacement of the centroid of the deformed cross-section in the initial state relative to the baseline 1 of the parallel plates of the rotational rheometer.

[0114] According to geometry, the displacement calculation formula of the centroid of the arc cross-section relative to its chord is:

[0115]

[0116] Wherein: x s0 is the lateral displacement of the centroid of the deformed cross-section in the initial state relative to the baseline 1 of the parallel plates of the rotational rheometer; h0 is the initial gap between the parallel plates 4 of the rotational rheometer, which is also the initial height of the resin asphalt sample 2; S (0) is the maximum distance between the sample profile arc and the baseline 1 of the parallel plates of the rotational rheometer in the initial state; A0 is the Figure 1 deformed cross-sectional area shown.

[0117] The calculation formula for the annular volume enclosed by the second part of the lateral deformation profile and the test plate baseline can be obtained as:

[0118]

[0119] Where: V2 is the annular volume enclosed by the transverse deformation profile and the baseline 1 of the parallel plates of the rotational rheometer; h0 is the initial gap between the parallel plates 4 of the rotational rheometer, that is, the initial height of the resin asphalt sample 2; S (0) is the maximum value of the distance of the sample profile arc relative to the baseline 1 of the parallel plates of the rotational rheometer in the initial state; r is the radius of the parallel plates 4 of the rotational rheometer.

[0120] Thus, it can be obtained that the volume of the resin asphalt sample 2 in the initial state is the sum of two volumes, and its calculation formula is as follows:

[0121]

[0122] Where: V0 is the volume of the resin asphalt sample 2 at the initial moment; r is the radius of the parallel plates 4 of the rotational rheometer; h0 is the initial gap between the parallel plates 4 of the rotational rheometer; S (0) is the maximum value of the distance of the profile arc of the resin asphalt sample 2 relative to the baseline 1 of the parallel plates of the rotational rheometer in the initial state.

[0123] As Figure 2 shown, for the calculation of the volume of the resin asphalt sample 2 at a certain moment during the curing process, the difference from the calculation method in the initial state is only that the transverse deformation profile at this time is a circular arc towards the inside of the resin asphalt sample 2. Similarly, the volume at this time should be the difference between the volume of the cylinder between the lines of the baseline 1 of the parallel plates of the rotational rheometer and the annular volume enclosed by the transverse deformation cross-section and the baseline 1 of the parallel plates of the rotational rheometer.

[0124] The calculation formula for the volume of the resin asphalt sample 2 during the curing process is as follows:

[0125]

[0126] Where, V (t) is the volume of the resin asphalt sample 2 at time t; r is the radius of the parallel plates 4 of the rotational rheometer; h (t) is the gap between the parallel plates 4 of the rotational rheometer at time t; S (t) is the maximum value of the distance of the profile arc of the resin asphalt sample 2 measured by the laser distance sensor 5 relative to the baseline 1 of the parallel plates of the rotational rheometer at time t.

[0127] The above is only a preferred embodiment of the present invention, and it is not a limitation to the present invention in any other form. Any modification or equivalent change made according to the technical essence of the present invention still belongs to the scope protected by the present invention.

Claims

1. An apparatus for measuring the volume shrinkage rate of resin asphalt, characterized in that, It includes a resin asphalt specimen (2), a parallel plate of a rotational rheometer (4), a laser ranging sensor (5), a rotational rheometer (8), a data acquisition system, and a computer (9); The parallel plate of the rotational rheometer (4) is arranged on the rotational rheometer (8) and is used for holding the resin asphalt specimen (2) and applying an axial force; The laser ranging sensor (5) is placed on one side of the resin asphalt specimen (2), and its height is flush with that of the resin asphalt specimen (2), so that the laser is perpendicular to the parallel plate of the rotational rheometer (4) and intersects the center point of the resin asphalt specimen (2), to ensure that the laser profile is consistent with the cross-sectional profile of the resin asphalt specimen (2), and is used for measuring the distance between the lateral deformation of the resin asphalt specimen (2) at any moment and the baseline of the parallel plate of the rotational rheometer (1); The rotational rheometer (8) is used for controlling the temperature, axial force, and real-time measuring the height of the resin asphalt specimen (2); The data acquisition system is respectively connected to the laser ranging sensor (5) and the rotational rheometer (8) and is used for collecting the distance between the lateral deformation of the resin asphalt specimen (2) and the baseline of the parallel plate of the rotational rheometer (1), and the axial height of the resin asphalt specimen (2); the data acquisition system is connected to the computer (9) and is used for calculating the volume shrinkage rate of the resin asphalt specimen (2) according to the change amount of the distance between the lateral deformation of the resin asphalt specimen (2) and the baseline of the parallel plate of the rotational rheometer (1) and the axial height of the resin asphalt specimen (2); It further includes a Peltier temperature control unit, and the Peltier temperature control unit is connected to the lower plate of the parallel plate of the rotational rheometer (4) and is used for controlling the temperature of the resin asphalt specimen (2) during the test.

2. The device for measuring the volume shrinkage rate of resin asphalt according to claim 1, wherein The rotational rheometer (8) adopts a force control gap tracking option, and uses 0±0.1N as the equipment limit of the compressive axial force, and the gap control range is 475-525μm.

3. The device for measuring the volume shrinkage rate of resin asphalt according to claim 1, wherein, The sampling frequency of the laser ranging sensor (5) is set to 25Hz, and the measurement distance is set within the range of 77.5mm - 92.5mm from the resin asphalt specimen (2).

4. A method for measuring the volume shrinkage rate of resin asphalt according to any one of claims 1-3, characterized in that, It includes the following steps: Step 1: Uniformly mix the resin asphalt specimen (2) to be tested in proportion and stir evenly; Step 2: Control the temperature of the lower plate of the parallel plate of the rotational rheometer (4) to the required temperature, evenly apply the resin asphalt specimen (2) on the lower plate of the parallel plate of the rotational rheometer (4), and lower the upper plate of the parallel plate of the rotational rheometer (4) until the gap reaches the set gap h0, and trim the edge of the resin asphalt specimen (2); Step 3: Install a laser distance sensor, and measure the maximum value S of the distance between the contour arc of the resin asphalt specimen (2) and the parallel plate baseline (1) of the rotational rheometer in the initial state by the laser distance sensor (5). (0) Measure and calculate the volume V0 of the resin asphalt specimen (2) in the initial state; Step 4: Start the rheometer software in the computer (9), and record the axial gap h of the resin asphalt specimen (2) at different times (t) ; Step 5: Measure the maximum value S of the distance between the contour arc of the resin asphalt specimen (2) and the parallel plate baseline (1) of the rotational rheometer at time t by means of a laser distance sensor (5). (t) , and calculate the volume V of the resin asphalt specimen (2) at time t (t) . Step 6: Calculate the volume shrinkage rate W of the resin asphalt sample (2) at a certain time t during the curing process according to the volume V0 of the resin asphalt sample (2) in the initial state and the volume V of the resin asphalt sample (2) at time t (t) , where the volume shrinkage rate W of the resin asphalt sample (2) at this moment is calculated (t) .

5. The method for measuring the volume shrinkage rate of resin asphalt according to claim 4, characterized in that In Step 2, the selected range of the test temperature of the lower plate of the parallel plate of the rotational rheometer (4) is 20-80°C.

6. A method for measuring the volume shrinkage rate of resin asphalt according to claim 4, characterized in that In Step 2, lower the upper plate of the parallel plate of the rotational rheometer (4) through a parallel plate fixture, and select a 25mm parallel plate for the parallel plate fixture.

7. A method for measuring the volume shrinkage rate of resin asphalt according to claim 4, characterized in that, In Step 3, assume that the contour geometry of the resin asphalt specimen (2) after lateral deformation is an arc.

8. A method for measuring the volume shrinkage rate of resin asphalt according to claim 4, characterized in that, In Step 3, the calculation formula for the initial volume V0 of the resin asphalt specimen (2) is as follows: In the formula, V0 is the volume of the resin asphalt sample (2) at the initial moment; r is the radius of the parallel plate (4) of the rotational rheometer; h0 is the initial gap of the parallel plate (4) of the rotational rheometer; S (0) is the maximum value of the distance between the contour arc of the resin asphalt sample (2) in the initial state and the baseline (1) of the parallel plate of the rotational rheometer.

9. A method for measuring the volume shrinkage rate of resin asphalt according to claim 4, characterized in that, In step 5, at a certain moment t during the curing process, the volume V of the resin asphalt sample (2) (t) The calculation formula is as follows: Wherein, V (t) is the volume of the resin asphalt sample (2) at time t; r is the radius of the parallel plate (4) of the rotational rheometer; h (t) is the gap of the parallel plate (4) of the rotational rheometer at time t; S (t) is the maximum value of the distance of the contour arc of the resin asphalt sample (2) measured by the laser distance sensor (5) relative to the baseline (1) of the parallel plate of the rotational rheometer at time t.

10. A method for measuring the volume shrinkage rate of resin asphalt according to claim 4, characterized in that, In Step 6, the calculation formula for the volume shrinkage rate of the resin asphalt specimen (2) at time t is as follows: Where, W (t) is the volume shrinkage rate of the resin asphalt sample (2) at a certain moment t; V0 is the volume of the resin asphalt sample (2) at the initial moment; V (t) is the volume of the resin asphalt sample (2) at time t.

Images