Asphalt mixture core sample shrinkage coefficient testing device
By designing a test device for the shrinkage coefficient of asphalt mixture core samples, and using a chassis and displacement sensors to monitor the shrinkage of core samples in real time, the problem of cumbersome preparation process and large measurement error in the existing technology has been solved, and efficient and accurate evaluation of low-temperature crack resistance performance has been achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2026-03-24
AI Technical Summary
Existing methods for testing the shrinkage coefficient of asphalt mixtures suffer from problems such as cumbersome preparation processes, large errors due to temperature changes after specimen removal, and the influence of friction on measurement accuracy, making it difficult to efficiently and accurately measure the low-temperature crack resistance of asphalt mixtures.
An asphalt mixture core sample shrinkage coefficient testing device is adopted, including a chassis and a displacement sensor. The chassis is equipped with a core sample placement groove and steel balls. The displacement sensor contacts the outside of the core sample to monitor the shrinkage of the core sample in different directions in real time, which simplifies the specimen preparation process and reduces the influence of temperature changes on the measurement.
It enables real-time multi-directional shrinkage monitoring of asphalt mixtures, simplifies the specimen preparation process, reduces measurement errors, expands the scope of application of the test, and improves measurement accuracy and efficiency.
Smart Images
Figure CN224035298U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the linear shrinkage coefficient test technical field of asphalt mixture especially relates to a kind of asphalt mixture core sample shrinkage coefficient testing device. BACKGROUND
[0002] Asphalt mixture is a temperature-sensitive material, and its mechanical properties and volume will change under the influence of temperature changes. The reduction of temperature will lead to the reduction of deformation performance of asphalt mixture, and the shrinkage cracking caused by rapid temperature reduction has always been one of the main forms of early damage to pavement. At the same time, its temperature sensitivity will cause micro-cracks in the coupling of load and temperature stress in areas with large temperature difference, which will further develop into more serious diseases, thereby affecting the normal use of the road.
[0003] The linear shrinkage coefficient of asphalt mixture is an important indicator for evaluating the low-temperature crack resistance of asphalt mixture, and it is also a necessary parameter for calculating temperature stress. It has important significance for improving the low-temperature shrinkage cracking resistance of asphalt pavement. At present, the method specified in "Highway Engineering Asphalt and Asphalt Mixture Test Regulations" JTGE20-2011 is mainly used to obtain the shrinkage coefficient of asphalt mixture. However, this method has some drawbacks, which are as follows:
[0004] 1. The test specifies that the rutting plate specimen formed by wheel rolling method is cut into a cuboid specimen with a size of 200mm×20mm×20mm, but the preparation of the specimen takes a long time, the preparation process is complicated, and the preparation efficiency of the specimen is low;
[0005] 2. After the specimen reaches the specified temperature and remains constant, in order to prevent the specimen from changing temperature and causing large measurement error of shrinkage coefficient, the specimen needs to be taken out from the constant-temperature water tank and measured within 5s, which requires high requirements for the test personnel;
[0006] 3. The specimen will expand after contacting with air during the test, which will cause artificial error to the test results;
[0007] 4. The specimen is placed horizontally on the bottom of the constant-temperature water tank, and the tank bottom has a large friction force on the specimen during the shrinkage process of the specimen, which will cause error in the test.
[0008] Based on the above drawbacks, it is of great practical value to develop a test device that can reduce the difficulty of testing the shrinkage coefficient of asphalt mixture. SUMMARY
[0009] In order to overcome the shortcomings of the prior art, the purpose of the utility model is to provide an asphalt mixture core sample shrinkage coefficient testing device which can reduce the difficulty of testing the shrinkage coefficient of asphalt mixture.
[0010] The utility model discloses a purpose adopts following technical scheme realization:
[0011] According to the embodiment of the present disclosure, a kind of asphalt mixture core sample shrinkage coefficient testing device is provided, including bottom disc, the top surface of the bottom disc is recessed with core sample placing groove, several steel balls are arranged in the core sample placing groove;Displacement sensor is arranged on the bottom disc and located the side of core sample placing groove, and displacement sensor is used to contact the outside of core sample in core sample placing groove.
[0012] As a preferred embodiment, four displacement sensors are evenly arranged around the core sample placing groove on the bottom disc.
[0013] As a preferred embodiment, the four displacement sensors are on the same plane.
[0014] As a preferred embodiment, the displacement sensor is square, and the outer wall of the displacement sensor towards the center side of the core sample placing groove is flush with the inner wall of the core sample placing groove.
[0015] As a preferred embodiment, the core sample placing groove is a circular groove.
[0016] As a preferred embodiment, the size of the core sample placing groove is 18cm in diameter and 15cm in length.
[0017] As a preferred embodiment, the diameter of the steel ball is 2mm.
[0018] As a preferred embodiment, the bottom disc is a component made of stainless steel.
[0019] As a preferred embodiment, the displacement sensor is a linear displacement meter.
[0020] In summary, compared with the prior art, the utility model has the following beneficial effects:
[0021] 1. In this application, cylindrical core samples obtained by indoor molding or on-site coring can be directly cut and placed in the core sample placing groove, and then the bottom disc is placed in a high-low temperature constant temperature environment box. Since the core sample test piece will shrink with temperature change, the application sets multiple displacement sensors in different directions to measure the shrinkage of the core sample in different directions in real time, thereby achieving the effect of real-time monitoring of data during the cooling process of the circular core sample.
[0022] 2. This application does not require a cuboid test piece, which simplifies the test piece preparation process of the shrinkage coefficient test and expands the application scope of the test. At the same time, it does not need to take out the test piece for quick measurement, which eliminates the time limit for taking out the test piece and reduces the failure probability of the test, and also eliminates the influence of temperature change on the measurement accuracy after taking out the test piece.
[0023] 3. This device, by setting up multiple displacement sensors, can measure the multi-directional shrinkage coefficient of the specimen in real time, taking into account the influence of the anisotropy of asphalt mixture, and solving the problems of poor accuracy of dial gauge and large error of manual reading in existing shrinkage coefficient tests. Attached Figure Description
[0024] Figure 1 This is a schematic diagram of the overall structure of the asphalt mixture core sample shrinkage coefficient testing device of this utility model;
[0025] The numbers and letters in the diagram represent the names of the corresponding components:
[0026] 1. Chassis; 2. Core sample placement slot; 3. Displacement sensor. Detailed Implementation
[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0028] Example: Figure 1 As shown, an asphalt mixture core sample shrinkage coefficient testing device includes a chassis 1, a core sample placement groove 2 recessed on the top surface of the chassis 1, and a number of steel balls (not shown) arranged in the core sample placement groove 2; a displacement sensor 3 is arranged on the chassis 1 on the side of the core sample placement groove 2, and the displacement sensor 3 is used to contact the outside of the core sample (not shown) in the core sample placement groove 2.
[0029] It should be noted that in this embodiment, the core sample is cylindrical in shape and has a diameter of 15cm.
[0030] Specifically, four displacement sensors 3 are evenly arranged around the core sample placement groove 2 on the chassis 1, such that the included angle between adjacent displacement sensors 3 is 90°.
[0031] In practice, the displacement sensor is a linear displacement gauge.
[0032] Specifically, the four displacement sensors 3 are located on the same plane.
[0033] This allows for more accurate real-time measurement of the shrinkage of the core sample in different directions.
[0034] Specifically, the displacement sensor 3 is square in shape, and the outer wall of the displacement sensor 3 facing the center of the core sample placement groove 2 is flush with the inner wall of the core sample placement groove 2.
[0035] Specifically, the core sample placement groove 2 is a circular groove. The groove size is 18 cm in diameter and 15 cm in length.
[0036] Specifically, the diameter of the steel ball is 2 mm.
[0037] In this way, the core sample is placed in the groove paved with 2 mm diameter steel balls, and the steel balls can reduce the constraint of the external environment on the test piece during the shrinkage process.
[0038] Specifically, the base plate 1 is a component made of stainless steel. In practice, the base plate is made of austenitic stainless steel, which has a small linear shrinkage coefficient, thereby avoiding affecting the test of the shrinkage coefficient of the mixed core sample.
[0039] In this embodiment, the test piece will shrink to different degrees in a constant temperature environment with temperature changes. The purpose of the shrinkage coefficient test is to test the shrinkage degree of the test piece at different temperatures, and then analyze and judge the shrinkage performance of the asphalt mixture. The four displacement sensors installed on the base plate test the length of the test piece in different directions at different temperatures, and the shrinkage coefficient is obtained by analyzing the displacement (i.e. length change).
[0040] When using the asphalt mixture core sample shrinkage coefficient test device of the present application for cold connection, the following steps are taken:
[0041] A. First, prepare the cylindrical core sample obtained from indoor molding or on-site coring, and the cylindrical core sample can be cut according to the requirements;
[0042] B. Place the core sample in the groove paved with 2 mm diameter steel balls, so that the circular arc surface of the core sample is in contact with the four displacement sensors, and the steel balls in the groove can reduce the constraint of the external environment on the test piece during the shrinkage process;
[0043] C. Place the test device in the environmental chamber, set the initial temperature, cooling rate, final temperature, etc. on the environmental chamber, and the displacement sensor can transmit the real-time monitored data to the external data collector. Specifically, if you want to measure the shrinkage coefficient in different temperature intervals, you can heat for a certain time after cooling by a certain temperature, and then use the displacement sensor to measure and record the data.
[0044] The above embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it cannot be understood as a limitation on the scope of the utility model patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are equivalent modifications and evolutions of the above embodiments according to the essential technology of the present application, and these all belong to the protection scope of the present application.
Claims
1. A device for testing the shrinkage coefficient of asphalt mixture core samples, characterized in that, The device includes a chassis, the top surface of which is recessed with a core sample placement groove, and a number of steel balls are arranged in the core sample placement groove. A displacement sensor is provided on the chassis to the side of the core sample placement groove, and the displacement sensor is used to contact the outside of the core sample in the core sample placement groove.
2. The asphalt mixture core sample shrinkage coefficient testing device according to claim 1, characterized in that, Four displacement sensors are evenly arranged around the core sample placement slot on the chassis.
3. The asphalt mixture core sample shrinkage coefficient testing device according to claim 2, characterized in that, The four displacement sensors are located on the same plane.
4. The asphalt mixture core sample shrinkage coefficient testing device according to claim 2, characterized in that, The displacement sensor is square in shape, and the outer wall of the displacement sensor facing the center of the core sample placement groove is flush with the inner wall of the core sample placement groove.
5. The asphalt mixture core sample shrinkage coefficient testing device according to claim 1, characterized in that, The core sample placement slot is a circular groove.
6. The asphalt mixture core sample shrinkage coefficient testing device according to claim 5, characterized in that, The core sample placement slot has a diameter of 18cm and a length of 15cm.
7. The asphalt mixture core sample shrinkage coefficient testing device according to claim 1, characterized in that, The steel ball has a diameter of 2 mm.
8. The asphalt mixture core sample shrinkage coefficient testing device according to claim 1, characterized in that, The chassis is a component made of stainless steel.
9. The asphalt mixture core sample shrinkage coefficient testing device according to claim 1, characterized in that, The displacement sensor is a linear displacement meter.