Deformation testing device for asphalt mixture

Abstract

The utility model discloses a deformation testing device for an asphalt mixture. The deformation testing device comprises a base, a mounting frame, a rotating wheel, a guide groove body, a pressing rod and a test piece seat, the mounting frame is mounted above the base; the test piece seat is fixed on the top surface of the base and is positioned below the mounting frame; the guide groove body is embedded in the middle of the mounting frame, and a guide groove which extends in the vertical direction and penetrates through the mounting frame is formed in the guide groove body; the pressing rod is vertically inserted into the guide groove, a plurality of tooth grooves are formed in the side face, away from the groove bottom of the guide groove, of the pressing rod, the tooth grooves extend in the horizontal direction, and the tooth grooves are sequentially distributed in the side face of the pressing rod; a gear shaft is arranged in the middle of the runner; the gear shaft extends in the horizontal direction, the two ends of the gear shaft are inserted into the mounting frames correspondingly, and the peripheral face of the gear shaft is meshed with the multiple tooth grooves. The runner drives the pressing rod to move through the gear shaft; the test piece seat is used for placing a test piece; the lower end of the pressing rod is used for abutting against the top face of the test piece and applying set test pressure. The structure is simple and can be installed and used on a construction site.

Description

Technical Field

[0001] The utility model relates to the technical field of asphalt mixture detection, in particular to a deformation testing device for asphalt mixture. Background Art

[0002] Cold-mix asphalt is a key material used in green road construction and maintenance. Depending on the severity of pavement damage, existing technologies utilize cold-mix asphalt in new construction, repair, and reconstruction.

[0003] Compared to hot-mix asphalt, the degree of deformation of cold-mix asphalt under load is affected by curing time. The deformation resistance of cold-mix asphalt is a key factor affecting the opening of a project to traffic. Currently, my country's curing time and testing for cold-mix asphalt mixtures refer to the 60°C dynamic stability test for cold-mix recycled mixtures in the "Technical Specification for Highway Asphalt Pavement Regeneration" (JTG / T 5521-2019) to determine the opening to traffic.

[0004] The existing dynamic stability test method is to use a wheel tracker to test the dynamic stability of a wheel track plate specimen made from core pieces cut on site, or a wheel track plate specimen made according to regulations using the cold-mix asphalt mixture used in construction, at a constant temperature of 60°C. Only when the dynamic stability test results of the specimen meet the quality standards of the corresponding highway grade, that is, the early deformation performance of the cold-mix asphalt mixture meets the standard requirements, will construction acceptance and opening to traffic be allowed.

[0005] To promptly confirm that the cold-mix asphalt mixture at the construction site meets the quality requirements for traffic, multiple inspections are required during the maintenance process. However, due to the large size and poor portability of wheel trackers, they are not easy to install at the construction site, requiring long-distance inspections, which reduces the efficiency of inspections. Utility Model Content

[0006] In view of the above-mentioned shortcomings, the purpose of the present invention is to provide a deformation testing device for asphalt mixture to solve the problems of inconvenient on-site testing of test pieces and low testing efficiency.

[0007] To achieve this purpose, the present invention adopts the following technical solutions:

[0008] A deformation testing device for asphalt mixture, comprising a base, a mounting frame, a runner, a guide trough, a pressure rod and a specimen seat;

[0009] The mounting frame is mounted above the base; the specimen seat is fixed to the top surface of the base, and the specimen seat is located below the mounting frame;

[0010] The guide groove body is embedded in the middle of the mounting frame, and the guide groove body is provided with a guide groove extending in a vertical direction and passing through the mounting frame;

[0011] The pressure rod is vertically inserted into the guide groove, and a plurality of tooth grooves are provided on the side of the pressure rod away from the bottom of the guide groove. The tooth grooves extend in the horizontal direction, and the plurality of tooth grooves are arranged in sequence from top to bottom on the side of the pressure rod;

[0012] A gear shaft is provided in the middle of the rotating wheel; the gear shaft extends in the horizontal direction, and both ends of the gear shaft are respectively inserted into the mounting frame, and the outer peripheral surface of the gear shaft is engaged with the plurality of teeth; the rotating wheel drives the pressure rod to move through the gear shaft;

[0013] The test piece seat is used to place the test piece; the lower end of the pressure rod is used to press the top surface of the test piece and apply a set test pressure.

[0014] Furthermore, it also includes a traction rope;

[0015] One end of the traction rope is wound around the outer circumference of the rotating wheel; the other end of the traction rope is used to hang a counterweight;

[0016] The test pressure applied to the lower end surface of the pressure rod is 0.7 MPa.

[0017] Furthermore, it also includes a crossbar;

[0018] The cross bar is mounted on the side of the mounting frame, the cross bar is located above the rotating wheel, and the extension direction of the cross bar is parallel to the extension direction of the gear shaft;

[0019] The other end of the traction rope passes over the cross bar from above and then extends downward to be used for hanging a counterweight.

[0020] Preferably, the diameter ratio of the rotating wheel to the gear shaft is 12:1 or 15:1.

[0021] Preferably, the diameter of the lower end portion of the pressure rod is 10.0-10.2 mm.

[0022] Preferably, the specimen seat is a cylinder, and the diameter of the specimen seat is 100-102 mm.

[0023] The beneficial effects of the technical solution of the present invention are as follows: the deformation testing device for asphalt mixture applies test pressure to the top surface of the test piece through the cooperation of the rotating wheel and the pressure rod, simulating the static pressure effect of the tire, has a simple structure, is easy to operate, has low installation requirements, has good portability, and can be installed and used nearby at the construction site. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural diagram of the test of the present utility model;

[0025] Figure 2 This is a schematic diagram of the installation structure of some parts of the testing device of the present utility model;

[0026] Among them: base 1; mounting frame 2; rotating wheel 3; guide trough body 4; pressure rod 5; specimen seat 6; cross bar 7; traction rope 8; gear shaft 31; tooth groove 51. DETAILED DESCRIPTION

[0027] The following is combined with Figure 1-2 The technical solution of the utility model is further illustrated through specific implementation methods.

[0028] The accompanying drawings are for illustrative purposes only and are not to be construed as limitations on this patent. To better illustrate this embodiment, some components of the accompanying drawings may be omitted, enlarged, or reduced in size, and do not represent the actual dimensions of the product. For those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted from the accompanying drawings.

[0029] In the description of this utility model, it should be noted that, unless otherwise specified or limited, the terms "mounted" and "connected" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integral connection; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium, which can be said to be the internal communication between two components. For those skilled in the art, the specific meanings of the above terms in this utility model can be understood by those skilled in the art in specific circumstances.

[0030] A deformation testing device for asphalt mixture, comprising a base 1, a mounting frame 2, a runner 3, a guide trough 4, a pressure rod 5 and a specimen seat 6;

[0031] The mounting frame 2 is mounted on the top of the base 1; the specimen seat 6 is fixed to the top surface of the base 1, and the specimen seat 6 is located below the mounting frame 2;

[0032] The guide slot body 4 is embedded in the middle of the mounting frame 2, and the guide slot body 4 is provided with a guide slot extending in the vertical direction and passing through the mounting frame 2;

[0033] The pressure rod 5 is vertically inserted into the guide groove. A plurality of tooth grooves 51 are provided on the side of the pressure rod 5 away from the bottom of the guide groove. The tooth grooves 51 extend in the horizontal direction. The plurality of tooth grooves 51 are arranged in sequence from top to bottom on the side of the pressure rod 5.

[0034] A gear shaft 31 is provided in the middle of the rotating wheel 3; the gear shaft 31 extends horizontally, and both ends of the gear shaft 31 are respectively inserted into the mounting frame 2, and the outer peripheral surface of the gear shaft 31 is engaged with the plurality of tooth grooves 51; the rotating wheel 3 drives the pressure rod 5 to move through the gear shaft 31;

[0035] The test piece seat 6 is used to place the test piece; the lower end of the pressure rod 5 is used to press the top surface of the test piece and apply a set test pressure.

[0036] The deformation testing device for asphalt mixture of the present invention utilizes the runner 3 to drive the pressure rod 5, and applies the test pressure to the top surface of the test piece through the lower end of the pressure rod 5 to simulate the static pressure effect of the tire; without the use of a wheel tracking instrument, the relevant deformation test can be simulated at the construction site to evaluate whether the strength and compressive deformation of the constructed cold-mix asphalt mixture meet the acceptance conditions, so that the piece can be sent for inspection at an appropriate time.

[0037] The deformation testing device for asphalt mixture of the present invention can select various test pieces made in different forms. The test pieces can be Marshall standard test pieces cut on site, Marshall standard test pieces made from the tested cold-mix asphalt mixture, or thin layer test pieces of corresponding layer thickness prepared from the tested cold-mix asphalt mixture, so as to meet the acceptance test evaluation of different grades of asphalt highway repairs and have a better scope of application.

[0038] During specific implementation, a driving device may be configured to drive the rotating wheel 3 to rotate, and the lower end surface of the pressure rod 5 is directed downward to apply a set test pressure to the test piece.

[0039] The early deformation rate V of the corresponding test piece is calculated according to the following formula:

[0040]

[0041] Where t is the time taken for compression rod 5 to displace during the test, in minutes; D is the displacement of the lower end of compression rod 3 during the test, in millimeters. During testing, the test piece was maintained at a constant temperature of 60°C, in accordance with the JTGE20-2019 test procedure, to avoid errors in the test results.

[0042] Furthermore, it also includes a traction rope 8;

[0043] One end of the traction rope 8 is wound around the outer circumference of the wheel 3; the other end of the traction rope 8 is used to hang a counterweight;

[0044] The test pressure applied to the lower end surface of the pressure rod 5 is 0.7 MPa.

[0045] A counterweight and a traction rope 8 are used to drive the wheel 3, so that the pressure rod 5 applies a test pressure of 0.7 MPa to the test piece to simulate the rutting load requirements specified in the JTGE20-2019 test regulations, thereby improving the reliability and accuracy of the simulation test of the deformation testing device for asphalt mixture.

[0046] Furthermore, it also includes a crossbar 7;

[0047] The cross bar 7 is mounted on the side of the mounting frame 2 , and is located above the rotating wheel 3 . The extending direction of the cross bar 7 is parallel to the extending direction of the gear shaft 31 .

[0048] The other end of the traction rope 8 passes over the cross bar 7 from above and then extends downward to suspend a counterweight.

[0049] like Figure 2 As shown, by suspending the other end of the traction rope 8 through the cross bar 7, the suspended counterweight can be prevented from being blocked by other objects when falling freely, thereby improving the effectiveness of the test.

[0050] Preferably, the diameter ratio of the rotating wheel 3 to the gear shaft 31 is 12:1 or 15:1.

[0051] By setting the diameter ratio of the runner 3 to the gear shaft 31 to 12:1 or 15:1, a transmission torque of 12:1 or 15:1 can be obtained accordingly. In this way, the test pressure applied to the top surface of the test piece can meet the test requirement of 0.7 MPa by using a light counterweight.

[0052] Preferably, the diameter of the lower end of the pressure rod 5 is 10.0-10.2 mm.

[0053] Under the condition that the driving force applied to the rotating wheel 3 is the same, the smaller the diameter of the lower end of the pressure rod 5, the greater the test pressure acting on the top surface of the test piece. The diameter of the lower end of the pressure rod 5 is selected to be 10.0-10.2 mm, which can not only avoid the test area being too small, but also ensure the effectiveness of the test.

[0054] Preferably, the specimen seat 6 is a cylinder, and the diameter of the specimen seat 6 is 100-102 mm.

[0055] The diameter ratio of the wheel 3 to the gear shaft 31 is set to 12:1 or 15:1, and the diameter of the lower end of the pressure rod 5 is set to 10.0-10.2 mm. A light counterweight can be used to ensure that the test pressure applied to the top surface of the test piece meets the test requirement of 0.7 MPa.

[0056] The diameter of the specimen holder 6 is set to 100-102 mm, and the diameter of the test piece is controlled to be around 100 mm, as long as it does not affect the test results. This can reduce test materials and lower test costs.

[0057] Examples 1-3

[0058] 1. According to the raw material parameters and composition ratios listed in Table 1, a Marshall specimen compactor was used to produce cylindrical test pieces of each embodiment with a thickness of 63.5±1.2 mm and a diameter of 101.6±0.2 mm. The test pieces were then placed in an oven at a constant temperature of 60°C for curing.

[0059] Table 1 Raw material parameters and composition ratios of each embodiment

[0060]

[0061]

[0062] 2. Using the test device described above, test the early deformation of the test piece of each embodiment according to the following steps. The specific steps are as follows:

[0063] S1) Place the test piece on the top surface of the test piece holder 6, and make the lower end surface of the pressure rod 5 contact the top surface of the test piece;

[0064] S2) Hanging a counterweight on the exposed end of the traction rope 8 wound around the rotating wheel 3, causing the rotating wheel 3 to rotate under the gravity of the counterweight, and causing the rotating wheel 3 to drive the pressure rod 5 vertically downward through the gear shaft 31 to apply a test pressure to the top surface of the test piece;

[0065] S3) testing the test pieces of each embodiment with curing times of 4 h, 8 h, 12 h, 16 h, 20 h, and 24 h, respectively, measuring and recording the displacement data of the pressure rod 5 and the corresponding displacement time of the pressure rod 5 during each test, and then plotting a curve based on the recorded data. The test results are shown in Table 2;

[0066] S4) According to the formula Calculate the early deformation rate V of the corresponding test piece, where t is the time taken for the compression rod 5 to displace, in min; D is the deformation displacement occurring during the test, in mm.

[0067] It should be noted that the diameter ratio of the wheel 3 to the gear shaft 31 of the test device used in the above test is 12:1, the diameter of the lower end of the pressure rod 5 is 10.0 mm, and the weight of the counterweight is 458 g.

[0068] Table 2 Early deformation rate and dynamic stability test results of various embodiments

[0069]

[0070]

[0071] When the deformation ratio of 45-60min in the test process of the early deformation rate V after two consecutive curing is less than 20% of the total change rate of the deformation rate V, it can be considered that the curing strength of the constructed cold-mix asphalt mixture has met the requirements and samples can be sent for dynamic stability testing.

[0072] In summary, the early deformation testing method of cold-mix asphalt mixture of the present invention applies a test pressure to the top surface of the test piece through the cooperation between the gear shaft 31 of the runner 3 and the tooth groove 51 of the pressure rod 5, which can simulate the static pressure effect of the tire. The deformation test can be simulated at the construction site without the use of a wheel tracking meter. It can be evaluated by itself whether the strength and compressive deformation resistance of the constructed cold-mix asphalt mixture meet the acceptance conditions, so that the piece can be sent for inspection at an appropriate time, thereby improving the convenience of deformation detection and the efficiency of detection work.

[0073] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are intended solely to illustrate the principles of the present invention and should not be construed in any way as limiting the scope of protection of the present invention. Based on the explanations herein, those skilled in the art will be able to devise other specific implementations of the present invention without inventive effort, and such implementations will fall within the scope of protection of the present invention.

Claims

1. A deformation testing device for asphalt mixture, characterized in that: It includes a base, a mounting frame, a rotating wheel, a guide trough, a pressure rod and a specimen seat; The mounting frame is mounted above the base; the specimen seat is fixed to the top surface of the base, and the specimen seat is located below the mounting frame; The guide groove body is embedded in the middle of the mounting frame, and the guide groove body is provided with a guide groove extending in a vertical direction and passing through the mounting frame; The pressure rod is vertically inserted into the guide groove, and a plurality of tooth grooves are provided on the side of the pressure rod away from the bottom of the guide groove. The tooth grooves extend in the horizontal direction, and the plurality of tooth grooves are arranged in sequence from top to bottom on the side of the pressure rod; A gear shaft is provided in the middle of the rotating wheel; the gear shaft extends in the horizontal direction, and both ends of the gear shaft are respectively inserted into the mounting frame, and the outer peripheral surface of the gear shaft is engaged with the plurality of teeth; the rotating wheel drives the pressure rod to move through the gear shaft; The test piece seat is used to place the test piece; the lower end of the pressure rod is used to press the top surface of the test piece and apply a set test pressure.

2. The deformation testing device for asphalt mixture according to claim 1, characterized in that: Also includes a leash; One end of the traction rope is wound around the outer circumference of the rotating wheel; the other end of the traction rope is used to hang a counterweight; The test pressure applied to the lower end surface of the pressure rod is 0.7 MPa.

3. The deformation testing device for asphalt mixture according to claim 2, characterized in that: Also includes crossbars; The cross bar is mounted on the side of the mounting frame, the cross bar is located above the rotating wheel, and the extension direction of the cross bar is parallel to the extension direction of the gear shaft; The other end of the traction rope passes over the cross bar from above and then extends downward to be used for hanging a counterweight.

4. The deformation testing device for asphalt mixture according to claim 2, characterized in that: The diameter ratio of the rotating wheel to the gear shaft is 12:1 or 15:

1.

5. The deformation testing device for asphalt mixture according to claim 2, characterized in that: The diameter of the lower end portion of the pressure rod is 10.0-10.2 mm.

6. The deformation testing device for asphalt mixture according to claim 2, characterized in that: The specimen seat is a cylinder, and the diameter of the specimen seat is 100-102 mm.

Images