CN107132137B - Device and method for rutting test of asphalt mixture constrained specimen - Google Patents

Abstract

The invention discloses a kind of asphalts to constrain test specimen wheel tracking test device and method, including environmental cabinet, shell in environmental cabinet and the controller in shell, hydraulic control box, headstock, support plate, tire, trolley, connecting rod, pedestal, four the first rubber pads, four the second rubber pads, side metal wooden partition, displacement sensor for detecting the pressure sensor of the active force between tire and test specimen to be measured and for detecting tire vertical displacement, the device and method can disclose the stress restraint state of test specimen to be measured and the relationship of rutting depth, and can measure bituminous pavement in real road engineering reach capacity rutting depth when be subjected to the equivalent axles of standard load.

Description

Device and method for rutting test of asphalt mixture constrained specimen

technical field

The invention relates to a rutting test device and method, in particular to a rutting test device and method for an asphalt mixture restrained specimen.

Background technique

In recent years, with the country's increasing investment in road construction, my country's road construction has been very rapid. However, due to the late start of highway construction in our country, insufficient experience and technical reserves, especially the complex climatic conditions in our country, severe traffic loads, and frequent occurrence of heavy and overloaded vehicles, a considerable part of the highways have been damaged within a short period of time. The long-term use of the road surface cannot be realized. Among them, pavement rutting is the most common form of damage in many pavement damages, which seriously affects the expected assumption of roads and also causes huge economic losses.

The main types of ruts are: structural ruts, fluid ruts, abrasive ruts and ruts caused by insufficient compaction. Practice has proved that different grades of asphalt pavement paved with the same specification of asphalt concrete have different forces on the internal structure of the pavement under the action of vehicle loads, and the rut depths formed are also different. Existing research methods for pavement rutting generally measure the depth of pavement rutting. The commonly used methods include: ruler measurement method, leveling method, surface elevation meter, laser profiler, ultrasonic range finder, etc. For the traditional rutting measurement method, the principle is simple and the operation is simple, but the workload is heavy, especially for the measurement of rutting on the asphalt road of the expressway, which is inconvenient to operate and has a certain impact on traffic. Now the rapid development of laser and ultrasonic testing is much more convenient and faster. Today's automatic detection technology needs to be further updated and developed in terms of data processing. For the future, more detection tends to be fully automated, and the data processing side will also be more accurate.

Both the traditional measurement method and today's automatic detection technology simply measure the rut depth value of a certain road surface, but neither can reveal the relationship between the force constraints of the test piece and the rut depth, and cannot measure the actual road. When the asphalt pavement reaches the limit rut depth in engineering, it is the equivalent axle times of the standard load.

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned shortcoming of prior art, provide a kind of asphalt mixture restraint test piece rutting test device and method, this device and method can reveal the relationship between the force restraint state of the test piece and the rut depth, and It can measure the equivalent axle times of the standard load when the asphalt pavement reaches the limit rut depth in actual road engineering.

In order to achieve the above object, the rutting test device for asphalt mixture constrained specimens of the present invention comprises an environmental chamber, a shell located in the environmental chamber and a controller located in the shell, a hydraulic control box, a power box, a support plate, tires, a trolley , connecting rod, base, four first rubber pads, four second rubber pads, side metal plate walls, pressure sensor for detecting the force between the tire and the test piece and displacement for detecting the vertical displacement of the tire sensor;

The hydraulic control box is fixed on the top of the shell, the power box is located at the bottom of the shell, the two ends of the support plate are respectively fixed on the side walls of the shell, the trolley is on the support plate, the base is fixed on the trolley, and there are slots on the support plate. Among them, the lower end of the connecting rod is connected with the power box, the upper end of the connecting rod is connected with the bottom of the trolley through the slot hole, the middle part of the upper surface of the base is provided with a rectangular boss, and the four first rubber pads are respectively facing the rectangular boss. The four sides of the first rubber pad are in contact with the sides of the rectangular boss, the upper surface of the rectangular boss is flush with the upper surfaces of the four first rubber pads, and the test piece is located between the rectangular boss and the four On one rubber pad, four second rubber pads are provided on the upper surface of the test piece, one second rubber pad is facing one first rubber pad, the side of the lower end of the side metal plate wall is connected with the side of the base, and the upper end of the side metal plate wall It is bent inward and connected with the upper surface of the second rubber pad, the middle part of the side metal plate wall is connected with the end surface of the test piece, the output shaft of the hydraulic control box is connected with the tire through a hydraulic telescopic rod, and the tire is located on the test piece superior;

The controller is connected with the control end of the power box, the control end of the hydraulic control box, the control end of the environment box, the output end of the pressure sensor and the output end of the displacement sensor.

The side of the lower end of the side metal plate wall is connected with the side of the base through the base fastening screws.

The trolley includes a flat plate and wheels located at the bottom of the flat plate, wherein the wheels are located on the support plate, the base is fixed on the flat plate, and the upper end of the connecting rod is connected with the flat plate.

The controller includes a control panel, a display screen and a power cord connected to an external power supply, among which, the control panel and display screen, the control terminal of the power box, the control terminal of the hydraulic control box, the control terminal of the environmental box, and the output terminal of the pressure sensor And the output terminal of the displacement sensor is connected.

The upper end of the side metal plate wall is bent inward and connected with the upper surface of the second rubber pad through longitudinal fastening screws.

The middle part of the side surface of the side metal plate wall is connected with the end surface of the test piece through an adhesive.

The base is fixed on the plate by bottom screws.

Asphalt mixture constraint test piece rutting test method of the present invention comprises the following steps:

The asphalt mixture specimen is divided into three specimens, and the first specimen is installed in the rutting test device of the asphalt mixture constrained specimen as the specimen to be tested. A test piece exerts force, and the controller controls the power box to drive the trolley to drive the first test piece, so that the tires do reciprocating rolling motion on the first test piece, and complete the rutting test of the first test piece. Depth d ₁ of the rut on the test piece under working conditions;

Replace the first test piece with the second test piece, and then remove the second rubber pads on the left and right sides and the side metal plate wall, and the controller controls the hydraulic control box to make the tire exert force on the second test piece through the hydraulic telescopic rod , the controller controls the power box to drive the trolley to drive the second test piece, so that the tires do reciprocating rolling motion on the second test piece to complete the rutting test of the second test piece, and obtain the depth of the rut d ₂ ;

Replace the second test piece with the third test piece, and remove all the second rubber pads and all the side metal plate walls. The controller controls the hydraulic control box to make the tire exert force on the third test piece through the hydraulic telescopic rod. The controller Control the power box to drive the trolley to drive the third test piece, make the tire do reciprocating rolling motion on the third test piece, complete the rutting test of the third test piece, and obtain the depth d ₃ of the rut on the test piece under unconstrained working conditions;

Calculate the free coefficient α ₁ of the test piece under fully constrained conditions, where, Calculate the free coefficient α ₂ of the test piece under local constraints, where,

Asphalt mixture constraint test piece rutting test method of the present invention comprises the following steps:

The controller controls the hydraulic control box to make the tire exert a force P _i on the test piece through the hydraulic telescopic rod, and the controller controls the power box to drive the trolley to drive the test piece to move, so that the tire performs continuous reciprocating rolling motion on the test piece until the test piece Until the depth of the rut on the test piece is equal to the preset limit rut depth, the equivalent shaft times N of the standard load when the asphalt pavement reaches the limit rut depth in actual road engineering, where, Among them, P is the standard axle load, and n is the rolling times of the tire to be tested before the test piece reaches the limit rut depth.

The present invention has the following beneficial effects:

The rutting test device and method of the asphalt mixture constrained specimen according to the present invention divides the asphalt mixture specimen into three specimens during specific operation, and then detects and obtains the depth d of the rut on the specimen to be tested under the full restraint condition ₁ ; Remove the second rubber pads on the left and right sides and the side metal plate walls, and then detect the depth d ₂ of the ruts on the test piece under local constraints; remove all the second rubber pads and all the side metal plate walls, and then detect Obtain the depth d ₃ of the rut on the test piece under the unconstrained condition, and then calculate the free coefficient α ₁ of the test piece under the full constraint condition and the free coefficient α ₂ of the test piece under the partial constraint condition, thus revealing the The relationship between the force constraint condition of parts and the rut depth is convenient and simple to operate. At the same time, in the specific operation of the present invention, the force P _i is applied to the test piece through the tire, and then the tire is continuously reciprocated on the test piece until the depth of the rut on the test piece is equal to the preset limit rut depth. , to obtain the equivalent axle times N of the standard load when the asphalt pavement reaches the limit rut depth in actual road engineering, the operation is simple and convenient, and the test results are relatively accurate.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is the structural representation of controller 17 among the present invention;

Fig. 3 is the position relationship diagram of base 13 and test piece 12 among the present invention;

Fig. 4 is the positional relationship diagram of the object to be tested 12 and the second rubber pad 11 in the present invention;

Fig. 5 is a structural schematic diagram of the trolley in the present invention.

Among them, 1 is the environmental box, 2 is the shell, 3 is the hydraulic control box, 4 is the hydraulic telescopic rod, 5 is the tire, 6 is the longitudinal fastening screw, 7 is the support plate, 8 is the connecting rod, 9 is the power box, 10 11 is the second rubber pad, 12 is the piece to be tested, 13 is the base, 14 is the plate, 15 is the wheel, 16 is the control panel, 17 is the controller, 18 is the display screen, 19 is the slot, 20 Be the side sheet metal wall, 21 is the base fastening screw.

Detailed ways

The present invention is described in further detail below in conjunction with accompanying drawing:

With reference to Fig. 1, Fig. 2, Fig. 3, Fig. 4 and Fig. 5, the asphalt mixture constrained specimen rutting test device according to the present invention comprises an environmental chamber 1, a housing 2 located in the environmental chamber 1 and a control system located in the housing 2 Device 17, hydraulic control box 3, power box 9, support plate 7, tire 5, trolley, connecting rod 8, base 13, four first rubber pads, four second rubber pads 11, side metal plate wall 20, for A pressure sensor for detecting the force between the tire 5 and the test piece 12 and a displacement sensor for detecting the vertical displacement of the tire 5; the hydraulic control box 3 is fixed on the top of the casing 2, and the power box 9 is located at the bottom of the casing 2, supporting The two ends of the plate 7 are respectively fixed on the side wall of the housing 2, the trolley is located on the support plate 7, the base 13 is fixed on the trolley, and the support plate 7 is provided with a slotted hole 19, wherein the lower end of the connecting rod 8 and the power box 9 connected, the upper end of the connecting rod 8 passes through the slot 19 and is connected to the bottom of the trolley, the middle part of the upper surface of the base 13 is provided with a rectangular boss, and the four first rubber pads face the four sides of the rectangular boss respectively, and the first The side of a rubber pad is in contact with the side of the rectangular boss, the upper surface of the rectangular boss is flush with the upper surfaces of the four first rubber pads, and the test piece 12 is located on the rectangular boss and the four first rubber pads. The upper surface of the test piece 12 is provided with four second rubber pads 11, one second rubber pad 11 is facing a first rubber pad, the side of the lower end of the side metal plate wall 20 is connected with the side of the base 13, and the side of the side metal plate wall 20 The upper end is bent inward and connected to the upper surface of the second rubber pad 11, the middle part of the side metal plate wall 20 is connected to the end surface of the test piece 12, and the output shaft of the hydraulic control box 3 is connected to the tire 5 through the hydraulic telescopic rod 4. Connected, the tire 5 is positioned on the piece to be tested 12; the controller 17 is connected with the control end of the power box 9, the control end of the hydraulic control box 3, the control end of the environment box 1, the output end of the pressure sensor and the output end of the displacement sensor .

The side of the lower end of the side metal plate wall 20 is connected to the side of the base 13 by the base fastening screw 21; On, the upper end of connecting rod 8 is connected with flat plate 14; Controller 17 comprises control panel 16, display screen 18 and the power cord that is connected with external power supply, wherein, control panel 16 and display screen 18, the control terminal of power box 9 , the control end of the hydraulic control box 3, the control end of the environmental box 1, the output end of the pressure sensor and the output end of the displacement sensor are connected; The upper surface of the pad 11 is connected; the middle part of the side metal plate wall 20 is connected with the end surface of the test piece 12 by adhesive; the base 13 is fixed on the flat plate 14 by bottom screws.

The controller 17 is connected with the control end of the power box 9 , the control end of the hydraulic control box 3 , the control end of the environment box 1 , the output end of the pressure sensor and the output end of the displacement sensor through the data line 10 .

The specific operation of the rutting test of the test piece 12 is:

First set the active force that the tire 5 exerts on the test piece 12 on the controller 17, and set the number of times n of rolling, the controller 17 controls the hydraulic control box 3 to apply the active force to the test piece 12 through the hydraulic telescopic rod 4 and the tire 5, Then the power box 9 drives the dolly to run through the connecting rod 8, thereby realizing the rolling of the tire 5 to the test piece 12, the real-time detection of the active force of the tire 5 to the test piece 12 by the pressure sensor, and the active force of the tire 5 to the test piece 12 Forward to the controller 17, the controller 17 shows the force curve of the tire 5 to be tested 12 by the display screen 18, when the number of rolling times of the tire 5 to be tested 12 reaches the set number of times, the power box 9 stops working, then measures The rutting depth on the surface of the test piece 12.

In actual road engineering, different road grades lead to different degrees of rutting on the road surface. For multi-lane expressways, the pavement rutting is generally less, which is not only related to the high level of design and good quality of materials, but also because of During the process, the other lanes provide the supporting effect of lateral force for the stressed lanes, so that the lateral displacement of the directly stressed lanes under the repeated rolling of loads will be reduced, and the final rut depth will be smaller; for low-grade roads , the number of lanes is small, and the mutual support between the various sections of the road surface is insufficient, so the road surface is more prone to large-scale rutting under the repeated action of vehicle loads. The purpose of the present invention is to study the difference in rut depth formed by the test piece 12 under different force constraints, and to explore the relationship between the rut depth and the constraint conditions.

Asphalt mixture constraint test piece rutting test method of the present invention comprises the following steps:

Divide the asphalt mixture specimen into three specimens, install the first specimen as the test specimen 12 in the asphalt mixture constrained specimen rutting test device, and the controller 17 controls the hydraulic control box 3 through the hydraulic telescopic rod 4 The tire 5 exerts force on the first test piece, and the controller 17 controls the power box 9 to drive the trolley to drive the first test piece, so that the tire 5 performs reciprocating rolling motion on the first test piece, and the first test piece is completed. For the rutting test of the piece, the depth d ₁ of the rut on the piece 12 to be tested is obtained under all constraints;

Replace the first test piece with the second test piece, then remove the second rubber pads 11 and the side metal plate walls 20 on the left and right sides, and the controller 17 controls the hydraulic control box 3 to make the tire 5 to the second through the hydraulic telescopic rod 4. The first test piece applies force, the controller 17 controls the power box 9 to drive the trolley to drive the second test piece, so that the tire 5 does reciprocating rolling motion on the second test piece, and completes the rutting test of the second test piece. Depth d ₂ of the rut on the test piece 12 under local constraints;

Replace the second test piece with the third test piece, then remove all the second rubber pads 11 and all the side metal plate walls 20, the controller 17 controls the hydraulic control box 3 to make the tire 5 align with the third test piece through the hydraulic telescopic rod 4 Apply force, the controller 17 controls the power box 9 to drive the trolley to drive the third test piece, so that the tire 5 does reciprocating rolling motion on the third test piece, and completes the rutting test of the third test piece. Depth d ₃ of the rut on the test piece 12;

Calculate the free coefficient α ₁ of the test piece 12 under fully constrained conditions, where, Calculate the free coefficient α ₂ of the test piece 12 under local constraints, where,

Asphalt mixture constraint test piece rutting test method of the present invention comprises the following steps:

The controller 17 controls the hydraulic control box 3 to make the tire 5 exert a force P _i on the test piece 12 through the hydraulic telescopic rod 4, and the controller 17 controls the power box 9 to drive the trolley to drive the test piece 12 to move, so that the tire 5 is on the test piece 12. Do continuous reciprocating rolling motion until the depth of the rut on the test piece 12 is equal to the preset limit rut depth, then the equivalent shaft times N of the standard load when the asphalt pavement reaches the limit rut depth in actual road engineering, where, Wherein, P is the standard axle load, and n is the rolling times of the test piece 12 by the tire 5 before the test piece 12 reaches the limit rut depth.

Claims (8)

1. A kind of asphalt mixture constraint specimen rutting test device, it is characterized in that, comprise environment box (1), be positioned at the shell (2) in the environment box (1) and be positioned at the controller (17) in the shell (2) , hydraulic control box (3), power box (9), support plate (7), tire (5), trolley, connecting rod (8), base (13), four first rubber pads, four second rubber pads pad (11), side metal plate wall (20), a pressure sensor for detecting the force between the tire (5) and the test piece (12), and a displacement sensor for detecting the vertical displacement of the tire (5); The hydraulic control box (3) is fixed on the top of the housing (2), the power box (9) is located at the bottom of the housing (2), the two ends of the support plate (7) are respectively fixed on the side walls of the housing (2), and the trolley is located on On the support plate (7), the base (13) is fixed on the trolley, and the support plate (7) is provided with a slotted hole (19), wherein, the lower end of the connecting rod (8) is connected with the power box (9), and the connecting rod The upper end of (8) passes through the slotted hole (19) and is connected with the bottom of the dolly, the middle part of the base (13) upper surface is provided with a rectangular boss, and four first rubber pads are facing four sides of the rectangular boss respectively, The side of the first rubber pad is in contact with the side of the rectangular boss, the upper surface of the rectangular boss is flush with the upper surfaces of the four first rubber pads, and the test piece (12) is located between the rectangular boss and the four first rubber pads. On the pad, the upper surface of the test piece (12) is provided with four second rubber pads (11), one second rubber pad (11) is facing a first rubber pad, the side of the lower end of the side metal plate wall (20) and the base The sides of (13) are connected, and the upper end of the side metal plate wall (20) is bent inwardly and is connected with the upper surface of the second rubber pad (11), and the middle part of the side metal plate wall (20) side is connected to the test piece (12) The end faces of the hydraulic control box (3) are connected with each other, and the output shaft of the hydraulic control box (3) is connected with the tire (5) through the hydraulic telescopic rod (4), and the tire (5) is positioned on the piece to be tested (12); The controller (17) is connected with the control end of the power box (9), the control end of the hydraulic control box (3), the control end of the environment box (1), the output end of the pressure sensor and the output end of the displacement sensor; The trolley comprises a flat plate (14) and a wheel (15) positioned at the bottom of the flat plate (14), wherein the wheel (15) is located on the support plate (7), the base (13) is fixed on the flat plate (14), and the connecting rod (8) The upper end of the plate (14) is connected. 2. The asphalt mixture constrained specimen rutting test device according to claim 1, characterized in that, the side of the lower end of the side metal plate wall (20) is connected to the side of the base (13) through base fastening screws (21). 3. asphalt mixture constraint test piece rutting test device according to claim 1, is characterized in that, controller (17) comprises control panel (16), display screen (18) and the power cord that is connected with external power supply, Among them, the control panel (16) and the display screen (18), the control end of the power box (9), the control end of the hydraulic control box (3), the control end of the environmental box (1), the output end of the pressure sensor and the displacement sensor The output terminal is connected. 4. Asphalt mixture constraint specimen rutting test device according to claim 1, characterized in that, the upper end of the side metal plate wall (20) is bent inwardly and is connected with the second rubber pad (11) by longitudinal fastening screws (6) ) connected to the upper surface. 5. The asphalt mixture constrained specimen rutting test device according to claim 1, characterized in that, the middle part of the side metal plate wall (20) side is connected with the end surface of the test piece (12) by an adhesive. 6. The asphalt mixture constrained specimen rutting test device according to claim 1, characterized in that the base (13) is fixed on the flat plate (14) by bottom screws. 7. A kind of asphalt mixture restraint specimen rutting test method, is characterized in that, based on the asphalt mixture restraint specimen rutting test device described in claim 1, comprises the following steps: Divide the asphalt mixture test piece into three test pieces, install the first test piece as the test piece (12) in the rutting test device for the asphalt mixture constrained test piece, and the controller (17) controls the hydraulic control box (3 ) through the hydraulic telescopic rod (4) to make the tire (5) exert force on the first test piece, and the controller (17) controls the power box (9) to drive the trolley to drive the first test piece, so that the tire (5) Do reciprocating rolling motion on one test piece, complete the rutting test of the first test piece, get the depth d1 _of the rut on the test piece (12) under all restraint working conditions; Replace the first test piece with the second test piece, then remove the second rubber pads (11) and side metal plate walls (20) on the left and right sides, and the controller (17) controls the hydraulic control box (3) to The rod (4) makes the tire (5) exert force on the second test piece, and the controller (17) controls the power box (9) to drive the trolley to drive the second test piece, so that the tire (5) is on the second test piece Do reciprocating rolling motion on the top, complete the rutting test of the second test piece, and obtain the depth _d2 of the rut on the test piece (12) under local constraints; Replace the second test piece with the third test piece, remove all the second rubber pads (11) and all the side metal plate walls (20), the controller (17) controls the hydraulic control box (3) through the hydraulic telescopic rod ( 4) Make the tire (5) exert a force on the third test piece, and the controller (17) controls the power box (9) to drive the trolley to drive the third test piece, so that the tire (5) does reciprocating rolling on the third test piece Motion, complete the rutting test of the third test piece, get the depth d ₃ of the rut on the test piece (12) under unrestrained working conditions; Calculate the free coefficient α ₁ of the test piece (12) under fully constrained conditions, where, Calculate the free coefficient α ₂ of the test piece (12) under local constraints, where, 8. A kind of asphalt mixture constraint specimen rutting test method, is characterized in that, based on the asphalt mixture constraint specimen rutting test device described in claim 1, comprises the following steps: The controller (17) controls the hydraulic control box (3) to make the tire (5) exert a force P _i on the test piece (12) through the hydraulic telescopic rod (4), and the controller (17) controls the power box (9) to drive the trolley The piece to be tested (12) moves so that the tire (5) performs continuous reciprocating rolling motion on the piece to be tested (12) until the depth of the rut on the piece to be tested (12) is equal to the preset limit rut depth. When the asphalt pavement reaches the limit rutting depth in the project, it is the equivalent shaft times N of the standard load, where, Wherein, P is the standard axle load, and n is the rolling times of the tire (5) for the test piece (12) before the test piece (12) reaches the limit rut depth.