Pavement nondestructive testing device based on dielectric properties of asphalt mixture

Abstract

The pavement nondestructive testing device comprises a ground penetrating radar body and a bearing device, the bearing device comprises racks on the left side and the right side, a center elastic column is connected to the inner side of the middle of each rack, the lower end of each center elastic column is connected with a bottom rod, and two idler wheels are rotationally connected to the bottom rods; two rows of bristles are arranged on the lower side of the bottom rod, gaps are reduced, a fixing lug is fixed to the rear side of the rack, a fan is clamped to the fixing lug, a front plate is installed on the front side of the rack, a lower guide plate is fixed to the front end of the bottom rod, and broken line shielding cloth is arranged between the rack and the bottom rod and between the front plate and the lower guide plate. The device is convenient to carry, small in size and convenient to unfold and fold, the stability of the ground penetrating radar body is improved through multiple buffering during moving, accumulated water and sundries at the bottom can be blown away through the fan, and the influence of the accumulated water or the sundries on the road surface is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of non-destructive testing of pavement, in particular to a non-destructive testing device for pavement based on the dielectric properties of an asphalt mixture. Background Art

[0002] Asphalt mixture is a multiphase system consisting of asphalt, mineral aggregate (including coarse and fine aggregate), and voids. Asphalt acts as a binder, bonding the various mineral aggregates of different particle sizes together to form a material with specific properties.

[0003] When asphalt concrete specimens contain water, their dielectric constant increases with increasing moisture content. Using ground-penetrating radar (GPR), combined with the dielectric model formula for asphalt mixtures, the water content can be determined by measuring the dielectric constant of the mixture, providing a theoretical basis for nondestructive testing of asphalt pavements. When electromagnetic pulses generated by GPR propagate through a multi-scale mixture with randomly varying electrical properties, the electromagnetic waves undergo transmission and reflection, forming a large number of incoherent bands. This results in random characteristics in the amplitude and phase of the electromagnetic waves. Based on the variations in parameters such as the amplitude and time window of the reflected wave signal received by the 3D GPR antenna, experimental analysis and other methods can accurately derive indicators such as the thickness, compaction, and moisture content of the pavement structure layer.

[0004] A Chinese patent discloses a portable asphalt pavement nondestructive testing device (authorization publication number CN 218938188U). This patented technology allows for cleaning of asphalt pavement prior to testing. However, after rain, shallow water accumulation can affect detection. Furthermore, uneven pavement surfaces cause vibrations during movement, adversely affecting measurement. Therefore, the present utility model provides a pavement nondestructive testing device based on the dielectric properties of asphalt mixtures to address the issues raised in the aforementioned background technology. Utility Model Content

[0005] The purpose of the present utility model is to provide a road surface non-destructive testing device based on the dielectric properties of asphalt mixtures, so as to solve the problems raised in the above background technology.

[0006] To achieve the above objectives, the present invention provides the following technical solutions:

[0007] A nondestructive road testing device based on the dielectric properties of asphalt mixtures includes a ground-penetrating radar body and a supporting device. The supporting device includes left and right frames. A central elastic column is connected to the inner side of the middle of the frame. The lower end of the central elastic column is connected to a bottom bar. Two rollers are rotatably connected to the bottom bar. The lower side of the bottom bar is provided with two rows of bristles to reduce gaps. The outer side of the roller is provided with an inflatable tire to reduce the impact of uneven road surface. The inner side of the bottom bar is provided with a pair of side elastic columns. The lower ends of the side elastic columns are connected to the front and rear ends of the receiving frame. The ground-penetrating radar body is clamped to the receiving frame.

[0008] The front and rear ends of the frame are both rotatably connected to a cross bar, which is hinged by two rods, and the hinge is connected by a threaded sleeve, and a fixing ear is fixed to the rear side of the frame, and the fixing ear is clamped with a fan, and a bolt hole is provided at the fixing ear. The base of the fan is clamped at the fixing ear and fixedly connected by bolts, and the air outlet of the fan faces downward, and an air guide cover is provided on the lower side of the fan. The air guide cover is made of elastic plastic, and a dense brush is provided on the lower side of the air guide cover to reduce the gap. A front plate is installed on the front side of the frame, and a lower guide plate is fixed on the front end of the bottom bar. A bearing is provided at the rotating shaft of the roller, and a spring is provided at the outer upper end of the bearing. The bearing is slidably connected in the fixing box of the bottom bar, so that when the roller vibrates up and down, the vibration amplitude of the bottom bar can be reduced. A connecting ear is fixed on the upper front side of the frame, and the connecting ear is connected to a traction device through a connecting rope. The traction device can be a person or a car to drive the device to move.

[0009] Preferably, the receiving frame is L-shaped, and a curved surface is provided on one side of the L-shaped vertical plate close to the frame for easy insertion.

[0010] Preferably, a socket is provided at the hinge between the crossbar and the frame, and a pin is inserted into the socket to fix the position of the crossbar.

[0011] Preferably, folded-line shielding cloth is provided between the frame and the bottom rod, and between the front plate and the lower guide plate to reduce the influence of external signals.

[0012] Preferably, the lower side of the lower guide plate is flush with the lower side of the bottom rod, and wind blows out from the lower side of the lower guide plate to flush away the accumulated water on the road surface, thereby reducing the impact on the measurement.

[0013] Preferably, a handle is provided on the middle part of the upper side of the ground penetrating radar body for easy lifting.

[0014] Compared with the prior art, the beneficial effects of the present invention are:

[0015] 1. This device is easy to carry, small in size, and easy to unfold and fold. It improves the stability of the ground penetrating radar body through multiple buffers when moving.

[0016] 2. This device can blow away the accumulated water and debris at the bottom through the setting of the fan, reducing the impact of accumulated water or debris on the road. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a structural diagram of a pavement nondestructive testing device based on the dielectric properties of asphalt mixtures.

[0018] Figure 2 This is a schematic diagram of the disassembled structure of a pavement non-destructive testing device based on the dielectric properties of asphalt mixtures.

[0019] Figure 3 This is a schematic structural diagram of a cross-section of a pavement non-destructive testing device at the crossbar based on the dielectric properties of asphalt mixtures.

[0020] In the figure: 1, frame; 2, central elastic column; 3, bottom bar; 4, roller; 5, folded line shielding cloth; 6, side elastic column; 7, receiving frame; 8, ground penetrating radar body; 9, cross bar; 10, latch;

[0021] 11. Screw sleeve; 12. Fixing ear; 13. Fan; 14. Air guide cover; 15. Connecting ear; 16. Front plate; 17. Lower guide plate. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] See also Figures 1 to 3 In an embodiment of the utility model, a road surface nondestructive testing device based on the dielectric properties of asphalt mixtures includes a ground penetrating radar body 8 and a carrying device. The carrying device includes a frame 1 on the left and right sides. A central elastic column 2 is connected to the inner side of the middle of the frame 1. The lower end of the central elastic column 2 is connected to the bottom rod 3. Two rollers 4 are rotatably connected to the bottom rod 3. Two rows of bristles are provided on the lower side of the bottom rod 3 to reduce the gap. An inflatable tire is provided on the outer side of the roller 4 to reduce the impact of uneven road surface. A pair of side elastic columns 6 are provided on the inner side of the bottom rod 3. The lower ends of the side elastic columns 6 are connected to the front and rear ends of the receiving frame 7. The ground penetrating radar body 8 is clamped on the receiving frame 7. The receiving frame 7 is L-shaped, and the L-shaped vertical plate is provided with an arc surface on the side close to the frame 1 for easy insertion.

[0024] The upper sides of the front and rear ends of the frame 1 are rotatably connected to the cross bar 9, which is formed by hinged connection of two rods. The hinge is connected by a threaded sleeve 11. The hinge of the cross bar 9 and the frame 1 is provided with a socket, and a pin 10 is inserted into the socket to fix the position of the cross bar 9. The rear side of the frame 1 is fixed with a fixing ear 12, and the fixing ear 12 is clamped with a fan 13. The fixing ear 12 is provided with a bolt hole. The base of the fan 13 is clamped with the fixing ear 12 and fixedly connected by bolts. The air outlet of the fan 13 faces downward, and the lower side of the fan 13 is provided with an air guide cover 14. The air guide cover 14 is made of elastic plastic, and the lower side of the air guide cover 14 is provided with a dense brush to reduce the gap. The front side of the frame 1 is installed with a front plate 16, and the front end of the bottom bar 3 is fixed with a lower Guide plate 17, a folded shielding cloth 5 is provided between the frame 1 and the bottom bar 3, and between the front plate 16 and the lower guide plate 17 to reduce the influence of external signals. The lower side of the lower guide plate 17 is flush with the lower side of the bottom bar 3. The wind blows out from the lower side of the lower guide plate 17 to flush away the accumulated water on the road surface, reducing the influence on the measurement. A bearing is provided at the rotating shaft of the roller 4, and a spring is provided at the upper end of the outer side of the bearing. The bearing is slidably connected in the fixed box of the bottom bar 3, so that when the roller 4 vibrates up and down, the vibration amplitude of the bottom bar 3 can be reduced. A connecting ear 15 is fixed on the upper side of the front end of the frame 1, and the connecting ear 15 is connected to the traction device through a connecting rope. The traction device can be a person or a car to drive the device to move. A handle is provided on the middle part of the upper side of the ground penetrating radar body 8 for easy lifting.

[0025] The working principle of the utility model is as follows: when in use, the carrying device is taken out from the box, the latch 10 is pulled out, the frame 1 is pulled open to the left and right sides, the cross bar 9 is in a straight line, the screw sleeve 11 is rotated, the screw sleeve 11 moves from one side of the rod to the hinge, the cross bar 9 is fixed in a straight line, and then the latch 10 is inserted into the socket to complete the overall fixation.

[0026] Insert the ground-penetrating radar body 8 into the middle of the frame 1 and press it on the receiving frame 7. Insert the fan 13 into the fixing ear 12 and fix it with bolts. The battery in the fan 13 supplies power, the ground-penetrating radar body 8 is turned on, and the detection data is stored in the memory card for convenience of later detection. During the test, the device is moved by pulling the rope. During the movement, multiple buffers are used to improve the stability of the ground-penetrating radar body 8. The tire of the roller 4, the spring at the bearing, the central elastic column 2 and the side elastic column 6 can all be used for buffering. The external electromagnetic signal is isolated by the folded line shielding cloth 5. The fan 13 blows air and blows the high-pressure wind to the bottom through the wind guide cover 14, and blows it out from the gap between the lower guide plate 17 on the front side and the ground along the frame 1. The dense brush reduces the gap, directs most of the wind to the front side, and blows the debris or water on the ground to the outside, so that the water level at the detection point is lowered, reducing the impact of water or debris on the road.

[0027] After the measurement is completed, the memory card is removed and the dielectric constant of the asphalt pavement at this time is derived using the formula recorded on the computer. The dielectric constant is then calculated by the computer to obtain the moisture content of the asphalt pavement. The moisture content is the relative density, and the dielectric constant will increase with the increase of moisture content. By comparing it with the standard asphalt pavement moisture content, the test result of the sampling point can be obtained. Multiple points are used in turn and the non-destructive testing results of the asphalt pavement are obtained after summarizing.

[0028] The above is only a preferred specific implementation method of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with the technical field within the technical scope disclosed by the present invention can make equivalent replacements or changes based on the technical solution and inventive concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A non-destructive testing device for a road surface based on the dielectric properties of an asphalt mixture, comprising a ground penetrating radar body (8) and a bearing device, characterized in that: The bearing device comprises a frame (1) on the left and right sides, a central elastic column (2) is connected to the inner side of the middle of the frame (1), the lower end of the central elastic column (2) is connected to the bottom rod (3), the bottom rod (3) is rotatably connected to two rollers (4), the lower side of the bottom rod (3) is provided with two rows of bristles, the outer side of the roller (4) is provided with an inflatable tire, the inner side of the bottom rod (3) is provided with a pair of side elastic columns (6), the lower ends of the side elastic columns (6) are connected to the front and rear ends of the receiving frame (7), and the ground penetrating radar body (8) is clamped on the receiving frame (7); The upper sides of the front and rear ends of the frame (1) are both rotatably connected to a cross bar (9), the cross bar (9) is formed by hinged connection of two bars, and the hinge is connected to a nut (11) by a thread, and a fixing ear (12) is fixed to the rear side of the frame (1), and a fan (13) is clamped to the fixing ear (12), and a bolt hole is provided at the fixing ear (12). The base of the fan (13) is clamped to the fixing ear (12) and fixedly connected by bolts, and the air outlet of the fan (13) faces downward, and the lower side of the fan (13) is provided with an air guide. The wind guide cover (14) is made of elastic plastic, and a dense brush is provided on the lower side of the wind guide cover (14). A front plate (16) is installed on the front side of the frame (1), and a lower guide plate (17) is fixed to the front end of the bottom rod (3). A bearing is provided at the rotating shaft of the roller (4), and a spring is provided at the upper end of the outer side of the bearing. The bearing is slidably connected in the fixed box of the bottom rod (3). A connecting ear (15) is fixed on the upper side of the front end of the frame (1), and the connecting ear (15) is connected to the traction device through a connecting rope.

2. The nondestructive testing device for pavement based on the dielectric properties of asphalt mixture according to claim 1, characterized in that: The receiving frame (7) is L-shaped, and a curved surface is provided on one side of the L-shaped vertical plate close to the frame (1).

3. The nondestructive testing device for pavement based on the dielectric properties of asphalt mixture according to claim 1, characterized in that: A socket is provided at the hinged portion between the crossbar (9) and the frame (1), and a latch (10) is inserted into the socket.

4. The nondestructive testing device for pavement based on the dielectric properties of asphalt mixture according to claim 1, characterized in that: A folded-line shielding cloth (5) is provided between the frame (1) and the bottom rod (3), and between the front plate (16) and the lower guide plate (17).

5. The nondestructive testing device for pavement based on the dielectric properties of asphalt mixture according to claim 1, characterized in that: The lower side of the lower guide plate (17) is flush with the lower side of the bottom rod (3).

6. The non-destructive testing device for pavement based on the dielectric properties of asphalt mixture according to claim 1, characterized in that: A handle is provided at the middle portion of the upper side of the ground penetrating radar body (8).

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