A method for detecting the water seepage performance of highway pavement engineering

Abstract

The present invention discloses a method for detecting the water seepage performance of a highway pavement engineering, belonging to the technical field of highway pavement detection. The pavement to be tested is cleaned so that there are no foreign objects on the pavement to be tested; a closed cofferdam frame is used to cover the cleaned pavement to be tested, and a sealing gasket made of rubber material is fixed to the bottom end surface of the cofferdam frame, and the sealing gasket is vertically pressed on the pavement to be tested; a set amount of water is injected into the cofferdam frame. When injecting water, stop injecting after the amount of injected water reaches the corresponding scale line on the side wall of the cofferdam frame; first stand still for a set time, and then observe whether the decrease of the water level scale line of the cofferdam frame meets the design requirements; pressurize the water in the cofferdam frame. Each time the pressure is increased to the set value, stand still for the set time, and then observe the decrease of the water level scale line of the cofferdam frame. Each time the pressure is increased, the pressure perpendicular to the pavement borne by the sealing gasket increases accordingly. The present invention is easy to detect and operate, can be detected on site, and the data authenticity is higher.

Description

Technical Field

[0001] The present invention relates to the technical field of highway pavement detection, and specifically relates to a method for detecting the water permeability performance of highway pavement engineering. Background Technique

[0002] The detection of highway pavement water permeability is the ability of pavement materials to penetrate water. It is an important indicator for evaluating pavement drainage performance, preventing water accumulation, and protecting the integrity of the pavement structure. Efficient pavement water permeability can not only improve driving safety, but also delay pavement aging and reduce maintenance costs. The commonly used methods for detecting pavement water permeability mainly include the falling hammer permeameter test method, which is one of the most commonly used on-site test methods. During the test, the instrument base is placed on the pavement to be tested, and by releasing a falling hammer of a specific weight, water is forced to pass through the pavement into the pavement layer, and the amount of water passing through the pavement per unit time is measured, thereby calculating the pavement water accumulation permeability coefficient. This method is simple and practical, but is greatly affected by the external environment, such as the types of pavement materials and subgrades, humidity, etc. In addition, there is also the constant head permeability test, that is, under laboratory conditions, the pavement sample is placed in a constant head permeameter, and water flows through the sample under a certain pressure, the amount of water flowing out and the required time are measured, and the permeability coefficient is calculated. This method can more accurately control variables and obtain highly repeatable data, but it does not fully represent the on-site situation.

[0003] In addition, there are also the vacuum suction method and the high performance liquid chromatography (HPLC). Among them, the vacuum suction method is suitable for testing the water permeability of pavement materials in the unsaturated state. It forms a negative pressure under the specimen through a vacuum pump to promote the extraction of water from the pavement materials, and calculates the water permeability according to the amount of water extracted per unit time. This method can better simulate the drainage performance of pavement materials under actual conditions. Although the high performance liquid chromatography is mainly used for the analysis of chemical substances, in certain specific situations, it can also be used to analyze the microstructure of pavement materials and indirectly calculate its water permeability. This method is more applied at the scientific research level to deeply explore the water permeability mechanism of pavement materials.

[0004] From the above existing conventional detection means, first, most of the detections themselves require sampling of the pavement, which involves the problems of sample accuracy and comprehensiveness. Second, this kind of laboratory detection after separate extraction is easy to be separated from the actual environment itself, and the detected data is only laboratory data, which still has a certain gap compared with the actual engineering application. Third, the operation is extremely complex and cumbersome, and the principle itself is relatively complex and professional, making it difficult to master. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the present invention provides a method for detecting the water seepage performance of highway pavement engineering. By using this method for detecting the water seepage performance of highway pavement engineering, the quality of the pavement water seepage can be simply and intuitively measured, which has the advantages of being easy to understand and operate, and the restoration of the pavement working conditions is more realistic.

[0006] To achieve the above object, the present invention provides the following technical solutions: A method for detecting the water seepage performance of highway pavement engineering, including the following steps,

[0007] S1. Clean the pavement to be tested so that there are no foreign objects on the pavement to be tested;

[0008] S2. Cover the cleaned pavement to be tested with a closed cofferdam frame. A sealing gasket made of rubber material is fixed to the bottom end face of the cofferdam frame, and the sealing gasket is vertically pressed against the pavement to be tested;

[0009] S3. Inject a set amount of water into the cofferdam frame. When injecting water, stop injecting after the amount of water reaches the corresponding scale line on the side wall of the cofferdam frame;

[0010] S4. First, let it stand for a set time, and then observe whether the decline of the water level scale line in the cofferdam frame meets the design requirements;

[0011] S5. Pressurize the water in the cofferdam frame. Each time the pressure is increased to the set value, let it stand for a set time, and then observe whether the decline of the water level scale line in the cofferdam frame meets the design requirements. And each time when pressurizing, the pressure perpendicular to the pavement borne by the sealing gasket increases accordingly.

[0012] Further, perform the detection of steps S1 - S5 on a known standard pavement that meets the design requirements, record the corresponding scale line decline values. Then, when detecting the pavement to be tested, compare the collected scale line decline values of each with those of the standard pavement. If the difference percentage is within the design requirements range, it is judged that the water seepage performance is qualified.

[0013] Further, take the scale line decline values collected during the detection of the standard pavement and the pavement to be tested as the ordinate, and each pressure value applied as the abscissa, and draw the change curves of their respective scale line decline values. Compare the change curve of the pavement to be tested with that of the standard pavement. If the curve shape is within the design requirements range, it is judged that the water seepage performance is qualified.

[0014] Further, the cofferdam frame includes a frame body with a smooth inner wall. The sealing gasket is fixedly embedded at the bottom end face of the frame body. A piston plate is vertically slidably installed in the frame body, and the piston plate is in dynamic sealing contact with the frame body, so that when the piston plate moves downward, a pressure on the water is formed, and then the water seepage performance of the pavement under the change of bearing load is tested.

[0015] Further, a drive shaft is perpendicularly connected to the central upper surface of the piston plate. The bottom end of the drive shaft is rotatably connected to the piston plate coaxially, but does not disengage axially. The drive shaft extends axially through the cover plate at the top end of the frame body and protrudes out. There are a pair of shoulders at the protruding end. A circular ring plate is rotatably installed between the two shoulders. A number of pressing arms that can only move vertically are fixed on the outside of the circular ring plate. The bottom end of each pressing arm presses perpendicularly on the upper end surface of the sealing gasket. The drive shaft is threadedly fitted through a threaded knob rotatably installed in place on the top surface of the cover plate. When the threaded knob is rotated, the drive shaft and the pressing arms move in the same direction, while pressurizing the water in the frame, the pressing force of the sealing gasket on the road surface is increased accordingly.

[0016] Further, a guiding block is installed on the outer side arm of the frame body, and the pressing arm is vertically slidably installed in the guiding block at its bottom end.

[0017] Further, a bearing spring is vertically installed between the piston plate and the cover plate, and the bearing spring always has an axial pushing force on the piston plate.

[0018] Further, the outer side of the threaded knob is processed into a gear-like structure, and a number of transmission gears are installed on the cover plate. The transmission gears are meshed with a driving gear driven by a power motor fixed on the cover plate. When applying pressure to the water in the frame body, the power motor is started to make the driving gear rotate, so that the threaded knob rotates in place, driving the drive shaft, the piston plate and the pressing arms to move in the same direction.

[0019] Further, the pressing arm is made into a structure in which the part near the bottom end can be vertically elastically telescoped.

[0020] Further, there is a slot on one side of the frame body, and the slot is closed by a transparent window plate made of tempered glass, and the scale line is vertically provided on the transparent window plate.

[0021] The present invention provides a method for detecting the water seepage performance in highway pavement engineering. It uses a very simple and intuitive principle to detect and study the water seepage of the road surface. Water is stored above the road surface to be measured, and the surrounding is sealed with a sealing gasket, so that the water can only leak out from the road surface. Then, by observing the water level scale line in the cofferdam frame, it can be directly judged whether the water seepage meets the requirements.

[0022] Moreover, in the present invention, with this kind of water seepage detection, there is no need to take samples of the road surface and then detect as in the prior art. It can be detected on the spot, restoring the actual working environment, and there is no obvious damage to the road surface. It can be inspected and removed at any time, and it is not easy to affect traffic.

[0023] Finally, in the present invention, the pressure of the water inside the cofferdam is specifically increased to dynamically test whether the water permeability of the road surface meets the requirements during the process of increasing the load. This is much more scientific and comprehensive than the traditional method of directly sampling the road surface in the laboratory for one-sided detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of a cofferdam frame used in the present invention.

[0025] In the figure: the road surface to be tested 1, the cofferdam frame 2, the frame body 201, the sealing gasket 202, the transparent window plate 203, the piston plate 3, the drive shaft 4, the cover plate 5, the threaded knob 6, the shaft shoulder 7, the circular ring plate 8, the transmission gear 9, the driving gear 10, the power motor 11, the pressing arm 12, the bearing spring 13. SPECIFIC EMBODIMENTS

[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0027] As one of the embodiments of the present invention, this embodiment introduces a method for detecting the water permeability performance of a highway pavement project. During the detection, it mainly includes the following steps. First, clean the road surface 1 to be tested so that there are no foreign objects on the road surface 1 to be tested, and the road surface remains dry. It is best to blow off the dust, and for the adhered asphalt, etc., it can be leveled. Then, on the cleaned road surface 1 to be tested, such as Figure 1As shown in the figure, a closed cofferdam frame 2 is specifically used to firmly cover the road surface 1 to be tested. This cofferdam frame 2 can be cylindrical or cubic, and is specifically selected adaptively according to the specific area shape of the road surface 1 to be tested and the requirements of the detection area. At the same time, a sealing gasket 202 made of rubber material is fixed at the bottom end face of the cofferdam frame 2. The sealing gasket 202 has a certain elasticity. Squeezing the sealing gasket 202 vertically on the road surface 1 can achieve the seal between the road surface and the sealing gasket 202. For example, for the detection occasion with low road surface quality, sealing materials such as plasticine can be used, so that when it bears sufficient extrusion, it can wedge into and fill the large depressions in the road surface part, or wrap the local raised parts to achieve the seal at the contact surface, mainly to prevent water from leaking out from the joint between the sealing gasket 202 at the bottom of the cofferdam frame 2 and the road surface. Then, the tester needs to inject a set amount of water into the cofferdam frame 2. The amount of water is adaptively selected based on the area of the road surface 1 to be tested and the leakage pressure. Specifically, when injecting water, when the amount of water reaches the corresponding scale line on the side wall of the cofferdam frame 2, immediately stop injecting. At this time, if the road surface is a rigid body without water permeability, the water level line will not change in a short time. However, as a qualified highway road surface, it has a certain water permeability. Therefore, after a certain period of time, the water will penetrate downward through the road surface. More specifically, after the water injection is completed, the cofferdam frame 2 needs to be kept static for a set time first, and then observe whether the decrease of the water level scale line of the cofferdam frame 2 meets the design requirements. For example, if it is lower than a certain scale line, the water permeability exceeds the standard; if it is higher than a certain scale line, it means that the water permeability is insufficient, which may cause long-term water accumulation on the road surface and make it easy to skid when driving. In addition to the above static test, this embodiment also needs to conduct a dynamic test with additional load, that is, in this embodiment, the water in the cofferdam frame 2 needs to be pressurized to make the water penetrate through the road surface more easily and quickly. During the detection, every time the water in the cofferdam frame 2 is pressurized to the set value, it is kept static for a set time to let the water gradually leak down, and then observe whether the decrease of the water level scale line of the cofferdam frame 2 meets the design requirements. Moreover, every time the pressure is applied, the pressure perpendicular to the road surface borne by the sealing gasket 202 increases accordingly, to avoid water leakage outside the cofferdam frame 2 due to loose sealing caused by pressurization.

[0028] For this detection method, it can be a specific parametric comparison, that is, according to the existing water permeability theory calculation, the value by which the water in the cofferdam frame 2 should drop is obtained; while this embodiment proposes a qualitative judgment method of intuitive comparison, that is, a standard road surface that meets the design requirements is subjected to the detection of steps S1 - S5. That is to say, this standard road surface is a section of road surface that exactly meets the design water permeability requirements. The water permeability detection method described in the above embodiment is used for detection, and the corresponding scale line drop value is recorded and used as a qualified reference standard in a visualized manner. Then, when detecting the road surface 1 to be measured, the scale line drop values collected are compared with the scale line drop values of the standard road surface. If the difference percentage is within the design requirements, it is judged that the water permeability is qualified. In addition, on this basis, more visualized analysis and comparison can be carried out using images: taking the scale line drop values collected during the detection of the standard road surface and the road surface 1 to be measured as the ordinate, and each pressure value to which the water in the cofferdam frame 2 is pressurized as the abscissa, the change curves of their respective scale line drop values are plotted. When the change curve of the road surface 1 to be measured is compared with the change curve of the standard road surface, if the curve shape is within the design requirements, it is judged that the water permeability is qualified.

[0029] In the above embodiments, for the specific production of the cofferdam frame 2, it can be as Figure 1 shown. This cofferdam frame 2 includes a frame body 201 with a smooth inner wall. A sealing gasket 202 is fixedly embedded at the bottom end surface of this frame body 201. A piston plate 3 is vertically slidably installed in the frame body 201, and the piston plate 3 is in dynamic sealing contact with the frame body 201, that is, the space where the piston plate 3 and the water below it form a closed effect. Thus, when the piston plate 3 moves downward, through this extrusion effect, a direct pressure on the water can be formed, and then the water permeability of the road surface when the bearing load changes can be tested, and the water permeability of the road surface can be measured more dimensionally.

[0030] As one of the specific implementation details, as Figure 1, a drive shaft 4 can be perpendicularly connected to the central upper surface of the piston plate 3. The bottom end of this drive shaft 4 is rotatably connected to the piston plate 3 coaxially, but they never disengage axially and maintain an effective connection. On the other hand, the drive shaft 4 extends axially and slidably through the cover plate 5 at the top end of the housing 201, and there are a pair of shoulders 7 at the extended end of the drive shaft 4. A circular ring plate 8 is rotatably installed between the two shoulders 7. A number of press arms 12 that can only move vertically are fixed on the outside of the circular ring plate 8. The press arms 12 can be generally L-shaped, preferably arranged in a circular array around the edge of the circular ring plate 8, and the bottom end of each press arm 12 presses perpendicularly on the upper end surface of the sealing gasket 202, thereby fixing the sealing gasket 202 and also playing a role in pulling down the cofferdam frame 2 body through the sealing gasket 202, making the cofferdam frame 2 body press more stably on the road surface 1 to be measured, and at the same time preventing the piston plate 3 and the press arms 12 from being blocked from moving downward together due to the rigidity of the cofferdam frame 2 body and being unable to be compressed and deformed. As for the piston plate 3 and the press arms 12 moving downward together, the drive shaft 4 can be threadedly engaged with a threaded knob 6 rotatably installed in place on the top end surface of the cover plate 5. When the threaded knob 6 is rotated during the detection, the drive shaft 4 will move axially accordingly, that is, the drive shaft 4 and the press arms 12 move downward in the same direction. While pressurizing the water in the frame, the squeezing force of the sealing gasket 202 on the road surface is increased accordingly, which is very ingenious and keeps the sealing gasket 202 always within a relatively reasonable squeezing range, neither being too loose nor being easily damaged due to being too tight for a long time. In specific practice, a guide block (not shown in the figure) can be installed on the outer arm of the housing 201. This guide block can be a block similar to a channel steel structure, with the opening facing the side of the press arm 12, and the back of the block is fixed to the outer wall of the housing 201. During use, the vertical end of the press arm 12 near its bottom end can be installed in the guide block in a vertically sliding manner, so that when the threaded knob 6 is rotated, the press arm 12 can be driven to move vertically more stably.

[0031] In order to keep the piston plate 3 always in relative stability, as Figure 1 , a bearing spring 13 is also vertically installed between the piston plate 3 and the cover plate 5. The bearing spring 13 always has an axial pushing force on the piston plate. This pushing force can ensure that the piston plate 3 will not rotate accidentally when the drive shaft 4 is stationary, nor prevent the rotation of the drive shaft 4 when the drive shaft 4 rotates, that is, keep the piston plate 3 relatively fixed when not in use and avoid misoperation of the drive shaft 4, and when in use, the drive shaft 4 can rotate relatively flexibly.

[0032] Regarding the specific driving method of the drive shaft 4, such as Figure 1As shown, the outer side of the threaded knob 6 can be machined into a gear-like structure, and a number of speed-changing gears 9 are installed on the cover plate 5 to achieve speed reduction. The speed-changing gear 9 meshes with the driving gear 10 driven by a power motor 11 fixed on the cover plate 5, thereby driving the threaded knob 6 to rotate. When applying pressure to the water in the housing 201, the power motor 11 is started to make the driving gear 10 rotate, so that the threaded knob 6 rotates in place, driving the drive shaft 4, the piston plate 3, and the pressure arm 12 to move in the same direction. Since the axial movement of the piston plate 3 in the housing 201 may have a very small stroke or a relatively large stroke (for example, there is a large space filled with air between the piston plate 3 and the water surface), the synchronous axial movement amplitude of the drive shaft 4 and the piston plate 3 will be greater than the movement amplitude of the pressure arm 12. Otherwise, the stroke of the pressure arm 12 is too large and will directly pierce through the above-mentioned sealing washer 202. Therefore, in this embodiment, the pressure arm 12 needs to be made into a structure in which the bottom part can vertically elastically expand and contract. When the drive shaft 4 moves downward, in addition to moving downward by a little displacement, the pressure arm 12 itself has a certain vertical contraction ability. For example, there is a component such as a spring in the pressure arm 12, then the spring is further compressed. While the pressure on the sealing washer 202 increases, it can also have an internal relative movement to match the linkage displacement relationship between the drive shaft 4 and the piston plate 3.

[0033] For easy observation, there can be a slot on one side of the housing 201, and the slot is closed by a transparent window plate 203 made of toughened glass. And scale lines are vertically provided on the transparent window plate 203 to observe the internal water level height and master the water seepage situation.

[0034] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device.

[0035] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for detecting water seepage performance for highway pavement engineering, characterized in that: The following steps are included: S1. Clean the road surface (1) to be tested so that there is no foreign matter on the road surface (1) to be tested; S2. A closed cofferdam frame (2) is used to cover the cleaned road surface to be tested (1), and a sealing gasket (202) made of a rubber material is fixed to the bottom end surface of the cofferdam frame (2), and the sealing gasket (202) is vertically squeezed on the road surface to be tested (1); S3. Inject a set amount of water into the cofferdam frame (2). When the water is injected, the injection is stopped after the amount of water reaches the corresponding scale line on the side wall of the cofferdam frame (2); S4. Let it stand for a set time, and then observe whether the water level mark of the cofferdam frame (2) drops in accordance with the design requirements; S5. Pressurize the water in the cofferdam frame (2), and each time the water is pressurized to a set value, let it stand for a set time, and then observe whether the drop of the water level scale line of the cofferdam frame (2) meets the design requirements, and each time the water is pressurized, the pressure perpendicular to the road surface borne by the sealing gasket (202) increases accordingly; Performing the test of steps S1-S5 on a known section of standard road surface that meets the design requirements, recording the corresponding scale line drop values, and then comparing the collected scale line drop values ​​with the scale line drop values ​​of the standard road surface when testing the road surface (1). If the difference percentage is within the design requirement range, it is judged that the water permeability is qualified; The cofferdam frame (2) comprises a frame body (201) with a smooth inner wall, the sealing gasket (202) is fixedly embedded in the bottom end surface of the frame body (201), a piston plate (3) is vertically slidably installed in the frame body (201), and the piston plate (3) and the frame body (201) are in dynamic sealing contact, so that when the piston plate (3) moves downward, pressure on water is generated, and then the water permeability of the road surface when the pressure load changes is tested; A driving shaft (4) is vertically connected to the central upper surface of the piston plate (3), and the bottom end of the driving shaft (4) is coaxially connected to the piston plate (3) but does not separate axially; the driving shaft (4) is axially slidably penetrated through the cover plate (5) at the top end of the frame (201) and then extends out, and a pair of shaft shoulders (7) are provided at the extended end, and a circular ring plate (8) is rotatably installed between the two shaft shoulders (7), and a plurality of pressure arms (12) that can only move vertically are fixed on the outer side of the circular ring plate (8), and the bottom end of each pressure arm (12) is vertically pressed on the upper end surface of the sealing gasket (202); the driving shaft (4) is threadedly fitted through a threaded knob (6) that is rotatably fitted in situ on the top end surface of the cover plate (5), and when the threaded knob (6) is rotated, the driving shaft (4) and the pressure arm (12) move in the same direction, pressurizing the water in the frame while increasing the squeezing force of the sealing gasket (202) on the road surface.

2. A method for detecting water seepage performance for highway pavement engineering according to claim 1, characterized in that: The scale line drop values ​​collected when the standard road surface and the road surface to be tested (1) are respectively tested are used as the ordinate, and each pressure value applied is used as the abscissa, and the change curves of the scale line drop values ​​of each are drawn. The change curve of the road surface to be tested (1) is compared with the change curve of the standard road surface. If the shape of the curve is within the design requirement range, it is judged that the water permeability is qualified.

3. A method for detecting water seepage performance for highway pavement engineering according to claim 1, characterized in that: A guide block is installed on the outer arm of the frame (201), and the pressure arm (12) is installed in the guide block in a vertically sliding manner at its bottom end.

4. A method for detecting water seepage performance for highway pavement engineering according to claim 1, characterized in that: A pressure spring (13) is also vertically installed between the piston plate (3) and the cover plate (5), and the pressure spring (13) always exerts an axial thrust on the piston plate (3).

5. A method for detecting water seepage performance for highway pavement engineering according to claim 1, characterized in that: The outer side of the threaded knob (6) is processed into a gear-shaped structure, and a plurality of speed gears (9) are installed on the cover plate (5). The speed gears (9) are meshed with a driving gear (10) driven by a power motor (11) fixed on the cover plate (5). When pressure is applied to water in the frame (201), the power motor (11) is started to rotate the driving gear (10), so that the threaded knob (6) rotates in place, and drives the driving shaft (4), the piston plate (3) and the pressure arm (12) to move in the same direction.

6. A method for detecting water seepage performance for highway pavement engineering according to claim 5, characterized in that: The pressure arm (12) is made into a structure in which the portion near the bottom end can be elastically retracted vertically.

7. A method for detecting water seepage performance for highway pavement engineering according to claim 1, characterized in that: A strip hole is provided on one side of the frame (201), the strip hole is closed by a transparent window plate (203) made of tempered glass, and the scale line is vertically provided on the transparent window plate (203).

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