A road surface local pre-maintenance device and related road pre-maintenance method

Abstract

The present invention discloses a local pre-maintenance device for a road surface layer and a related road pre-maintenance method. The device comprises a pressure supply device, a slurry inlet, a slurry outlet, a slurry outlet pipeline, a gas-liquid two-phase storage tank, an air inlet pipeline, a gas-liquid isolation element group, an air inlet, an air outlet, an air outlet pipeline, an air flow control element group, a slurry inlet pipeline, a slurry flow control device and a liquid discharge pipe; the pre-maintenance device is provided with an air flow path and a slurry flow path, and the two paths intersect at the gas-liquid two-phase storage tank, and the related road pre-maintenance method comprises the steps of slurry preparation, grouting and equipment cleaning. The present invention reduces the local porosity of the road surface layer and improves the strength, impermeability and water damage resistance of the road surface layer in a way that does not disturb or less disturbs the original materials and structures during the new road construction stage, before the occurrence of diseases or at a stage where the degree of diseases is relatively mild.

Description

Technical Field

[0001] The invention relates to the field of road engineering, and in particular to a road surface local pre-maintenance device and a related road pre-maintenance method. Background Art

[0002] Flexible pavement surface structures represented by asphalt mixtures may have defects such as insufficient local compaction and excessive voids due to material design, construction errors, plane position, unfavorable control of necessary construction and maintenance conditions, etc. Such local defects will reduce the strength, impermeability and deformation resistance of flexible (asphalt mixture) pavement, accelerate the occurrence and development of various diseases such as rutting, local settlement, cracks, looseness, and bottom voiding, and have a serious adverse impact on the road's traffic capacity, safety, aesthetics and driving comfort.

[0003] At present, local defects in the surface layer of flexible pavements and the diseases caused by them are usually maintained and repaired by the method of partial crushing, removal and re-paving. However, this treatment method is complicated and costly (personnel, materials, equipment turnover, etc.), and there are many problems such as poor aesthetics of the repaired area. The traditional maintenance and repair workflow includes at least crushing, cleaning, leveling, sawing, cleaning, paving, compacting, etc., which is much more complicated than the construction of new pavement. Local defects are mostly randomly or discretely distributed. The traditional local replacement method requires a large number of personnel, complex equipment, low equipment and personnel turnover efficiency, and high cost. In addition, the color of the re-paved area is difficult to coordinate with the surrounding area, and it is easy to form a "patch" appearance, which seriously affects the appearance of the road.

[0004] The most serious problem with this type of treatment method is that it not only causes serious waste of materials, but also often has poor durability. Traditional replacement repairs require a significant expansion of the scope of crushing with the local disease as the center, which not only wastes the residual strength of the material in the disease area, but also may cause unnecessary disturbances in the surrounding areas of the surface layer. In fact, for local small-scale paving or locations around wells, road edges, etc., due to cost or construction conditions (such as limitations of existing surface materials or road ancillary facilities in the surrounding area), large-scale paving or rolling machinery is usually not available, or the use of machinery still results in poor construction results, resulting in the re-paved surface layer still having defects such as insufficient local compaction and excessive porosity. Therefore, replacement repair can only temporarily eliminate rutting, local settlement, cracks, looseness, bottom voiding and other diseases on the surface, but cannot completely eliminate the causes of the diseases. The same or more serious diseases are very likely to occur again in the same location in a short period of time.

[0005] In fact, although excessive local porosity will affect the material strength, stability and impermeability, the surface material still has a certain strength and can partially bear vehicle loads. If the original pavement structure and materials can be retained, the defects such as excessive local porosity in the surface layer of the flexible pavement can be treated in advance in a way that does not disturb or less disturbs the original materials and structures during the new road construction stage, before the disease occurs or when the disease is relatively mild, that is, preventive maintenance, it can effectively improve the performance and durability of the road. However, at this stage, relevant ideas, plans, equipment, methods and technologies are relatively lacking. Summary of the invention

[0006] The purpose of the present invention is to provide a road surface local pre-maintenance device and a related road pre-maintenance method.

[0007] The object of the pre-maintenance method proposed in the present invention is a flexible road surface layer that has been paved and has defects such as excessive local void ratio.

[0008] The present invention proposes a special device for local pre-maintenance of road surface layer and a related road pre-maintenance method. On the basis of retaining 80% to 100% of the original surface layer material in the defective area, the reinforcing slurry is made to seep into and fill the internal voids of the reinforced object by using the compressed gas pressure and the self-weight of the reinforcing slurry, and after the process of maintenance or curing, a solid or semi-solid is formed, thereby reducing the local void ratio of the surface layer material and improving the surface layer strength, impermeability and water damage resistance. The reinforcing slurry refers to any one of a fluid liquid, a solid-liquid mixture, a gas-liquid mixture or a gas-solid-liquid mixture.

[0009] The present invention proposes a road surface local pre-maintenance device, comprising a pressure supply device 1, a slurry discharge pipeline 4, a gas-liquid two-phase storage tank 5, an air intake pipeline 8, a gas-liquid isolation element group 9, an air outlet pipeline 12, an air flow control element group 13, a slurry intake pipeline 14, a slurry flow control device 15 and a liquid discharge pipe 16; the pre-maintenance device is provided with an air flow path and a slurry flow path, and the two paths intersect at the gas-liquid two-phase storage tank 5, wherein:

[0010] The gas flow path is the flow path of the compressed gas in the pre-curing equipment; the slurry flow path refers to the flow path of the reinforcing slurry in the pre-curing equipment; the reinforcing slurry refers to any one of a fluid liquid, a solid-liquid mixture, a gas-liquid mixture or a gas-solid-liquid mixture;

[0011] The gas-liquid two-phase storage tank 5 is a container including a cavity area 6 and a slurry storage area 7; the cavity area 6 refers to the area at the top of the gas-liquid two-phase storage tank 5 where there is no reinforcing slurry; the slurry storage area 7 refers to the storage area of ​​the reinforcing slurry or the reinforcing slurry raw material at the bottom of the gas-liquid two-phase storage tank 5; the gas-liquid two-phase storage tank 5 is provided with an air inlet 10, an air outlet 11, a slurry inlet 2 and a slurry outlet 3;

[0012] The pressure supply device 1 is connected to the air inlet 10 of the gas-liquid two-phase storage tank 5 through the air inlet pipeline 8, and a gas-liquid isolation element group 9 is arranged in the air inlet pipeline 8 to prevent the reinforcing slurry from flowing back into the pressure supply device 1; the air outlet 11 is connected to the air outlet pipeline 12; the air flow control element group 13 is arranged in the air inlet pipeline 8 and / or the air outlet pipeline 12; the pressure supply device 1, the air inlet pipeline 8, the air flow control element group 13, the gas-liquid isolation element group 9, the air inlet 10, the gas-liquid two-phase storage tank 5, the air outlet 11 and the air outlet pipeline 12 constitute an air flow path; the complete air flow path is that the compressed gas is generated or released by the pressure supply device 1, passes through the air inlet pipeline 8, enters the gas-liquid two-phase storage tank 5 from the air inlet 10, gathers in the cavity area 6, and is finally discharged in a controlled manner through the air outlet 11 and the air outlet pipeline 12;

[0013] The slurry flow path is composed of a slurry inlet pipeline 14, a slurry inlet 2, a gas-liquid two-phase storage tank 5, a slurry outlet 3, a slurry flow control device 15 and a slurry outlet pipeline 4 and / or a drainage pipe 16; the slurry inlet is externally connected to the slurry inlet pipeline 14; the slurry outlet 3 is externally connected to the slurry outlet pipeline 4; the slurry outlet pipeline 4 or the drainage pipe 16 is connected from the slurry outlet 3; a slurry flow control device 15 is arranged in the slurry outlet pipeline 4 and / or the slurry outlet 3; the complete slurry flow path is that the reinforced slurry enters the gas-liquid two-phase storage tank 5 from the slurry inlet pipeline 14 through the slurry inlet 2, is temporarily stored in the gas-liquid two-phase storage tank 5, and finally is either injected into the reinforced object through the slurry outlet 3 and the slurry outlet pipeline 4 in a controlled manner, or is discharged through the drainage pipe 16.

[0014] In the present invention, when the gas-liquid two-phase storage tank 5 stores slurry and compressed gas flows into the gas-liquid two-phase storage tank 5 through the gas inlet 10, the compressed gas passes through the gas-liquid two-phase storage tank 5 to reinforce the slurry and gathers in the cavity area 6.

[0015] In the present invention, the air inlet 10 is arranged at the bottom or body of the gas-liquid two-phase storage tank 5, and the air inlet 10 is lower than the lowest liquid level of the slurry during grouting.

[0016] In the present invention, the airflow control element group 13 is a series, parallel or series-parallel combination of one or more of the fluid and flow control elements such as a shut-off valve, a flow valve, a constant pressure valve, a pressure reducing valve, a one-way valve or a pressure gauge; the gas-liquid isolation element group 9 is a series, parallel or series-parallel combination of one or more of the fluid or flow control elements such as a shut-off valve, a flow valve, a constant pressure valve, a pressure reducing valve, a one-way valve, a pressure gauge.

[0017] In the present invention, the slurry outlet 3 is arranged at the bottom or body of the gas-liquid two-phase storage tank 5, and the slurry outlet 3 is lower than the lowest liquid level of the slurry during grouting.

[0018] In the present invention, a drain pipe 16 is provided at the bottom of the gas-liquid two-phase storage tank 5 for draining the waste slurry or other liquids in the tank, or the slurry outlet pipeline 4 can be used as a drain pipe.

[0019] The present invention provides a method for pre-maintaining a flexible pavement surface layer using a local pre-maintenance device for a road surface layer. The method includes grout preparation, grouting and equipment cleaning. The specific steps are as follows:

[0020] (1) After the pre-curing equipment and the reinforcing slurry raw materials are in place, the slurry preparation operation is carried out. According to the pressure state of the gas-liquid two-phase storage tank 5 and the actual amount of slurry, the slurry preparation operation includes depressurizing the gas-liquid two-phase storage tank 5, filling and temporarily storing the reinforcing slurry;

[0021] (1.1) Depressurization of the gas-liquid two-phase storage tank 5: This is performed before the gas-liquid two-phase storage tank 5 is loaded with reinforcing slurry; the air inlet pipe 8 is closed and the air outlet pipe 12 is opened, so that the pressure in the cavity area 6 is equal to the pressure at the end of the air outlet pipe 12 away from the gas-liquid two-phase storage tank 5;

[0022] (1.2) Filling the reinforcing slurry into a tank: The reinforcing slurry or the reinforcing slurry raw material is poured into the gas-liquid two-phase storage tank 5 through the slurry inlet 3 by one or more methods selected from the group consisting of self-weight drop, pumping, vacuum negative pressure suction, and air pressure push, so that the slurry liquid level in the gas-liquid two-phase storage tank 5 is at least higher than the slurry outlet 3 and at least 5 cm lower than the gas outlet 11; after the reinforcing slurry is filled into a tank or the reinforcing slurry raw material is filled, the slurry inlet 2 is closed, and a cavity area 6 is formed above the slurry liquid level;

[0023] (1.3) Temporary storage: When there is reinforcing slurry or reinforcing slurry raw material retained in the gas-liquid two-phase storage tank 5, the airflow control element group 13 is adjusted so that compressed gas flows in both the air inlet pipe 8 and the air outlet pipe 12 within a certain period of time. The compressed gas flow during this period may be continuous or intermittent, but the single interruption time shall not exceed 30 minutes. Temporary storage may be started at any time from 0 to 30 minutes after the reinforcing slurry filling is started to the completion of the reinforcing slurry filling. The timing starts from the first opening of any airflow control element group 13 after the reinforcing slurry filling is started, and the timing starts no later than 15 minutes after the slurry inlet 2 is closed and earlier than the opening of the slurry outlet 3. The maximum allowable time for temporary storage shall not exceed 120 minutes.

[0024] (2) When the reinforcing slurry is filled into a tank or the reinforcing slurry temporarily stored in the gas-liquid two-phase storage tank 5 is sufficient, grouting is performed; the grouting is to open the slurry outlet 3 so that the reinforcing slurry is injected into the reinforcement object through the slurry outlet pipeline 4; the grouting also includes pressurizing the gas-liquid two-phase storage tank 5, stabilizing the pressure and flow during the grouting, replenishing the pressure, and terminating;

[0025] (2.1) Boosting the pressure of the gas-liquid two-phase storage tank 5: Keep the slurry outlet 3 and the slurry outlet pipeline 4 closed, and at the same time close or reduce the compressed gas outflow of the gas outlet pipeline 12, so that the compressed gas inflow of the gas-liquid two-phase storage tank 5 is higher than the outflow, so that the gas pressure in the cavity area 6 reaches or exceeds the specified pressure difference; the specified pressure difference refers to a value higher than the atmospheric pressure of the environment in which the equipment is located, and the optional range is 0.01~1.60MPa;

[0026] (2.2) Stable pressure and flow during grouting: Open the slurry outlet 3, and use the slurry flow control device 15 to control and adjust the slurry flow so that the reinforcement slurry flow is maintained in a stable state. The stable state means that during the grouting process, the grouting pressure on the slurry outflow side of the slurry outlet pipeline 4 close to the slurry flow control device 15 does not exceed the planned grouting pressure by ±20%, and the ratio of the peak value to the valley value of the pressure fluctuation is not less than 0.7; the optional range of the planned grouting pressure is 0.01~1.60MPa;

[0027] (2.3) Pressure replenishment: During the grouting process, when the grouting pressure is lower than the target pressure by more than 20%, the outflow of compressed gas in the gas outlet pipeline 12 is automatically or manually reduced or stopped until the outflow pressure is restored to at least the planned grouting pressure;

[0028] (2.4) Termination: Close the grouting pipeline 4, the air inlet pipeline 8 and the air outlet pipeline 12. When the grouting at a single location is completed or any other situation occurs that requires stopping the grouting for processing, the grouting can be terminated. After the grouting is temporarily terminated, the grouting can be restarted after performing the necessary equipment cleaning, slurry preparation and / or grouting process steps;

[0029] (3) After the grouting operation is completed, or when the time required to change the operation point exceeds 30 minutes, when the slurry is transported over long distances or temporarily stored and reaches the waste condition, or when the type of slurry needs to be changed, the equipment shall be cleaned; before cleaning, the connection between the slurry outlet 3 and the pre-maintenance object (road surface layer) shall be disconnected; cleaning shall be carried out using a cleaning fluid, which is a solution, suspension, emulsion, solid-liquid mixture or solid-liquid-gas mixture prepared by water and / or organic solvent or two of the above solvents and one or more of surfactants and / or stabilizers, modifiers, and solid particles. The cleaning fluid can be used once or recycled; cleaning includes depressurization, cleaning fluid canning, cleaning execution and cleaning fluid emptying;

[0030] (3.1) Pressure relief: close the air inlet 10 and open the air outlet 11 to eliminate the pressure difference between the cavity area 6 and the ambient atmosphere of the equipment;

[0031] (3.2) Cleaning liquid filling: filling the cleaning liquid through the slurry inlet 2;

[0032] (3.3) Perform cleaning: open and adjust the airflow control element group 13 and the gas-liquid isolation element group 9 to keep the compressed gas flowing along the airflow path; the cleaning method is a combination of one or more of closed cleaning, single flushing or cyclic flushing; the closed cleaning is to close the pulp inlet 2 and the pulp outlet 3 to keep the compressed gas flowing along the entire airflow path; the single flushing is to open the pulp outlet 3 and / or the drain pipe 16 while filling the cleaning liquid to allow the cleaning liquid to flow out; the cyclic flushing is to refill the outflowing cleaning liquid into the gas-liquid two-phase storage tank 5 on the basis of the single flushing;

[0033] (3.4) Draining the cleaning liquid: After the cleaning operation is completed, the remaining cleaning liquid in the gas-liquid two-phase storage tank 5 is discharged through the drain pipe 16.

[0034] In the present invention, the required permeation and seepage pressure of the maintenance method is provided by the pressure of the compressed gas in the cavity area 6 and the deadweight of the slurry in the gas-liquid two-phase storage tank 5; the steps of implementing the process all include the operation of adjusting the opening and closing state of the airflow path and / or the slurry flow path through the airflow control element group 13 and / or the slurry flow control device 15. The adjustment of the airflow path refers to the release and / or lifting of the pressure of the cavity area 6 and the slurry outlet 3 by opening and closing or adjusting the airflow control element group 13 of the air inlet pipeline 8 and / or the air outlet pipeline 12; the adjustment of the opening and closing state of the slurry flow path refers to the start, pause or stop of the outflow of the slurry by opening and closing or adjusting the slurry flow control device 15 of the slurry outlet pipeline 4. The grouting pressure is generated by using the pressure of the compressed gas in the cavity area 6 and the deadweight of the reinforcing slurry, so that the reinforcing slurry is injected into the road surface layer with excessive local voids (including but not limited to local porous, loose or cracked cracks) in the form of permeation and seepage, filling the voids, and forming solid filling through the process of maintenance or curing. The method for pre-maintaining the flexible pavement surface layer by the local pre-maintenance equipment for the road surface layer proposed by the present invention adopts cement slurry, emulsified asphalt slurry, polymer slurry, modified products of the above slurries, mixtures of the above slurries or any one of the modified mixtures as reinforcing slurry.

[0035] The beneficial effects of the present invention are:

[0036] The present invention fills the technical gap and realizes the early treatment of defects such as excessive local void ratio in the surface layer of a flexible pavement without disturbing or less disturbing the original materials and structure, while retaining the original pavement structure and materials.

[0037] The present invention can eliminate the problem of excessive local void ratio in the surface layer of a flexible road surface when the surface layer is newly constructed, repaved, before the occurrence of a disease or when the degree of the disease is relatively mild, and fundamentally eliminate or significantly reduce the defects of the surface layer material. The present invention can effectively improve the strength, impermeability and water damage resistance of the surface layer, prevent and significantly slow down the occurrence and development of diseases. And because it starts from the inside of the surface layer, it has little effect on the aesthetics of the road.

[0038] The invention has a wide range of applications. It can be used for both newly paved surfaces and old road surfaces, and is applicable before a disease occurs, when a minor disease occurs, or when a serious disease occurs but the road surface is not completely broken or peeled off.

[0039] The special equipment and implementation process proposed in the present invention can effectively ensure the rapid balance and stability of the reinforcement slurry flow, prevent the slurry from anti-settling, and are very friendly to cleaning and turnover. The present invention proposes that the air flow path and the slurry flow path intersect in the gas-liquid two-phase storage tank 5, which can not only reduce the risk of slurry separation and precipitation in the tank by gas agitation, but also improve the fluidity of the slurry, ensure the effect of slurry seepage inside the reinforcement object, and reduce the fluctuation of grouting pressure during equipment startup, debugging and operation. In addition, constant and controllable steady-pressure seepage grouting can also effectively avoid the disturbance and damage of the original structure of the surface layer caused by excessive peak pressure and pulse pressure during grouting.

[0040] The present invention has good economic benefits. The present invention has high operating efficiency, fast turnover speed, simple and efficient supporting implementation process, few personnel required for process implementation, and much lower pre-maintenance cost than traditional surface replacement methods. The present invention can prevent and delay the occurrence and development of diseases, reduce the frequency of maintenance, and can reduce the direct economic costs in the process of road management and maintenance, as well as the increase in indirect economic costs (vehicle maintenance costs, etc.) caused by poor road operation.

[0041] The present invention also has outstanding environmental benefits, and its energy conservation, emission reduction and sustainable development value are high. The amount of preventive maintenance reinforcement slurry used is relatively small, which can make full use of the road surface material and greatly reduce the waste of raw materials caused by surface layer replacement. The reinforcement slurry can be configured, replaced and adjusted as needed, and can be fully or partially selected for normal temperature construction, which can effectively avoid and reduce the energy consumed by heating asphalt and flexible pavement (asphalt mixture) when replacing the flexible pavement surface layer and the secondary pollution of the hot mix to the surrounding environment.

[0042] In addition, the present invention has good social benefits. As a preventive maintenance measure, it can effectively prevent and delay the occurrence of diseases before they occur, effectively improve the safety and comfort of vehicles during passage, improve the user experience, and enhance the satisfaction of social users. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] FIG. 1 is a diagram showing the equipment system combination and principle diagram of the present invention.

[0044] FIG. 2 shows the pre-curing equipment used in Example 1 of the present invention.

[0045] The numbers in the figure are: 1 is the pressure supply device, 2 is the slurry inlet, 3 is the slurry outlet, 4 is the slurry outlet pipeline, 5 is the gas-liquid two-phase storage tank, 6 is the cavity area, 7 is the slurry storage area, 8 is the air inlet pipeline, 9 is the gas-liquid isolation element group, 10 is the air inlet, 11 is the air outlet, 12 is the air outlet pipeline, 13 is the air flow control element group, 14 is the slurry inlet pipeline, 15 is the slurry flow control device, and 16 is the liquid discharge pipe. The white hollow arrow indicates the air flow direction; the black solid arrow indicates the flow direction of the reinforcing slurry. DETAILED DESCRIPTION

[0046] The present invention is further described below by way of embodiments in conjunction with the accompanying drawings.

[0047] Example 1:

[0048] Special pre-curing equipment designed and manufactured based on the method of the present invention (such as Figure 1 2), the equipment includes: a pressure supply device 1, a slurry outlet pipeline 4, a gas-liquid two-phase storage tank 5, a cavity area 6, a slurry storage area 7, an air inlet pipeline 8, a gas-liquid isolation element group 9, an air outlet pipeline 12, an air flow control element group 13, a slurry inlet pipeline 14, a slurry flow control device 15, a discharge pipe 16 and other components.

[0049] The body of the gas-liquid two-phase storage tank is opened to form an air inlet 10, an air outlet 11, a slurry inlet 2, a slurry outlet 3 and an interface of a drain pipe 16; the cavity area 6 is located in the upper area of ​​the gas-liquid two-phase storage tank 5 without reinforcing slurry; the slurry storage area 7 is located in the storage area of ​​the reinforcing slurry at the lower part of the gas-liquid two-phase storage tank 5; the volume of the upper cavity area 6 of the gas-liquid two-phase storage tank 5 is maintained at more than 25% of the volume of the gas-liquid two-phase storage tank 5; the slurry inlet 2 is arranged on one side of the top of the gas-liquid two-phase storage tank 5; the air inlet 10 is arranged at the bottom of the gas-liquid two-phase storage tank 5; the air outlet The port 11 is arranged on the top of the gas-liquid two-phase storage tank 5; the slurry outlet 3 is arranged on the body of the gas-liquid two-phase storage tank 5, 5 cm away from the lowest point of the tank bottom, and the lowest slurry liquid level when the equipment is designed to be in operation is 10 cm. The slurry outlet 3 is lower than the lowest liquid level of the slurry during grouting; the air inlet 10, the air outlet 11, the slurry inlet 2 and the slurry outlet 3 are respectively connected to the air inlet pipeline 8, the air outlet pipeline 12, the slurry inlet pipeline 14 and the slurry outlet pipeline 4; the air inlet pipeline 8 and the air outlet pipeline 12 are both provided with an airflow control element group 13; the slurry outlet pipeline 4 is provided with a slurry flow control device 15.

[0050] The pressure supply device 1 is connected to the air inlet 10 of the gas-liquid two-phase storage tank 5 through the air inlet pipeline 8; a gas-liquid isolation element group 9 is arranged in the air inlet pipeline 8, and the gas-liquid isolation element group 9 is a series combination of a flow valve, a one-way valve and a shut-off valve.

[0051] An airflow control element group 13 is provided in the air inlet pipeline 8 and the air outlet pipeline 12. The airflow control element group 13 in the air inlet pipeline 8 is a series combination of a shut-off valve, a flow valve, and a constant pressure valve with a pressure gauge; the airflow control element group 13 in the air outlet pipeline 12 is a series combination of a shut-off valve, a flow valve, and a constant pressure valve with a pressure gauge (including a parallel combination of a pressure reducing valve and a shut-off valve).

[0052] A separate drain pipe 16 is provided at the bottom of the tank for draining away waste slurry or other liquids in the tank;

[0053] like Figure 2As shown, two intersecting material flow paths, namely, an air flow path and a slurry flow path, are arranged inside the pre-curing equipment, and the two paths intersect and separate at the gas-liquid two-phase storage tank 5. The air flow path is the flow path of the compressed gas in the equipment; the air flow path is composed of the compressed gas pressure supply device 1, the air inlet pipeline 8, the air inlet 10, the gas-liquid two-phase storage tank 5, the air outlet 11 and the air outlet pipeline 12; the complete air flow path specifically refers to the compressed gas generated or released by the pressure supply device 1, through the air inlet pipeline 8, into the gas-liquid two-phase storage tank 5 from the air inlet 10, then through the slurry in the tank, gather in the cavity area 6, and finally be discharged in a controlled manner through the air outlet 11 and the air outlet pipeline 12.

[0054] The slurry flow path refers to the flow path of the reinforcement slurry in the equipment; the slurry flow path is composed of a slurry inlet pipeline 14, a slurry inlet 2, a gas-liquid two-phase storage tank 5, a slurry outlet 3 and a slurry outlet pipeline 4 or a drainage pipe 16; a complete slurry flow path means that the slurry starts from the slurry inlet pipeline 14 through the slurry inlet 2, is temporarily stored in the gas-liquid two-phase storage tank 5, and passes through the slurry outlet 3 during grouting, passes through the slurry outlet pipeline 4, is injected into the reinforcement object or is discharged through the drainage pipe 16.

[0055] Figure 2 The solid arrows in the middle are the flow path of the reinforcing slurry, and the white hollow arrows are the flow path of the compressed gas.

[0056] The pre-curing method includes grout preparation, grouting and equipment cleaning. The specific steps are as follows:

[0057] (1) After the treatment equipment and the reinforcing slurry raw materials are in place, the slurry preparation operation is carried out. According to the pressure state of the gas-liquid two-phase storage tank 5 and the actual amount of slurry, the slurry preparation operation includes depressurizing the gas-liquid two-phase storage tank 5, filling and temporarily storing the reinforcing slurry;

[0058] (1.1) Depressurization of the gas-liquid two-phase storage tank 5: This is performed before the gas-liquid two-phase storage tank 5 is loaded with reinforcing slurry; the air inlet pipe 8 is closed and the air outlet pipe 12 is opened, so that the pressure in the cavity area 6 is equal to the pressure at the end of the air outlet pipe 12 away from the gas-liquid two-phase storage tank 5, that is, equal to the atmospheric pressure;

[0059] (1.2) Filling the reinforcing slurry into a tank: The reinforcing slurry or the reinforcing slurry raw material is poured into the gas-liquid two-phase storage tank 5 through the slurry inlet 3 by a combination of self-weight drop and pumping, so that the slurry liquid level in the gas-liquid two-phase storage tank 5 is at least 5 cm higher than the slurry outlet 3 and at least 5 cm lower than the gas outlet 11; after the reinforcing slurry is filled into a tank, the slurry inlet 2 is closed, and a cavity area 6 is formed above the slurry liquid level;

[0060] (1.3) Temporary storage: When there is reinforcement slurry or slurry raw material retained in the gas-liquid two-phase storage tank 5, the air flow control element group 13 is adjusted so that compressed gas flows in both the air inlet pipe 8 and the air outlet pipe 12 within a certain period of time. The compressed gas flow during this period can be continuous or intermittent, but the single interruption time does not exceed 30 minutes. Temporary storage can be started at any time from 0 to 30 minutes after the start of reinforcement slurry filling to the completion of reinforcement slurry filling. The timing starts from the first opening of any air flow control element group 13 after the start of reinforcement slurry filling, and the timing starts no later than 15 minutes after the slurry inlet 2 is closed and earlier than the time when the slurry outlet 3 is opened; the maximum allowable time for temporary storage does not exceed 120 minutes;

[0061] (2) When the reinforcing slurry is filled into a tank or the reinforcing slurry temporarily stored in the gas-liquid two-phase storage tank 5 is sufficient, grouting is performed; the grouting is to open the slurry outlet 3 so that the reinforcing slurry is injected into the reinforcement object through the slurry outlet pipeline 4; the grouting also includes pressurizing the gas-liquid two-phase storage tank 5, stabilizing the pressure and flow during the grouting, replenishing the pressure, and terminating;

[0062] (2.1) Boosting the pressure of the gas-liquid two-phase storage tank 5: Keep the slurry outlet 3 and the slurry outlet pipeline 4 closed, and at the same time close or reduce the compressed gas outflow of the gas outlet pipeline 12, so that the compressed gas inflow of the gas-liquid two-phase storage tank 5 is higher than the outflow, so that the gas pressure in the cavity area 6 reaches or exceeds the specified pressure difference; the specified pressure difference refers to a value higher than the atmospheric pressure of the environment in which the equipment is located, and the optional range is 0.01~1.60MPa;

[0063] (2.2) Stable pressure and flow during grouting: Open the slurry outlet 3, and use the slurry flow control device 15 to control and adjust the slurry flow so that the reinforcement slurry flow is maintained in a stable state. The stable state means that during the grouting process, the grouting pressure on the slurry outflow side of the slurry outlet pipeline 4 close to the slurry flow control device 15 does not exceed the planned grouting pressure by ±20%, and the ratio of the peak value to the valley value of the pressure fluctuation is not less than 0.7; the optional range of the planned grouting pressure is 0.01~1.60MPa;

[0064] (2.3) Pressure replenishment: During the grouting process, when the grouting pressure is lower than the target pressure by more than 20%, the outflow of compressed gas in the gas outlet pipeline 12 is automatically or manually reduced or stopped until the outflow pressure is restored to at least the planned grouting pressure;

[0065] (2.4) Termination: Close the grouting pipeline 4, the air inlet pipeline 8 and the air outlet pipeline 12. When the grouting at a single location is completed or any other situation occurs that requires stopping the grouting for processing, the grouting can be terminated. After the grouting is temporarily terminated, the grouting can be restarted after performing the necessary equipment cleaning, slurry preparation and / or grouting process steps;

[0066] (3) After the grouting operation is completed, or when the time required to change the operation point exceeds 30 minutes, when the slurry is transported over long distances or temporarily stored and reaches the waste condition, or when the type of slurry needs to be changed, the equipment shall be cleaned; before cleaning, the connection between the slurry outlet 3 and the pre-maintenance object (road surface layer) shall be disconnected; cleaning shall be carried out using a cleaning fluid, which is a solution, suspension, emulsion, solid-liquid mixture or solid-liquid-gas mixture prepared by water and / or organic solvent or two of the above solvents and one or more of surfactants and / or stabilizers, modifiers, and solid particles. The cleaning fluid can be used once or recycled; cleaning includes depressurization, cleaning fluid canning, cleaning execution and cleaning fluid emptying;

[0067] (3.1) Pressure relief: close the air inlet 10 and open the air outlet 11 to eliminate the pressure difference between the cavity area 6 and the ambient atmosphere of the equipment;

[0068] (3.2) Cleaning liquid filling: filling the cleaning liquid through the slurry inlet 2;

[0069] (3.3) Perform cleaning: open and adjust the airflow control element group 13 and the gas-liquid isolation element group 9 to keep the compressed gas flowing along the airflow path; the cleaning method is a combination of one or more of closed cleaning, single flushing or cyclic flushing; the closed cleaning is to close the slurry inlet 2 and the slurry outlet 3 to keep the compressed gas flowing along the entire airflow path; the single flushing is to open the slurry outlet 3 and / or the drain pipe 16 while filling the cleaning liquid to allow the cleaning liquid to flow out; the cyclic flushing is to refill the outflowing cleaning liquid into the gas-liquid two-phase storage tank 5 on the basis of the single flushing;

[0070] (3.4) Draining the cleaning liquid: After the cleaning operation is completed, the remaining cleaning liquid in the gas-liquid two-phase storage tank 5 is discharged through the drain pipe 16.

[0071] Cement slurry, emulsified asphalt slurry, polymer slurry, modified products of the above slurries, mixtures of the above slurries or modified mixtures may be used as the reinforcing slurry.

[0072] The flexible surface layer (mainly asphalt mixture) around some rainwater and sewage wells in some sections of a city road in a certain area in East China did not reach the designed compaction degree, resulting in excessive local void ratio, low strength and poor impermeability. The above-mentioned local pre-maintenance equipment and related road pre-maintenance method designed and manufactured based on the present invention were used to pre-maintain the asphalt mixture pavement surface layer around some problematic wells at a specified pressure difference of 0.6MPa and plain cement slurry as the reinforcing slurry.

[0073] The pre-cured pavement surface has no significant apparent difference from the surrounding mixture, but has better performance. The comparison with the surface layer with excessive porosity but without pre-curing shows that the water permeability coefficient around the well after pre-curing reaches or exceeds the design requirements of the surface layer flexible pavement (asphalt mixture). The water permeability coefficient of the uncured position is lower than the design requirements. After opening for 3 to 6 months, there is no obvious deformation and disease around the pre-cured well, while the settlement difference around the uncured well can reach more than 10 mm, and settlement, deformation, uplift and other diseases are common.

[0074] Comparison of core samples shows that there are a large number of connected voids visible to the naked eye in the core samples at the uncured positions, and there are signs of scouring in the base layer below the surface layer, which indicates that there has been deformation due to loss of base material and other reasons. Core samples at the precured positions show that the solidified reinforcing slurry fully fills the voids, and there are no signs of scouring in the base layer below the surface layer.

Claims

1. A method for pre-maintaining a flexible pavement surface layer using a road surface pre-maintenance device, characterized in that: The road surface pre-maintenance equipment comprises a pressure supply device (1), a slurry discharge pipeline (4), a gas-liquid two-phase storage tank (5), an air intake pipeline (8), a gas-liquid isolation element group (9), an air outlet pipeline (12), an air flow control element group (13), a slurry intake pipeline (14), a slurry flow control device (15) and a liquid discharge pipe (16); the pre-maintenance equipment is provided with an air flow path and a slurry flow path, and the two paths intersect at the gas-liquid two-phase storage tank (5), wherein: The gas flow path is the flow path of the compressed gas in the pre-curing equipment; the slurry flow path refers to the flow path of the reinforcing slurry in the pre-curing equipment; the reinforcing slurry refers to any one of a fluid liquid, a solid-liquid mixture, a gas-liquid mixture or a gas-solid-liquid mixture; The gas-liquid two-phase storage tank (5) is a container including a cavity area (6) and a slurry storage area (7), wherein the cavity area (6) refers to an area at the upper part of the gas-liquid two-phase storage tank (5) where no reinforcing slurry is stored, and the slurry storage area (7) refers to an area at the lower part of the gas-liquid two-phase storage tank (5) where the reinforcing slurry is stored; the gas-liquid two-phase storage tank (5) is provided with an air inlet (10), an air outlet (11), a slurry inlet (2) and a slurry outlet (3); The pressure supply device (1) is connected to the air inlet (10) of the gas-liquid two-phase storage tank (5) through an air inlet pipeline (8); a gas-liquid isolation element group (9) is arranged in the air inlet pipeline (8); the air outlet (11) is connected to the air outlet pipeline (12); an air flow control element group (13) is arranged in the air inlet pipeline (8) and / or the air outlet pipeline (12); the pressure supply device (1), the air inlet pipeline (8), and the air flow control element group (13) , a gas-liquid isolation element group (9), an air inlet (10), a gas-liquid two-phase storage tank (5), an air outlet (11) and an air outlet pipeline (12) constitute an air flow path; the complete air flow path is that the compressed gas is generated or released by the pressure supply device (1), passes through the air inlet pipeline (8), enters the gas-liquid two-phase storage tank (5) from the air inlet (10), gathers in the cavity area (6), and is finally discharged in a controlled manner through the air outlet (11) and the air outlet pipeline (12); The slurry flow path is composed of a slurry inlet pipeline (14), a slurry inlet (2), a gas-liquid two-phase storage tank (5), a slurry outlet (3), a slurry flow control device (15), and a slurry outlet pipeline (4) and / or a liquid discharge pipe (16); the slurry inlet (2) is externally connected to the slurry inlet pipeline (14), and the slurry outlet (3) is externally connected to the slurry outlet pipeline (4); the slurry outlet pipeline (4) or the liquid discharge pipe (16) is connected to the slurry outlet (3); the slurry flow control device (15) is arranged in the slurry outlet pipeline (4) and / or the slurry outlet (3); the complete slurry flow path is that the reinforcement slurry enters the gas-liquid two-phase storage tank (5) from the slurry inlet pipeline (14) through the slurry inlet (2), is temporarily stored in the gas-liquid two-phase storage tank (5), is controlled to be injected into the reinforcement object through the slurry outlet (3) and the slurry outlet pipeline (4), or is discharged through the liquid discharge pipe (16); When the gas-liquid two-phase storage tank (5) stores slurry and compressed gas flows into the gas-liquid two-phase storage tank (5) through the gas inlet (10), the compressed gas passes through the gas-liquid two-phase storage tank (5) to reinforce the slurry and gathers in the cavity area (6); The air inlet (10) is arranged at the bottom or body of the gas-liquid two-phase storage tank (5), and the air inlet (10) is lower than the lowest liquid level of the slurry during grouting; The airflow control element group (13) is one or more of a shut-off valve, a flow valve, a constant pressure valve, a pressure reducing valve, a one-way valve or a pressure gauge, which are connected in series, in parallel or in series-parallel combination; the gas-liquid isolation element group (9) is one or more of a shut-off valve, a flow valve, a constant pressure valve, a pressure reducing valve, a one-way valve or a pressure gauge, which are connected in series, in parallel or in series-parallel combination; The slurry outlet (3) is arranged at the bottom or body of the gas-liquid two-phase storage tank (5), and the slurry outlet (3) is lower than the lowest liquid level of the slurry during grouting; The pre-curing method includes grout preparation, grouting and equipment cleaning implementation processes, and the specific steps are as follows: (1) After the pre-curing equipment and the reinforcing slurry raw materials are in place, the slurry preparation operation is carried out. According to the pressure state of the gas-liquid two-phase storage tank (5) and the actual amount of slurry, the slurry preparation operation includes depressurizing the gas-liquid two-phase storage tank (5), filling and temporarily storing the reinforcing slurry; (1.1) Depressurization of the gas-liquid two-phase storage tank (5): This is performed before the gas-liquid two-phase storage tank (5) is loaded with reinforcing slurry; the air inlet pipe (8) is closed and the air outlet pipe (12) is opened, so that the pressure in the cavity area (6) is equal to the pressure at the end of the air outlet pipe (12) away from the gas-liquid two-phase storage tank (5); (1.2) Filling the reinforcing slurry into a tank: The reinforcing slurry is poured into the gas-liquid two-phase storage tank (5) through the slurry inlet (2) by one or more methods selected from the group consisting of self-weight drop, pumping, vacuum negative pressure suction, and air pressure push, so that the liquid level in the gas-liquid two-phase storage tank (5) is at least higher than the slurry outlet (3) and at least 5 cm lower than the gas outlet (11); after the reinforcing slurry is filled into a tank, the slurry inlet (2) is closed, and a cavity area (6) is formed above the slurry liquid level; (1.3) Temporary storage: When reinforcing slurry is retained in the gas-liquid two-phase storage tank (5), the air flow control element group (13) is adjusted so that compressed gas flows in both the air inlet pipe (8) and the air outlet pipe (12). The compressed gas flows continuously or intermittently, but the single interruption time does not exceed 30 minutes. Temporary storage starts at any time between 0 and 30 minutes after the reinforcing slurry filling is started and completed. The timing starts when any air flow control element group (13) is opened for the first time after the reinforcing slurry filling starts, and the timing starts no later than 15 minutes after the slurry inlet (2) is closed and earlier than the time when the slurry outlet (3) is opened. The maximum allowable time for temporary storage does not exceed 120 minutes. (2) When the reinforcing slurry is filled into a tank or the reinforcing slurry temporarily stored in the gas-liquid two-phase storage tank (5) is sufficient, grouting is performed; the grouting is performed by opening the grout outlet (3) to allow the reinforcing slurry to be injected into the reinforcement object through the grout outlet pipeline (4); the grouting also includes pressurizing the gas-liquid two-phase storage tank (5), stabilizing the pressure and flow during the grouting, replenishing the pressure, and terminating the grouting; (2.1) Boosting the pressure of the gas-liquid two-phase storage tank (5): Keep the slurry outlet (3) and the slurry outlet pipeline (4) closed, and at the same time close or reduce the compressed gas outflow of the gas outlet pipeline (12), so that the compressed gas inflow of the gas-liquid two-phase storage tank (5) is higher than the outflow, so that the gas pressure in the cavity area (6) reaches or exceeds the specified pressure difference; the specified pressure difference refers to a value higher than the atmospheric pressure of the environment in which the equipment is located, and the range is 0.01~1.60MPa; (2.2) Stable pressure and flow during grouting: Open the slurry outlet (3), use the slurry flow control device (15) to control and adjust the slurry flow, so that the reinforcement slurry flow is maintained in a stable state. The stable state means that during the grouting process, the grouting pressure on the slurry outflow side of the slurry outlet pipeline (4) close to the slurry flow control device (15) does not exceed the planned grouting pressure by ±20%, and the ratio of the peak value to the valley value of the pressure fluctuation is not less than 0.7; the planned grouting pressure range is 0.01~1.60MPa; (2.3) Pressure replenishment: During the grouting process, when the grouting pressure is lower than the target pressure by more than 20%, the outflow of compressed gas in the gas outlet pipeline (12) is automatically or manually reduced or stopped until the outflow pressure is restored to at least the planned grouting pressure; (2.4) Termination: closing the grouting pipeline (4), the air inlet pipeline (8) and the air outlet pipeline (12). When the grouting at a single location is completed or any other situation occurs that requires stopping the grouting for processing, the grouting is terminated. After the grouting is temporarily terminated, the grouting is restarted after performing the necessary equipment cleaning, grouting preparation and / or grouting process steps; (3) After the grouting operation is completed, or when the time required to change the operation point exceeds 30 minutes, when the slurry is transported over long distances or temporarily stored and reaches the waste condition, or when the type of slurry needs to be changed, the equipment shall be cleaned; before cleaning, the connection between the slurry outlet (3) and the pre-curing object shall be disconnected; cleaning shall be carried out using a cleaning liquid, which is a solution, suspension, emulsion, solid-liquid mixture or solid-liquid-gas mixture prepared by water and / or organic solvent or two of the above solvents and one or more of surfactants and / or stabilizers, modifiers, and solid particles. The cleaning liquid can be used once or recycled; cleaning includes pressure relief, cleaning liquid canning, cleaning execution and cleaning liquid emptying; (3.1) Pressure relief: close the air inlet (10) and open the air outlet (11) to eliminate the pressure difference between the cavity area (6) and the ambient atmosphere of the equipment; (3.2) Cleaning liquid filling: filling the cleaning liquid through the slurry inlet (2); (3.3) Perform cleaning: open and adjust the airflow control element group (13) and the gas-liquid isolation element group (9) to keep the compressed gas flowing along the airflow path; the cleaning method is a combination of one or more of closed cleaning, single flushing or cyclic flushing; the closed cleaning is to close the slurry inlet (2) and the slurry outlet (3) to keep the compressed gas flowing along the entire airflow path; the single flushing is to open the slurry outlet (3) and / or the drain pipe (16) while filling the cleaning liquid to allow the cleaning liquid to flow out; the cyclic flushing is to refill the outflowing cleaning liquid into the gas-liquid two-phase storage tank (5) on the basis of the single flushing; (3.4) Draining the cleaning liquid: After the cleaning operation is completed, the remaining cleaning liquid in the gas-liquid two-phase storage tank (5) is discharged through the drain pipe (16).

2. The method for pre-maintaining a flexible pavement surface layer using the road surface pre-maintenance equipment according to claim 1, characterized in that: The reinforcing slurry is any one of cement slurry, emulsified asphalt slurry, polymer slurry, modified products of the above slurries, mixtures of the above slurries or modified mixtures.

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