An asphalt pavement coring hole prefabricated filling method based on deformation amount

Abstract

The application discloses a kind of asphalt pavement coring hole prefabricated filling method based on deformation, comprising the following steps: drilling hole sampling in asphalt pavement;Measure the depth H of road hole T ;Measure the total thickness of asphalt mixture layer;Consult the initial thickness of asphalt mixture layer;Calculate the deformation of asphalt mixture layer;Prepare new upper layer test piece, middle layer test piece and lower layer test piece, and concentrically stack from top to bottom, obtain the combined test piece consistent with initial thickness;Use tools to press the center of combined test piece, until the amount of downward movement is equal to the deformation of asphalt mixture layer;Drilling core is carried out at the position of the center of combined test piece, and the asphalt mixture layer filling piece is filled;Prepare roadbed filling piece;Asphalt mixture layer filling piece and roadbed filling piece are stacked and bonded to obtain road surface filling piece;Fill the road surface filling piece into the road hole.The filling method has the advantages of same material, same porosity, similar mechanical properties, similar deformation performance and high construction efficiency.

Description

Technical Field

[0001] This invention relates to road repair methods, specifically to a method for prefabricating and filling core holes in asphalt pavement based on deformation. Background Technology

[0002] Asphalt pavement is the main pavement type for high-grade highways in my country. It uses asphalt mixtures, which consist of asphalt, aggregates, and porosity. Asphalt pavement is generally a multi-layered structure; for example, highway asphalt pavement typically has four layers: top layer, middle layer, bottom layer, and subgrade. The top three layers are made of asphalt mixture, with different aggregates and asphalt used in each layer, and each layer also has a different porosity. The subgrade is generally made of low-cement-content cement concrete. After asphalt pavement construction is completed, cylindrical core samples are frequently drilled using a core drill to measure porosity and verify if the construction quality meets specifications. During service, core samples are also frequently drilled to check for transverse shrinkage cracks or complex-shaped fatigue cracks. The core sample diameter is generally 10cm or 15cm, and the height is generally greater than the thickness of the asphalt mixture layer (approximately 18cm for highways). Core sampling typically penetrates the asphalt mixture layer and then proceeds to the subgrade. After core sampling, cylindrical holes will be produced in the asphalt pavement.

[0003] Existing methods for repairing coring holes mainly include two types: on-site tamping repair and laboratory prefabrication repair.

[0004] First, on-site compaction repair generally involves three steps: (1) injecting high-temperature asphalt mixture (150-180℃) of the same material as the surface layer of the asphalt pavement into the sampling hole; (2) manually compacting the high-temperature asphalt mixture in the hole. The more compacted the asphalt mixture, the lower the porosity and the higher the strength; (3) manually removing excess asphalt mixture from the upper surface so that the height of the repair hole is flush with the surrounding original pavement.

[0005] The above method has the following problems:

[0006] 1. The filling material of the cavity is different from that of the surrounding original pavement. The original pavement has a multi-layer structure, and the asphalt mixture of each layer is different, while the filling material of the cavity is the same asphalt mixture.

[0007] 2. The compaction degree of the cavity-filled section differs from that of the surrounding original pavement. During construction, the original pavement undergoes repeated compaction with a road roller, ensuring the asphalt mixture meets specifications. During service, the pavement is subjected to repeated compaction by vehicles overhead, further increasing compaction and decreasing porosity. In contrast, conventional cavity-filling methods involve manual compaction, resulting in a significantly lower compaction degree and a significantly higher porosity compared to the original pavement after machine and vehicle compaction.

[0008] 3. The asphalt mixture in the cavity-filled area has lower strength. Under vehicle load, stress concentration will occur at this location, making the road surface more prone to damage around the cavity-filled area.

[0009] 4. Grooves are easily formed in the cavity-filled areas. Because the porosity of the cavity-filled areas is greater than that of the original road surface, the cavity-filled areas are more prone to compaction deformation under the same vehicle load, while the surrounding original road surface undergoes significantly less deformation. Therefore, grooves will form in the cavity-filled areas.

[0010] 5. The grooves in the cavity filling section will store rainwater under rainfall conditions. The rainwater in the grooves will seep into the interior of the asphalt pavement, which will reduce the strength of the asphalt pavement and cause premature damage.

[0011] 6. The flatness and compaction of the filling of the holes depend entirely on the on-site operation of the construction personnel, making it difficult to control the construction quality.

[0012] 7. Conventional on-site pouring repair methods require heating the asphalt mixture to 150-180℃ first, and then cooling the temperature of the filled part of the hole to room temperature before the road can be opened to traffic. This method is inefficient and affects the road traffic for a long time.

[0013] Secondly, laboratory prefabrication repair, which involves prefabricating asphalt mixture specimens in a laboratory, is an effective method to address the problem of excessive porosity in the repaired area during on-site manual repair. It can increase the porosity of the asphalt mixture, making the porosity of the repaired area closer to that of the original pavement. However, due to the presence of viscous deformation in the asphalt mixture, this method still has some limitations. Asphalt pavement deforms under the combined action of vehicle loads and temperature loads. Pavement deformation can generally be categorized into elastic deformation, plastic deformation, and viscous deformation. Elastic deformation recovers immediately after the vehicle load is removed; plastic deformation is permanent deformation on the asphalt pavement and does not disappear after the vehicle load is removed; while viscous deformation recovers slowly after the vehicle load is removed. Under high temperature and high load, the asphalt pavement deforms rapidly overall, but viscous deformation accounts for a relatively high proportion; while under low temperature and low load, the asphalt mixture deforms more slowly overall, but viscous deformation accounts for a lower proportion.

[0014] In laboratory molding of asphalt mixture specimens, Marshall compaction and rotary compaction methods are generally used. The process generally involves the following steps: (1) heating the asphalt mixture to 160-180℃, at which temperature the asphalt mixture has a certain fluidity; (2) then pouring the mixture into a mold and then performing compaction. Specific problems with this indoor molding method are as follows:

[0015] 1. The mixture formed at this temperature exhibits a significant proportion of viscous deformation, which recovers over time. Therefore, its actual height is generally greater than the designed height during forming. Due to the substantial differences in viscous recovery performance among different types of asphalt mixtures, the final height of indoor-formed specimens is difficult to control accurately. In contrast, the actual deformation of asphalt pavement occurs under normal vehicle loads and temperatures. The actual pavement temperature generally does not exceed 60℃. Furthermore, asphalt pavement hardly produces rutting deformation below 20℃. Therefore, the actual rutting temperature of asphalt pavement is between 20-60℃, resulting in a lower proportion of viscous deformation in the rutting deformation, far lower than that of indoor-formed specimens.

[0016] 2. After the indoor molded specimen has been placed for a long time, its viscous deformation recovers more, which leads to an increase in its diameter. Therefore, it may not be able to be placed into the original size of the road hole.

[0017] 3. Even if the precast asphalt mixture specimen is filled into the hole of the pavement within a short period of time during specimen molding, the recovery of the viscous deformation of the asphalt mixture specimen formed at high temperature in the room will not stop. Its lateral deformation is squeezed by the original pavement, which will increase its longitudinal deformation, thus causing the upper surface of the precast filler to be higher than the original pavement. Summary of the Invention

[0018] The purpose of this invention is to overcome the above-mentioned problems and provide a prefabricated filling method for coring holes in asphalt pavement based on deformation. This filling method has the advantages of using the same material, having the same porosity, similar mechanical properties, similar deformation properties, and high construction efficiency.

[0019] The objective of this invention is achieved through the following technical solution:

[0020] A method for prefabricating and filling core holes in asphalt pavement based on deformation includes the following steps:

[0021] (1) Drill holes in the asphalt pavement to obtain pavement core samples and form core sampling holes on the pavement; measure the diameter 2R of the pavement core sample;

[0022] (2) Process the bottom of the core sampling hole on the road surface to form a cylindrical road hole with a flat bottom, and measure the depth H of the road hole. T ;

[0023] (3) The thicknesses of the top, middle, and bottom layers of the road surface core sample were measured as H. N1 H N2 and H N3 The total thickness H of the asphalt mixture layer N =H N1 +H N2 +H N3 The thickness of the hole in the roadbed is H. B =H T -H N ;

[0024] (4) Based on the design data of the asphalt pavement, the initial thickness and design porosity of each structural layer of the pavement are obtained. The initial thicknesses of the top layer, middle layer and bottom layer are H, respectively. S1 H S2 and H S3 The initial thickness of the asphalt mixture layer is H. S =H S1 +H S2 +H S3 The designed porosities of the top layer, middle layer, and bottom layer are A1, A2, and A3, respectively.

[0025] (5) Calculate the deformation of the asphalt mixture layer d = H S -H N ;

[0026] (6) Prepare the top layer specimen, the middle layer specimen, and the bottom layer specimen in the laboratory. The top layer specimen has a diameter of 6R and a thickness of H. S1 The porosity is A1, and the diameter of the intermediate layer specimen is 6R and the thickness is H. S2 The porosity is A2, and the diameter of the lower layer specimen is 6R and the thickness is H. S3 The porosity is A3;

[0027] (7) Stack the top layer specimen, middle layer specimen, and bottom layer specimen concentrically from top to bottom, and bond the layers together with adhesive to obtain a composite specimen with the same thickness as the initial asphalt pavement layers. The height of this composite specimen is H. S The diameter is 6R.

[0028] (8) Conduct a permanent deformation test by compressing the center of the composite specimen; stop the test when the amount of pressure on the composite specimen is equal to the deformation d of the asphalt mixture layer.

[0029] (9) Drill a core at the center of the assembled specimen after the permanent deformation test to obtain a core with a diameter of 2R and a height of H. N Asphalt mixture layer filler;

[0030] (10) Based on the design data of the asphalt pavement, the mix proportion of the base cement concrete is obtained, and a concrete substrate with a diameter of 2R and a height of H is prepared according to the mix proportion. B Roadbed filling components;

[0031] (11) The asphalt mixture layer filler and the subgrade filler are stacked and bonded together to obtain a diameter of 2R and a height of H. T Road surface filler;

[0032] (12) Fill the road surface filler into the road surface holes.

[0033] In a preferred embodiment of the present invention, in step (8), the operation of the permanent deformation experiment is specifically as follows:

[0034] The combined specimen was placed on the test bench of the material mechanics testing machine and subjected to a permanent deformation test in a temperature-controlled chamber;

[0035] Place a pressure plate with a diameter of 2R at the center of the upper surface of the composite specimen, so that the axis of the pressure plate coincides with the axis of the pressure bar of the material mechanics testing machine;

[0036] The pressure bar is driven to move up and down by a material mechanics testing machine to apply pressure to the pressure plate and the composite specimen; the composite specimen gradually undergoes compression deformation, and the pressure plate gradually moves downward. When the downward movement of the pressure plate is equal to the deformation d of the asphalt mixture layer, the experiment is stopped.

[0037] Furthermore, in the permanent deformation test, a materials mechanics testing machine (UTM) or MTS is used for loading.

[0038] Furthermore, the formula for calculating the temperature value in the temperature control box is as follows:

[0039]

[0040] In the formula, n is the number of days in a year where the average daily temperature is greater than 20℃, and Tn is the daily average temperature sequence in that period, where Tn>20℃.

[0041] Furthermore, the formula for calculating the load force used in the permanent deformation test is as follows:

[0042] F = πR 2 ×P;

[0043] In the formula, P is the pressure exerted by the pressure plate on the upper surface of the combined specimen.

[0044] Furthermore, the formula for calculating pressure P is:

[0045]

[0046] In the formula, m is the number of cars with axle count greater than or equal to 3 that have been operating locally for more than a year, and Pm is the sequence of ground pressure of car tires with axle count greater than or equal to 3 during that time period.

[0047] Furthermore, the permanent deformation experiment uses an intermittent half-sine wave loading force with a loading frequency of 1 Hz, a loading duration of 0.1 seconds per cycle, and an interval duration of 0.9 seconds.

[0048] Compared with the prior art, the present invention has the following advantages:

[0049] 1. The materials in the same layer are basically the same: the filling part of the hole and the surrounding original road surface are both multi-layered structures made of the same material.

[0050] 2. Porosity is basically the same in the same layer: The porosity of each layer of asphalt pavement is the same as that of the surrounding original pavement in the void-filled part. The void-filled part undergoes the same degree of deformation as the surrounding original pavement and will not form grooves.

[0051] 3. The mechanical properties of the same layer are basically the same: The mechanical properties of each layer of asphalt pavement in the cavity filling part are similar to those of the surrounding original pavement, eliminating the stress concentration effect caused by the lower strength of the cavity filling part and the higher strength of the surrounding original pavement.

[0052] 4. The deformation performance of the same layer is basically the same: the deformation performance of each layer of asphalt pavement in the cavity filling part is similar to that of the surrounding original pavement, eliminating the potholes caused by the faster deformation of the cavity filling part and the slower deformation of the surrounding original pavement.

[0053] 5. High construction efficiency: Precast components are fabricated in the laboratory and filled into the holes. Precast components can be fabricated in advance, improving construction efficiency, saving construction time, and minimizing disruption to road traffic. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of the road surface structure of the present invention.

[0055] Figure 2 This is a schematic diagram of the initial thickness of each structural layer of the road surface according to the present invention.

[0056] Figure 3 This is a schematic diagram of the road surface core sample of the present invention.

[0057] Figure 4 This is a schematic diagram of the road surface hole of the present invention.

[0058] Figure 5 This is a schematic diagram of the combined specimen of the present invention.

[0059] Figure 6 This is a schematic diagram of the preparation of the asphalt mixture layer filler of the present invention.

[0060] Figure 7 This is a schematic diagram of the preparation of the road filler of the present invention. Detailed Implementation

[0061] To enable those skilled in the art to fully understand the technical solutions of the present invention, the present invention will be further described below in conjunction with embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0062] See Figure 1-7 The prefabrication filling method for asphalt pavement coring holes 8 based on deformation in this embodiment includes the following steps:

[0063] (1) Drill holes in the asphalt pavement to obtain pavement core sample 7 and form core sampling hole 8 on the pavement; measure the diameter 2R of pavement core sample 7.

[0064] (2) Process the bottom of the core sampling hole 8 on the road surface to form a cylindrical road hole 5 with a flat bottom, and measure the depth H of the road hole 5. T .

[0065] (3) The thicknesses of the top layer 1, middle layer 2, and bottom layer 3 of the road surface core sample 7 were measured to be H respectively. N1 H N2 and H N3 The total thickness H of the asphalt mixture layer 6 N =H N1 +H N2 +H N3 The thickness of the hole 5 in the roadbed 4 section is H. B =H T -H N ,like Figure 3-4 .

[0066] (4) Based on the design data of the asphalt pavement, the initial thickness and design porosity of each structural layer of the pavement are obtained. The initial thicknesses of the upper layer 1, the middle layer 2, and the lower layer 3 are H, respectively. S1 H S2 and H S3 The initial thickness of asphalt mixture layer 6 is H. S =H S1 +H S2 +H S3 ,like Figure 2 The designed porosities of the top layer 1, the middle layer 2, and the bottom layer 3 are A1, A2, and A3, respectively.

[0067] (5) Calculate the deformation of asphalt mixture layer 6, d = H S -H N .

[0068] (6) Prepare the top layer specimen 9, the middle layer specimen 10, and the bottom layer specimen 11 in the laboratory. The top layer specimen 9 has a diameter of 6R and a thickness of H. S1 The porosity is A1, and the diameter of the intermediate layer specimen 10 is 6R and the thickness is H. S2 The porosity is A2, and the diameter of the lower layer specimen 11 is 6R and the thickness is H. S3 Porosity is A3, such as Figure 5 .

[0069] (7) Stack the top layer specimen 9, the middle layer specimen 10, and the bottom layer specimen 11 concentrically from top to bottom, and bond the layers together with adhesive to obtain a composite specimen 12 with the same thickness as the initial asphalt pavement layers. The height of the composite specimen 12 is H. S A diameter of 6R, such as Figure 5 .

[0070] (8) Place the combined specimen 12 on the test bench 15 of the material mechanics testing machine and conduct a permanent deformation test in the temperature control chamber 16.

[0071] A pressure plate 14 with a diameter of 2R is placed at the center of the upper surface of the combined specimen 12, so that the axis of the pressure plate 14 coincides with the axis of the pressure rod 13 of the material mechanics testing machine.

[0072] The pressure bar 13 is moved up and down by a materials mechanics testing machine to apply pressure to the pressure plate 14 and the composite specimen 12; the composite specimen 12 gradually undergoes compressive deformation, and the pressure plate 14 gradually moves downward. The experiment is stopped when the downward movement of the pressure plate 14 equals the deformation d of the asphalt mixture layer 6. Figure 6 .

[0073] (9) A core was drilled at the center of the assembled specimen 12 after the permanent deformation test to obtain a core with a diameter of 2R and a height of H. N Asphalt mixture layer filler 17, such as Figure 6 .

[0074] (10) Based on the design data of the asphalt pavement, the mix proportion of the base cement concrete is obtained, and a concrete substrate with a diameter of 2R and a height of H is prepared according to the mix proportion. B Roadbed filling component 18, such as Figure 7 .

[0075] (11) The asphalt mixture layer filler 17 and the subgrade filler 18 are stacked and bonded together to obtain a diameter of 2R and a height of H. T Road surface filler 19, such as Figure 7 .

[0076] (12) Fill the road surface filler 19 into the road surface hole 5.

[0077] Furthermore, in step (8), in the permanent deformation test, a material mechanics testing machine (UTM) or MTS is used for loading.

[0078] Furthermore, in step (8), the formula for calculating the temperature value in the temperature control box 16 is as follows:

[0079]

[0080] In the formula, n is the number of days in a year where the average daily temperature is greater than 20℃, and Tn is the daily average temperature sequence in that period, where Tn>20℃.

[0081] Furthermore, in step (8), the formula for calculating the load force used in the permanent deformation experiment is as follows:

[0082] F = πR 2 ×P;

[0083] In the formula, P is the pressure exerted by the pressure plate 14 on the upper surface of the combined specimen 12.

[0084] Furthermore, the formula for calculating pressure P is:

[0085]

[0086] In the formula, m is the number of cars with axle count greater than or equal to 3 that have been operating locally for more than a year, and Pm is the sequence of ground pressure of car tires with axle count greater than or equal to 3 during that time period.

[0087] Furthermore, in step (8), the form of the loading force used in the permanent deformation experiment is an intermittent half-sine wave with a loading frequency of 1Hz, a loading duration of 0.1 seconds for each cycle, and an interval duration of 0.9 seconds.

[0088] The above are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above content. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for prefabricating and filling core holes in asphalt pavement based on deformation, characterized in that, Includes the following steps: (1) Drill holes in the asphalt pavement to obtain pavement core samples and form core sampling holes on the pavement. Measure the diameter 2R of the pavement core sample. (2) Process the bottom of the core sampling hole on the road surface to form a cylindrical road hole with a flat bottom, and measure the depth H of the road hole. T ; (3) The thicknesses of the top, middle, and bottom layers of the road surface core sample were measured as H. N1 H N2 and H N3 The total thickness H of the asphalt mixture layer N =H N1 +H N2 +H N3 The thickness of the hole in the roadbed is H. B =H T -H N ; (4) Based on the design data of the asphalt pavement, the initial thickness and design porosity of each structural layer of the pavement are obtained. The initial thicknesses of the top layer, middle layer and bottom layer are H, respectively. S1 H S2 and H S3 The initial thickness of the asphalt mixture layer is H. S =H S1 +H S2 +H S3 The designed porosities for the top, middle, and bottom layers are A1, A2, and A3, respectively. (5) Calculate the deformation of the asphalt mixture layer d = H S -H N ; (6) Prepare the top layer specimen, the middle layer specimen, and the bottom layer specimen in the laboratory. The top layer specimen has a diameter of 6R and a thickness of H. S1 The porosity is A1, and the diameter of the intermediate layer specimen is 6R and the thickness is H. S2 The porosity is A2, and the diameter of the lower layer specimen is 6R and the thickness is H. S3 The porosity is A3; (7) Stack the top layer specimen, middle layer specimen, and bottom layer specimen concentrically from top to bottom, and bond the layers together with adhesive to obtain a composite specimen with the same thickness as the initial asphalt pavement layers. The height of this composite specimen is H. S The diameter is 6R; (8) Conduct a permanent deformation test by pressing the center of the composite specimen; stop the test when the amount of pressure on the composite specimen is equal to the deformation amount d of the asphalt mixture layer. (9) Drill a core at the center of the assembled specimen after the permanent deformation test to obtain a core with a diameter of 2R and a height of H. N Asphalt mixture layer filler; (10) Based on the design data of the asphalt pavement, the mix proportion of the base cement concrete is obtained, and a concrete substrate with a diameter of 2R and a height of H is prepared according to the mix proportion. B Roadbed filling components; (11) The asphalt mixture layer filler and the subgrade filler are stacked and bonded together to obtain a diameter of 2R and a height of H. T Road surface filler; (12) Fill the road surface filler into the road surface holes.

2. The method for prefabricating and filling core holes in asphalt pavement based on deformation according to claim 1, characterized in that, In step (8), the operation of the permanent deformation experiment is specifically as follows: The combined specimen was placed on the test bench of the material mechanics testing machine and subjected to a permanent deformation test in a temperature-controlled chamber; Place a pressure plate with a diameter of 2R at the center of the upper surface of the composite specimen, so that the axis of the pressure plate coincides with the axis of the pressure bar of the material mechanics testing machine; The pressure bar is driven to move up and down by a material mechanics testing machine to apply pressure to the pressure plate and the composite specimen; the composite specimen gradually undergoes compression deformation, and the pressure plate gradually moves downward. When the downward movement of the pressure plate is equal to the deformation d of the asphalt mixture layer, the experiment is stopped.

3. The method for prefabricating and filling core holes in asphalt pavement based on deformation according to claim 2, characterized in that, In step (8), in the permanent deformation test, a material mechanics testing machine (UTM) or MTS is used for loading.

4. The method for prefabricating and filling core holes in asphalt pavement based on deformation according to claim 2, characterized in that, In step (8), the formula for calculating the temperature value in the temperature control box is as follows: In the formula, n is the number of days in a year where the average daily temperature is greater than 20℃, and Tn is the daily average temperature sequence in that period, where Tn>20℃.

5. The method for prefabricating and filling core holes in asphalt pavement based on deformation according to claim 2, characterized in that, In step (8), the formula for calculating the load force used in the permanent deformation experiment is: F=πR 2 ×p; In the formula, P is the pressure exerted by the pressure plate on the upper surface of the combined specimen.

6. The method for prefabricating and filling core holes in asphalt pavement based on deformation according to claim 5, characterized in that, The formula for calculating pressure P is: In the formula, m is the number of cars with axle count greater than or equal to 3 that have been operating locally for more than a year, and Pm is the sequence of ground pressure of car tires with axle count greater than or equal to 3 during that time period.

7. The method for prefabricating and filling core holes in asphalt pavement based on deformation according to claim 2, characterized in that, In step (8), the permanent deformation experiment uses an intermittent half-sine wave loading force with a loading frequency of 1 Hz, a loading duration of 0.1 seconds for each cycle, and an interval duration of 0.9 seconds.

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