Asphalt pavement coring hole prefabricating and filling method based on deformation

Abstract

The invention discloses an asphalt pavement coring hole prefabricating and filling method based on deformation. The method comprises the following steps that drilling and sampling are conducted on an asphalt pavement; measuring the depth HT of the pavement hole; measuring the total thickness of the asphalt mixture layer; looking up the initial thickness of the asphalt mixture layer; calculating the deformation of the asphalt mixture layer; preparing a new upper surface layer test piece, a new middle surface layer test piece and a new lower surface layer test piece, and concentrically overlapping the test pieces from top to bottom to obtain a combined test piece consistent with the initial thickness; pressing the center of the combined test piece downwards by adopting a tool until the downward movement amount is equal to the deformation amount of the asphalt mixture layer; drilling a core at the circle center position of the combined test piece, and filling an asphalt mixture layer; preparing a roadbed filling piece; the asphalt mixture layer filling piece and the roadbed filling piece are stacked and bonded, and a pavement filling piece is obtained; and filling the pavement filling piece into the pavement hole. The filling method has the advantages of identical materials, identical porosity, approximate mechanical properties, approximate deformation performance, high construction efficiency and the like.

Description

Technical Field

[0001] The invention relates to a road surface repair method, and in particular to a method for prefabricating and filling core holes in an asphalt road surface based on deformation. Background Art

[0002] Asphalt pavement is the main pavement form of my country's high-grade highways. The material used is asphalt mixture, which is composed of asphalt, aggregate and pores. Asphalt pavement is generally a multi-layer structure. For example, the asphalt pavement of a highway can generally be four layers, from top to bottom, the upper layer, the middle layer, the lower layer and the roadbed; the upper three layers are made of asphalt mixture, and the aggregates and asphalt used in each layer of asphalt mixture are different, and the porosity of each layer is also different; the material of the roadbed is generally cement concrete with low cement content. After the asphalt pavement construction is completed, it is often necessary to drill a cylindrical asphalt pavement core sample through a core drill to measure the porosity to check whether the construction quality meets the specification requirements; during the service of the asphalt pavement, it is also often necessary to drill an asphalt pavement core sample to check whether there are transverse shrinkage cracks or complex fatigue cracks inside the asphalt pavement. The diameter of the pavement core sample is generally 10cm or 15cm, and the height is generally greater than the thickness of the asphalt mixture layer (about 18cm for highways). Drilling sampling generally penetrates the asphalt mixture layer and turns into the roadbed. After core sampling, cylindrical holes will appear in the asphalt pavement.

[0003] The existing repair methods of coring holes mainly include on-site ramming repair and laboratory prefabrication repair:

[0004] First, on-site ramming repair is generally divided into three steps: (1) Use a high-temperature asphalt mixture (150-180℃) made of the same material as the upper layer of the asphalt pavement to pour into the sampling holes; (2) Manually compact the high-temperature asphalt mixture in the holes. The more compacted the asphalt mixture is, the lower the porosity and the higher the strength; (3) Manually remove excess asphalt mixture on the upper surface so that the height of the repaired hole is flush with the surrounding original road surface.

[0005] The above method has the following problems:

[0006] 1. The hole filling part is made of different materials from the surrounding original pavement. The original pavement is a multi-layer structure, and the asphalt mixture of each layer is different, while the hole filling part is made of the same asphalt mixture.

[0007] 2. The degree of compaction of the hole filling part is different from that of the surrounding original road surface. The original road surface is repeatedly rolled by rollers during construction, so that the compaction degree of the asphalt mixture meets the specification requirements. During the service process, the road surface is repeatedly rolled by vehicles above the road surface, and the compaction degree is further improved, while the porosity is further reduced. In the conventional hole filling method, manual compaction is used, and the compaction degree is significantly lower than the original road surface after compaction by rollers and vehicles, and its porosity is significantly greater than the original road surface.

[0008] 3. The strength of the asphalt mixture in the hole filling part is relatively low. Under the action of vehicle load, stress concentration will form at this location, making the road surface more susceptible to damage around the hole filling part.

[0009] 4. Grooves are easily formed in the hole-filled part. Since the porosity of the hole-filled part is greater than that of the original road surface, the hole-filled part is more likely to be compacted and deformed under the same vehicle load, while the deformation of the surrounding original road surface is significantly less, thus, grooves will be formed in the hole-filled part.

[0010] 5. The grooves in the hole filling part will store rainwater under rainfall conditions. The rainwater in the grooves will penetrate 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 compactness of the hole filling part depends entirely on the on-site operation of the construction workers, and the construction quality is difficult to control.

[0012] 7. The conventional on-site pouring repair method requires the asphalt mixture to be heated to 150-180°C first. After the repair, the temperature of the hole filling part needs to be lowered to room temperature before traffic can begin. The construction efficiency is low and the road traffic is affected for a long time.

[0013] Second, laboratory prefabrication repair, prefabrication of asphalt mixture specimens in the laboratory, is an effective way to solve the problem of excessive porosity of the repaired part during on-site manual repair methods. It can increase the porosity of the asphalt mixture, making the porosity of the repaired part close to the porosity of the original pavement. However, due to the existence of viscous deformation in asphalt mixtures, this method still has some problems. Asphalt pavement deforms under the combined action of vehicle load and temperature load. Pavement deformation can generally be divided into elastic deformation, plastic deformation and viscous deformation. Elastic deformation will recover immediately after the vehicle load disappears; plastic deformation is a permanent deformation on the asphalt pavement, which will not disappear after the vehicle load disappears; and viscous deformation gradually recovers slowly after the vehicle load disappears. Under high temperature and high load, the asphalt pavement deforms rapidly as a whole, but the viscous deformation accounts for a high proportion; while under low temperature and low load, the asphalt mixture deforms slowly as a whole, but the viscous deformation accounts for a low proportion.

[0014] The Marshall compaction method and the rotary compaction method are generally used to form asphalt mixture specimens in the laboratory. The process is generally divided into the following steps: (1) heating the asphalt mixture to 160-180°C, at which the asphalt mixture has a certain fluidity; (2) then pouring the mixture into a mold and then performing a compaction operation. The specific problems of this indoor forming method are as follows:

[0015] 1. The mixture formed at this temperature has a large proportion of viscous deformation in its deformation, which will recover after a period of time, so its actual height is generally greater than the designed height when formed. Due to the large difference in the viscous recovery performance of different types of asphalt mixtures, it is difficult to accurately control the final height of the test specimen formed indoors. The actual deformation of the asphalt pavement is formed under normal vehicle loads and normal temperatures. The actual pavement temperature generally does not exceed 60°C. In addition, the asphalt pavement hardly produces rutting deformation when the temperature is below 20°C. Therefore, the actual rutting temperature of the asphalt pavement is between 20-60°C, and the proportion of viscous deformation in the rutting deformation is low, much lower than that of the indoor formed specimens.

[0016] 2. After the indoor molded specimens have been placed for a long time, their viscous deformation recovers more, which leads to an increase in their diameter, so they may not be placed in the original-sized road hole.

[0017] 3. Even if the prefabricated asphalt mixture specimens are filled into the road holes within a short period of time after the specimens are formed, the recovery of the viscous deformation of the asphalt mixture specimens formed at high temperature indoors will not stop. The lateral deformation will be squeezed by the original road surface, which will increase its longitudinal deformation, and thus cause the upper end surface of the prefabricated filling part to be higher than the original road surface. Summary of the invention

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

[0019] The purpose of the present invention is achieved through the following technical solutions:

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

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

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

[0023] (3) The thickness of the upper layer, middle layer and lower layer of the pavement core sample are measured as H N1 , H N2 and H N3 , the total thickness of the asphalt mixture layer H N =H N1 +H N2 +H N3 , then the thickness of the road 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 thickness of the upper layer, middle layer and lower layer are H, 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 porosity of the upper layer, middle layer and lower layer are A 1 , A 2 and A 3 .

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

[0026] (6) Prepare the upper layer specimen, middle layer specimen and lower layer specimen in the laboratory. The diameter of the upper layer specimen is 6R and the thickness is H. S1 , porosity is A 1 The diameter of the middle surface layer specimen is 6R and the thickness is H S2 , porosity is A 2 The diameter of the lower layer specimen is 6R and the thickness is H S3 , porosity A 3 ;

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

[0028] (8) Conduct a permanent deformation test by squeezing the center of the composite specimen; stop the test when the 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 diameter of 2R and a height of H. N Asphalt mixture layer filling parts;

[0030] (10) According to the design data of the asphalt pavement, the mix ratio of the base cement concrete is obtained, and a concrete block with a diameter of 2R and a height of H is prepared according to the mix ratio. B Roadbed filling parts;

[0031] (11) The asphalt mixture layer filling piece and the roadbed filling piece are stacked and bonded to obtain a diameter of 2R and a height of H. T road filling parts;

[0032] (12) Fill the road surface holes with road surface filling pieces.

[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 is placed on the test bench of the material mechanics testing machine, and a permanent deformation test is carried out in a temperature-controlled box;

[0035] Place a pressure plate with a diameter of 2R at the center of the circle on the upper surface of the combined specimen so that the axis of the pressure plate coincides with the axis of the pressure rod of the material mechanics testing machine;

[0036] The pressure rod is driven to move up and down by the material mechanics testing machine to apply pressure to the pressure plate and the combined specimen; the combined specimen gradually produces 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 experiment, loading is performed using a material mechanics testing machine UTM or MTS.

[0038] Furthermore, the calculation formula for the temperature value in the temperature control box is:

[0039]

[0040] Where n is the number of days in a year when the local average daily temperature is greater than 20°C, Tn is the daily average temperature sequence in this time period, Tn>20°C.

[0041] Furthermore, the calculation formula of the load force used in the permanent deformation experiment is:

[0042] F=πR 2 ×P;

[0043] Where P is the pressure of the pressure plate on the upper surface of the combined specimen.

[0044] Furthermore, the calculation formula of pressure P is:

[0045]

[0046] Where m is the number of cars with axle numbers greater than or equal to 3 in the local area for more than one year, and Pm is the sequence of the ground contact pressure of the car tires with axle numbers greater than or equal to 3 at that time.

[0047] Furthermore, the loading force used in the permanent deformation experiment is in the form of an intermittent half-sine wave, the loading frequency is 1 Hz, the loading time of each cycle is 0.1 second, and the intermittent time is 0.9 second.

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

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

[0050] 2. The porosity of the same layer is basically the same: the porosity of each layer of asphalt pavement in the hole-filled part and the surrounding original pavement is the same. The hole-filled part and the surrounding original pavement produce the same degree of deformation, and no grooves will be formed.

[0051] 3. The mechanical properties of the same layers are basically the same: the mechanical properties of each layer of asphalt pavement of the hole-filled part and the surrounding original pavement are similar, eliminating the stress concentration effect caused by the lower strength of the hole-filled 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 of the hole filling part and the surrounding original road surface is similar, eliminating potholes caused by the faster deformation of the hole filling part and the slower deformation of the surrounding original road surface.

[0053] 5. High construction efficiency: Prefabricated parts are made in the laboratory and filled into the holes. Prefabricated parts can be made in advance, which improves construction efficiency, saves construction time, and has less impact on road traffic. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 It is a schematic diagram of the pavement structure of the present invention.

[0055] Figure 2 It is a schematic diagram of the initial thickness of each structural layer of the pavement of the present invention.

[0056] Figure 3 Schematic diagram of the pavement core sample of the present invention.

[0057] Figure 4 Schematic diagram of a road hole according to the present invention.

[0058] Figure 5 It is a schematic diagram of the combined test piece of the present invention.

[0059] Figure 6 Schematic diagram of preparing asphalt mixture layer filling member of the present invention

[0060] Figure 7 It is a schematic diagram of preparing a road surface filling member according to the present invention. DETAILED DESCRIPTION

[0061] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0062] See also Figure 1-7 The method for prefabricating and filling the asphalt pavement coring hole 8 based on the deformation amount of this embodiment includes the following steps:

[0063] (1) Drilling a hole in the asphalt pavement to obtain a pavement core sample 7 and forming a coring hole 8 on the pavement; measuring the diameter 2R of the pavement core sample 7.

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

[0065] (3) The thickness of the upper layer 1, middle layer 2 and lower layer 3 of the pavement core sample 7 are measured as H N1 , H N2 and H N3 , the total thickness H of the asphalt mixture layer 6 N =H N1 +H N2 +H N3 , then the thickness of the road hole 5 in the roadbed 4 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 and H, respectively. S1 , H S2 and H S3 , the initial thickness of the asphalt mixture layer 6 is H S =H S1 +H S2 +H S3 ,like Figure 2 The designed porosity of the upper layer 1, the middle layer 2 and the lower layer 3 are A 1 , A 2 and A 3 .

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

[0068] (6) In the laboratory, the upper layer specimen 9, the middle layer specimen 10 and the lower layer specimen 11 are prepared respectively. The diameter of the upper layer specimen 9 is 6R and the thickness is H. S1 , porosity A 1 The diameter of the middle surface layer specimen 10 is 6R and the thickness is H S2 , porosity A 2 The diameter of the lower layer specimen 11 is 6R and the thickness is H S3 , porosity A 3 ,like Figure 5 .

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

[0070] (8) The combined test piece 12 is placed on a test bench 15 of a material mechanics testing machine, and a permanent deformation test is performed in a temperature control box 16.

[0071] A pressure plate 14 with a diameter of 2R is placed at the center of the upper surface of the combined test piece 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 material mechanics testing machine drives the pressure rod 13 to move up and down, and applies pressure to the pressure plate 14 and the combined test piece 12; the combined test piece 12 gradually produces compression deformation, and the pressure plate 14 gradually moves downward. When the downward movement of the pressure plate 14 is equal to the deformation d of the asphalt mixture layer 6, the experiment is stopped. Figure 6 .

[0073] (9) Drill a core at the center of the combined 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 filling member 17, such as Figure 6 .

[0074] (10) According to the design data of the asphalt pavement, the mix ratio of the base cement concrete is obtained, and a concrete block with a diameter of 2R and a height of H is prepared according to the mix ratio. B The roadbed filling member 18, such as Figure 7 .

[0075] (11) The asphalt mixture layer filling member 17 and the roadbed filling member 18 are stacked and bonded to obtain a diameter of 2R and a height of H.T The road filling member 19, such as Figure 7 .

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

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

[0078] Further, in step (8), the temperature in the temperature control box 16 is calculated using the following formula:

[0079]

[0080] Where n is the number of days in a year when the local average daily temperature is greater than 20°C, Tn is the daily average temperature sequence in this time period, Tn>20°C.

[0081] Furthermore, in step (8), the calculation formula of the load force used in the permanent deformation test is:

[0082] F=πR 2 ×P;

[0083] Wherein P is the pressure of the pressure plate 14 on the upper surface of the combined test piece 12.

[0084] Furthermore, the calculation formula of pressure P is:

[0085]

[0086] Where m is the number of cars with axle numbers greater than or equal to 3 in the local area for more than one year, and Pm is the sequence of the ground contact pressure of the car tires with axle numbers greater than or equal to 3 at that time.

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

[0088] The above is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited to the above content. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principles of the present invention should be equivalent replacement methods and are included in 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: The following steps are involved: (1) Drill holes in the asphalt pavement to obtain pavement core samples and form coring holes on the pavement to measure the diameter 2R of the pavement core samples; (2) Process the bottom of the coring hole on the road surface to form a cylindrical road surface hole with a flat bottom, and measure the depth H of the road surface hole T ; (3) The thickness of the upper layer, middle layer and lower layer of the pavement core sample are measured as H N1 , H N2 and H N3 , the total thickness of the asphalt mixture layer H N =H N1 +H N2 +H N3 , then the thickness of the road 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 thickness of the upper layer, middle layer and lower layer are H, 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 porosity of the upper layer, middle layer and lower layer are A1, A2 and A3 respectively; (5) Calculate the deformation of the asphalt mixture layer d = H S -H N ; (6) Prepare the upper layer specimen, middle layer specimen and lower layer specimen in the laboratory. The diameter of the upper layer specimen is 6R and the thickness is H. S1 The porosity is A1, the diameter of the middle surface layer specimen is 6R, the thickness is H S2 , porosity is A2, the diameter of the lower layer specimen is 6R, the thickness is H S3 , porosity is A3; (7) The upper layer specimen, the middle layer specimen and the lower layer specimen are stacked concentrically from top to bottom, and the layers are glued together to obtain a composite specimen with the same thickness as the initial asphalt pavement. The height of the composite specimen is H. S , diameter is 6R; (8) Conduct a permanent deformation test by squeezing the center of the composite specimen; when the pressure on the composite specimen is equal to the deformation d of the asphalt mixture layer, stop the test; (9) Drill a core at the center of the assembled specimen after the permanent deformation test to obtain a diameter of 2R and a height of H. N Asphalt mixture layer filling parts; (10) According to the design data of the asphalt pavement, the mix ratio of the base cement concrete is obtained, and a concrete block with a diameter of 2R and a height of H is prepared according to the mix ratio. B Roadbed filling parts; (11) The asphalt mixture layer filling piece and the roadbed filling piece are stacked and bonded to obtain a diameter of 2R and a height of H. T road filling parts; (12) Fill the road surface holes with road surface filling pieces.

2. The method for prefabricating and filling asphalt pavement coring holes based on deformation according to claim 1 is characterized in that: In step (8), the operation of the permanent deformation experiment is specifically as follows: The combined specimen is placed on the test bench of the material mechanics testing machine, and a permanent deformation test is carried out in a temperature-controlled box; Place a pressure plate with a diameter of 2R at the center of the circle on the upper surface of the combined specimen so that the axis of the pressure plate coincides with the axis of the pressure rod of the material mechanics testing machine; The pressure rod is driven to move up and down by the material mechanics testing machine to apply pressure to the pressure plate and the combined specimen; the combined specimen gradually produces 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 asphalt pavement coring holes based on deformation according to claim 2 is characterized in that: In step (8), in the permanent deformation test, loading is performed using a material mechanics testing machine UTM or MTS.

4. The method for prefabricating and filling asphalt pavement coring holes based on deformation according to claim 2 is characterized in that: In step (8), the temperature in the temperature control box is calculated using the following formula: Where n is the number of days in a year when the local average daily temperature is greater than 20°C, Tn is the daily average temperature sequence in this time period, Tn>20°C.

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

6. The method for prefabricating and filling asphalt pavement coring holes based on deformation according to claim 5 is characterized in that: The calculation formula of pressure P is: Where m is the number of cars with axle numbers greater than or equal to 3 in the local area for more than one year, and Pm is the sequence of the ground contact pressure of the car tires with axle numbers greater than or equal to 3 at that time.

7. The method for prefabricating and filling asphalt pavement coring holes based on deformation according to claim 2 is characterized in that: In step (8), the loading force used in the permanent deformation experiment is in the form of an intermittent half-sine wave, the loading frequency is 1 Hz, the loading time of each cycle is 0.1 second, and the intermittent time is 0.9 second.

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