Traceless repairing method for asphalt pavement cracks based on tailing sand

Abstract

The invention relates to the technical field of repairing, in particular to an asphalt pavement crack traceless repairing method based on tailing sand, which comprises the following steps: preparing a crack gap filling material for filling a residual structural layer of an asphalt pavement, and filling the crack gap for the first time through the gap filling material; the method comprises the following steps: completely filling crack gaps in a residual structural layer of an asphalt pavement, drilling a core sample on an original pavement, detecting the compaction degree, the maximum theoretical density, the old asphalt mixture gradation and the asphalt consumption of the original pavement through the core sample, calculating the gradation of a fresh asphalt mixture required for filling the crack gaps according to the old asphalt mixture gradation and the asphalt consumption, and filling the new asphalt mixture into the original pavement. A three-dimensional laser radar is used for collecting three-dimensional digital information of the pavement along cracks, a cloth liner is laid on the surface of the compacted joint filling material, the cloth liner is made of one of polyester glass fiber cloth or polypropylene filament geotextile, a newly-mixed asphalt mixture is poured into the vacant part of the asphalt pavement, paving and rolling are conducted, and the pavement is formed. A traceless pavement is formed in the processed crack area.

Description

Technical Field

[0001] This invention relates to the field of repair technology, and specifically to a method for seamless repair of asphalt pavement cracks based on tailings sand. Background Technology

[0002] Most of the road surface structures of highways and urban roads of grade A and above in my country are asphalt pavement. As the service life increases, the pavement is prone to cracks due to factors such as temperature changes, wet and dry cycles and repeated loading. If cracks are not maintained or repaired in time, they will expand or the entire road will be damaged. To avoid this accelerated road damage, it is necessary to repair the cracks in the asphalt pavement.

[0003] For cracks in asphalt pavement, the usual methods to treat them are to inject hot asphalt into the surface, or to seal the cracks with sealant or to stick crack tape. However, these methods have poor durability and are prone to cracking or falling off again. Moreover, because the materials are different from the original pavement surface materials, the treatment marks are obvious and affect the aesthetics.

[0004] In view of the problems of the traditional repair methods for asphalt pavement cracks, a traceless repair method for asphalt pavement cracks based on tailings sand is proposed. Summary of the Invention

[0005] In order to solve the technical problems existing in the prior art, the present invention provides a method for seamless repair of asphalt pavement cracks based on tailings sand.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for seamless repair of asphalt pavement cracks based on tailings sand, comprising the following steps:

[0007] Step S1: Clean the surface of the asphalt pavement and remove dust and debris from the cracks and crevices, so that the cracks and crevices and adjacent asphalt pavement surfaces are free of debris.

[0008] Step S2: Prepare a joint filler material for filling the cracks and voids in the remaining structural layer of the asphalt pavement. Use the joint filler material to fill the cracks and voids for the first time, and completely fill the cracks and voids in the remaining structural layer of the asphalt pavement.

[0009] Step S3: Drill core samples from the original road surface and use the core samples to detect the original road surface compaction degree γ, maximum theoretical density ρ, old asphalt mixture gradation and asphalt content δ1.

[0010] Step S4: Calculate the gradation of the fresh asphalt mixture needed to fill the cracks and voids based on the gradation of the old asphalt mixture and the asphalt content δ1.

[0011] Step S5: Using microwave heating, heat the asphalt pavement surface layer within a range of 0.5 to 1.0m along the crack. After the surface layer softens, loosen the asphalt pavement surface layer along the crack gaps, collect the loosened old asphalt mixture, and place it into the asphalt mixture mixing tank.

[0012] Step S6: Clean up the loose asphalt mixture that fell into the cracks and gaps due to the loosening of the asphalt pavement surface layer, and return it to the asphalt mixture mixing tank.

[0013] Step S7: Use a three-dimensional lidar to collect three-dimensional digital information of the road surface with a width of 0.5 to 1.0m along the crack, and obtain the volume V of the crack void within the upper layer thickness H within the crack length L range from the three-dimensional digital information;

[0014] Step S8: Calculate the required total amount of new asphalt mixture by using the volume V of the crack voids, and prepare the required amount of new asphalt in the asphalt mixing tank according to the final gradation of the new asphalt mixture.

[0015] Step S9: Spray hot asphalt on the surface and sides of the asphalt pavement, lay a mat on the compacted joint filler material, and select either polyester fiberglass cloth or polypropylene filament geotextile as the mat. Pour the fresh asphalt mixture into the voids in the asphalt pavement, spread and compact it, and the treated cracked area forms a traceless pavement.

[0016] Preferably, in step S2, the joint filler is composed of petroleum asphalt, tailings sand, hydrated lime powder and viscosity reducer mixed in a ratio of 100:10:5:0.5 and heated at a temperature of 170°C.

[0017] Preferably, step S2 further includes step S21, which involves compacting the filling material to ensure full contact with the crack gaps, and laying a pad on the surface of the compacted filling material. The pad can be either polyester fiberglass cloth or polypropylene filament geotextile.

[0018] Preferably, step S4 includes:

[0019] Step S41, calculate the design void ratio VV of the fresh asphalt mixture. 理论 ;

[0020] Step S42: Use fresh asphalt mixture to form Marshall specimens, and measure the porosity VV of the mixture using the Marshall specimens. 真实 ;

[0021] Step S43: Establish a formula for determining the tailings sand proportion P, and determine the proportion P of tailings sand that needs to be replaced in the gradation of fresh asphalt mixture according to the formula:

[0022]

[0023] In the formula, V ca V represents the loose packing gap ratio of coarse aggregate. fa γ represents the loose packing gap ratio of tailings sand. ca γ represents the apparent density of coarse aggregate. fa VV represents the apparent density of the tailings sand. 真实 VV represents the true void ratio of fresh asphalt mixture. 理论 The design void ratio of fresh asphalt mixture;

[0024] Step S44: Determine the final gradation of the fresh asphalt mixture based on the obtained tailings sand ratio P.

[0025] Preferably, in step S43, VV 理论 =1-γ,V ca V fa γ ca and γ fa All were obtained through testing of graded raw materials.

[0026] Preferably, in step S5, the temperature of the upper layer mixture needs to reach 100°C.

[0027] Preferably, step S7 includes:

[0028] Step S71, establish the formula (1) for calculating the volume V of the upper layer crack voids:

[0029] V=∑(l j ×S j (1)

[0030] In the formula, l j S represents the length of the segmented three-dimensional crack volume in the three-dimensional lidar scan image. j The area of ​​the three-dimensional crack volume segmented in the three-dimensional lidar scan image;

[0031] Step S72, establish the area S of the three-dimensional crack volume. j The calculation formula (2):

[0032] S j =∑(m ij -n ij )×h ij (2)

[0033] In the formula, m ij n represents the maximum x-coordinate of the segmented 3D crack volume in the 3D lidar scan image. ij h represents the minimum abscissa of the segmented three-dimensional crack volume in the three-dimensional lidar scan image. ij The height value of the segmented three-dimensional crack volume in the three-dimensional LiDAR scan image;

[0034] Step S73, the area S of the three-dimensional crack volume j and the length l of the three-dimensional crack j Substituting d into the calculation formula (1) yields the volume V of the upper layer crack voids.

[0035] Preferably, step S8 includes:

[0036] Step S81: Based on the crack void volume V, the compaction degree γ of the original pavement surface layer, and the maximum theoretical density ρ, establish a formula for calculating the required total amount of newly added asphalt mixture m. The total amount of newly added asphalt mixture m is then calculated using this formula.

[0037] m = V × γ × ρ;

[0038] Step S82, calculate the mass m1 of asphalt in the fresh asphalt mixture:

[0039] m1 = m × δ1;

[0040] Step S83, calculate the mass m2 of aggregate in fresh asphalt:

[0041] m2 = m - m1;

[0042] Step S84: Prepare fresh asphalt in the asphalt mixing tank according to the mass m1 of the asphalt in the fresh asphalt and the mass m2 of the aggregate in the fresh asphalt.

[0043] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0044] 1. In this invention, the gradation of the original asphalt pavement is obtained through preliminary measurement, the fine material in the original gradation is replaced with tailings sand, and the cracks and voids in the asphalt pavement are filled with fresh asphalt. Then, the precise amount of fresh asphalt required is obtained through laser measurement, thereby improving the integration of the fresh asphalt mixture with the original pavement and achieving the purpose of seamless repair. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the process of the present invention;

[0046] Figure 2 This is a schematic diagram of the asphalt pavement layering of the present invention. Detailed Implementation

[0047] The present invention will be further described below with reference to the accompanying drawings and embodiments, which illustrate the above and other technical features and advantages of the present invention. However, the following embodiments are merely preferred embodiments of the present invention and are not exhaustive.

[0048] Example 1:

[0049] like Figures 1-2As shown, this invention provides a method for seamless repair of asphalt pavement cracks based on tailings sand, comprising the following steps:

[0050] Step S1: Clean the surface of the asphalt pavement and remove dust and debris from the cracks and crevices, so that the cracks and crevices and adjacent asphalt pavement surfaces are free of debris.

[0051] Step S2: Prepare a joint filler material for filling cracks and voids in the remaining structural layer of the asphalt pavement. The joint filler material is composed of petroleum asphalt, tailings sand, hydrated lime powder and viscosity reducer mixed in a ratio of 100:10:5:0.5 and heated at a temperature of 170°C. The joint filler material is used to fill the cracks and voids for the first time, completely filling the cracks and voids in the remaining structural layer of the asphalt pavement. The filled joint filler material is compacted to ensure full contact with the cracks and voids. Hot asphalt is sprayed on the surface and sides of the asphalt pavement. A mat is laid on the compacted joint filler material. The mat can be either polyester fiberglass cloth or polypropylene filament geotextile.

[0052] Step S3: Drill core samples from the original road surface and use the core samples to detect the original road surface compaction degree γ, maximum theoretical density ρ, old asphalt mixture gradation and asphalt content δ1.

[0053] Step S4: Calculate the gradation of the fresh asphalt mixture needed to fill the cracks and voids based on the gradation of the old asphalt mixture and the asphalt content δ1, prepare fresh asphalt according to the new gradation, inject the fresh asphalt into the cracks and voids, and lay the mat along the cracks and voids.

[0054] Step S4 includes:

[0055] Step S41, calculate the design void ratio VV of the fresh asphalt mixture. 理论 VV 理论 =1-γ;

[0056] Step S42: Use fresh asphalt mixture to form Marshall specimens, and measure the porosity VV of the mixture using the Marshall specimens. 真实 ;

[0057] Step S43: Establish a formula for determining the tailings sand proportion P, and determine the proportion P of tailings sand that needs to be replaced in the gradation of fresh asphalt mixture according to the formula:

[0058]

[0059] In the formula, V ca V represents the loose packing gap ratio of coarse aggregate. fa γ represents the loose packing gap ratio of tailings sand. ca γ represents the apparent density of coarse aggregate. fa VV represents the apparent density of the tailings sand. 真实VV represents the true void ratio of fresh asphalt mixture. 理论 VV is the design void ratio of fresh asphalt mixture. 理论 =1-γ,V ca V fa γ ca and γ fa All were obtained through testing of graded raw materials;

[0060] Step S44: Determine the final gradation of the fresh asphalt mixture based on the obtained tailings sand ratio P.

[0061] Step S5: Using microwave heating, heat the asphalt pavement surface layer within a range of 0.5 to 1.0m along the crack, so that the temperature of the surface layer mixture needs to reach 100℃. After the surface layer is softened, loosen the asphalt pavement surface layer along the crack gaps, collect the loose old asphalt mixture and place it into the asphalt mixture mixing tank.

[0062] Step S6: Clean up the loose asphalt mixture that fell into the cracks and gaps due to the loosening of the asphalt pavement surface layer, and return it to the asphalt mixture mixing tank.

[0063] Step S7: Use a three-dimensional lidar to collect three-dimensional digital information of the road surface with a width of 0.5 to 1.0m along the crack, and obtain the volume V of the crack void within the upper layer thickness H within the crack length L range from the three-dimensional digital information;

[0064] Step S71, establish the formula (1) for calculating the volume V of the upper layer crack voids:

[0065] V=∑(l j ×S j (1)

[0066] In the formula, l j S represents the length of the segmented three-dimensional crack volume in the three-dimensional lidar scan image. j The area of ​​the three-dimensional crack volume segmented in the three-dimensional lidar scan image;

[0067] Step S72, establish the area S of the three-dimensional crack volume. j The calculation formula (2):

[0068] S j =∑(m ij -n ij )×h ij (2)

[0069] In the formula, m ij n represents the maximum x-coordinate of the segmented 3D crack volume in the 3D lidar scan image. ij h represents the minimum abscissa of the segmented three-dimensional crack volume in the three-dimensional lidar scan image.ij The height value of the segmented three-dimensional crack volume in the three-dimensional LiDAR scan image;

[0070] Step S73, the area S of the three-dimensional crack volume j and the length l of the three-dimensional crack j Substituting d into the calculation formula (1) yields the volume V of the upper layer crack voids;

[0071] Step S8: Calculate the required total amount of new asphalt mixture by using the volume V of the crack voids, and prepare the required amount of new asphalt in the asphalt mixing tank according to the final gradation of the new asphalt mixture.

[0072] Step S81: Based on the crack void volume V, the compaction degree γ of the original pavement surface layer, and the maximum theoretical density ρ, establish a formula for calculating the required total amount of newly added asphalt mixture m. The total amount of newly added asphalt mixture m is then calculated using this formula.

[0073] m = V × γ × ρ;

[0074] Step S82, calculate the mass m1 of asphalt in the fresh asphalt mixture:

[0075] m1 = m × δ1;

[0076] Step S83, calculate the mass m2 of aggregate in fresh asphalt:

[0077] m2 = m - m1;

[0078] Step S84: Prepare fresh asphalt in the asphalt mixing tank according to the mass m1 of asphalt in the fresh asphalt and the mass m2 of aggregate in the fresh asphalt.

[0079] Step S9: Spray hot asphalt on the surface and sides of the asphalt pavement, lay a mat on the surface of the compacted joint filler material, and select either polyester fiberglass cloth or polypropylene filament geotextile as the mat. Pour the fresh asphalt mixture into the voids in the asphalt pavement and the cracks in the upper layer of the asphalt pavement, and spread and compact it. The treated crack area forms a traceless pavement.

[0080] Example 2:

[0081] Clean the surface of the asphalt pavement and remove dust and debris from the cracks and crevices, so that the cracks and crevices and adjacent asphalt pavement surfaces are free of debris;

[0082] Core samples were drilled from the original road surface. Testing of the core samples revealed that the original road surface had a compaction degree γ = 94.5% and a maximum theoretical density ρ = 2.552 g / cm³. 3 The gradation and asphalt content δ1 of the old asphalt mixture are 5.033%;

[0083] Based on the gradation of the old asphalt mixture and the asphalt content δ1, calculate the gradation of the fresh asphalt mixture needed to fill the cracks and voids.

[0084] Calculate the design void VV of fresh asphalt mixture 理论 =1-γ=5.5%, Marshall specimens were formed using fresh asphalt mixture, and the porosity VV of the mixture was measured using the Marshall specimens. 真实 =5.7%;

[0085] Establish a formula for determining the proportion P of tailings sand, and determine the proportion P of tailings sand that needs to be replaced in the gradation of fresh asphalt mixture based on the formula:

[0086]

[0087] In the formula, V ca V represents the loose packing gap ratio of coarse aggregate. ca It is 42%, V fa V represents the loose packing gap ratio of tailings sand. fa 15%, γ ca γ represents the apparent density of coarse aggregate. ca 2.75 g / cm 3 γ fa γ is the apparent density of the tailings sand. fa It is 2.62 g / cm 3 ;

[0088] The calculated proportion of tailings sand, P, is 38.3%, with the remaining 61.7% consisting of coarse aggregate. The final density of the asphalt mixture is...

[0089] ρ = 2.557 g / cm³ 3 ;

[0090] Three-dimensional lidar was used to collect three-dimensional digital information of the road surface with a width of 0.5 to 1.0 m along the crack, and the volume V of the crack void within the upper layer thickness H within the crack length L range was obtained from the three-dimensional digital information.

[0091] The calculated total volume of newly added asphalt mixture is 1350 cm3, with a total mass of 3452 g of new mixture, 174 g of new asphalt, 2023 g of new coarse aggregate, and 1256 g of new tailings sand.

[0092] The above description is merely a preferred embodiment of the present invention and is illustrative rather than restrictive. Those skilled in the art will understand that many changes, modifications, and even equivalents can be made within the spirit and scope defined by the claims of the present invention, all of which will fall within the protection scope of the present invention.

Claims

1. A method for seamless repair of asphalt pavement cracks based on tailings sand, characterized in that, Includes the following steps: Step S1: Clean the surface of the asphalt pavement and remove dust and debris from the cracks and crevices, so that the cracks and crevices and adjacent asphalt pavement surfaces are free of debris. Step S2: Prepare a joint filler material for filling the cracks and voids in the remaining structural layer of the asphalt pavement. Use the joint filler material to fill the cracks and voids for the first time, and completely fill the cracks and voids in the remaining structural layer of the asphalt pavement. Step S3: Drill core samples from the original road surface and use the core samples to detect the original road surface compaction degree γ, maximum theoretical density ρ, old asphalt mixture gradation and asphalt content δ1. Step S4: Calculate the gradation of the fresh asphalt mixture needed to fill the cracks and voids based on the gradation of the old asphalt mixture and the asphalt content δ1. Step S5: Using microwave heating, heat the asphalt pavement surface layer within a range of 0.5 to 1.0m along the crack. After the surface layer softens, loosen the asphalt pavement surface layer along the crack gaps, collect the loosened old asphalt mixture, and place it into the asphalt mixture mixing tank. Step S6: Clean up the loose asphalt mixture that fell into the cracks and gaps due to the loosening of the asphalt pavement surface layer, and return it to the asphalt mixture mixing tank. Step S7: Use a three-dimensional lidar to collect three-dimensional digital information of the road surface with a width of 0.5 to 1.0m along the crack, and obtain the volume V of the crack void within the upper layer thickness H within the crack length L range from the three-dimensional digital information; Step S8: Calculate the required total amount of new asphalt mixture by using the volume V of the crack voids, and prepare the required amount of new asphalt in the asphalt mixing tank according to the final gradation of the new asphalt mixture. Step S9: Spray hot asphalt on the surface and sides of the asphalt pavement, lay a mat on the compacted joint filler material, and select either polyester fiberglass cloth or polypropylene filament geotextile as the mat. Pour the fresh asphalt mixture into the voids in the asphalt pavement, spread and compact it, and the treated cracked area forms a traceless pavement.

2. The method for seamless repair of asphalt pavement cracks based on tailings sand as described in claim 1, characterized in that, In step S2, the joint filler is composed of petroleum asphalt, tailings sand, hydrated lime powder and viscosity reducer mixed in a ratio of 100:10:5:0.5 and heated at a temperature of 170°C.

3. The method for seamless repair of asphalt pavement cracks based on tailings sand as described in claim 2, characterized in that, Step S2 further includes step S21, which involves compacting the filling material to ensure it is in full contact with the cracks and gaps.

4. The method for seamless repair of asphalt pavement cracks based on tailings sand as described in claim 1, characterized in that, Step S4 includes: Step S41, calculate the design void ratio VV of the fresh asphalt mixture. 理论 ; Step S42: Use fresh asphalt mixture to form Marshall specimens, and measure the porosity VV of the mixture using the Marshall specimens. 真实 ; Step S43: Establish a formula for determining the tailings sand proportion P, and determine the proportion P of tailings sand that needs to be replaced in the gradation of fresh asphalt mixture according to the formula: In the formula, V ca V represents the loose packing gap ratio of coarse aggregate. fa γ represents the loose packing gap ratio of tailings sand. ca γ represents the apparent density of coarse aggregate. fa VV represents the apparent density of the tailings sand. 真实 VV represents the true void ratio of fresh asphalt mixture. 理论 The design void ratio of fresh asphalt mixture; Step S44: Determine the final gradation of the fresh asphalt mixture based on the obtained tailings sand ratio P.

5. The method for seamless repair of asphalt pavement cracks based on tailings sand as described in claim 4, characterized in that, In step S43, VV 理论 =1-γ,V ca V fa γ ca and γ fa All were obtained through testing of graded raw materials.

6. The method for seamless repair of asphalt pavement cracks based on tailings sand as described in claim 1, characterized in that, In step S5, the temperature of the upper layer mixture needs to reach 100°C.

7. The method for seamless repair of asphalt pavement cracks based on tailings sand as described in claim 1, characterized in that, Step S7 includes: Step S71, establish the formula (1) for calculating the volume V of the upper layer crack voids: V=∑(l j ×S j ) (1) In the formula, l j S represents the length of the segmented three-dimensional crack volume in the three-dimensional lidar scan image. j The area of ​​the three-dimensional crack volume segmented in the three-dimensional lidar scan image; Step S72, establish the area S of the three-dimensional crack volume. j The calculation formula (2): S j =∑(m ij -n ij )×h ij (2) In the formula, m ij n represents the maximum x-coordinate of the segmented 3D crack volume in the 3D lidar scan image. ij h represents the minimum abscissa of the segmented three-dimensional crack volume in the three-dimensional lidar scan image. ij The height value of the segmented three-dimensional crack volume in the three-dimensional LiDAR scan image; Step S73, the area S of the three-dimensional crack volume j and the length l of the three-dimensional crack j Substituting d into the calculation formula (1) yields the volume V of the upper layer crack voids.

8. The method for seamless repair of asphalt pavement cracks based on tailings sand as described in claim 1, characterized in that, Step S8 includes: Step S81: Based on the crack void volume V, the compaction degree γ of the original pavement surface layer, and the maximum theoretical density ρ, establish a formula for calculating the required total amount of newly added asphalt mixture m. The total amount of newly added asphalt mixture m is then calculated using this formula. m = V × γ × ρ; Step S82, calculate the mass m1 of asphalt in the fresh asphalt mixture: m1 = m × δ1; Step S83, calculate the mass m2 of aggregate in fresh asphalt: m2 = m - m1; Step S84: Prepare fresh asphalt in the asphalt mixing tank according to the mass m1 of the asphalt in the fresh asphalt and the mass m2 of the aggregate in the fresh asphalt.

Images