Pavement structure for repairing damage of asphalt pavement

Abstract

The utility model discloses a pavement structure for repairing the damage of an asphalt pavement. The pavement structure comprises a surface layer, a base layer and a subbase layer, the subbase layer comprises a plurality of gravel unit layers or comprises a plurality of gravel unit layers from bottom to top, and a polyurethane doping layer is further embedded between any two adjacent gravel unit layers. According to the utility model, by designing the subbase layer with the plurality of gravel unit layers and the embedded polyurethane doping layers, the cold-state construction can be realized, the maintenance is not needed, and the construction cost is reduced; and the construction is fast and convenient, the deep repair of the subbase layer of the pavement is realized, the construction requirement of immediate repair and immediate dredging is met, the service life is long, the practicability is high, and a new way is provided for the deep repair of the damaged asphalt pavement. In addition, the pavement structure also has the characteristics of simple overall structure, quickness in construction, convenience in maintenance, high practicability, easiness in popularization and the like.

Description

Technical Field

[0001] The utility model relates to a road surface repair technology, in particular to a road surface structure used for repairing damaged asphalt road surfaces, and belongs to the technical field of road surface repair. Background Art

[0002] More than 90% of my country's highways use semi-rigid base asphalt pavement. However, since the inorganic binder (such as cement) in the semi-rigid base material is greatly affected by temperature and humidity, it is easy to shrink and dry shrink, which makes the semi-rigid base prone to shrinkage cracks and temperature shrinkage cracks. Then, under the action of load, the stress concentration at the top of the crack leads to reflective cracks in the asphalt pavement. If the cracks are not controlled in a timely and reasonable manner, rainwater or road surface water will penetrate into the base along the cracks, and then the semi-rigid base is likely to become loose and damaged under the action of heavy vehicle load coupled with dry-wet or freeze-thaw cycles. At this time, the asphalt surface layer usually shows concave cracks or potholes, which seriously damages the service function of the road and reduces the service life of the pavement structure.

[0003] At present, the measures to deal with the above-mentioned pavement diseases caused by the damage of the semi-rigid base of the asphalt pavement mainly include treatment technologies such as grouting, grouting, and adding overlays. Although these technologies have certain effects in the short term, they are only temporary solutions and cannot fundamentally solve the above-mentioned disease problems. In addition, there are also methods to repair the semi-rigid base by digging out the damaged base and backfilling with inorganic binder materials of the same type as the original pavement. However, the strength formation of inorganic binder materials requires a long maintenance cycle. If the road is opened to traffic before reaching sufficient strength, it is easy to cause rutting or subsidence at the repair location. It is not suitable for highways that have been opened to traffic (it needs to meet the high-efficiency construction requirements of immediate repair and opening). At the same time, conventional hot-mix asphalt mixtures are also used to backfill the repair base, but due to its high construction temperature, it takes a long time for the base material to cool to room temperature before the surface material can be paved, which is also not suitable for highways that have been opened. If the surface material is paved when the base material temperature is high, the cooling rate of the base material will be slower. When traffic is opened, it is easy to cause the base to deform significantly due to the high temperature, thereby causing structural rutting on the pavement. In addition, the existing technology for repairing broken roads often only targets the surface layer and the base layer, and pays little attention to the subbase layer. The subbase layer is the main supporting layer of the road. If it is damaged, even if the base layer and the surface layer above it are repaired, it is easy to be damaged again under the action of external forces if no special maintenance is carried out. That is, the service life of the repaired road surface is not long, and it may even further affect the surrounding roads, causing the road damage to worsen. Utility Model Content

[0004] In view of the shortcomings of existing pavement repair technologies that require a long time for maintenance and do not specifically repair the base pavement, the utility model provides a pavement structure for repairing damaged asphalt pavements. By designing a base layer with multiple crushed stone unit layers and embedded with a polyurethane doped layer, cold construction can be achieved, no maintenance is required, and the construction is quick and convenient, which not only achieves deep repair of the pavement base layer, but also meets the construction requirements of immediate repair and immediate passage. It has a long service life and strong practicality, can be promoted and applied on a large scale, and provides a new way for deep repair of damaged asphalt pavements.

[0005] In order to achieve the above technical objectives, the technical solutions adopted by the present utility model are specifically described as follows:

[0006] A pavement structure for repairing damaged asphalt pavement comprises a surface layer, a base layer and a subbase layer. The subbase layer comprises or is composed of a plurality of crushed stone unit layers from bottom to top, and a polyurethane doping layer is embedded between any two adjacent crushed stone unit layers.

[0007] Preferably, the number of the multiple crushed stone unit layers is 1 to 20 layers, preferably 2 to 15 layers, and more preferably 3 to 10 layers.

[0008] Preferably, the average particle size of each layer of crushed stone in the multiple crushed stone unit layers decreases layer by layer from bottom to top.

[0009] Preferably, the maximum particle size of the crushed stones in the multiple crushed stone unit layers is 31.5 to 53 mm, and the minimum particle size is no more than 1.18 mm.

[0010] Preferably, multiple gravel unit layers are numbered 1, 2, 3, ..., m from bottom to top. And all gravels in the m-layer gravel unit layer 301 are divided into 1st-level gravel, 2nd-level gravel, 3rd-level gravel, ..., nth-level gravel according to their particle sizes from large to small, where: n≥m. The first gravel unit layer is a mixed gravel layer composed of 1st-level gravel and one or more other gravels of smaller particle sizes, and the proportion of 1st-level gravel is not less than 40-80%. The second gravel unit layer is a mixed gravel layer composed of 2nd-level gravel and one or more other gravels of smaller particle sizes, and the proportion of 2nd-level gravel is not less than 40-80%. The third gravel unit layer is a mixed gravel layer composed of 3rd-level gravel and one or more other gravels of smaller particle sizes, and the proportion of 3rd-level gravel is not less than 40-80%, and so on.

[0011] Preferably, the thicknesses of the multiple gravel unit layers are the same or different.

[0012] Preferably, the thickness of each of the multiple crushed stone unit layers decreases layer by layer from bottom to top.

[0013] Preferably, the thickness of the subbase accounts for 15-40% of the total thickness of the entire pavement structure, preferably 20-35%, and more preferably 22-30%.

[0014] Preferably, the base layer is composed of at least one layer of warm-mix asphalt macadam mixture. The maximum particle size of the macadam in the warm-mix asphalt macadam mixture layer is 37.5 to 63 mm, preferably 53 to 63 mm.

[0015] Preferably, the thickness of the base layer accounts for 30-70% of the total thickness of the entire pavement structure, preferably 40-65%, and more preferably 45-60%.

[0016] Preferably, the surface layer is composed of at least one asphalt concrete layer.

[0017] In the utility model, for the repair of the road subbase, a special structure is designed, that is, a structure of a subbase with multiple crushed stone unit layers and a composite polyurethane doped layer, which can fundamentally solve the road disease problem caused by the damage of the semi-rigid base of the asphalt road. The structure has a short construction period and strong overall bearing capacity and anti-deformation ability. The various structural layers are closely combined and the stiffness is coordinated. After the repair is completed, the road surface is highly durable.

[0018] In the utility model, the crushed stones of the multi-crushed stone unit layer are mainly natural rocks with good strength, such as basalt crushed stones. Through the interlocking of the polyurethane layer, on the one hand, the polyurethane layer can fill the gaps between the crushed stones and achieve efficient bonding between the crushed stones, which can realize the cold construction of the crushed stones, reduce the construction difficulty, and can be opened for use simply or even without maintenance after the construction is completed; on the other hand, through the action of the polyurethane layer, it can play a certain buffering role between the crushed stones, which is conducive to releasing the force applied by the road surface, avoiding squeezing and crushing between the crushed stones, and thus avoiding affecting the integrity of the base layer.

[0019] Compared with the prior art, the beneficial technical effects of the utility model are as follows:

[0020] 1: The pavement structure for repairing damaged asphalt pavement described in the utility model can realize cold construction, no maintenance is required, and the construction is quick and convenient, which not only realizes the deep repair of the pavement subbase, but also meets the construction requirements of immediate repair and immediate paving. It has a long service life and strong practicality, and provides a new way for the deep repair of damaged asphalt pavement.

[0021] 2: The pavement structure of the utility model for repairing damaged asphalt pavement also has the characteristics of simple overall structure, quick construction, convenient maintenance, strong practicality, and easy promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1This is a schematic diagram of the repaired pavement structure of Application Example 1 of the utility model.

[0023] Figure 2 This is a schematic diagram of the repaired pavement structure of Application Example 2 of the utility model.

[0024] Figure 3 This is a schematic diagram of the repaired pavement structure of Application Example 3 of the utility model.

[0025] Figure 4 This is a schematic diagram of the repaired pavement structure of Application Example 4 of the utility model.

[0026] Figure 5 This is a schematic diagram of the repaired pavement structure of Application Example 5 of the utility model.

[0027] Figure 6 This is a schematic diagram of the repaired pavement structure of comparative example 1 of the utility model.

[0028] Figure 7 This is a schematic diagram of the repaired pavement structure of comparative example 2 of the present utility model.

[0029] Figure numerals: 1: surface layer; 2: base layer; 3: subbase layer; 301: crushed stone unit layer; 302: polyurethane doping layer. DETAILED DESCRIPTION

[0030] The technical solution of the utility model is illustrated below, and the scope of protection requested for the utility model includes but is not limited to the following embodiments.

[0031] A pavement structure for repairing damaged asphalt pavement, the pavement structure comprises a surface layer 1, a base layer 2 and a subbase layer 3. The subbase layer 3 comprises or is composed of a plurality of crushed stone unit layers 301 from bottom to top, and a polyurethane doping layer 302 is also embedded between any two adjacent crushed stone unit layers 301.

[0032] Preferably, the number of the plurality of crushed stone unit layers 301 is 1 to 20 layers, preferably 2 to 15 layers, and more preferably 3 to 10 layers.

[0033] Preferably, the average particle size of each layer of crushed stone in the multiple crushed stone unit layers 301 decreases layer by layer from bottom to top.

[0034] Preferably, the maximum particle size of the crushed stones in the multiple crushed stone unit layers 301 is 31.5-53 mm, and the minimum particle size is no more than 1.18 mm.

[0035] Preferably, the multiple gravel unit layers 301 are numbered 1, 2, 3, ..., m from bottom to top. And all the gravels in the m-layer gravel unit layer 301 are divided into 1st-level gravel, 2nd-level gravel, 3rd-level gravel, ..., nth-level gravel according to their particle sizes from large to small, where: n≥m. The first gravel unit layer 301 is a mixed gravel layer composed of 1st-level gravel and one or more other gravels of smaller particle sizes, and the proportion of 1st-level gravel is not less than 40-80%. The second gravel unit layer 301 is a mixed gravel layer composed of 2nd-level gravel and one or more other gravels of smaller particle sizes, and the proportion of 2nd-level gravel is not less than 40-80%. The third gravel unit layer 301 is a mixed gravel layer composed of 3rd-level gravel and one or more other gravels of smaller particle sizes, and the proportion of 3rd-level gravel is not less than 40-80%, and so on.

[0036] Preferably, the thicknesses of the multiple gravel unit layers 301 are the same or different.

[0037] Preferably, the thickness of each of the multiple crushed stone unit layers 301 decreases layer by layer from bottom to top.

[0038] Preferably, the thickness of the subbase 3 accounts for 15-40% of the total thickness of the entire pavement structure, preferably 20-35%, and more preferably 22-30%.

[0039] Preferably, the base layer 2 is composed of at least one layer of warm-mix asphalt macadam mixture. The maximum particle size of the macadam in the warm-mix asphalt macadam mixture layer is 37.5 to 63 mm, preferably 53 to 63 mm.

[0040] Preferably, the thickness of the base layer 2 accounts for 30-70% of the total thickness of the entire pavement structure, preferably 40-65%, and more preferably 45-60%.

[0041] Preferably, the surface layer 1 is composed of at least one asphalt concrete layer.

[0042] Example 1

[0043] like Figure 1-5 As shown, a pavement structure for repairing damaged asphalt pavement comprises a surface layer 1, a base layer 2 and a subbase layer 3. The subbase layer 3 comprises or is composed of a plurality of crushed stone unit layers 301 from bottom to top, and a polyurethane doping layer 302 is also embedded between any two adjacent crushed stone unit layers 301.

[0044] Example 2

[0045] Example 1 is repeated, except that the number of the plurality of crushed stone unit layers 301 is one layer.

[0046] Example 3

[0047] Example 1 is repeated, except that the number of the plurality of crushed stone unit layers 301 is three.

[0048] Example 4

[0049] Example 1 is repeated, except that the number of the plurality of crushed stone unit layers 301 is 7 layers.

[0050] Example 5

[0051] Example 4 is repeated, except that the average particle size of each layer of crushed stone in the multiple crushed stone unit layers 301 decreases layer by layer from bottom to top.

[0052] Example 6

[0053] Example 5 is repeated, except that the maximum particle size of the crushed stones in the multiple crushed stone unit layers 301 is 37.5 mm, and the minimum particle size is less than 0.075 mm.

[0054] Example 7

[0055] Repeat Example 6, except that the multiple gravel unit layers 301 are numbered 1, 2, 3, ..., m from bottom to top. And all the gravels in the m-layer gravel unit layer 301 are divided into 1st-level gravel, 2nd-level gravel, 3rd-level gravel, ..., nth-level gravel according to their particle sizes from large to small, where: n≥m. The first gravel unit layer 301 is a mixed gravel layer composed of 1st-level gravel and one or more other gravels of smaller particle sizes, and the proportion of 1st-level gravel is not less than 60%. The second gravel unit layer 301 is a mixed gravel layer composed of 2nd-level gravel and one or more other gravels of smaller particle sizes, and the proportion of 2nd-level gravel is not less than 60%. The third gravel unit layer 301 is a mixed gravel layer composed of 3rd-level gravel and one or more other gravels of smaller particle sizes, and the proportion of 3rd-level gravel is not less than 60%, and so on.

[0056] Example 8

[0057] Example 7 is repeated except that the thickness of each of the multiple crushed stone unit layers 301 is the same.

[0058] Example 9

[0059] Example 8 is repeated, except that the thicknesses of the multiple crushed stone unit layers 301 are different.

[0060] Example 10

[0061] Example 9 is repeated, except that the thickness of each of the multiple crushed stone unit layers 301 decreases layer by layer from bottom to top.

[0062] Embodiment 11

[0063] Example 10 was repeated except that the thickness of the subbase 3 accounted for 21% of the total thickness of the entire pavement structure.

[0064] Example 12

[0065] Example 11 is repeated, except that the base layer 2 is composed of two layers of warm-mix asphalt macadam mixture. The maximum particle size of the macadam in the warm-mix asphalt macadam mixture layer is in the range of 53 to 63 mm.

[0066] Embodiment 13

[0067] Example 12 is repeated except that the thickness of the base layer 2 accounts for 50% of the total thickness of the entire pavement structure.

[0068] Embodiment 14

[0069] Example 13 was repeated, except that the surface layer 1 consisted of 3 asphalt concrete layers.

[0070] Application Example 1

[0071] The pavement structure described in the utility model is used to repair the semi-rigid base asphalt pavement at the K460+035 position of the main line of Jiangxi Kangda Expressway. The pavement structure to be repaired is: upper layer, 4cm thick fine-grained asphalt concrete; middle layer, 6cm thick medium-grained asphalt concrete; lower layer, 8cm thick coarse-grained asphalt concrete; upper base, 18cm thick cement-stabilized crushed stone; lower base, 18cm thick cement-stabilized crushed stone; subbase, 18cm thick cement-stabilized gravel. The base (cement-stabilized crushed stone layer) and subbase (cement-stabilized gravel) here are both broken and loose. In order to repair the pavement, the upper layer, middle layer, lower layer, base layer and subbase of the original pavement are first milled, and then the following pavement structure is used for repair:

[0072] The pavement structure used for repair is subbase, base layer and surface layer from bottom to top.

[0073] The base layer is composed of 5 layers of crushed stone units (the particle composition of which is shown in Table 1) with high-quality graded crushed stone (basalt) added with 1.5% polyurethane, the total thickness of the base layer is 15 cm, and the control range of its rebound modulus is 500-900 MPa.

[0074] Table 1 Particle composition of graded crushed stone

[0075] Screen size / mm 37.5 31.5 19.0 9.5 4.75 2.36 0.6 0.075 Pass rate / % 100 95 80 58 37 25 14 3

[0076] The first (i.e., the bottom) gravel unit layer has a gravel particle size range of >19 mm (gravel with a particle size between 31.5 and 37.5 mm accounts for about 60%), and its thickness is 4 cm.

[0077] The second layer (i.e., the sub-bottom layer) of gravel unit layer has a gravel particle size range of 9.5 to 31.5 mm (gravel with a particle size between 19 and 31.5 mm accounts for about 60%), and its thickness is 3 cm.

[0078] The third layer (i.e., the middle layer) of the gravel unit layer has a gravel particle size range of 4.75 to 19 mm (the gravel with a particle size between 9.5 and 19 mm accounts for about 60%), and its thickness is 3 cm.

[0079] The fourth (i.e., the second-upper) gravel unit layer has a gravel particle size range of 2.36 to 9.5 mm (gravel with a particle size between 4.75 and 9.5 mm accounts for about 60%), and its thickness is 2.5 cm.

[0080] The fifth (i.e., the uppermost) gravel unit layer has a gravel particle size range of <4.75 mm (gravel with a particle size between 2.36 and 4.75 mm accounts for about 60%), and its thickness is 2.5 cm.

[0081] The base layer adopts an ultra-large particle size warm mix asphalt macadam mixture layer with a maximum aggregate particle size of 53 mm (its particle composition is shown in Table 2), a warm mix agent dosage of 2.5% (accounting for the mass of asphalt), an oil-stone ratio of 2.8%, a compaction temperature of 130°C, a thickness of 36 cm, and is paved in two layers. The void ratio is controlled to be 3.7-4.6%, and the dynamic compression modulus is controlled in the range of 11000-14000 MPa under the conditions of 20°C and 5Hz.

[0082] Table 2 Gradation composition of super-large particle size warm mix asphalt macadam mixture

[0083] Screen size / mm 53.0 37.5 19.0 9.5 4.75 2.36 1.18 0.6 0.3 0.15 0.075 Pass rate / % 100 72 61 43 35 25 17 14 10 7 5

[0084] The surface layer includes an upper layer, a middle layer and a lower layer, wherein the upper layer is: AC-13 modified asphalt mixture, wherein the anti-rutting agent is 0.9%, the void ratio is controlled at 4%-5.5%, the oil-stone ratio is about 4.5%, the aggregate is basalt, the thickness is 5cm, and the dynamic compression modulus is controlled in the range of 10500-14000MPa under the conditions of 20°C and 10Hz;

[0085] The middle surface layer is: AC-20 modified asphalt mixture, in which the anti-rutting agent is 0.9%, the void ratio is controlled at 4%-6%, the oil-stone ratio is about 4.4%, the aggregate is basalt, the thickness is 6cm, and the dynamic compression modulus is controlled in the range of 11000-14000MPa under the conditions of 20℃ and 10Hz;

[0086] The lower layer is: AC-25 modified asphalt mixture, in which the anti-rutting agent is 0.8%, the void ratio is controlled at about 4.3%, the oil-stone ratio is about 4.2%, the aggregate is basalt, the thickness is 10cm, and the dynamic compression modulus is controlled in the range of 10500-14000MPa under the conditions of 20℃ and 10Hz. The bonding layer between each structural layer adopts a modified emulsified asphalt impermeable bonding layer.

[0087] Application Example 2

[0088] The pavement structure of the utility model is used to repair the semi-rigid base asphalt pavement at the EK40+834 position of Sanyi E ramp of Jiangxi Kangda Expressway. The pavement structure is: upper layer, 4cm thick fine-grained asphalt concrete; middle layer, 6cm thick medium-grained asphalt concrete; lower layer, 6cm thick coarse-grained asphalt concrete; base layer, 19cm thick cement-stabilized crushed stone; subbase layer, 20cm thick cement-stabilized gravel. Here, both the base layer (cement-stabilized crushed stone layer) and the subbase layer (cement-stabilized gravel) are broken and loose. In order to repair the pavement, the upper layer, middle layer, lower layer, base layer and subbase layer of the original pavement are first milled, and then the following pavement structure is used for repair:

[0089] The pavement structure used for repair is subbase, base layer and surface layer from bottom to top.

[0090] The base layer is composed of three layers of crushed stone units (the particle composition of which is shown in Table 3) with high-quality graded crushed stone (basalt) added with 1.7% polyurethane, the total thickness of the base layer is 15 cm, and the control range of its rebound modulus is 600-1000 MPa.

[0091] Table 3 Particle composition of graded crushed stone

[0092] Screen size / mm 31.5 19.0 9.5 4.75 2.36 0.6 0.075 Pass rate / % 100 92 63 42 26 14 4

[0093] The first (i.e., the bottom) gravel unit layer has a gravel particle size range of no less than 9.5 mm (gravel with a particle size between 19 and 31.5 mm accounts for about 65%), and its thickness is 6 cm.

[0094] The second layer (i.e., the middle layer) of the gravel unit layer has a gravel particle size range of 2.36 to 19 mm (the gravel with a particle size between 9.5 and 19 mm accounts for about 65%), and its thickness is 5 cm.

[0095] The third (i.e., the topmost) gravel unit layer has a gravel particle size range of no more than 4.75 mm (gravel with a particle size between 2.36 and 4.75 mm accounts for about 60%), and its thickness is 4 cm.

[0096] The base layer adopts an ultra-large particle size warm mix asphalt macadam mixture layer with a maximum aggregate particle size of 53 mm (its particle composition is shown in Table 4), the warm mix agent dosage is 2.5% (accounting for the asphalt mass), the oil-stone ratio is 2.8%, the compaction temperature is 130°C, the thickness is 19 cm, the void ratio is controlled to be about 4.1%, and the dynamic compression modulus control range is 11000-14000MPa under 20°C and 5Hz conditions.

[0097] Table 4 Gradation composition of super-large particle size warm mix asphalt crushed stone mixture

[0098] Screen size / mm 53.0 37.5 19.0 9.5 4.75 2.36 1.18 0.6 0.3 0.15 0.075 Pass rate / % 100 75 63 42 33 27 19 16 9 8 4

[0099] The surface layer includes an upper layer, a middle layer and a lower layer, wherein the upper layer is: AC-13 modified asphalt mixture, wherein the anti-rutting agent is 0.95%, the void ratio is controlled at 4.2%-5.6%, the oil-stone ratio is about 4.4%, the aggregate is basalt, the thickness is 5cm, and the dynamic compression modulus is controlled in the range of 11000-14000MPa under the conditions of 20°C and 10Hz;

[0100] The middle surface layer is: AC-20 modified asphalt mixture, in which the anti-rutting agent is 0.9%, the void ratio is controlled at 4%-6%, the oil-stone ratio is about 4.4%, the aggregate is basalt, the thickness is 7cm, and the dynamic compression modulus is controlled in the range of 10000-14000MPa under the conditions of 20℃ and 10Hz;

[0101] The lower layer is: AC-25 modified asphalt mixture, in which the anti-rutting agent is 0.85%, the void ratio is controlled at 4%-5.8%, the oil-stone ratio is about 4.1%, the aggregate is basalt, the thickness is 9cm, and the dynamic compression modulus is controlled in the range of 9500-14000MPa under the conditions of 20℃ and 10Hz. The bonding layer between each structural layer adopts a modified emulsified asphalt impermeable bonding layer.

[0102] Application Example 3

[0103] Example 1 was applied repeatedly, except that the base layer was a single-layer crushed stone unit layer with high-quality graded crushed stone (basalt) added with 1.5% polyurethane, the crushed stone particle size range of the single-layer crushed stone unit layer was >19 mm (the crushed stone with a particle size between 31.5 and 37.5 mm accounted for about 60%), and its thickness was 15 cm.

[0104] Application Example 4

[0105] Example 1 was repeatedly applied, except that the base layer was two layers of crushed stone unit layers with 1.5% polyurethane added to high-quality graded crushed stone (basalt); the crushed stone particle size range of the bottom crushed stone unit layer was >19 mm (the crushed stone with a particle size between 31.5 and 37.5 mm accounted for about 60%), and its thickness was 10 cm.

[0106] The particle size range of the surface gravel unit layer is 2.36-9.5 mm (the gravel with a particle size between 4.75 and 9.5 mm accounts for about 60%), and its thickness is 5 cm.

[0107] Application Example 5

[0108] Example 2 was applied repeatedly, except that the base layer was two layers of crushed stone unit layers with 1.7% polyurethane added to high-quality graded crushed stone (basalt), wherein the crushed stone particle size range of the bottom crushed stone unit layer was 19 to 31.5 mm and the thickness was 9 cm.

[0109] The particle size of the surface gravel unit layer ranges from 2.36 to 9.5 mm, and its thickness is 6 cm.

[0110] Comparative Example 1

[0111] Example 1 was repeated except that the subbase was not repaired.

[0112] Comparative Example 2

[0113] Example 2 was repeated except that the subbase was not repaired.

[0114] In order to compare the differences in the repaired pavement structures of the above-mentioned different application embodiments and the comparative examples, the dynamic weighing data of Kangda Expressway was used, and the mechanical response analysis was carried out using the actual Kangda pavement axle load spectrum, where the traffic volume statistics are as follows: the two-way annual average daily traffic AADTT for 2-axle 6-wheel and above vehicles is 13181, the directional coefficient DDF is 0.52, the lane coefficient LDF is 0.7, the traffic growth rate is 5.58%, and the vehicle type distribution coefficient and the equivalent design axle load conversion coefficient are shown in the table below.

[0115] Table 5 Vehicle type distribution coefficient

[0116] Design indicators Category 2 Category 3 Category 4 5 categories 6 categories 7 categories 8 categories 9 categories 10 categories 11 categories Vehicle type distribution coefficient / % 3.28 15.17 12.82 14.77 0.42 9.11 0.34 43.47 0.61 0

[0117] Table 6 Equivalent design axle load conversion factors

[0118]

[0119] Table 6 shows the design axle load conversion factors. When the tensile strain at the bottom of the asphalt mixture layer or the permanent deformation of the asphalt mixture layer is used as the design indicator, the conversion factors used in the calculation are consistent.

[0120] After calculation, the comparison of various index data of the repaired pavement structure is as follows:

[0121] Table 7 Calculation results of various indicators of the repaired pavement structure

[0122]

[0123] It can be seen from Table 7 that due to the changes in the combined structure of the subbase crushed stone unit layer between Example 1, Example 4, and Example 3, and between Example 2 and Example 5, the overall performance of the repaired pavement structure also fluctuates in a corresponding manner. Among them, when the base and surface repair structures are the same, Example 1, Example 4, and Example 3 are significantly better than Comparative Example 1, and Example 2 and Example 5 are significantly better than Comparative Example 2. Compared with Example 2 and Example 5, the base repair thickness of Comparative Example 1 is increased by nearly 1 times relative to Example 2 and Example 5, but the overall performance of the repaired pavement structure of Comparative Example 1 is only slightly better than that of Example 2 and Example 5.

Claims

1. A pavement structure for repairing damaged asphalt pavement, characterized in that: The pavement structure comprises a surface layer (1), a base layer (2) and a subbase layer (3); the subbase layer (3) comprises, from bottom to top, a plurality of crushed stone unit layers (301) or is composed of a plurality of crushed stone unit layers (301), and a polyurethane doping layer (302) is embedded between any two adjacent crushed stone unit layers (301).

2. The pavement structure according to claim 1, characterized in that: The number of the multiple gravel unit layers (301) is 2 to 15 layers.

3. The pavement structure according to claim 2, characterized in that: The number of the multiple gravel unit layers (301) is 3 to 10 layers.

4. The pavement structure according to claim 1, characterized in that: The average particle size of each layer of crushed stone in the multiple crushed stone unit layers (301) decreases layer by layer from bottom to top.

5. The pavement structure according to claim 4, characterized in that: The maximum particle size of the crushed stones in the multiple crushed stone unit layers (301) is 31.5-53 mm, and the minimum particle size is no greater than 1.18 mm.

6. The pavement structure according to claim 4, characterized in that: The multiple gravel unit layers (301) are numbered 1, 2, 3, ..., m from bottom to top; and all the gravels in the m-layer gravel unit layer (301) are divided into 1st-level gravel, 2nd-level gravel, 3rd-level gravel, ..., nth-level gravel according to their particle sizes from large to small, wherein: n≥m; the 1st gravel unit layer (301) is a mixed gravel layer composed of 1st-level gravel and one or more other gravels of smaller particle sizes, and the proportion of 1st-level gravel is not less than 40-80%; the 2nd gravel unit layer (301) is a mixed gravel layer composed of 2nd-level gravel and one or more other gravels of smaller particle sizes, and the proportion of 2nd-level gravel is not less than 40-80%; the 3rd gravel unit layer (301) is a mixed gravel layer composed of 3rd-level gravel and one or more other gravels of smaller particle sizes, and the proportion of 3rd-level gravel is not less than 40-80%, and so on.

7. The pavement structure according to claim 1, characterized in that: The thicknesses of the multiple crushed stone unit layers (301) are the same or different.

8. The pavement structure according to claim 7, characterized in that: The thickness of each of the multiple crushed stone unit layers (301) decreases layer by layer from bottom to top.

9. The pavement structure according to claim 1, characterized in that: The thickness of the subbase (3) accounts for 15-40% of the total thickness of the pavement structure.

10. The pavement structure according to claim 9, characterized in that: The thickness of the subbase (3) accounts for 20-35% of the total thickness of the pavement structure.

11. The pavement structure according to claim 10, characterized in that: The thickness of the subbase (3) accounts for 22-30% of the total thickness of the pavement structure.

12. The pavement structure according to claim 1, characterized in that: The base layer (2) is composed of at least one layer of warm-mix asphalt macadam mixture; the maximum particle size of the macadam in the warm-mix asphalt macadam mixture layer is 37.5-63 mm.

13. The pavement structure according to claim 12, characterized in that: The maximum particle size of the crushed stones in the warm mix asphalt crushed stone mixture layer is 37.5-53 mm.

14. The pavement structure according to claim 12, characterized in that: The thickness of the base layer (2) accounts for 30% to 70% of the total thickness of the pavement structure.

15. The pavement structure according to claim 14, characterized in that: The thickness of the base layer (2) accounts for 40-65% of the total thickness of the pavement structure.

16. The pavement structure according to claim 15, characterized in that: The thickness of the base layer (2) accounts for 45-60% of the total thickness of the pavement structure.

17. The pavement structure according to any one of claims 1 to 16, characterized in that: The surface layer (1) is composed of at least one asphalt concrete layer.

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