Foamed asphalt combined pavement reconstruction construction method based on in-situ cold regeneration technology

Abstract

The invention relates to the technical field of road construction, and discloses a foamed asphalt combined pavement reconstruction construction method based on an in-situ cold regeneration technology. Comprising the following steps: 1) carrying out traffic closing on a construction road section; (2) milling a base layer and a bottom surface layer of the construction pavement to form an old asphalt material; (3) mixing the old asphalt material, water, cement and the new aggregate, and uniformly stirring to form a regenerated foamed asphalt mixture; (4) a modified asphalt hot-mixed gravel stress absorption base layer is laid on the surface of the milling position, and then the regenerated foam asphalt mixture is laid on the modified asphalt hot-mixed gravel stress absorption base layer and compacted and maintained to form a regenerated foam asphalt pavement layer; (5) a modified asphalt hot-mixed gravel stress absorption surface layer is sprayed on the regenerated foamed asphalt pavement layer, and then a single-layer modified asphalt concrete overlay is laid; and therefore, interlayer combination is ensured, a novel pavement structure form is formed, diseases caused by a semi-rigid base layer are avoided, and the service life of a road is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of road construction, and in particular to a foamed asphalt composite pavement reconstruction construction method based on in-situ cold regeneration technology. Background Art

[0002] With the rapid development of highway construction in my country, many highways have entered a period of "equal emphasis on construction and maintenance". Recycling of original road waste materials is one of the effective ways to achieve green construction, and has received widespread attention and attention from the whole society.

[0003] The existing foamed asphalt cold recycling technology usually involves crushing and screening the old materials recovered from asphalt pavement milling, adding a certain proportion of new aggregates, active fillers and water, spraying foamed asphalt, mixing at room temperature, and then paving and rolling. It has the advantages of energy saving, environmental protection, convenience and efficiency, and is an effective way to achieve the recycling of waste materials.

[0004] However, since a large number of microcracks are easily formed inside the old asphalt materials during the crushing process, the pavement structure is prone to further cracking of the microcracks when under pressure, and may even cause the old asphalt materials to shatter, which can easily affect the wear resistance and durability of the pavement structure. Therefore, there is still room for improvement. Summary of the invention

[0005] The purpose of the present invention is to provide a foamed asphalt composite pavement reconstruction construction method based on in-situ cold regeneration technology, aiming to solve the problem in the prior art that the pavement structure is prone to further cracking of microcracks when subjected to pressure.

[0006] The present invention is implemented in this way: a foamed asphalt composite pavement reconstruction construction method based on in-situ cold regeneration technology comprises the following steps:

[0007] 1) Construction preparation, traffic closure of the construction section;

[0008] 2) Use a cold regeneration machine to mill the base and bottom surface of the construction road surface, take out the milled material, crush and screen it to form asphalt waste material;

[0009] 3) Mix the old asphalt material, water, cement and new aggregate, and mix them evenly to form a recycled foamed asphalt mixture;

[0010] 4) Spreading a modified asphalt hot-mixed macadam stress-absorbing base on the surface of the milling position, and then spreading the regenerated foamed asphalt mixture prepared in the above step (3) on the modified asphalt hot-mixed macadam stress-absorbing base and compacting and curing to form a regenerated foamed asphalt pavement layer;

[0011] 5) Spreading a modified asphalt hot mix crushed stone stress absorption surface layer on the regenerated foam asphalt pavement layer, and paving a single layer of modified asphalt concrete overlay on the modified asphalt hot mix crushed stone stress absorption surface layer, the pavement maintenance construction can be completed.

[0012] Furthermore, in the construction step 1), the milling depth of the original road surface is 18-25 cm, in the construction step 4), the thickness of the modified asphalt hot mix macadam stress absorption base layer is 3-5 cm, and the thickness of the regenerated foam asphalt pavement layer is 10-20 cm.

[0013] Furthermore, in the construction step 5), the thickness of the modified asphalt hot mix crushed stone stress absorption surface layer is 2-4 cm.

[0014] Furthermore, in the construction step 3), the weight ratio of old asphalt material to new aggregate, cement and water in the materials constituting the regenerated foamed asphalt mixture cold regenerated mixture is: 80-100 parts of old asphalt material: 2-4 parts of new aggregate: 1-3 parts of cement: 4-12 parts of water.

[0015] Furthermore, in the construction step 3), the recycled foamed asphalt mixture also includes no more than 25 parts by weight of fine aggregate.

[0016] Furthermore, in the construction step 4), the modified asphalt hot-mixed crushed stone stress absorption base layer is composed of SBS modified asphalt and hot-mixed crushed stone, wherein the spraying amount of SBS modified asphalt is 1.7-2.5 kg / m, and the spreading rate of hot-mixed crushed stone is 50%-60%.

[0017] Furthermore, in the construction step 3), the new aggregate includes the following components in parts by mass: 1-5 parts of mineral powder.

[0018] Furthermore, in the construction step 4), inclined base layers are extended outwardly on both sides of the modified asphalt hot mix macadam stress absorbing base layer, one end of the inclined base layer is butted against one end of the modified asphalt hot mix macadam stress absorbing base layer, and the other end of the inclined base layer is arranged to be inclined upward, and the bottom of the regenerated foamed asphalt pavement layer is respectively butted against the top of the modified asphalt hot mix macadam stress absorbing base layer and the top of the inclined base layer.

[0019] Furthermore, in the construction step 3), a recovery chamber is provided in the cold regeneration machine, an absorber is provided on the cold regeneration machine, one end of the absorber is connected to the recovery chamber, and the other end of the absorber is exposed outside the bottom of the cold regeneration machine, and a plowing wheel is provided in the bottom of the cold regeneration machine, the plowing wheel and the absorber are arranged side by side and relatively spaced apart, and the absorber is located behind the plowing wheel.

[0020] Furthermore, the absorber includes a connecting pipe and an exhaust fan, the exhaust fan is connected to the connecting pipe, the air outlet of the connecting pipe is connected to the recovery chamber, the air inlet of the connecting pipe is connected to the absorption pipe, the connecting pipe and the absorption pipe are arranged vertically, a plurality of absorption joints arranged inclined downward are provided on the absorption pipe, the plurality of absorption joints are arranged in sequence at intervals along the length direction of the absorption pipe, absorption joints arranged inclined in the opposite direction are provided between adjacent absorption joints, and the absorption joints are arranged relatively at intervals from the bottom layer.

[0021] Compared with the prior art, the foamed asphalt composite pavement reconstruction construction method based on in-situ cold regeneration technology provided by the present invention paves a modified asphalt hot-mixed crushed stone stress absorption base layer on the milling position surface and between the regenerated foamed asphalt pavement layer to ensure interlayer bonding, forming a new type of pavement structure, avoiding diseases caused by a semi-rigid base layer, extending the service life of the road, and reducing the porosity inside the regenerated foamed asphalt pavement layer, which is beneficial to better enhance the compressive strength of the pavement structure while better improving the waterproof performance of the pavement structure, thereby extending the durability of the pavement structure; and a modified asphalt hot-mixed crushed stone stress absorption surface layer is paved between the regenerated foamed asphalt pavement layer and the single-layer modified asphalt concrete overlay to ensure interlayer bonding. Compared with the two-layer overlay layer in the existing project, it can save money and reduce the problem of further cracking of microcracks in the pavement structure when it is under pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the construction process of the foamed asphalt composite pavement reconstruction construction method based on the in-situ cold regeneration technology provided by the present invention;

[0023] Figure 2 It is a schematic diagram of the structure of a pavement of a foamed asphalt composite pavement reconstruction construction method based on the in-situ cold regeneration technology provided by the present invention;

[0024] Figure 3 It is a structural schematic diagram of the cold regeneration machine provided by the present invention;

[0025] Figure 4 is a schematic diagram of a side cutaway structure of an absorber provided by the present invention;

[0026] Figure 5 It is a schematic diagram of the front view cross-section structure of the absorber provided by the present invention.

[0027] In the figure: modified asphalt hot mix crushed stone stress absorbing base layer 10, recycled foam asphalt pavement layer 20, modified asphalt hot mix crushed stone stress absorbing surface layer 30, single-layer modified asphalt concrete overlay 40, cold regeneration machine 50, plowing wheel 60, absorber 70, recovery chamber 51, connecting pipe 71, exhaust fan 72, absorption pipe 73, absorption joint 74. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0029] The implementation of the present invention is described in detail below in conjunction with specific embodiments.

[0030] The same or similar numbers in the drawings of this embodiment correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the drawings, it is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limitations on the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0031] Reference Figure 1-5 The figure shows a preferred embodiment of the present invention.

[0032] The foamed asphalt composite pavement reconstruction construction method based on in-situ cold recycling technology includes the following steps:

[0033] 1) Construction preparation, traffic closure of the construction section;

[0034] 2) The cold regenerator 50 is used to mill the base layer and the bottom surface layer of the construction road surface, and the milled material is taken out, crushed and screened to form asphalt waste material;

[0035] 3) Mix old asphalt material, water, cement and new aggregate, mix evenly to form recycled foamed asphalt mixture;

[0036] 4) Spreading a modified asphalt hot mix macadam stress absorbing base layer 10 on the surface of the milling position, and then spreading the regenerated foamed asphalt mixture prepared in the above step (3) on the modified asphalt hot mix macadam stress absorbing base layer 10 and compacting and curing to form a regenerated foamed asphalt pavement layer 20;

[0037] 5) Spread the modified asphalt hot mix crushed stone stress absorbing surface layer 30 on the regenerated foamed asphalt pavement layer 20, and lay a single layer of modified asphalt concrete overlay 40 on the modified asphalt hot mix crushed stone stress absorbing surface layer 30, and the pavement maintenance construction can be completed.

[0038] The foamed asphalt composite pavement reconstruction construction method based on the in-situ cold regeneration technology provided above is to pave a modified asphalt hot-mixed crushed stone stress absorbing base layer 10 between the milling position surface and the regenerated foamed asphalt pavement layer 20 to ensure interlayer bonding, thereby forming a new type of pavement structure, avoiding diseases caused by a semi-rigid base layer, and extending the service life of the road. The porosity inside the regenerated foamed asphalt pavement layer 20 is reduced, which is beneficial to better enhance the compressive strength of the pavement structure while better improving the waterproof performance of the pavement structure, thereby extending the durability of the pavement structure; and a modified asphalt hot-mixed crushed stone stress absorbing surface layer 30 is paved between the regenerated foamed asphalt pavement layer 20 and the single-layer modified asphalt concrete overlay 40 to ensure interlayer bonding. Compared with the two-layer overlay layer in the existing project, it can save money and reduce the problem of further cracking of microcracks in the pavement structure when it is under pressure.

[0039] In construction step 1), the milling depth of the original road surface is 18-25 cm. In construction step 4), the thickness of the modified asphalt hot mix macadam stress absorption base layer 10 is 3-5 cm, and the thickness of the regenerated foam asphalt pavement layer 20 is 10-20 cm.

[0040] In construction step 5), the thickness of the modified asphalt hot mix macadam stress absorbing surface layer 30 is 2-4 cm.

[0041] In construction step 3), the weight ratio of old asphalt material to new aggregate, cement and water in the materials constituting the cold recycled mixture of the recycled foamed asphalt mixture is: 80-100 parts of old asphalt material: 2-4 parts of new aggregate: 1-3 parts of cement: 4-12 parts of water.

[0042] In construction step 3), the recycled foamed asphalt mixture further includes no more than 25 parts by weight of fine aggregate.

[0043] In construction step 4), the modified asphalt hot-mixed crushed stone stress absorption base layer 10 is composed of SBS modified asphalt and hot-mixed crushed stone, wherein the spraying amount of SBS modified asphalt is 1.7-2.5 kg / m, and the spreading rate of hot-mixed crushed stone is 50%-60%.

[0044] In construction step 3), the new aggregate includes the following components in parts by mass: 1-5 parts of mineral powder.

[0045] In this embodiment, in construction step 4), both sides of the modified asphalt hot mix macadam stress absorbing base layer 10 are extended outwardly with inclined base layers, one end of the inclined base layer is butted with one end of the modified asphalt hot mix macadam stress absorbing base layer 10, and the other end of the inclined base layer is arranged upwardly inclined, and the bottom of the regenerated foamed asphalt pavement layer 20 is respectively butted against the top of the modified asphalt hot mix macadam stress absorbing base layer 10 and the top of the inclined base layer. In this way, the modified asphalt hot mix macadam stress absorbing base layer 10 can increase the contact area with the regenerated foamed asphalt pavement layer 20 through the inclined base layer, thereby increasing the bonding between the layers and increasing the stability of the overall structure.

[0046] In this embodiment, in construction step 3), a recovery chamber 51 is provided in the cold regeneration machine 50, an absorber 70 is provided on the cold regeneration machine 50, one end of the absorber 70 is connected to the recovery chamber 51, and the other end of the absorber 70 is exposed outside the bottom of the cold regeneration machine 50, and a plowing wheel 60 is provided in the bottom of the cold regeneration machine 50, and the plowing wheel 60 and the absorber 70 are arranged side by side with relative intervals, and the absorber 70 is located behind the plowing wheel 60.

[0047] The cold regeneration machine 50 can mill the base layer and the bottom surface layer of the construction road surface through the planing wheel 60. The cold regeneration machine 50 can use the absorber 70 to recycle the dust raised during the milling process, and can recycle the old asphalt material particles remaining in the bottom surface layer during the milling process, thereby improving the recycling rate of old asphalt materials and avoiding dust.

[0048] In this embodiment, the absorber 70 includes a connecting pipe 71 and an exhaust fan 72, the exhaust fan 72 is connected to the connecting pipe 71, the air outlet of the connecting pipe 71 is connected to the recovery chamber 51, the air inlet of the connecting pipe 71 is connected to the absorption pipe 73, the connecting pipe 71 and the absorption pipe 73 are arranged vertically, and a plurality of absorption joints 74 arranged inclined downward are provided on the absorption pipe 73, and the plurality of absorption joints 74 are arranged in sequence along the length direction of the absorption pipe 73 at intervals, and absorption joints 74 arranged inclined in the opposite direction are provided between adjacent absorption joints 74, and the absorption joints 74 are arranged relatively spaced apart from the bottom surface layer.

[0049] The absorber 70 generates negative pressure suction in the connecting pipe 71 through the exhaust fan 72, so that the connecting pipe 71 cooperates with the absorption pipe 73 to absorb and recover the old asphalt particles in the bottom layer through multiple absorption joints 74, and utilizes the multi-angle inclined arrangement between the multiple absorption joints 74 to increase the absorption range of the absorber 70, improve the recycling rate of the old asphalt, and avoid dust.

[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A foamed asphalt composite pavement reconstruction construction method based on in-situ cold regeneration technology, characterized in that: The following steps are involved: 1) Construction preparation, traffic closure of the construction section; 2) Use a cold regeneration machine to mill the base and bottom surface of the construction road surface, take out the milled material, crush and screen it to form asphalt waste material; 3) Mix the old asphalt material, water, cement and new aggregate, and mix them evenly to form a recycled foamed asphalt mixture; 4) Spreading a modified asphalt hot-mixed macadam stress-absorbing base on the surface of the milling position, and then spreading the regenerated foamed asphalt mixture prepared in the above step (3) on the modified asphalt hot-mixed macadam stress-absorbing base and compacting and curing to form a regenerated foamed asphalt pavement layer; 5) Spreading a modified asphalt hot mix crushed stone stress absorption surface layer on the regenerated foam asphalt pavement layer, and paving a single layer of modified asphalt concrete overlay on the modified asphalt hot mix crushed stone stress absorption surface layer, the pavement maintenance construction can be completed.

2. The foamed asphalt composite pavement reconstruction construction method based on in-situ cold regeneration technology according to claim 1 is characterized in that: In the construction step 1), the milling depth of the original road surface is 18-25 cm. In the construction step 4), the thickness of the modified asphalt hot-mixed macadam stress absorption base layer is 3-5 cm, and the thickness of the regenerated foam asphalt pavement layer is 10-20 cm.

3. The foamed asphalt composite pavement reconstruction construction method based on in-situ cold regeneration technology as claimed in claim 2 is characterized in that: In the construction step 5), the thickness of the modified asphalt hot mix crushed stone stress absorption surface layer is 2-4 cm.

4. The foamed asphalt composite pavement reconstruction construction method based on in-situ cold regeneration technology as claimed in claim 3 is characterized in that: In the construction step 3), the weight ratio of old asphalt material to new aggregate, cement and water in the materials constituting the regenerated foamed asphalt mixture cold regenerated mixture is: 80-100 parts of old asphalt material: 2-4 parts of new aggregate: 1-3 parts of cement: 4-12 parts of water.

5. The foamed asphalt composite pavement reconstruction construction method based on in-situ cold regeneration technology according to claim 4 is characterized in that: In the construction step 3), the regenerated foamed asphalt mixture further comprises no more than 25 parts by weight of fine aggregate.

6. The foamed asphalt composite pavement reconstruction construction method based on in-situ cold regeneration technology according to claim 5 is characterized in that: In the construction step 4), the modified asphalt hot-mixed crushed stone stress absorption base layer is composed of SBS modified asphalt and hot-mixed crushed stone, wherein the spraying amount of SBS modified asphalt is 1.7-2.5 kg / m, and the spreading rate of hot-mixed crushed stone is 50%-60%.

7. The foamed asphalt composite pavement reconstruction construction method based on in-situ cold regeneration technology according to claim 6 is characterized in that: In the construction step 3), the new aggregate includes the following components in parts by mass: 1-5 parts of mineral powder.

8. The foamed asphalt composite pavement reconstruction construction method based on in-situ cold regeneration technology according to any one of claims 1 to 7, characterized in that: In the construction step 4), inclined base layers are extended outwardly on both sides of the modified asphalt hot mix macadam stress absorbing base layer, one end of the inclined base layer is butted against one end of the modified asphalt hot mix macadam stress absorbing base layer, and the other end of the inclined base layer is arranged to be inclined upward, and the bottom of the regenerated foamed asphalt pavement layer is respectively butted against the top of the modified asphalt hot mix macadam stress absorbing base layer and the top of the inclined base layer.

9. The foamed asphalt composite pavement reconstruction construction method based on in-situ cold regeneration technology according to any one of claims 1 to 7, characterized in that: In the construction step 3), a recovery chamber is provided in the cold regeneration machine, an absorber is provided on the cold regeneration machine, one end of the absorber is connected to the recovery chamber, and the other end of the absorber is exposed outside the bottom of the cold regeneration machine, a plowing wheel is provided in the bottom of the cold regeneration machine, the plowing wheel and the absorber are arranged side by side with relative intervals, and the absorber is located behind the plowing wheel.

10. The foamed asphalt composite pavement reconstruction construction method based on in-situ cold regeneration technology according to claim 9, characterized in that: The absorber includes a connecting pipe and an exhaust fan, the exhaust fan is connected to the connecting pipe, the air outlet of the connecting pipe is connected to the recovery chamber, the air inlet of the connecting pipe is connected to the absorption pipe, the connecting pipe and the absorption pipe are arranged vertically, a plurality of absorption joints arranged inclined downward are arranged on the absorption pipe, the plurality of absorption joints are arranged in sequence and spaced apart along the length direction of the absorption pipe, absorption joints arranged inclined in the opposite direction are arranged between adjacent absorption joints, and the absorption joints are arranged relatively spaced apart from the bottom surface layer.

Images