A method for in-situ thermal regeneration and maintenance of multi-layer depth of ultra-deep rutting asphalt pavement

Abstract

The present invention relates to the field of road engineering technology, and in particular to a method for in-situ hot regeneration and maintenance of multi-layer depth of ultra-deep rutting asphalt pavement, including optimizing the design of the mix ratio of three-layer in-situ hot regeneration asphalt mixture; verifying the road performance of the three-layer in-situ hot regeneration asphalt mixture; in-situ hot harrowing and recycling of the upper layer, remixing and regenerating the middle layer, and remixing and regenerating the lower layer; using a paver to simultaneously pave and roll the entire surface layer; and finally evaluating the construction quality of ultra-deep rutting in-situ hot regeneration. The present invention can be applied to the rapid repair of ultra-deep rutting diseases on asphalt pavements, solve the problem of insufficient interlayer adhesion caused by single-layer paving of asphalt mixtures, maintain the integrity of the regenerated pavement and the original pavement, greatly improve the rutting resistance of the original pavement, and achieve 100% recycling of the upper, middle and lower layer materials, greatly reduce the mining of natural sand and gravel and crude oil asphalt, and save natural resources.

Description

Technical Field

[0001] The invention relates to the technical field of road engineering, in particular to a method for in-situ thermal regeneration and maintenance of multi-surface depths of an ultra-deep rutting asphalt pavement. Background Art

[0002] With the continuous acceleration of asphalt road construction, the matching and replacement of maintenance methods are becoming increasingly important. At present, the main type of pavement disease during the 3-5 years of heavy traffic section opening to traffic is mainly rutting, and it develops rapidly, and the rutting layer affects the upper, middle and lower layers. Traditional maintenance plans often use special milling and resurfacing of the surface layer or in-situ hot regeneration of the upper layer. However, this maintenance plan cannot eradicate the pavement disease problem when the rutting develops to the middle and lower layers. About a year after resurfacing, rutting diseases will quickly occur again, especially on the lanes and intersections of national and provincial trunk roads. The traditional special milling and resurfacing is extremely wasteful of road material resources. Traffic needs to be closed during construction, which affects the normal operation of the road. The regeneration depth of the upper layer geothermal regeneration process is small. These two conventional maintenance plans cannot fundamentally solve the problem of deep rutting on the road, which creates hidden dangers for the later operation of the road.

[0003] Asphalt roads have a multi-layered structure, and the bonding state between layers seriously affects the durability of each structural layer. When any two layers of the upper, middle, and lower layers are not completely continuous, the bottom of the discontinuous layer will be in a tensile state for a long time, and fatigue, cracks, potholes, and other problems are very likely to occur. Therefore, it is very important to maintain interlayer continuity during asphalt pavement construction. The full-width surface layer synchronous in-situ hot regeneration technology can solve the problem of insufficient interlayer adhesion of asphalt mixtures caused by single-layer paving, maintain the integrity of the regenerated pavement and the original pavement, and greatly improve the rutting resistance of the original pavement. Compared with the single-layer paving and rolling technology, the full-width surface layer synchronous paving and rolling technology can ensure zero pollution in the construction of the asphalt surface layer, further consolidate the interlayer continuity, and extend the service life of the asphalt pavement.

[0004] According to the pain points of deep rutting asphalt road diseases and considering the impact on resources and the environment, domestic and foreign scholars have begun to try to use double-layer regeneration paving technology to solve it. However, the actual stress state (compression, tension and shear) of each asphalt layer in the surface structure and its layer function are rarely considered during regeneration maintenance. In addition, when the rutting disease develops to the lower layer, there is still no suitable maintenance and disposal plan. Therefore, under the strategic background of a strong transportation country and low-carbon development, solving the problem of ultra-deep rutting on asphalt pavements is an urgent task for the development of road maintenance. Summary of the invention

[0005] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0006] In view of the above-mentioned and / or existing problems in a method for in-situ thermal regeneration and maintenance of multiple surface layers of an ultra-deep rutting asphalt pavement, the present invention is proposed.

[0007] Therefore, the problem to be solved by the present invention is how to provide a method for in-situ thermal regeneration and maintenance of multi-layer depth of ultra-deep rutting asphalt pavement, reduce smoke emissions, and achieve flexible heating.

[0008] In order to solve the above technical problems, the present invention provides the following technical solutions: a method for in-situ thermal regeneration and maintenance of multi-layer depth of ultra-deep rutting asphalt pavement, comprising:

[0009] Optimization design of the mix ratio of three-layer hot-in-place recycled asphalt;

[0010] Conduct road performance verification of three-layer hot-in-place recycled asphalt mixture;

[0011] The upper layer is hot-raked and recycled in situ, the middle layer is remixed and regenerated for storage, and the lower layer is remixed and regenerated;

[0012] The paver is used to simultaneously pave and roll the entire surface layer; finally, the construction quality evaluation of ultra-deep rutting in-situ hot regeneration is carried out.

[0013] As a preferred scheme of the in-situ hot regeneration and maintenance method for multiple surface layers of ultra-deep rutting asphalt pavement described in the present invention, the three-layer in-situ hot regeneration asphalt mixture mix ratio optimization design is to recycle the hot raking loose materials of the upper, middle and lower layers of the deep rutting section of the original road surface for extraction and screening, determine the ratio of the regeneration agent to the recycled asphalt through the performance design method, and determine the type and amount of external admixtures, the amount of new material, and the new material oil-stone ratio of each layer of the regenerated asphalt mixture in turn according to the stress state between the structural layers of the asphalt pavement and the mix ratio test.

[0014] As a preferred solution of the method for in-situ hot regeneration and maintenance of multi-layer deep ultra-deep rutting asphalt pavement described in the present invention, the road performance verification of the three-layer in-situ hot-regenerated asphalt mixture is to verify the water stability, low-temperature crack resistance and high-temperature rutting resistance of each layer of the hot-regenerated mixture by molding test pieces based on the mix ratio of the hot-regenerated asphalt mixture;

[0015] The water stability performance is determined by the immersion Marshall test and the freeze-thaw splitting test, the low-temperature crack resistance is determined by the small beam bending test, the high-temperature rutting resistance of each layer of recycled mixture is determined by the indoor rutting test, and the high-temperature rutting resistance of the full-width surface layer depth is determined by the indoor ring load wheel test.

[0016] As a preferred solution of the method for in-situ hot regeneration and maintenance of multi-layer depth of ultra-deep rutting asphalt pavement described in the present invention, the in-situ hot harrowing and recycling of the upper layer is to uniformly preheat and hot harrow the old material on the surface of the original pavement in situ, add a regeneration agent and stir with the old material to form a material cage, add a high modulus modified asphalt mixture and remix, obtain the high modulus modified recycled asphalt mixture of the upper layer, and recycle and store the recycled mixture of the upper layer in an insulated material truck;

[0017] The middle surface layer remixing and recycling storage is that after the upper layer is milled, the old material of the middle surface layer is evenly heated and hot-raked in situ, a regeneration agent is added to mix with the old material to form a material cage, and a high-viscosity modified asphalt mixture is added for remixing to obtain a high-viscosity modified recycled asphalt mixture of the middle surface layer, and the recycled mixture of the middle surface layer is recycled and stored in an insulated material truck;

[0018] The bottom layer remixing and regeneration is that after the middle surface layer is hot-raked and loosened, the old material of the bottom layer is evenly heated and hot-raked in situ, a regeneration agent is added and stirred with the old material to form a material cage, a fiber-modified asphalt mixture is added for remixing and regeneration, the modified recycled material is transported to the mixing tank for secondary mixing, and the fiber-modified recycled mixture of the bottom layer is spread through the front ironing plate of the paver;

[0019] The external admixture uses a high modulus agent in the upper layer of the asphalt pavement with larger vertical compressive stress, a high viscosity agent in the middle layer with larger shear stress, and a fiber modifier in the lower layer with larger bending and tensile stress.

[0020] As a preferred solution of the method for in-situ hot regeneration and maintenance of multi-layer depth of ultra-deep rutting asphalt pavement described in the present invention, the synchronous paving and rolling of the full-width surface layer is to lift and heat-insulate the recycled mixture of the middle surface layer to the paver of the hot regeneration unit while spreading the fiber-modified recycled mixture of the lower layer, and pour it into the hopper of the full-width surface layer paver at a fixed time and quantity, and then lift and flatten it to the middle ironing plate through the scraper. At the same time, the upper layer of high modulus modified recycled asphalt mixture in the heat-insulated material car is poured into the hopper at a fixed time and quantity and transported to the rear ironing plate, and finally the three layers are synchronously paved and rolled to achieve synchronous in-situ hot regeneration and maintenance of the full-width surface layer depth.

[0021] As a preferred scheme of the in-situ hot regeneration and maintenance method of multi-layer depth of ultra-deep rutting asphalt pavement described in the present invention, the construction quality evaluation of the ultra-deep rutting in-situ hot regeneration is to take three-layer rutting plate samples of the hot regenerated pavement for indoor ring load wheel test, record the rutting depth change curve, and calculate the average pseudo-strain dissipated energy and composite stability index as two indicators to evaluate the engineering construction quality of the in-situ hot regenerated asphalt pavement.

[0022] As a preferred scheme of the in-situ hot regeneration and maintenance method for multi-layer depth of ultra-deep rutting asphalt pavement described in the present invention, the indoor ring load wheel rutting test adopts an annular basin design structure, and its test piece consists of eight groups of parallel specimens. The front and rear end surfaces of each specimen are sprayed with white spray paint, and grid lines are drawn to realize the identification and detection of the rutting depth of each layer of recycled mixture, and determine the contribution rate of each layer of recycled mixture to the rutting resistance of the overall structure.

[0023] As a preferred solution of the method for in-situ thermal regeneration and maintenance of multi-layer depth of ultra-deep rutting asphalt pavement described in the present invention, the specific calculation formula of the average pseudo-strain dissipated energy and the composite stability index is as follows:

[0024]

[0025] σ h (τ) is the loading stress; ε R (τ) is the viscoelastic strain response; τ is the time variable; N is the number of loadings; NT is the loading time, t 60 The loading time is 60 seconds; 1 and d 2 are the rutting depth and time recorded during the test, respectively; v and l are the loading speed and one-way travel distance, respectively, t 1 and t 2 To record the start and end time, the average pseudo-strain dissipated energy is DPSE, and the composite stability index is CSI;

[0026] The average pseudo-strain energy dissipation is used to evaluate the average energy dissipation after removing viscoelasticity in each loading cycle during the test; the composite stability index represents the number of repeated loads that produce a rutting depth of 1 mm. The larger the average pseudo-strain energy dissipation index, the greater the rutting depth produced, while the composite stability index is the opposite.

[0027] A computer device comprises a memory and a processor, wherein the memory stores a computer program, and wherein the processor implements the steps of the above method when executing the computer program.

[0028] A computer-readable storage medium stores a computer program, wherein the computer program implements the steps of the above method when executed by a processor.

[0029] The beneficial effects of the present invention are that the water stability is determined by the immersion Marshall test and the freeze-thaw splitting test, the low-temperature crack resistance is determined by the small beam bending test, the high-temperature rutting resistance of each layer of recycled mixture is determined by the indoor rutting test, and the high-temperature rutting resistance of the full-width surface layer depth is determined by the indoor ring load wheel test.

[0030] As the on-site uniform preheating described in the present invention, a multi-stage indirect low-temperature infrared flexible radiation heating technology is adopted, and the full-depth infrared radiation makes the material heated evenly, and the vertical and horizontal bidirectional pressurized wind screen can avoid asphalt aging, reduce smoke emissions, and realize flexible heating;

[0031] It can be used to quickly repair ultra-deep rutting damage on asphalt pavements, solve the problem of insufficient interlayer adhesion of asphalt mixtures caused by single-layer paving, maintain the integrity of the regenerated pavement and the original pavement, and greatly improve the anti-rutting performance of the original pavement. It can achieve 100% recycling of upper, middle and lower layer materials, greatly reduce the mining of natural sand and gravel and crude oil asphalt, save natural resources, and help achieve carbon peak and carbon neutrality. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0033] Figure 1 The present invention is a flow chart of a multi-layer in-situ hot regeneration maintenance method for ultra-deep rutting asphalt pavement.

[0034] Figure 2 The diagram is a vehicle group diagram of a method for in-situ hot regeneration maintenance of multi-layer depth of ultra-deep rutting asphalt pavement.

[0035] Figure 3 This is the overall effect diagram of an indoor ring load wheel rutting tester for a multi-layer in-situ hot regeneration maintenance method for ultra-deep rutting asphalt pavement.

[0036] Figure 4 A top view of an indoor ring-track load wheel rutting tester for an in-situ hot regeneration maintenance method for multi-layer depth of ultra-deep rutting asphalt pavement.

[0037] Figure 5 The schematic diagram of the pavement structure is a method for in-situ hot regeneration maintenance of multi-layer depth of ultra-deep rutting asphalt pavement. DETAILED DESCRIPTION

[0038] In order to make the above objects, features, and advantages of the present invention more obvious and understandable, the following will provide a detailed description of the specific embodiments of the present invention in conjunction with the accompanying drawings of the specification.

[0039] In the following description, many specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention may be implemented in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0040] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation manner of the present invention. The phrase "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that mutually excludes other embodiments.

[0041] Embodiment 1

[0042] Refer to Figures 1 to 5 , which is the first embodiment of the present invention, including

[0043] As Figure 1 shown, for the optimized design of the mix proportion of the three-layer in-situ hot recycling asphalt mixture;

[0044] Conduct the verification of the road performance of the three-layer in-situ hot recycling asphalt mixture;

[0045] The upper layer is raked and recovered in-situ by hot raking, the middle layer is remix recycled and stored, and the lower layer is remix recycled;

[0046] Use the paver to synchronously pave and roll the entire surface layer; finally, conduct the construction quality evaluation of the in-situ hot recycling for ultra-deep ruts.

[0047] The optimized design of the mix proportion of the three-layer in-situ hot recycling asphalt mixture is to extract and screen the hot raked materials from the upper, middle, and lower layers of the deep rut section of the original road surface, determine the ratio of the recycling agent to the recovered asphalt through the performance design method, and sequentially determine the types and dosages of the external admixtures, the new material dosage, and the new material asphalt-aggregate ratio of the recycled asphalt mixture for each layer according to the interlayer stress state and mix proportion test of each structural layer of the asphalt pavement.

[0048] The verification of the road performance of the three-layer in-situ hot recycling asphalt mixture is to form specimens according to the mix proportion of the hot recycled asphalt mixture and verify the water stability performance, low-temperature anti-cracking performance, and high-temperature rutting resistance performance of each layer of the hot recycled mixture;

[0049] The water stability performance is determined by the immersion Marshall test and the freeze-thaw splitting test, the low-temperature anti-cracking performance is determined by the beam bending test, the high-temperature rutting resistance performance of each layer of the recycled mixture is determined by the indoor rutting test, and the high-temperature rutting resistance performance of the entire surface layer depth is determined by the indoor circular track load wheel test.

[0050] The upper layer in-situ hot harrowing recycling is to evenly preheat and hot harrow the old material on the original pavement surface, add the regeneration agent and mix it with the old material to form a material cage, add the high modulus modified asphalt mixture and remix it to obtain the upper layer of high modulus modified recycled asphalt mixture, and recycle and store the upper layer recycled mixture in the insulation material truck;

[0051] The middle surface layer remixing and recycling storage is to evenly heat and loosen the old materials in the middle surface layer on site after the upper layer is milled, add the regeneration agent and mix with the old materials to form a material cage, add high-viscosity modified asphalt mixture and remix to obtain the high-viscosity modified recycled asphalt mixture of the middle surface layer, and recycle and store the recycled mixture of the middle surface layer in the insulation material truck;

[0052] The remixing and recycling of the lower layer is to heat and loosen the middle surface layer in situ, evenly heat and hot-rake the lower layer of old materials in situ, add regeneration agent and mix with the old materials to form a material cage, add fiber-modified asphalt mixture for remixing and recycling, transport the modified recycled materials to the mixing tank for secondary mixing, and spread the fiber-modified recycled mixture of the lower layer through the front ironing plate of the paver;

[0053] As for admixtures, high modulus agents are used in the upper layer of asphalt pavement where vertical compressive stress is greater, high viscosity agents are used in the middle layer where shear stress is greater, and fiber modifiers are used in the lower layer where bending and tensile stress is greater.

[0054] like Figure 2 The full-width surface layer synchronous paving and rolling shown in the figure is that while the fiber-modified recycled mixture of the lower layer is being spread, the recycled mixture of the middle surface layer is lifted, insulated and transported to the paver of the hot regeneration unit, and poured into the hopper of the full-width surface layer paver at a fixed time and quantity, and then lifted and flattened to the middle ironing plate by the scraper. At the same time, the upper layer of high modulus modified recycled asphalt mixture in the insulation material car is poured into the hopper at a fixed time and quantity and transported to the rear ironing plate, and finally the three layers are synchronously paved and rolled to achieve synchronous in-situ hot regeneration maintenance of the full-width surface layer depth.

[0055] The quality evaluation of in-situ hot regeneration construction with ultra-deep rutting is to conduct indoor ring load wheel test on three-layer rutting plate samples of hot regenerated pavement, record the rutting depth change curve, and calculate the average pseudo-strain dissipated energy and composite stability index to evaluate the engineering construction quality of in-situ hot regenerated asphalt pavement.

[0056] The indoor ring track load wheel rutting test adopts an annular basin design structure. Its test specimens consist of eight groups of parallel specimens. The front and rear end surfaces of each specimen are sprayed with white spray paint, and grid lines are drawn to identify and detect the rutting depth of each layer of recycled mixture and determine the contribution rate of each layer of recycled mixture to the anti-rutting performance of the overall structure.

[0057] The specific calculation formulas of average pseudo-strain dissipated energy and composite stability index are as follows:

[0058]

[0059] σ h (τ) is the loading stress; ε R (τ) is the viscoelastic strain response; τ is the time variable; N is the number of loadings; NT is the loading time, t 60 The loading time is 60 seconds; 1 and d 2 are the rutting depth and time recorded during the test, respectively; v and l are the loading speed and one-way travel distance, respectively, t 1 and t 2 To record the start and end time, the average pseudo-strain dissipated energy is DPSE, and the composite stability index is CSI;

[0060] The average pseudo-strain energy dissipation is used to evaluate the average energy dissipation after removing viscoelasticity in each loading cycle during the test; the composite stability index represents the number of repeated loads that produce a rutting depth of 1 mm. The larger the average pseudo-strain energy dissipation index, the greater the rutting depth produced, while the composite stability index is the opposite.

[0061] Example 2

[0062] The second embodiment of the present invention is different from the first two embodiments in that:

[0063] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0064] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0065] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0066] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0067] Example 3

[0068] Reference Figures 1 to 5 , which is the third embodiment of the present invention, and which is different from the first two embodiments in that:

[0069] The present invention discloses a method for in-situ hot regeneration and maintenance of multi-surface layers of ultra-deep rutting asphalt pavement. The technology involves a method for synchronous in-situ hot regeneration and maintenance of all layers of the upper, middle and lower layers of the asphalt pavement, including four parts: optimization design of the mix ratio of three-layer in-situ hot regeneration asphalt mixture, road performance verification of three-layer in-situ hot regeneration asphalt mixture, in-situ hot regeneration and maintenance construction of the full-width surface layer, and in-situ hot regeneration construction quality evaluation. The in-situ hot regeneration and maintenance construction of the full-width surface layer includes the following processes: Figure 2 The upper layer is shown as preheating, the old material of the upper layer is hot-raked in situ, remixed (regenerating agent and new material are added), recycled and lifted for transportation; the middle layer is preheated, the middle layer is hot-raked, the middle layer is remixed (regenerating agent and new material are added), and the middle layer recycled material is transported and stored; the lower layer is preheated, the old material of the lower layer is hot-raked in situ, the lower layer is regenerated and remixed, the lower layer is toughened and modified recycled fabric, the middle layer is highly viscous and modified recycled fabric, the upper layer is high modulus modified recycled fabric, and the surface layer is fully paved and rolled. The construction quality of the hot regenerated pavement project is evaluated by indoor loop load wheel test, and the energy dissipation index is established to evaluate the multi-layer anti-rutting performance of the hot regenerated asphalt mixture to determine whether it meets the requirements for deep rutting treatment of asphalt pavement. The present invention can realize the full-width and depth synchronous in-situ hot regeneration of the asphalt pavement surface layer, and the upper, middle and lower layer asphalt mixtures are 100% original in-situ recycled and reused, and the in-situ hot regeneration depth is increased from 4cm to 18cm. This technology can be used to quickly repair ultra-deep rutting damage on asphalt pavements, solve the problem of insufficient interlayer adhesion of asphalt mixtures caused by single-layer paving, maintain the integrity of the regenerated pavement and the original pavement, and greatly improve the rutting resistance of the original pavement. It can achieve 100% recycling of upper, middle and lower layer materials, greatly reduce the mining of natural sand and gravel and crude oil asphalt, save natural resources, and help achieve carbon peak and carbon neutrality.

[0070] The specific calculation formulas of average pseudo strain dissipated energy (DPSE) and composite stability index (CSI) are as follows:

[0071]

[0072] DPSE formula letter explanation: σ h (τ) is the loading stress; ε R (τ) is the viscoelastic strain response; τ is the time variable; N is the number of loadings; NT is the loading time, t 60 The loading time is 60 seconds; 1 and d 2 are the rutting depth and time recorded during the test; in this experiment, t 1 and t 2 The recommendations are 198 minutes and 213 minutes respectively; v and l are the loading speed and one-way moving distance respectively.

[0073] When t 1 and t2 At 198 minutes and 213 minutes respectively, the final geothermal regeneration maintenance results are as follows Figure 5 shown.

[0074] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for in-situ thermal regeneration and maintenance of multi-layer depth of ultra-deep rutted asphalt pavement. Features: include Optimization design of the mix ratio of three-layer hot-in-place recycled asphalt; Conduct road performance verification of three-layer hot-in-place recycled asphalt mixture; The upper layer is hot-raked and recycled in situ, the middle layer is remixed and regenerated for storage, and the lower layer is remixed and regenerated; The full width of the surface layer is paved and rolled synchronously by a paver; finally, the quality evaluation of the ultra-deep rutting in-situ hot regeneration construction is carried out; The three-layer hot-regenerated asphalt mixture mix ratio optimization design is to recycle the hot harrowed loose materials of the upper, middle and lower layers of the original road surface in deep rutting sections for extraction and screening, determine the ratio of the regeneration agent to the recycled asphalt by the performance design method, and determine the type and amount of the admixtures, the amount of new materials, and the new material oil-stone ratio of each layer of the regenerated asphalt mixture in turn according to the interlayer stress state of each structural layer of the asphalt pavement and the mix ratio test; The in-situ hot raking and recycling of the upper layer is to uniformly preheat and hot rake the old material on the original pavement surface in situ, add a regeneration agent and stir with the old material to form a material cage, add a high modulus modified asphalt mixture and remix, obtain the high modulus modified recycled asphalt mixture of the upper layer, and recycle and store the recycled mixture of the upper layer in an insulated material truck; The middle surface layer remixing and recycling storage is that after the upper layer is milled, the old material of the middle surface layer is evenly heated and hot-raked in situ, a regeneration agent is added to mix with the old material to form a material cage, and a high-viscosity modified asphalt mixture is added for remixing to obtain a high-viscosity modified recycled asphalt mixture of the middle surface layer, and the recycled mixture of the middle surface layer is recycled and stored in an insulated material truck; The bottom layer remixing and regeneration is that after the middle surface layer is hot-raked and loosened, the old material of the bottom layer is evenly heated and hot-raked in situ, a regeneration agent is added and stirred with the old material to form a material cage, a fiber-modified asphalt mixture is added for remixing and regeneration, the modified recycled material is transported to the mixing tank for secondary mixing, and the fiber-modified recycled mixture of the bottom layer is spread through the front ironing plate of the paver; The external admixture uses a high modulus agent in the upper layer of the asphalt pavement with larger vertical compressive stress, a high viscosity agent in the middle layer with larger shear stress, and a fiber modifier in the lower layer with larger bending and tensile stress.

2. A method for in-situ thermal regeneration and maintenance of multi-layer super-deep rutting asphalt pavement as claimed in claim 1, Features: The road performance verification of the three-layer hot-regenerated asphalt mixture is to verify the water stability, low-temperature crack resistance and high-temperature rutting resistance of each layer of the hot-regenerated asphalt mixture by molding test pieces according to the mix ratio of the hot-regenerated asphalt mixture; The water stability performance is determined by the immersion Marshall test and the freeze-thaw splitting test, the low-temperature crack resistance is determined by the small beam bending test, the high-temperature rutting resistance of each layer of recycled mixture is determined by the indoor rutting test, and the high-temperature rutting resistance of the full-width surface layer depth is determined by the indoor ring load wheel test.

3. A method for in-situ thermal regeneration and maintenance of multi-layer depth of ultra-deep rutting asphalt pavement as claimed in claim 1 or 2, Features: The synchronous paving and rolling of the full-width surface layer is that while the lower layer of fiber-modified recycled mixture is being spread, the middle surface layer of recycled mixture is lifted, insulated and transported to the paver of the hot regeneration unit, poured into the hopper of the full-width surface layer paver at a regular time and in a fixed quantity, lifted and flattened to the middle ironing plate by the scraper, at the same time, the upper layer of high modulus modified recycled asphalt mixture in the insulation material car is poured into the hopper at a regular time and in a fixed quantity and transported to the rear ironing plate, finally the three layers are synchronously paved and rolled to realize the synchronous in-situ hot regeneration and maintenance of the full-width surface layer depth.

4. A method for in-situ thermal regeneration and maintenance of multi-layer depth of ultra-deep rutting asphalt pavement as claimed in claim 3, Features: The ultra-deep rutting in-situ hot regeneration construction quality evaluation is to take three-layer rutting plate samples of the hot regenerated pavement for indoor ring load wheel test, record the rutting depth change curve, and calculate the average pseudo-strain dissipated energy and composite stability index two indicators to evaluate the engineering construction quality of the in-situ hot regenerated asphalt pavement.

5. A method for in-situ thermal regeneration and maintenance of multi-layer depth of ultra-deep rutting asphalt pavement as claimed in claim 4, Features: The indoor ring track load wheel rutting test adopts an annular basin design structure. Its test specimens consist of eight groups of parallel specimens. The front and rear end surfaces of each specimen are sprayed with white spray paint, and grid lines are drawn to identify and detect the rutting depth of each layer of recycled mixture and determine the contribution rate of each layer of recycled mixture to the anti-rutting performance of the overall structure.

6. A method for in-situ thermal regeneration and maintenance of multi-layer depth of ultra-deep rutting asphalt pavement as claimed in claim 4 or 5, Features: The specific calculation formulas of average pseudo-strain dissipated energy and composite stability index are as follows: σ h (τ) is the loading stress; ε R (τ) is the viscoelastic strain response; τ is the time variable; N is the number of loadings; NT is the loading time, t 60 The loading time is 60 seconds; 1 and d 2 are the rutting depth and time recorded during the test, respectively; v and l are the loading speed and one-way travel distance, respectively, t 1 and t 2 To record the start and end time, the average pseudo-strain dissipated energy is DPSE, and the composite stability index is CSI; The average pseudo-strain energy dissipation was used to evaluate the average energy dissipation after removing the viscoelasticity in each loading cycle during the test; The composite stability index represents the number of repeated loads that produce a rutting depth of 1 mm. The larger the average pseudo-strain energy dissipation index, the greater the rutting depth produced, while the composite stability index is the opposite.

7. An intelligent computer device, It is characterized in that The method comprises a memory and a processor, wherein the memory stores computer-readable instructions, and the processor implements the steps of the method according to any one of claims 1 to 6 when executing the computer-readable instructions.

8. A computer-readable storage medium, It is characterized in that The computer-readable storage medium stores computer-readable instructions, and when the computer-readable instructions are executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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