An aggregate skeleton interlock structure layer, its preparation method, and a standardized high-performance ultra-thin wearing course

Abstract

The present invention relates to the technical field of pavement materials, and provides an aggregate skeleton interlocking structure layer, a preparation method thereof, and a standardized high-performance ultra-thin wearing course. The crushed stones in the aggregate skeleton interlocking structure layer provided by the present invention are distributed and interlocked in an array, with a compact structure. Moreover, the internal structure of single crushed stones is reinforced by a basalt three-dimensional net and a chopped basalt fiber net, so that the skeleton has high strength and good bonding performance. The standardized high-performance ultra-thin wearing course provided by the present invention comprises an aggregate skeleton interlocking structure layer and asphalt mortar filled in the aggregate skeleton interlocking structure layer; the crushed stones of this standardized high-performance ultra-thin wearing course are not easily variable, and are not prone to durability diseases such as looseness, particle detachment, and potholes. The pavement skeleton has high strength, good bonding performance, a long service life, convenient and fast construction, requires fewer construction machines, has fast traffic opening, and low traffic interference degree.

Description

Technical Field

[0001] The present invention relates to the technical field of pavement materials, and particularly to an aggregate skeleton interlocking structure layer, a preparation method thereof, and a standardized high-performance ultra-thin wearing course. Background Art

[0002] An ultra-thin wearing course asphalt pavement refers to laying a surface layer material with a thickness of 1 - 3 cm on the surface of an existing asphalt concrete pavement, so as to extend the service life of the original pavement, improve indexes such as pavement flatness and anti-skid performance, and at the same time reduce noise and improve water mist. Compared with paving a common asphalt surface layer, its thickness is greatly reduced, thereby reducing construction costs, material usage, and carbon emissions; at the same time, its construction period is short and the traffic disturbance is low, so it has become a very efficient asphalt pavement maintenance measure at the present stage. However, due to its thin thickness, the ultra-thin wearing course has high requirements for material properties and construction processes, and requires the use of high-performance asphalt and high-strength crushed stones to meet its requirements for bonding performance and durability.

[0003] However, in actual engineering applications, the dosage scales of asphalt and crushed stones are huge, and it is difficult to accurately control the quality stability of raw material processing; in addition, problems such as night construction and short open traffic time often occur during the construction of the ultra-thin wearing course, resulting in difficulties in balancing the requirements of construction quality and progress during on-site construction. The above problems all lead to the frequent premature occurrence of durability diseases such as loosening, stripping, and potholes during the application of the ultra-thin wearing course, and only conventional repair measures can be used in the repair of its diseases, making it difficult to achieve a repair effect with the same performance level as the ultra-thin wearing course, thus greatly reducing its service life and restricting its popularization and application. Therefore, it is necessary to invent a standardized high-performance ultra-thin wearing course. Summary of the Invention

[0004] In view of this, the present invention provides an aggregate skeleton interlocking structure layer, a preparation method thereof, and a standardized high-performance ultra-thin wearing course. The crushed stone interlocking structure in the aggregate skeleton interlocking structure layer provided by the present invention is tight, and the standardized high-performance ultra-thin wearing course prepared by using it has high skeleton strength, good bonding performance, and a long service life.

[0005] In order to achieve the above invention purpose, the present invention provides the following technical solutions:

[0006] An aggregate skeleton interlocking structure layer, comprising a basalt fiber three-dimensional net and a crushed stone structure layer embedded in the basalt fiber three-dimensional net; the crushed stone structure layer is formed by standard artificial crushed stones; a short-cut basalt fiber net is arranged inside the standard artificial crushed stones; the standard artificial crushed stones in the crushed stone structure layer form an interlocking structure through an array, and the void ratio of the crushed stone structure layer is 14 - 18%;

[0007] The indexes of the standard artificial crushed stones include: the flakiness index is 1.6 ± 0.3, the angularity index is 1.6 ± 0.3, and the fractal dimension is 2.35 ± 0.5.

[0008] Preferably, the particle size of the standard artificial crushed stones is 9.5 - 37.5 mm.

[0009] Preferably, the chopped basalt fiber mesh is formed by stirring chopped basalt fibers; the length of the chopped basalt fibers is 4 - 10 mm, and the diameter is less than 0.2 mm.

[0010] Preferably, the basalt fiber three-dimensional mesh includes several layers of basalt fiber meshes, and the distance between adjacent basalt fiber meshes is 5.0 ± 1.0 mm; the basalt fiber mesh is formed by interweaving continuous basalt fiber rovings in the horizontal and vertical directions; the single-strand diameter of the continuous basalt fiber rovings is 0.02 - 0.04 mm; in each layer of the basalt fiber mesh, the distance between adjacent two continuous basalt fiber rovings in each direction is 5.0 ± 1.0 mm.

[0011] The present invention also provides a preparation method for the aggregate skeleton interlock structure layer described in the above solution, including the following steps:

[0012] Provide an aggregate skeleton interlock structure casting mold, which is divided into upper and lower parts. After the two parts are closed, a casting cavity matching the size of the standard artificial crushed stones in the crushed stone structure layer is formed; several grouting channels are provided on the upper part, and the grouting channels are in one-to-one correspondence and communication with the casting cavity; three-dimensional mesh loading channels are respectively provided on one side of the closing surface of the upper part and the lower part; the three-dimensional mesh loading channels are used to clamp the basalt fiber three-dimensional mesh, so that the upper part and the lower part can pass through the basalt fiber three-dimensional mesh for closing.

[0013] Place the chopped basalt fiber mesh into each casting cavity, then place the basalt fiber three-dimensional mesh between the upper part mold and the lower part mold, and close the upper part mold and the lower part mold; inject cement mortar into each casting cavity through the grouting channels, and then perform static placement, demolding and curing in sequence to obtain the aggregate skeleton interlock structure layer.

[0014] Preferably, the preparation method of the aggregate skeleton interlock structure casting mold includes:

[0015] Design an aggregate skeleton interlock structure casting mold model, then use stereolithography technology for 3D printing, and soak and cure the obtained printed part in alcohol to obtain the aggregate skeleton interlock structure casting mold.

[0016] Preferably, the design method of the aggregate skeleton interlock structure casting mold model includes:

[0017] Select 2 to 4 crushed stones that meet the index requirements as standard crushed stones, scan the contours of the standard crushed stones to generate a crushed stone model; use the method of replication or array to splice multiple crushed stone models to form a crushed stone structural layer model.

[0018] According to the crushed stone structural layer model, construct a three-dimensional model of the casting mold foundation by reverse molding, and then divide the foundation three-dimensional model into upper and lower parts. Then, dig out three-dimensional mesh loading channels in the upper and lower parts respectively, and dig out a grouting channel in the upper part to obtain the casting mold model of the aggregate skeleton interlocking structure.

[0019] Preferably, by mass, the components of the cement mortar include: 90 - 110 parts of cement, 10 - 14 parts of fly ash, 5 - 7 parts of silica fume, 40 - 50 parts of sand, 1 - 1.5 parts of water reducing agent, 2 - 4 parts of expansive agent, 0.5 - 1.2 parts of silica sol, 0.8 - 1.5 parts of styrene-butadiene emulsion, and 25 - 35 parts of water.

[0020] The present invention also provides a standardized high-performance ultra-thin wearing course, which includes an aggregate skeleton interlocking structure layer and asphalt mortar filled in the aggregate skeleton interlocking structure layer; the aggregate skeleton interlocking structure layer is the aggregate skeleton interlocking structure layer described in the above solution or the aggregate skeleton interlocking structure layer prepared by the preparation method described in the above solution.

[0021] The present invention also provides a construction method for the standardized high-performance ultra-thin wearing course described in the above solution, including the following steps: Sprinkle a layer of emulsified asphalt tack coat on the construction interface, then spread the aggregate skeleton interlocking structure layer, and spray the asphalt mortar into the aggregate skeleton interlocking structure layer.

[0022] The present invention provides an aggregate skeleton interlocking structure layer, which includes a basalt fiber three-dimensional network and a crushed stone structure layer embedded in the basalt fiber three-dimensional network; the crushed stone structure layer is formed by standard artificial crushed stones; a short-cut basalt fiber network is arranged inside the standard artificial crushed stones; the standard artificial crushed stones in the crushed stone structure layer form an interlocking structure through an array, and the void ratio of the crushed stone structure layer is 14-18%; the indexes of the standard artificial crushed stones include: the flaky index is 1.6±0.3, the angularity index is 1.6±0.3, and the fractal dimension is 2.35±0.5. In the aggregate skeleton interlocking structure layer provided by the present invention, the crushed stones are distributed and interlocked in an array, and the structure is compact. In the ultra-thin wearing course prepared therefrom, the crushed stones are all of the designed size, shape and direction, eliminating the construction weak points caused by the variability of crushed stones in the construction process of traditional asphalt pavements; moreover, by using a basalt three-dimensional network and a short-cut basalt fiber network to reinforce the internal structure of single crushed stones, the pavement skeleton strength is increased by about 150% compared with traditional asphalt mixtures; furthermore, after pouring asphalt mortar subsequently, the basalt three-dimensional network can connect the overall structure of the wearing course, sharing the stress while the bonding performance is increased by about 80% compared with traditional processes, thus greatly improving the service life of the wearing course.

[0023] The present invention also provides a preparation method for the aggregate skeleton interlocking structure layer described in the above solution. The present invention uses an aggregate skeleton interlocking structure pouring mold, fills the short-cut basalt fiber network into the pouring cavity, and installs the basalt fiber three-dimensional network device into the mold, and then forms standardized crushed stones through pouring. The shape, size and direction of the formed crushed stones are consistent with the designed parameters in the mold. Therefore, there are no construction weak points such as loose interlocking and local lack of particles after conventional pavement construction, thus eliminating the influence of pavement quality fluctuations caused by construction factors.

[0024] The present invention also provides a standardized high-performance ultra-thin wearing course, which includes the aggregate skeleton interlocking structure layer described in the above solution and asphalt mortar filled in the aggregate skeleton interlocking structure layer; the standardized high-performance ultra-thin wearing course provided by the present invention has crushed stones that are not easily variable, and are not prone to durability diseases such as looseness, particle loss, and potholes. The pavement skeleton has high strength, good bonding performance and long service life.

[0025] The present invention also provides a construction method for the standardized high-performance ultra-thin wearing course described in the above solution. By using the method of the present invention to construct the standardized high-performance ultra-thin wearing course, the test performance differences caused by factors such as aggregate variation and distribution are greatly reduced, which is extremely convenient for researchers to conduct test research in this field; and it simplifies the traditional pavement construction process, prefabricates the aggregate skeleton interlocking structure layer in the factory, is convenient and fast to construct, requires less construction machinery, has fast traffic opening, and has a low degree of interference with traffic. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1It is a top view of the aggregate skeleton interlock structure layer;

[0027] Figure 2 It is a top view of the basalt fiber three-dimensional net;

[0028] Figure 3 It is a top view of the cross-section of the pouring mold for the aggregate skeleton interlock structure;

[0029] Figure 4 It is a schematic diagram of the pouring production of the aggregate skeleton interlock structure layer;

[0030] Figure 5 It is a schematic diagram of the standardized high-performance ultra-thin wearing course structure;

[0031] Figures 1 to 5 In the figure: 1 - basalt fiber three-dimensional net, 2 - standard artificial crushed stones, 3 - short-cut basalt fiber net, 4 - grid frame, 5 - pouring mold for the aggregate skeleton interlock structure, 6 - pouring cavity, 7 - upper part of the pouring mold for the aggregate skeleton interlock structure, 8 - lower part of the pouring mold for the aggregate skeleton interlock structure, 9 - grouting channel, 10 - loading channel for the three-dimensional net, 11 - grouting head group, 12 - asphalt mortar, 13 - emulsified asphalt tack coat, 14 - original road surface. Specific implementation manners

[0032] The present invention provides an aggregate skeleton interlock structure layer, which includes a basalt fiber three-dimensional net and a crushed stone structure layer embedded in the basalt fiber three-dimensional net; the crushed stone structure layer is formed by standard artificial crushed stones; short-cut basalt fiber nets are arranged inside the standard artificial crushed stones; the standard artificial crushed stones in the crushed stone structure layer form an interlock structure through an array, and the void ratio of the crushed stone structure layer is 14 - 18%;

[0033] The indexes of the standard artificial crushed stones include: the flakiness index (shape index) is 1.6 ± 0.3, the angularity index (angularity index) is 1.6 ± 0.3, and the fractal dimension (texture index) is 2.35 ± 0.5.

[0034] In the present invention, the top view of the aggregate skeleton interlock structure layer is as Figure 1 shown.

[0035] In the present invention, the particle size of the standard artificial crushed stones is preferably 9.5 - 37.5 mm; in the present invention, the size, shape and orientation of the standard artificial crushed stones are controlled to be able to form a good interlocking structure, and the void ratio of the crushed stone structure layer is maintained between 14% and 18%; in a specific embodiment of the present invention, the crushed stone structure layer is specifically formed by sequentially arranging 2 - 4 (preferably 3) standard artificial crushed stones with different particle sizes, and the particle sizes of the 2 - 4 standard artificial crushed stones with different particle sizes are all within the above range and are based on being able to form a good interlocking structure; specifically, the standard artificial crushed stones are classified into levels in ascending order of particle size, and the particle size difference between adjacent-level crushed stones is preferably 6 - 7 mm; in a specific embodiment of the present invention, when three standard artificial crushed stones with different particle sizes are used, the particle sizes of the three artificial crushed stones are preferably 25.5 - 26.5 mm, 18 - 20 mm and 12.2 - 14.2 mm respectively; in the present invention, the crushed stone structure layer is a single-layer structure, that is, it is formed by laying standardized crushed stones flat.

[0036] In the present invention, the chopped basalt fiber mesh is preferably formed by stirring chopped basalt fibers, specifically a fluffy mass of chopped basalt fibers; the length of the chopped basalt fibers is preferably 4 - 10 mm, and the diameter is preferably less than 0.2 mm; in a specific embodiment of the present invention, the chopped basalt fiber mesh is preferably formed by stirring chopped basalt fibers with lengths of 4 - 5 mm, 5 - 6 mm, 6 - 7 mm, 7 - 8 mm, 8 - 9 mm and 9 - 10 mm, and the mass ratio of the chopped basalt fibers with lengths of 4 - 5 mm, 5 - 6 mm, 6 - 7 mm, 7 - 8 mm, 8 - 9 mm and 9 - 10 mm is preferably 14 - 16:19 - 21:9 - 11:9 - 11:19 - 21:24 - 26, more preferably 15:20:10:10:20:25; the stirring is preferably dry mixing, that is, stirring is carried out in a dry environment, and the dry environment is based on a relative humidity less than 30%. Stirring in a dry environment can avoid fiber moisture agglomeration; the dry mixing time is preferably 5 - 10 s. Through dry mixing, fibers of different lengths are fluffed and intertwined to form a fluffy mass. In the present invention, the fluffy chopped fibers are placed in an artificial crushed stone model, and after casting and molding, the fibers will form a three-dimensional interpenetrating network structure inside the artificial crushed stones, which can significantly improve the toughness, wear resistance and crack resistance of the artificial crushed stones.

[0037] In the present invention, the filaments in the basalt fiber three-dimensional net pass through the interior of standard artificial crushed stones, thereby achieving the integral connection of the crushed stone structure layer; the basalt fiber three-dimensional net includes several layers of basalt fiber nets, and the distance between adjacent basalt fiber nets is 5.0 ± 1.0 mm; the basalt fiber net is formed by interweaving continuous basalt fiber twisted rovings in the horizontal and vertical directions; the single-strand diameter of the continuous basalt fiber twisted roving is preferably 0.02 - 0.04 mm; in each layer of the basalt fiber net, the distance between two adjacent continuous basalt fiber twisted rovings in each direction is preferably 5.0 ± 1.0 mm; in the present invention, the thickness of the basalt fiber three-dimensional net is preferably determined according to the largest-sized crushed stone in the artificial crushed stones, so as to ensure that all the crushed stones in the crushed stone structure layer can be fully anchored in the basalt fiber three-dimensional net; in a specific embodiment of the present invention, the number of layers of the basalt fiber net is preferably 3 - 8 layers. In a specific embodiment of the present invention, it is preferred to open holes in the grid frame, and use a wire threading machine to arrange multiple layers of basalt fiber nets in a staggered manner in the horizontal and vertical directions, and the grid frame is preferably a metal grid frame; the present invention uses the basalt fiber three-dimensional net to connect the integral crushed stone structure layer, which can significantly improve the strength of the crushed stone structure layer, and the continuous basalt fiber twisted rovings used in the present invention are used to prepare the basalt fiber three-dimensional net. The continuous basalt fiber twisted rovings are multi-filament twisted, and have relatively rich texture structures on the surface, which can enhance the anchoring ability with the crushed stones; the structure of the basalt fiber three-dimensional net is as Figure 2 shown.

[0038] The present invention also provides a preparation method for the aggregate skeleton interlock structure layer described in the above solution, including the following steps:

[0039] Provide an aggregate skeleton interlock structure pouring mold. The aggregate skeleton interlock structure pouring mold is divided into upper and lower parts. After the two parts are closed, a pouring cavity matching the standard crushed stones in the crushed stone structure layer is formed; several grouting channels are provided on the upper part, and the grouting channels are in one-to-one correspondence and communication with the pouring cavity; three-dimensional net loading channels are respectively provided on one side of the closing surface of the upper part and the lower part; the three-dimensional net loading channels are used to clamp the basalt fiber three-dimensional net, so that the upper part and the lower part can pass through the basalt fiber three-dimensional net for closing;

[0040] Place a chopped basalt fiber net into each pouring cavity, then place the basalt fiber three-dimensional net between the upper part mold and the lower part mold, and close the upper part mold and the lower part mold; inject cement mortar into each pouring cavity through the grouting channels, and then carry out static placement, demolding and maintenance in sequence to obtain the aggregate skeleton interlock structure layer.

[0041] In the present invention, the top view of the cross-section of the aggregate skeleton interlock structure pouring mold is as Figure 3 shown, and the schematic diagram of the pouring production of the aggregate skeleton interlock structure layer is asFigure 4 As shown below. The following will be described in detail in conjunction with Figures 3 to 4 this.

[0042] In the present invention, the width of the grouting channel is preferably 3 mm; the width of the three-dimensional mesh loading channel is preferably 0.2 mm.

[0043] In the present invention, the preparation method of the aggregate skeleton interlocking structure casting mold preferably includes:

[0044] Design an aggregate skeleton interlocking structure casting mold model, and then use stereolithography technology for 3D printing. Soak the obtained printed part in alcohol and perform secondary curing to obtain the aggregate skeleton interlocking structure casting mold.

[0045] The present invention first designs an aggregate skeleton interlocking structure casting mold model. In the present invention, the design method of the aggregate skeleton interlocking structure casting mold model preferably includes:

[0046] Select 2 to 4 crushed stones that meet the index requirements as standard crushed stones, scan the contours of the standard crushed stones to generate crushed stone models; use the method of replication or array to splice multiple crushed stone models to form a crushed stone structure layer model;

[0047] According to the crushed stone structure layer model, construct a basic three-dimensional model of the casting mold through reverse molding. Then divide the basic three-dimensional model into upper and lower parts, and then dig out three-dimensional mesh loading channels in the upper and lower parts respectively, and dig out a grouting channel in the upper part to obtain the aggregate skeleton interlocking structure casting mold model.

[0048] According to existing research, the shape and particle size combination of the crushed stones used in the asphalt surface layer largely determine the stability effect of the pavement skeleton interlocking, and have a greater impact on performance indicators such as anti-skid performance, wear resistance, and crushing value; in the specific embodiments of the present invention, it is preferred to analyze the specific requirements and performance focuses of the ultra-thin wearing course construction project, and then select 2 to 4 crushed stones with relatively ideal shape and particle size combination as standard crushed stones; the scanning is preferably performed using a three-dimensional scanner with a scanning accuracy of more than 0.05 mm, specifically preferably an AutoScan three-dimensional scanner; the index requirements of the standard crushed stones are the same as the above-mentioned scheme and will not be elaborated here.

[0049] In the present invention, the replication or array is preferably performed using software capable of three-dimensional modeling processing, specifically preferably Materialise magics software; the present invention uses splicing techniques such as replication and array to construct and design a crushed stone structure layer model, and leaves a gap of 14 to 18% between the crushed stones for the penetration and filling of asphalt mortar.

[0050] In the present invention, when the basic three-dimensional model is segmented, preferably in the transverse direction, it is segmented along the center line of the basic three-dimensional model, as Figure 4 shown.

[0051] After obtaining the aggregate skeleton interlock structure casting mold model, the present invention uses stereolithography technology for 3D printing, soaks the obtained printed part in alcohol and cures it to obtain the aggregate skeleton interlock structure casting mold. In the present invention, the 3D printing is preferably carried out using a printing device with a printing accuracy higher than 0.05 mm, specifically preferably a stereolithography 3D printer; the consumable for 3D printing is preferably photosensitive resin, more preferably ProtoGenZR710 photosensitive resin; the volume fraction of the alcohol is preferably 95%, the soaking time of the alcohol is preferably 20-22 min; the curing is preferably carried out in a curing box, and the curing conditions preferably include: the power of the UV curing lamp is 80-120 W / cm 2 , the rotation rate of the base is 6-10 r / min, and the curing time is preferably 30-33 min.

[0052] After obtaining the aggregate skeleton interlock structure casting mold, the present invention places a chopped basalt fiber mesh in each of the casting cavities, then places the basalt fiber three-dimensional mesh between the upper part mold and the lower part mold, and closes the upper part mold and the lower part mold; injects cement mortar into each of the casting cavities through the grouting channel, and then performs static setting, demolding and maintenance in sequence to obtain the aggregate skeleton interlock structure layer. In the present invention, before using the aggregate skeleton interlock structure casting mold, it is preferably smeared with vaseline inside the mold to facilitate demolding; the dosage of the chopped basalt fiber mesh is such that the diameter of the fluffy mass of chopped basalt fibers is ≥ 80% of the longest axis of the casting cavity without applying external force.

[0053] In the present invention, when placing the basalt fiber three-dimensional mesh, specifically, the basalt fiber three-dimensional mesh fixed in the mesh frame is directly placed between the upper part mold and the lower part mold, and after subsequent demolding, the mesh frame is removed; the wire in the basalt fiber three-dimensional mesh is embedded in the three-dimensional mesh loading channel.

[0054] In the present invention, a cement-based material is used as the bonding material for artificial crushed stone molding. When pouring with the addition of materials such as sand and ash, it is necessary to take into account the strength, wear resistance, fluidity, etc. of the formed crushed stone at the same time. When used in specific projects, specific performance adjustments must be made according to the characteristics of the project environment, traffic volume, economy, etc. Only a general formula is given here. In the present invention, in parts by mass, the components of the cement mortar preferably include: 90 to 110 parts of cement, preferably 100 parts, 10 to 14 parts of fly ash, preferably 12 parts, 5 to 7 parts of silica fume, preferably 6 parts, 40 to 50 parts of sand, preferably 46.75 parts, 1 to 1.5 parts of water reducing agent, preferably 1.36 parts, 2 to 4 parts of expansion agent, preferably 3 parts, 0.5 to 1.2 parts of silica sol, preferably 0.7 parts, 0.8 to 1.5 parts of styrene-butadiene emulsion, preferably 1.3 parts, and 25 to 35 parts of water, preferably 28.5 parts. In the present invention, the water reducing agent is preferably a polycarboxylate-based water reducing agent, and the expansion agent is preferably a calcium sulfoaluminate-based expansion agent; the mass fraction of silicon dioxide in the silica sol is preferably 20% to 25%; the model of the styrene-butadiene emulsion is preferably BSF7623.

[0055] In the present invention, the mixing method of the cement mortar is preferably as follows: Pour cement, fly ash, silica fume and sand into a mixer according to the weight ratio, mix at a rotation speed of 25 to 35 r / min for 95 to 110 s, mix water and water reducing agent and pour 50% of the weight ratio into the mixer, and mix at a rotation speed of 25 to 35 r / min for 70 to 80 s; Mix the expansion agent, silica sol, styrene-butadiene emulsion and the remaining 50% of water and water reducing agent and pour them into the mixer, and mix at a rotation speed of 25 to 35 r / min for 70 to 80 s.

[0056] In a specific embodiment of the present invention, after mixing, the prepared cement mortar needs to be poured within 30 min to avoid segregation of each component inside the mortar or reduction of fluidity caused by excessive evaporation of water.

[0057] In the present invention, it is preferred to use a grouting head group for automatic pouring of the cement mortar, as Figure 4 shown; after the cement mortar is injected into the pouring cavity, it solidifies to form artificial crushed stone. After the injection of the cement mortar is completed, it is preferred to let the poured mold stand at room temperature. The standing time is preferably 24 h. After standing, the artificial crushed stone reaches the demolding strength, and then the demolding process can be carried out; the mold and the grid frame after demolding can be used for the next round of pouring.

[0058] In the present invention, the curing is preferably normal temperature wet curing or water bath curing; the time of the normal temperature wet curing is preferably 7 days, the temperature of the water bath curing is preferably 60 °C, and the time is preferably 3 days; after curing, the obtained aggregate skeleton interlocking structure layer can meet the road use performance strength.

[0059] In the present invention, during specific use, it is preferable to splice multiple aggregate skeleton interlocking structure layers on a plane to fit the size of the construction section. When splicing, it is preferable to tie the basalt fibers at the ends of adjacent aggregate skeleton interlocking structure layers to each other, and then it can be wound up for transportation.

[0060] The present invention also provides a standardized high-performance ultra-thin wearing course, which includes an aggregate skeleton interlocking structure layer and asphalt mortar filled in the aggregate skeleton interlocking structure layer; the aggregate skeleton interlocking structure layer is the aggregate skeleton interlocking structure layer described in the above solution or the aggregate skeleton interlocking structure layer prepared by the preparation method described in the above solution. In the present invention, the asphalt mortar is preferably obtained by mixing stone chips and asphalt. The specification of the stone chips is preferably 0-5 mm, and the asphalt is preferably SBS modified asphalt or high-viscosity special asphalt. In the specific embodiments of the present invention, the type of asphalt is preferably determined according to the traffic load level; the weight ratio of the stone chips to the asphalt is preferably 1:9. The schematic diagram of the structure of the standardized high-performance ultra-thin wearing course is as Figure 5 shown.

[0061] The present invention also provides a construction method for the standardized high-performance ultra-thin wearing course described in the above solution, including the following steps: spraying a layer of emulsified asphalt tack coat on the construction interface, and then spreading the aggregate skeleton interlocking structure layer, and spraying the asphalt mortar into the aggregate skeleton interlocking structure layer.

[0062] In the present invention, it is preferable to first clean the original road surface to ensure maximum cleanliness, and then spray the emulsified asphalt tack coat; the spraying amount of the emulsified asphalt is preferably 0.5-0.7 kg / m 2 ; the present invention has no special requirements for the cleaning method, and it can be carried out by means of a forest fire extinguisher or a sweeper, etc.;

[0063] After spraying the emulsified asphalt tack coat, the present invention spreads the aggregate skeleton interlocking structure layer on the emulsified asphalt tack coat, and stretches it in all directions during the spreading process to avoid the overlapping and misalignment of aggregate particles.

[0064] After the spreading of the aggregate skeleton interlocking structure layer is completed, the asphalt mortar is sprayed into the aggregate skeleton interlocking structure layer; the spraying amount of the asphalt mortar is preferably 2.5-3.5 kg / m 2 . In the specific embodiments of the present invention, after spraying the asphalt mortar, after the asphalt mortar fully infiltrates and fills the gaps between the aggregate skeleton interlocking structure layers, manual inspection is carried out to check whether there are exposed and weak parts of the skeleton. If so, the same asphalt mortar material is used for supplementary spraying; after the spraying of the asphalt mortar is completed, when the road surface temperature drops below 60 °C, the traffic can be opened.

[0065] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0066] Example 1

[0067] 1. Fabrication of the casting mold for the aggregate skeleton interlocking structure:

[0068] Select 3 gravels with relatively ideal shapes and particle size combinations. Use an AutoScan 3D scanner to scan each gravel with different particle sizes to obtain their three-dimensional contour information. The gravel particle sizes are 25.8 mm, 19.3 mm, and 13.1 mm respectively. The flakiness index is within the range of 1.6 ± 0.3, the angularity index is within the range of 1.6 ± 0.3, and the fractal dimension is within the range of 2.35 ± 0.5. Use Materialise magics software to construct a three-dimensional model of the designed gravel structure layer by means of splicing such as copying and arraying using the scanned target-shaped gravel models. The gravels form an interlocking structure, and 16% voids are left between the gravels for the penetration and filling of asphalt mortar.

[0069] Adopt the established three-dimensional model of the single-layer gravel structure layer to construct the three-dimensional model of the casting mold by reverse molding. Divide the casting mold model into upper and lower parts, and then dig out the loading channel for the three-dimensional grid of basalt fibers. The width of the channel is designed to be 0.2 mm, and a grouting channel is dug in the upper part with a width of 3 mm. After obtaining the casting mold model, use a stereolithography 3D printer and use the ProtoGen ZR710 photosensitive resin for mold printing. After printing, immerse the mold in 95% alcohol for 20 minutes, and then place it in a curing box for 30 minutes for secondary curing.

[0070] 2. Fabrication of the chopped basalt fiber mesh

[0071] Put chopped basalt fibers with lengths of 4 - 5 mm, 5 - 6 mm, 6 - 7 mm, 7 - 8 mm, 8 - 9 mm, and 9 - 10 mm (diameter < 0.02 mm) into a stirring pot according to a mass ratio of 15:20:10:10:20:25, and dry mix for 10 s. The relative humidity of the environment during the dry mixing process is less than 30%, so that fibers of different lengths are fluffed and intertwined together to obtain a chopped basalt fiber mesh (i.e., a fluffy mass of chopped basalt fibers).

[0072] 3. Preparation of the three-dimensional basalt fiber mesh

[0073] Holes are opened on the metal grid, and a threading machine is used to set up multiple layers of three-dimensional fiber mesh in the horizontal and vertical directions. The distance between adjacent lines in each direction is set to 5mm. The single basalt fiber is continuous basalt fiber twisted roving with a single strand diameter of 0.02mm.

[0074] 4. Preparation of cement mortar

[0075] The components of cement mortar are, in parts by mass, 100 parts of cement, 12 parts of fly ash, 6 parts of silica fume, 46.75 parts of sand, 1.36 parts of water reducer, 3 parts of expansion agent, 0.7 parts of silica sol, 1.3 parts of styrene-butadiene emulsion, and 28.5 parts of water; wherein, the water reducer is a polycarboxylic acid-based water reducer, the expansion agent is a calcium sulfoaluminate expansion agent, the mass fraction of silicon dioxide in the silica sol is preferably 20%, and the model of the styrene-butadiene emulsion is BSF7623. The mixing process is as follows: Cement, fly ash, silica fume, and sand are added to a mixer according to their weight ratio and mixed at 30 r / min for 1000 seconds. Water and a water reducer are mixed and added to a 50% weight ratio of the mixture and mixed at 30 r / min for 70 seconds. The expansion agent, silica sol, styrene-butadiene emulsion, and the remaining 50% of the water and water reducer are mixed and added to the mixer and mixed at 30 r / min for 70 seconds. After mixing, the cement mortar should be poured within 30 minutes.

[0076] 5. Pouring and curing of aggregate skeleton embedded structure layer

[0077] Apply vaseline to the upper and lower parts of the aggregate skeleton embedded structure casting mold to facilitate demoulding, put a fluffy ball of chopped basalt fiber into each casting cavity, and then embed, assemble and fix it in the order of "lower part mold, net, upper part mold".

[0078] The grouting head assembly is used to automatically pour cement mortar. After pouring, the mold is placed at room temperature for 24 hours to achieve the required demoulding strength. After demoulding, the mold and grid are ready for the next round of pouring.

[0079] The aggregate skeleton embedded structure layer can be placed in a wet curing at room temperature for 7 days, or cured in a water bath at 60℃ for 3 days to meet the road performance strength requirements.

[0080] Multiple aggregate skeleton embedded structure layers are spliced together, and the basalt fibers between adjacent aggregate skeleton embedded structure layers are tied and connected to each other to assemble them to fit the size of the construction section, and then they can be rolled up for transportation.

[0081] 6. Standardized high-performance ultra-thin wearing layer construction

[0082] For the original road surface, clean it by using forest fire extinguishers, road sweepers, etc. to ensure maximum cleanliness. Then, use a hot asphalt distributor to spray a layer of emulsified asphalt tack coat with a spraying amount of 0.5 kg / m 2 .

[0083] Unroll the aggregate skeleton interlocking structure layer onto the construction interface, and stretch it in all directions during the unrolling process to avoid overlapping and misalignment of aggregate particles.

[0084] Select stone chips with a specification of 0 - 5 mm and SBS modified asphalt, and mix them in a weight ratio of 1:9 to obtain asphalt mortar material. Use a hot asphalt distributor to spray the mixed asphalt mortar onto the aggregate skeleton interlocking structure layer with a spraying amount of 3 kg / m 2 .

[0085] Wait for the asphalt mortar to fully penetrate and fill the gaps between the aggregate skeleton interlocking structure layers. Have workers patrol to check for exposed and weak parts of the skeleton, and re - spray with the same asphalt mortar material.

[0086] When the road surface temperature drops below 60°C, traffic can be opened.

[0087] Test example

[0088] Since the ultra - thin wearing course is a single - layer structure, the aggregate crushing value test can be used to characterize the skeleton strength. According to the method in Example 1, use a mold to prepare crushed stones without placing basalt fiber three - dimensional nets and chopped basalt fiber nets, and only use cement mortar to prepare artificial crushed stones. Refer to the "Technical Specification for Construction of Highway Asphalt Pavements" (JTGF40 - 2004) to test the crushing value of the obtained artificial crushed stones. The results show that the crushing value of the artificial crushed stones prepared by the present invention is 10.5%, and the crushing value of conventional basalt crushed stones for highway use is about 16%. This shows that using the aggregate skeleton interlocking structure layer provided by the present invention to prepare the ultra - thin wearing course can effectively improve the skeleton strength of the road surface.

[0089] The bonding performance between the aggregate and asphalt of a conventional asphalt pavement can be tested by a pull - out test. Usually, the pull - out strength of the ultra - thin wearing course is between 0.4 - 1.0 MPa, while the bonding ability of the ultra - thin wearing course prepared by the present invention mainly relies on continuous basalt fiber twisted yarns. Test the tensile strength of the continuous basalt fiber twisted yarns according to the density of 5 mm * 5 mm set by the three - dimensional net, and it can stably reach more than 1.5 MPa. This shows that the bonding performance of the ultra - thin wearing course prepared by the present invention is significantly improved compared with the traditional process.

[0090] Currently, the biggest problems restricting the lifespan of the ultra - thin wearing course are the skeleton strength and bonding performance. The two aspects of performance of the standardized high - performance ultra - thin wearing course provided by the present invention have been greatly improved, so as to effectively extend the service life.

[0091] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. An aggregate skeleton embedded structural layer, characterized in that: The invention comprises a basalt fiber three-dimensional mesh and a crushed stone structure layer embedded in the basalt fiber three-dimensional mesh; the crushed stone structure layer is formed of standard artificial crushed stone; the standard artificial crushed stone is provided with a short-cut basalt fiber mesh inside; the standard artificial crushed stone in the crushed stone structure layer is formed into an embedded structure by an array, and the porosity of the crushed stone structure layer is 14-18%; The indicators of the standard artificial gravel include: needle-like index of 1.6±0.3, angularity index of 1.6±0.3, and fractal dimension of 2.35±0.5; The preparation method of the aggregate skeleton embedded structure layer comprises the following steps: A casting mold for an aggregate skeleton embedded extruded structure is provided. The mold is divided into an upper and lower part. When the two parts are closed, a casting cavity is formed that matches the size of standard artificial gravel in the gravel structure layer. The upper part is provided with a plurality of grouting channels, which are connected to the casting cavity in a one-to-one correspondence. A three-dimensional mesh loading channel is provided on one side of the closed surface of the upper and lower parts respectively. The three-dimensional mesh loading channel is used to clamp the basalt fiber three-dimensional mesh, so that the upper and lower parts can pass through the basalt fiber three-dimensional mesh to be closed. A chopped basalt fiber mesh is placed in each of the casting cavities, and then the three-dimensional basalt fiber mesh is placed between the upper mold and the lower mold, and the upper mold and the lower mold are closed; cement mortar is injected into each of the casting cavities through the grouting channel, and then the casting is allowed to stand, demolded and cured in sequence to obtain the aggregate skeleton embedded structure layer.

2. The aggregate skeleton embedded structural layer according to claim 1, characterized in that: The particle size of the standard artificial gravel is 9.5 to 37.5 mm.

3. The aggregate skeleton embedded structural layer according to claim 1, characterized in that: The chopped basalt fiber mesh is formed by stirring chopped basalt fibers; the chopped basalt fibers have a length of 4 to 10 mm and a diameter of less than 0.2 mm.

4. The aggregate skeleton embedded structural layer according to claim 1, characterized in that: The three-dimensional basalt fiber mesh includes several layers of basalt fiber mesh, and the distance between adjacent basalt fiber meshes is 5.0±1.0 mm. The basalt fiber mesh is formed by interlacing continuous basalt fiber twisted rovings in the horizontal and vertical directions. The single strand diameter of the continuous basalt fiber twisted rovings is 0.02-0.04 mm. In each layer of the basalt fiber mesh, the distance between two adjacent continuous basalt fiber twisted rovings in each direction is 5.0±1.0 mm.

5. The method for preparing the aggregate skeleton embedded structure layer according to any one of claims 1 to 4, characterized in that: The following steps are involved: A casting mold for an aggregate skeleton embedded extruded structure is provided. The mold is divided into an upper and lower part. When the two parts are closed, a casting cavity is formed that matches the size of standard artificial gravel in the gravel structure layer. The upper part is provided with a plurality of grouting channels, which are connected to the casting cavity in a one-to-one correspondence. A three-dimensional mesh loading channel is provided on one side of the closed surface of the upper and lower parts respectively. The three-dimensional mesh loading channel is used to clamp the basalt fiber three-dimensional mesh, so that the upper and lower parts can pass through the basalt fiber three-dimensional mesh to be closed. A chopped basalt fiber mesh is placed in each of the casting cavities, and then the three-dimensional basalt fiber mesh is placed between the upper mold and the lower mold, and the upper mold and the lower mold are closed; cement mortar is injected into each of the casting cavities through the grouting channel, and then the casting is allowed to stand, demolded and cured in sequence to obtain the aggregate skeleton embedded structure layer.

6. The preparation method according to claim 5, characterized in that The preparation method of the aggregate skeleton embedded extrusion structure casting mold comprises: A casting mold model of the aggregate skeleton embedded extruded structure was designed, and then 3D printing was performed using light-curing stereolithography technology. The obtained print was soaked in alcohol and cured to obtain the casting mold of the aggregate skeleton embedded extruded structure.

7. The preparation method according to claim 6, characterized in that The design method of the aggregate skeleton embedded extrusion structure casting mold model includes: Two to four crushed stones that meet the index requirements are selected as standard crushed stones, and the contours of the standard crushed stones are scanned to generate a crushed stone model; multiple crushed stone models are spliced by replication or array method to form a crushed stone structure layer model; based on the crushed stone structure layer model, a three-dimensional model of the casting mold foundation is constructed by reverse molding, and then the three-dimensional model is divided into upper and lower parts, and then three-dimensional mesh loading channels are dug out in the upper and lower parts respectively, and a grouting channel is dug out in the upper part to obtain the casting mold model of the aggregate skeleton embedded structure.

8. The preparation method according to claim 6, characterized in that The components of the cement mortar include, by mass, 90 to 110 parts of cement, 10 to 14 parts of fly ash, 5 to 7 parts of silica fume, 40 to 50 parts of sand, 1 to 1.5 parts of water reducer, 2 to 4 parts of expansion agent, 0.5 to 1.2 parts of silica sol, 0.8 to 1.5 parts of styrene-butadiene emulsion, and 25 to 35 parts of water.

9. A standardized high-performance ultra-thin wear layer, characterized in that: It comprises an aggregate skeleton embedded structure layer and asphalt mortar filled in the aggregate skeleton embedded structure layer; the aggregate skeleton embedded structure layer is the aggregate skeleton embedded structure layer described in any one of claims 1 to 4 or the aggregate skeleton embedded structure layer prepared by the preparation method described in any one of claims 5 to 8.

10. The construction method of the standardized high-performance ultra-thin wearing layer according to claim 9, characterized in that: The following steps are involved: A layer of emulsified asphalt adhesive layer is spread on the construction interface, and then the aggregate skeleton embedded structure layer is spread, and asphalt mortar is sprayed into the aggregate skeleton embedded structure layer.

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