A thin road wear layer and its construction method

Abstract

This invention discloses an ultra-thin road wearing course and its construction method. The emulsified asphalt mixture for the emulsified asphalt layer includes modified glass fiber, sodium alginate, and high-viscosity modified emulsified asphalt. The ultra-thin wearing course mixture includes filler, SBS modified asphalt, sodium alginate, modified glass fiber, and aggregate. The high aggregate content provides micro-texture, and the coarse aggregate gradation provides macro-structure, ensuring good short-term and long-term skid resistance. Modified glass fiber is added to both the emulsified asphalt layer and the ultra-thin wearing course mixture, strengthening the bond between them while reducing the porosity of the ultra-thin wearing course to below 6%. This prevents rainwater residue inside the pavement, effectively improves water stability, and provides good durability. The optimal paving thickness can be reduced to 2cm, with a minimum thickness of 1.5cm, a reduction of over 25% compared to 2.5cm, effectively saving on project investment.

Description

Technical Field

[0001] This invention relates to the field of engineering materials for road traffic, specifically to an ultra-thin wear layer for roads and its construction method. Background Technology

[0002] Ultra-thin wearing courses are wear-resistant surface layers that combine asphalt mixtures with modified emulsified asphalt tack coats. They can address minor to moderate cracking, reduced skid resistance, and micro-rutting, restoring the surface function of old pavements. Compared to traditional asphalt pavement wearing courses, this technology can reduce the construction thickness to 15-25mm, significantly lowering construction costs while maintaining better pavement performance and extending pavement lifespan, resulting in significant socio-economic benefits and widespread popularity both domestically and internationally. The primary function of ultra-thin wearing courses is to restore the pavement's surface function, rather than emphasizing structural load-bearing capacity or extending the pavement structure's lifespan; they are mainly used in the maintenance of older roads. Compared to other preventative maintenance measures such as crack sealing, chip seal, fog seal, and slurry seal, ultra-thin wearing courses not only improve pavement smoothness and skid resistance, enhancing driving safety, but also reduce water damage through the application of a waterproof tack coat, delaying pavement strength degradation and further improving highway service levels. For preventative maintenance of high-grade highways, ultra-thin wearing courses are one of the most effective measures for improving pavement surface function and performance, offering greater efficiency and durability. As a surface functional layer, the ultra-thin wear layer is subject to long-term influence from vehicle loads and environmental factors such as atmosphere, rain and sunlight. Furthermore, the reduced structural thickness places higher demands on the performance of raw materials.

[0003] Currently, several issues remain to be addressed regarding ultrathin wear-resistant coatings. Proprietary technologies, such as Shell's NovaChip, require specialized materials and equipment, resulting in high costs, complex processes, and limited large-scale application. Abrasive-based coatings, on the other hand, suffer from issues such as a suspended structure, weak interlayer bonding, rapid deterioration of anti-slip properties, susceptibility to water damage and peeling, and poor durability. There is an urgent need to develop ultrathin wear-resistant coatings that offer high performance in anti-slip, water damage, and aging resistance, are cost-effective, have simple construction methods, do not rely on specialized equipment, and are easy to promote and apply. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide a road ultrathin wearing layer and its construction method that offers high performance in terms of anti-skid, anti-water damage, and anti-aging properties, low cost, simple construction method, no reliance on specialized equipment, and high promotional value.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: an ultra-thin road wear layer, comprising an emulsified asphalt layer laid from bottom to top on the road surface and an ultra-thin wear layer; the emulsified asphalt layer uses an emulsified asphalt mixture comprising, by weight percentage: modified glass fiber: 0.15%–0.18%, sodium alginate: 0.01%–0.03%, with the remainder being high-viscosity modified emulsified asphalt;

[0006] The ultra-thin wear layer mixture comprises, by weight percentage: filler: 0.6%–0.9%, SBS modified bitumen: 7%–11%, sodium alginate: 0.01%–0.03%, modified glass fiber: 0.30%–0.35%, with the remainder being aggregate;

[0007] The modified glass fiber is prepared by: 1) first passivating the short glass fiber with a strong acid, then immersing the passivated glass fiber in a dicarboxylic acid composed of lauric acid and acetic acid, taking it out, drying it, and obtaining dicarboxylic acid modified glass fiber; 2) weighing 16-20 parts of glass fiber with surface grafted cyclodextrin and 30-35 parts of dicarboxylic acid modified glass fiber according to the weight, mixing them evenly, and obtaining the modified glass fiber.

[0008] Furthermore, a road ultrathin wearing course is provided, the road ultrathin wearing course comprising an emulsified asphalt layer laid from bottom to top of the road surface and an ultrathin wearing course; the emulsified asphalt layer comprises, by weight percentage, modified glass fiber: 0.16% to 0.18%, sodium alginate: 0.02% to 0.03%, and the balance being high-viscosity modified emulsified asphalt;

[0009] The ultra-thin wear layer mixture comprises, by weight percentage: filler: 0.7%–0.9%, SBS modified bitumen: 8%–11%, sodium alginate: 0.02%–0.03%, modified glass fiber: 0.32%–0.35%, with the remainder being aggregate;

[0010] The modified glass fiber is prepared as follows: 1) First, passivate the chopped glass fiber with a strong acid, then impregnate the passivated glass fiber in a diacid composed of lauric acid and silicic acid, remove it, and dry it to obtain diacid-modified glass fiber; 2) Weigh 17-20 parts by weight of surface-grafted cyclodextrin glass fiber and 32-35 parts by weight of diacid-modified glass fiber, mix them evenly, and obtain the modified glass fiber. Further, the filler is limestone powder.

[0011] Furthermore, the aggregate is one or more of granite, diabase, and basalt.

[0012] Furthermore, the aggregate gradation satisfies the following: particles with a size <12.6mm account for 100%, particles with a size <9.0mm account for 90-100%, and particles with a size <5.2mm account for 75-100%.

[0013] Further, the preparation method of the modified glass fiber is as follows: 1) First, passivate the short glass fiber with 3-5 mol / L hydrochloric acid, then soak the passivated glass fiber in a diacid composed of lauric acid and acetic acid, take it out, and dry it to obtain diacid-modified glass fiber; the diacid is ethanol as solvent, the content of lauric acid is 0.13-0.15 g / ml, and the content of acetic acid is 0.3-0.5 g / ml; 2) Weigh 16-20 parts of glass fiber with surface grafted cyclodextrin and 30-35 parts of diacid-modified glass fiber according to the weight parts, mix them evenly, and obtain the modified glass fiber.

[0014] Furthermore, 0.12 to 0.15% of graphite fiber is added to the ultrathin wear layer mixture.

[0015] This invention also provides a method for constructing an ultra-thin wear layer for roads, comprising the following steps:

[0016] (1) After treating the road surface defects, the road surface is milled and then the road surface is maintained.

[0017] (2) The emulsified asphalt layer is evenly sprayed onto the road surface to be maintained in step (1) using the emulsified asphalt layer mixture;

[0018] (3) While spraying the emulsified asphalt layer mixture for the emulsified asphalt layer, the ultra-thin wear layer mixture for the ultra-thin wear layer is also laid.

[0019] (4) Use an 11-13t double drum roller to statically compact the road 2-3 times;

[0020] (5) After the compaction operation is completed, the road surface temperature is below 50°C and the road is opened to traffic.

[0021] Furthermore, in step (2), the spraying amount of the emulsified asphalt layer mixture for the emulsified asphalt layer is 0.6 to 0.8 kg / m².

[0022] Furthermore, in step (3), the amount of emulsified asphalt mixture used in the emulsified asphalt layer is controlled according to the thickness of the ultra-thin wear layer of the road, and the thickness of the ultra-thin wear layer of the road is controlled between 1.5 and 2.0 cm.

[0023] This invention discloses an ultra-thin road wearing course and its construction method. By utilizing a high aggregate content to provide micro-texture and coarse aggregate gradation to provide macro-structure, it ensures excellent short-term and long-term skid resistance. Modified glass fiber is added to both the emulsified asphalt layer and the ultra-thin wearing course mixture, strengthening the bond between them while reducing the porosity of the ultra-thin wearing course to below 6%. This prevents rainwater retention inside the road surface, effectively improves water stability, and provides excellent durability. It solves the problem of previous technologies relying excessively on special materials and equipment to prepare ultra-thin wearing courses due to excessive porosity, significantly reducing costs and facilitating widespread adoption. Widely applicable; the optimal paving thickness can be reduced to 2cm, with an extreme thinnest reaching 1.5cm, a reduction of over 25% compared to 2.5cm, effectively saving on engineering investment; in the preparation of dicarboxylic acid modified glass fibers, passivation with a strong acid is performed first, followed by impregnation with a dicarboxylic acid composed of lauric acid and acetic acid, which maximizes the exposure of hydroxyl groups on the glass fiber surface. The modified glass fibers also contain surface-grafted cyclodextrin, possessing the adsorption properties of cyclodextrin. Under the action of these two phases, the connection between the emulsified asphalt layer and the ultra-thin wearing layer is further strengthened, causing the porosity of the ultra-thin wearing layer to decrease by approximately 0.5%, and enhancing the dispersion performance of the modified glass fibers. This process prevents modified glass fibers from clumping or forming balls, improving the overall stability of the ultra-thin road wear layer. It also results in slow decline in anti-skid performance, reduced water damage and peeling, and high durability. Sodium alginate is added as a dispersant and stabilizer for the modified glass fibers. Sodium alginate is a water-soluble polymer with significant dispersing ability and stable viscosity, further enhancing the dispersion performance of the modified glass fibers. This prevents clumping and forming balls, improving the overall stability of the ultra-thin road wear layer, slow decline in anti-skid performance, reduced water damage and peeling, and high durability. It also effectively improves the interlayer bonding between the ultra-thin road wear layer and the existing road surface, preventing the ultra-thin road wear layer from... The existing pavement has suffered from defects such as peeling, particle loss, and detachment. The ultra-thin wear-resistant layer of this invention improves the overall durability of the pavement structure. By using a dense ultra-thin wear-resistant layer, it has excellent anti-skid and anti-water damage properties, effectively reducing the pumping effect of traffic loads in rainy weather and greatly improving water stability. This results in excellent durability of the entire pavement structure, extending its service life by more than double compared to existing technologies. Specifically, the service life of sand-type pavement is 2 years, and that of NovaChip is 4 years. The ultra-thin wear-resistant layer of this invention was applied to the Nanyou Expressway in 2017 and has been in use for 5 years. Currently, its road condition score is around 94 points, and it is expected to continue to be used for another 3-4 years.

[0024] This invention discloses an ultra-thin wear-resistant layer for roads and its construction method. The ultra-thin wear-resistant layer mixture also incorporates an appropriate amount of graphite fiber. The graphite fiber is a fiber with a layered hexagonal lattice graphite structure, whose molecular structure is graphitized and whose carbon content is higher than 99%. It possesses fiber characteristics, as well as high mechanical strength and corrosion resistance. It can strengthen the tight connection between the emulsified asphalt layer and the ultra-thin wear-resistant layer, while also improving the corrosion resistance of the ultra-thin wear-resistant layer to acids, alkalis, and salts, thereby enhancing the durability of the ultra-thin wear-resistant layer.

[0025] Instruction manual illustrations

[0026] Figure 1 Schematic diagram of the modified glass fiber preparation process

[0027] Figure 2 Schematic diagram of the preparation process of emulsified asphalt mixture for emulsified asphalt layers

[0028] Figure 3 Schematic diagram of the preparation process of asphalt mixture for ultra-thin wearing course

[0029] Figure 4 This is a schematic diagram of the construction process for an ultra-thin wear layer.

[0030] Figure 5(a) shows the original road surface condition in Example 1;

[0031] Figure 5(b) shows the milling process of the original road surface in Example 1;

[0032] Figure 5(c) shows the road surface cleaning process after milling in Example 1;

[0033] Figure 5(d) shows the final milling effect in Example 1;

[0034] Figure 6(a) shows the effect of spreading emulsified asphalt mixture in Example 1;

[0035] Figure 6(b) shows the paving effect of the asphalt mixture for the ultra-thin wear layer in Example 1;

[0036] Figure 7 This is a diagram showing the effect of rolling and forming the ultra-thin wear layer in Example 1. Detailed Implementation

[0037] The following embodiments can help those skilled in the art to more fully understand the present invention, but should not be construed as limiting the present invention in any way.

[0038] This invention relates to an ultra-thin wear layer for roads and its construction method. The high-viscosity modified emulsified asphalt refers to modified emulsified asphalt with a dynamic viscosity of 60,000 Pa·s or higher at 60°C. In the following examples, Guochuang high-viscosity modified asphalt with a dynamic viscosity of 66,000 Pa·s at 60°C is selected.

[0039] This invention relates to an ultra-thin wear layer for roads and its construction method. In the following embodiments, the chopped glass fibers are alkali-free chopped glass fibers with a diameter of 10-15 μm and a fiber length of 1-10 mm.

[0040] This invention discloses an ultra-thin road wear layer and its construction method. The results of comparing this ultra-thin road wear layer with the NovaChip ultra-thin wear layer are shown in Table 1 below.

[0041] Table 1 Comparative Analysis of Road Ultra-Thin Wear Coating and NovaChip Ultra-Thin Wear Coating

[0042]

[0043] This invention discloses an ultra-thin road wear layer and its construction method. The construction temperature control requirements are shown in Table 2 below:

[0044] Table 2 Temperature control requirements for the construction of a road ultra-thin wearing layer

[0045]

[0046]

[0047] This invention discloses an ultra-thin road wear layer and its construction method. The performance requirements of the filler are shown in Table 3 below:

[0048] Table 3 Packing Performance Requirements

[0049] Technical indicators Require Technical indicators Require Apparent relative density ≥2.50 Moisture content / % ≤1 Appearance No granules, no clumps hydrophilicity coefficient ＜1

[0050] The present invention discloses an ultra-thin wear-resistant layer for roads and its construction method, wherein the aggregate gradation satisfies the following: the proportion of particles with a particle size <12.6mm reaches 100%, the proportion of particles with a particle size <9.0mm is 90-100%, and the proportion of particles with a particle size <5.2mm is 75-100%.

[0051] Example 1: Construction method of ultra-thin road wearing course

[0052] An ultra-thin road wear layer, comprising an emulsified asphalt layer laid from bottom to top on the road surface and an ultra-thin wear layer; the emulsified asphalt layer comprises, by weight percentage, modified glass fiber: 0.15%, sodium alginate: 0.01%, and the balance being high-viscosity modified emulsified asphalt;

[0053] The ultra-thin wear layer mixture comprises, by weight percentage: filler: 0.6%, SBS modified bitumen: 7%, sodium alginate: 0.01%, modified glass fiber: 0.30%, graphite fiber: 0.12%, with the remainder being aggregate; the filler is limestone powder; the aggregate is granite.

[0054] The modified glass fiber is prepared as follows: 1) First, passivate the short glass fiber with 3 mol / L hydrochloric acid, then immerse the passivated glass fiber in a diacid composed of lauric acid and acetic acid, remove it, and dry it to obtain diacid-modified glass fiber; the diacid is ethanol as solvent, the content of lauric acid is 0.13 g / ml, and the content of acetic acid is 0.3 g / ml; 2) Weigh 16 parts of surface-grafted cyclodextrin glass fiber and 30 parts of diacid-modified glass fiber according to the weight, mix them evenly, and obtain the modified glass fiber.

[0055] A method for constructing an ultra-thin wear-resistant layer for roads includes the following steps:

[0056] (1) After treating the road surface defects, the road surface is milled and then the road surface is maintained.

[0057] (2) The emulsified asphalt layer is evenly sprayed onto the road surface to be maintained in step (1) using emulsified asphalt layer mixture, with a spraying amount of 0.6 kg / m².

[0058] (3) While spraying the emulsified asphalt layer mixture for the emulsified asphalt layer, the ultra-thin wear layer mixture for the ultra-thin wear layer is laid; the amount of emulsified asphalt layer mixture for the emulsified asphalt layer is controlled according to the thickness of the ultra-thin wear layer of the road, and the thickness of the ultra-thin wear layer of the road is controlled at 1.5 cm.

[0059] (4) Use an 11t double-drum roller to perform static compaction twice;

[0060] (5) After the compaction operation is completed, the road surface temperature is below 50°C and the road is opened to traffic.

[0061] Example 2: Construction method of ultra-thin road wearing course

[0062] An ultra-thin road wear course, comprising an emulsified asphalt layer laid from bottom to top on the road surface and an ultra-thin wear course; the emulsified asphalt layer comprises, by weight percentage, modified glass fiber: 0.18%, sodium alginate: 0.03%, with the remainder being high-viscosity modified emulsified asphalt;

[0063] The ultra-thin wear layer mixture comprises, by weight percentage: filler: 0.9%, SBS modified bitumen: 11%, sodium alginate: 0.03%, modified glass fiber: 0.35%, graphite fiber: 0.15%, with the remainder being aggregate; the filler is limestone powder; the aggregate is diabase.

[0064] The modified glass fiber is prepared as follows: 1) First, passivate the short glass fiber with 5 mol / L hydrochloric acid, then immerse the passivated glass fiber in a diacid composed of lauric acid and acetic acid, remove it, and dry it to obtain diacid-modified glass fiber; the diacid is ethanol as solvent, the content of lauric acid is 0.15 g / ml, and the content of acetic acid is 0.5 g / ml; 2) Weigh 20 parts of glass fiber with surface grafted cyclodextrin and 35 parts of diacid-modified glass fiber according to the weight, mix them evenly, and obtain the modified glass fiber.

[0065] A method for constructing an ultra-thin wear-resistant layer for roads includes the following steps:

[0066] (1) After treating the road surface defects, the road surface is milled and then the road surface is maintained.

[0067] (2) The emulsified asphalt layer is evenly sprayed onto the road surface to be maintained in step (1) using emulsified asphalt layer mixture, with a spraying amount of 0.8 kg / m².

[0068] (3) While spraying the emulsified asphalt layer mixture for the emulsified asphalt layer, the ultra-thin wear layer mixture for the ultra-thin wear layer is laid; the amount of emulsified asphalt layer mixture for the emulsified asphalt layer is controlled according to the thickness of the ultra-thin wear layer of the road, and the thickness of the ultra-thin wear layer of the road is controlled at 2.0 cm.

[0069] (4) Use a 13t double drum roller to perform static compaction 3 times;

[0070] (5) After the compaction operation is completed, the road surface temperature is below 50°C and the road is opened to traffic.

[0071] Example 3: Construction method of ultra-thin road wearing course

[0072] An ultra-thin road wear course, comprising an emulsified asphalt layer laid from bottom to top on the road surface and an ultra-thin wear course; the emulsified asphalt layer comprises, by weight percentage, modified glass fiber: 0.16%, sodium alginate: 0.02%, and the balance being high-viscosity modified emulsified asphalt;

[0073] The ultra-thin wear layer mixture comprises, by weight percentage: filler: 0.7%, SBS modified bitumen: 8%, sodium alginate: 0.02%, modified glass fiber: 0.32%, graphite fiber: 0.13%, with the remainder being aggregate; the filler is limestone powder; the aggregate is basalt.

[0074] The modified glass fiber is prepared as follows: 1) First, passivate the short glass fiber with 4 mol / L hydrochloric acid, then immerse the passivated glass fiber in a diacid composed of lauric acid and acetic acid, remove it, and dry it to obtain diacid-modified glass fiber; the diacid is ethanol as solvent, the content of lauric acid is 0.14 g / ml, and the content of acetic acid is 0.4 g / ml; 2) Weigh 17 parts of glass fiber with surface grafted cyclodextrin and 32 parts of diacid-modified glass fiber according to the weight, mix them evenly, and obtain the modified glass fiber.

[0075] A method for constructing an ultra-thin wear-resistant layer for roads includes the following steps:

[0076] (1) After treating the road surface defects, the road surface is milled and then the road surface is maintained.

[0077] (2) The emulsified asphalt layer is evenly sprayed onto the road surface to be maintained in step (1) using emulsified asphalt layer mixture, with a spraying amount of 0.7 kg / m².

[0078] (3) While spraying the emulsified asphalt layer mixture for the emulsified asphalt layer, the ultra-thin wear layer mixture for the ultra-thin wear layer is laid; the amount of emulsified asphalt layer mixture for the emulsified asphalt layer is controlled according to the thickness of the ultra-thin wear layer of the road, and the thickness of the ultra-thin wear layer of the road is controlled at 1.8 cm.

[0079] (4) Use a 12t double-drum roller to perform static compaction 3 times;

[0080] (5) After the compaction operation is completed, the road surface temperature is below 50°C and the road is opened to traffic.

[0081] Example 4: Construction method of ultra-thin road wearing course

[0082] An ultra-thin road wear course, comprising an emulsified asphalt layer laid from bottom to top on the road surface and an ultra-thin wear course; the emulsified asphalt layer comprises, by weight percentage, modified glass fiber: 0.16%, sodium alginate: 0.02%, and the balance being high-viscosity modified emulsified asphalt;

[0083] The ultra-thin wear layer mixture comprises, by weight percentage: filler: 0.7%, SBS modified bitumen: 8%, sodium alginate: 0.02%, modified glass fiber: 0.32%, with the remainder being aggregate; the filler is limestone powder; the aggregate is basalt.

[0084] The modified glass fiber is prepared as follows: 1) First, passivate the short glass fiber with 4 mol / L hydrochloric acid, then immerse the passivated glass fiber in a diacid composed of lauric acid and acetic acid, remove it, and dry it to obtain diacid-modified glass fiber; the diacid is ethanol as solvent, the content of lauric acid is 0.14 g / ml, and the content of acetic acid is 0.4 g / ml; 2) Weigh 17 parts of glass fiber with surface grafted cyclodextrin and 32 parts of diacid-modified glass fiber according to the weight, mix them evenly, and obtain the modified glass fiber.

[0085] A method for constructing an ultra-thin wear-resistant layer for roads includes the following steps:

[0086] (1) After treating the road surface defects, the road surface is milled and then the road surface is maintained.

[0087] (2) The emulsified asphalt layer is evenly sprayed onto the road surface to be maintained in step (1) using emulsified asphalt layer mixture, with a spraying amount of 0.7 kg / m².

[0088] (3) While spraying the emulsified asphalt layer mixture for the emulsified asphalt layer, the ultra-thin wear layer mixture for the ultra-thin wear layer is laid; the amount of emulsified asphalt layer mixture for the emulsified asphalt layer is controlled according to the thickness of the ultra-thin wear layer of the road, and the thickness of the ultra-thin wear layer of the road is controlled at 1.8 cm.

[0089] (4) Use a 12t double-drum roller to perform static compaction 3 times;

[0090] (5) After the compaction operation is completed, the road surface temperature is below 50°C and the road is opened to traffic.

[0091] Comparative Example 1: Construction Method of Ultra-thin Wearing Layer for Roads

[0092] An ultra-thin road wear course, comprising an emulsified asphalt layer laid from bottom to top on the road surface and an ultra-thin wear course; the emulsified asphalt layer comprises, by weight percentage, modified glass fiber: 0.16%, with the remainder being high-viscosity modified emulsified asphalt;

[0093] The ultra-thin wear layer mixture comprises, by weight percentage: filler: 0.7%, SBS modified bitumen: 8%, modified glass fiber: 0.32%, graphite fiber: 0.13%, with the remainder being aggregate; the filler is limestone powder; the aggregate is basalt.

[0094] The modified glass fiber is prepared as follows: 1) First, passivate the short glass fiber with 4 mol / L hydrochloric acid, then immerse the passivated glass fiber in a diacid composed of lauric acid and acetic acid, remove it, and dry it to obtain diacid-modified glass fiber; the diacid is ethanol as solvent, the content of lauric acid is 0.14 g / ml, and the content of acetic acid is 0.4 g / ml; 2) Weigh 17 parts of glass fiber with surface grafted cyclodextrin and 32 parts of diacid-modified glass fiber according to the weight, mix them evenly, and obtain the modified glass fiber.

[0095] A method for constructing an ultra-thin wear-resistant layer for roads includes the following steps:

[0096] (1) After treating the road surface defects, the road surface is milled and then the road surface is maintained.

[0097] (2) The emulsified asphalt layer is evenly sprayed onto the road surface to be maintained in step (1) using emulsified asphalt layer mixture, with a spraying amount of 0.7 kg / m².

[0098] (3) While spraying the emulsified asphalt layer mixture for the emulsified asphalt layer, the ultra-thin wear layer mixture for the ultra-thin wear layer is laid; the amount of emulsified asphalt layer mixture for the emulsified asphalt layer is controlled according to the thickness of the ultra-thin wear layer of the road, and the thickness of the ultra-thin wear layer of the road is controlled at 1.8 cm.

[0099] (4) Use a 12t double-drum roller to perform static compaction 3 times;

[0100] (5) After the compaction operation is completed, the road surface temperature is below 50°C and the road is opened to traffic.

[0101] Comparative Example 2: Construction Method of Ultra-thin Wearing Layer for Roads

[0102] An ultra-thin road wear course, comprising an emulsified asphalt layer laid from bottom to top on the road surface and an ultra-thin wear course; the emulsified asphalt layer comprises, by weight percentage, modified glass fiber: 0.16%, sodium alginate: 0.02%, and the balance being high-viscosity modified emulsified asphalt;

[0103] The ultra-thin wear layer mixture comprises, by weight percentage: filler: 0.7%, SBS modified bitumen: 8%, sodium alginate: 0.02%, modified glass fiber: 0.32%, graphite fiber: 0.13%, with the remainder being aggregate; the filler is limestone powder; the aggregate is basalt.

[0104] The modified glass fiber is prepared by first passivating the short glass fiber with 4 mol / L hydrochloric acid, then immersing the passivated glass fiber in a dicarboxylic acid composed of lauric acid and acetic acid, removing it, and drying it to obtain the modified glass fiber; the dicarboxylic acid is ethanol as solvent, the content of lauric acid is 0.14 g / ml, and the content of acetic acid is 0.4 g / ml.

[0105] A method for constructing an ultra-thin wear-resistant layer for roads includes the following steps:

[0106] (1) After treating the road surface defects, the road surface is milled and then the road surface is maintained.

[0107] (2) The emulsified asphalt layer is evenly sprayed onto the road surface to be maintained in step (1) using emulsified asphalt layer mixture, with a spraying amount of 0.7 kg / m².

[0108] (3) While spraying the emulsified asphalt layer mixture for the emulsified asphalt layer, the ultra-thin wear layer mixture for the ultra-thin wear layer is laid; the amount of emulsified asphalt layer mixture for the emulsified asphalt layer is controlled according to the thickness of the ultra-thin wear layer of the road, and the thickness of the ultra-thin wear layer of the road is controlled at 1.8 cm.

[0109] (4) Use a 12t double-drum roller to perform static compaction 3 times;

[0110] (5) After the compaction operation is completed, the road surface temperature is below 50°C and the road is opened to traffic.

[0111] Comparative Example 3: Construction Method of Ultra-thin Wearing Layer for Roads

[0112] An ultra-thin road wear course, comprising an emulsified asphalt layer laid from bottom to top on the road surface and an ultra-thin wear course; the emulsified asphalt layer comprises, by weight percentage, the emulsified asphalt mixture as follows: glass fiber with surface grafted cyclodextrin: 0.16%, sodium alginate: 0.02%, and the balance being high-viscosity modified emulsified asphalt;

[0113] The ultra-thin wear layer mixture comprises, by weight percentage: filler: 0.7%, SBS modified bitumen: 8%, sodium alginate: 0.02%, glass fiber with surface grafted cyclodextrin: 0.32%, graphite fiber: 0.13%, and the balance being aggregate; the filler is limestone powder; and the aggregate is basalt.

[0114] A method for constructing an ultra-thin wear-resistant layer for roads includes the following steps:

[0115] (1) After treating the road surface defects, the road surface is milled and then the road surface is maintained.

[0116] (2) The emulsified asphalt layer is evenly sprayed onto the road surface to be maintained in step (1) using emulsified asphalt layer mixture, with a spraying amount of 0.7 kg / m².

[0117] (3) While spraying the emulsified asphalt layer mixture for the emulsified asphalt layer, the ultra-thin wear layer mixture for the ultra-thin wear layer is laid; the amount of emulsified asphalt layer mixture for the emulsified asphalt layer is controlled according to the thickness of the ultra-thin wear layer of the road, and the thickness of the ultra-thin wear layer of the road is controlled at 1.8 cm.

[0118] (4) Use a 12t double-drum roller to perform static compaction 3 times;

[0119] (5) After the compaction operation is completed, the road surface temperature is below 50°C and the road is opened to traffic.

[0120] Comparative Example 4: Construction Method of Ultra-thin Wearing Layer for Roads

[0121] An ultra-thin road wear layer, comprising an emulsified asphalt layer laid from bottom to top on the road surface and an ultra-thin wear layer; the emulsified asphalt layer comprises, by weight percentage, the emulsified asphalt mixture as follows: glass fiber: 0.16%, sodium alginate: 0.02%, with the remainder being high-viscosity modified emulsified asphalt;

[0122] The ultra-thin wear layer mixture comprises, by weight percentage: filler: 0.7%, SBS modified bitumen: 8%, sodium alginate: 0.02%, glass fiber: 0.32%, graphite fiber: 0.13%, with the remainder being aggregate; the filler is limestone powder; the aggregate is basalt.

[0123] A method for constructing an ultra-thin wear-resistant layer for roads includes the following steps:

[0124] (1) After treating the road surface defects, the road surface is milled and then the road surface is maintained.

[0125] (2) The emulsified asphalt layer is evenly sprayed onto the road surface to be maintained in step (1) using emulsified asphalt layer mixture, with a spraying amount of 0.7 kg / m².

[0126] (3) While spraying the emulsified asphalt layer mixture for the emulsified asphalt layer, the ultra-thin wear layer mixture for the ultra-thin wear layer is laid; the amount of emulsified asphalt layer mixture for the emulsified asphalt layer is controlled according to the thickness of the ultra-thin wear layer of the road, and the thickness of the ultra-thin wear layer of the road is controlled at 1.8 cm.

[0127] (4) Use a 12t double-drum roller to perform static compaction 3 times;

[0128] (5) After the compaction operation is completed, the road surface temperature is below 50°C and the road is opened to traffic.

[0129] The test results of the ultrathin wear layers in Examples 1-4 and Comparative Examples 1-4 are shown in Table 4 below:

[0130] Table 4

[0131]

[0132] Comparing the corrosion resistance of the ultra-thin road wear layer to acids, alkalis, and salts in Examples 3 and 4, it can be seen that the addition of graphite fibers can effectively improve the corrosion resistance of the ultra-thin road wear layer to acids, alkalis, and salts. From the experimental results of Examples 1-4 and Comparative Examples 1-4, it can be seen that the ultra-thin road wear layer and its construction method of the present invention, by providing micro-texture through high aggregate content and providing macro-structure through coarse aggregate gradation, ensure good short-term and long-term skid resistance. Adding modified glass fibers to the emulsified asphalt layer and the ultra-thin wear layer mixture respectively strengthens the connection between the emulsified asphalt layer and the ultra-thin wear layer, while reducing the porosity of the ultra-thin road wear layer to below 6%, preventing rainwater residue inside the road surface and effectively improving water stability. It exhibits excellent durability, solving the problem of previous technologies that relied excessively on special materials and equipment to prepare ultra-thin wearing layers due to excessive porosity. This significantly reduces costs and facilitates widespread application. The optimal paving thickness can be reduced to 2cm, with a minimum thickness of 1.5cm, representing a reduction of over 25% compared to 2.5cm, effectively saving on project investment. In preparing the dicarboxylic acid modified glass fiber, it is first passivated with a strong acid, then impregnated with a dicarboxylic acid composed of lauric acid and acetic acid. This maximizes the exposure of the hydroxyl groups on the glass fiber surface. The modified glass fiber also contains surface-grafted cyclodextrin, which possesses the adsorption properties of cyclodextrin. Under the action of these two phases, the connection between the emulsified asphalt layer and the ultra-thin wearing layer is further strengthened, causing the porosity of the ultra-thin road wearing layer to continue to decrease.Approximately 5% of the modified glass fiber is added, which enhances its dispersion performance, prevents clumping and spheroidization, improves the overall stability of the ultra-thin wear layer, slows down skid resistance, reduces water damage and peeling, and enhances durability. Sodium alginate is also added as a dispersant and stabilizer for the modified glass fiber. Sodium alginate is a water-soluble polymer with significant dispersing ability and stable viscosity, further enhancing the dispersion performance of the modified glass fiber, preventing clumping and spheroidization, improving the overall stability of the ultra-thin wear layer, slowing down skid resistance, reducing water damage and peeling, enhancing durability, and effectively improving the interlayer bonding between the ultra-thin wear layer and the old road, preventing peeling, particle shedding, and detachment. This invention's ultra-thin wear layer improves the overall durability of the pavement structure. By using a dense ultra-thin wear layer, it exhibits excellent skid resistance and anti-skid properties. The water loss performance effectively reduces the pumping effect of traffic loads in rainy weather, greatly improving water stability and giving the entire paving structure excellent durability, extending its service life by more than double compared to existing technologies. Specifically, the service life of sand-type paving is 2 years, and that of NovaChip is 4 years. This invention's ultra-thin wear-resistant layer was applied to the Nanyou Expressway in 2017 and has been in use for 5 years, currently scoring around 94 points in road condition, and is expected to continue to be used for another 3-4 years. The ultra-thin wear-resistant layer mixture also incorporates an appropriate amount of graphite fiber. Graphite fiber is a layered hexagonal lattice graphite structure with a graphitized molecular structure and a carbon content higher than 99%. It possesses fiber characteristics, high mechanical strength, and corrosion resistance, strengthening the bond between the emulsified asphalt layer and the ultra-thin wear-resistant layer while also improving the ultra-thin wear-resistant layer's resistance to acid, alkali, and salt corrosion, thus enhancing its durability.

[0133] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A road ultra-thin wear layer, characterized in that: The ultra-thin wear layer of the road includes an emulsified asphalt layer and an ultra-thin wear layer laid from bottom to top of the road surface; the emulsified asphalt layer uses emulsified asphalt mixture by weight percentage, including: modified glass fiber: 0.15% to 0.18%, sodium alginate: 0.01% to 0.03%, and the balance is high viscosity modified emulsified asphalt; The ultra-thin wear layer mixture comprises, by weight percentage: filler: 0.6%–0.9%, SBS modified bitumen: 7%–11%, sodium alginate: 0.01%–0.03%, modified glass fiber: 0.30%–0.35%, with the remainder being aggregate; The modified glass fiber is prepared by: 1) first passivating the short glass fiber with a strong acid, then immersing the passivated glass fiber in a dicarboxylic acid composed of lauric acid and acetic acid, taking it out, drying it, and obtaining dicarboxylic acid modified glass fiber; 2) weighing 16-20 parts of glass fiber with surface grafted cyclodextrin and 30-35 parts of dicarboxylic acid modified glass fiber according to the weight, mixing them evenly, and obtaining the modified glass fiber.

2. The ultra-thin wear layer for roads according to claim 1, characterized in that: The ultra-thin wear-resistant layer of the road includes an emulsified asphalt layer and an ultra-thin wear-resistant layer laid from bottom to top of the road surface; the emulsified asphalt layer uses emulsified asphalt mixture by weight percentage, including: modified glass fiber: 0.16% to 0.18%, sodium alginate: 0.02% to 0.03%, and the balance is high-viscosity modified emulsified asphalt; The ultra-thin wear layer mixture comprises, by weight percentage: filler: 0.7%–0.9%, SBS modified bitumen: 8%–11%, sodium alginate: 0.02%–0.03%, modified glass fiber: 0.32%–0.35%, with the remainder being aggregate; The modified glass fiber is prepared by: 1) first passivating the short glass fiber with a strong acid, then immersing the passivated glass fiber in a dicarboxylic acid composed of lauric acid and silicic acid, taking it out, drying it, and obtaining dicarboxylic acid modified glass fiber; 2) weighing 17-20 parts of glass fiber with surface grafted cyclodextrin and 32-35 parts of dicarboxylic acid modified glass fiber according to the weight, mixing them evenly, and obtaining the modified glass fiber.

3. The ultra-thin wear layer for roads according to claim 1, characterized in that: The filler is limestone ore powder.

4. The ultra-thin wear layer for roads according to claim 1, characterized in that: The aggregate is one or more of granite, diabase, and basalt.

5. The ultra-thin wear layer for roads according to claim 1, characterized in that: The aggregate gradation satisfies the following: particles with a size <12.6mm account for 100%, particles with a size <9.0mm account for 90-100%, and particles with a size <5.2mm account for 75-100%.

6. The ultra-thin wear layer for roads according to claim 1, characterized in that: The modified glass fiber is prepared as follows: 1) First, passivate the short glass fiber with 3-5 mol / L hydrochloric acid, then immerse the passivated glass fiber in a diacid composed of lauric acid and acetic acid, remove it, and dry it to obtain diacid-modified glass fiber; the diacid is ethanol as solvent, the content of lauric acid is 0.13-0.15 g / ml, and the content of acetic acid is 0.3-0.5 g / ml; 2) Weigh 16-20 parts of surface-grafted cyclodextrin glass fiber and 30-35 parts of diacid-modified glass fiber according to the weight parts, mix them evenly, and obtain the modified glass fiber.

7. The ultra-thin wear layer for roads according to claim 1, characterized in that: The ultrathin wear layer mixture also contains 0.12-0.15% graphite fiber.

8. A construction method for an ultra-thin wear-resistant layer for roads according to any one of claims 1-7, characterized in that: Includes the following steps: (1) After treating the road surface defects, the road surface is milled and then the road surface is maintained. (2) The emulsified asphalt layer is evenly sprayed onto the road surface to be maintained in step (1) using the emulsified asphalt layer mixture; (3) While spraying the emulsified asphalt layer mixture for the emulsified asphalt layer, the ultra-thin wear layer mixture for the ultra-thin wear layer is also laid. (4) Use an 11-13t double-drum roller to perform static compaction 2-3 times; (5) After the compaction operation is completed, the road surface temperature is below 50°C and the road is opened to traffic.

9. The construction method of an ultra-thin wear layer for roads according to claim 8, characterized in that: The spraying amount of the emulsified asphalt mixture used in step (2) is 0.6 to 0.8 kg / m².

10. The construction method of an ultra-thin wear layer for roads according to claim 8, characterized in that: In step (3), the amount of emulsified asphalt mixture used in the emulsified asphalt layer is controlled according to the thickness of the ultra-thin wear layer of the road, and the thickness of the ultra-thin wear layer of the road is controlled between 1.5 and 2.0 cm.

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