Method for sanding asphalt pavement and newly laid asphalt pavement

Abstract

The application discloses a kind of ground glass asphalt pavement and the ground glass construction method of newly built asphalt pavement, the ground glass asphalt pavement is sequentially arranged from top to bottom surface layer ground glass layer, rich oil asphalt upper layer, asphalt middle layer, asphalt lower layer and base, surface layer ground glass layer is built by ground glass material, part of ground glass material is embedded in the asphalt mortar of rich oil asphalt upper layer, and the remaining part is exposed outside.The ground glass construction method includes the following steps: selecting the particle size and spreading amount of ground glass material;According to the set process, the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of the first pass of

Description

Technical Field

[0001] This invention belongs to the field of road engineering technology, specifically relating to a sanded asphalt pavement and a sanding construction method for newly paved asphalt pavements. Background Technology

[0002] Over the entire lifespan of asphalt pavement, the changes in skid resistance can be divided into three stages: a brief improvement stage, a rapid decline stage, and a gradual plateauing stage. During the brief improvement stage, the surface asphalt of the pavement is gradually worn away, exposing the microstructure of the aggregate, thus improving the pavement's skid resistance. Therefore, the initial skid resistance of asphalt pavements in the early stages of traffic requires attention, as it does not yet reach its maximum value. This is especially true for rich asphalt pavements, where excess surface asphalt covers the microstructure, leading to insufficient early skid resistance, and even situations where the initial skid resistance fails to meet acceptance requirements. This is particularly pronounced in pavements with thicker asphalt films, such as drainage asphalt pavements and SMA pavements. In the early stages of traffic, in addition to the initial insufficient anti-skid due to the micro-texture of the road surface covered by the asphalt film, there may also be a rapid decline in anti-skid due to the "oil drift" phenomenon. That is, in the summer high-temperature season, the asphalt becomes more fluid due to the high temperature. The asphalt film exists between the road surface and the vehicle tires and plays a lubricating role. When the thickness of the asphalt film reaches a certain value, the tires will lose contact with the road surface when the vehicle is traveling at high speed. At this time, the vehicle will lose control and is very likely to cause traffic accidents.

[0003] my country pays little attention to the skid resistance of asphalt pavements in the early stages of operation, and corresponding improvement measures are almost non-existent. However, the skid resistance of asphalt pavements in the early stages of operation is a real problem. In some projects in my country, there have even been cases where the skid resistance did not meet the specifications during the final acceptance inspection. This is related to the rapid decline in the skid resistance of the surface layer of asphalt pavement.

[0004] Currently, improvements to the skid resistance of asphalt pavements in my country are primarily reactive. When road condition inspections reveal insufficient skid resistance, preventative maintenance measures such as thin overlays and fog seals are used to enhance skid resistance and improve driving safety. However, this reactive approach ignores the impact of early road opening on skid resistance. Furthermore, preventative maintenance technologies are designed for a 2-5 year lifespan, and the actual lifespan of the road may be even shorter, requiring multiple maintenance cycles throughout the road's lifespan and causing significant traffic disruption.

[0005] Therefore, in response to the aforementioned impact of asphalt on the anti-skid performance of road surfaces in the early stages of road opening, namely, the fact that asphalt covers the micro-texture of the road surface, resulting in the initial anti-skid not reaching the maximum anti-skid value of the asphalt pavement, or even the initial anti-skid not meeting the acceptance requirements for anti-skid performance, there is an urgent need to develop a sanding asphalt pavement and a sanding construction method for newly paved asphalt pavements.

[0006] The invention patent application CN105421184A discloses a method for fine surface treatment of sand-containing asphalt pavement. The method involves mixing the components of an epoxy asphalt binder according to requirements, adding a certain proportion of fine sand, mixing thoroughly, and then spraying the mixture evenly onto the asphalt pavement under pressure while continuously stirring to form a waterproof and anti-skid protective layer. This technical solution is suitable for repairing existing asphalt pavements (i.e., old asphalt pavements) to improve their anti-skid performance, but not for improving the anti-skid performance of roads in the early stages of operation. Summary of the Invention

[0007] To address the problems existing in the prior art, the present invention provides a frosted asphalt pavement comprising a five-layer structure, from top to bottom: a surface frosted layer, an oil-rich asphalt top layer, an asphalt intermediate layer, an asphalt bottom layer, and a base layer; the surface frosted layer is constructed from frosted material, the oil-rich asphalt top layer is constructed from asphalt mixture, and the aggregates in the asphalt mixture are coated with asphalt mortar; a portion of the frosted material is embedded in the asphalt mortar, and the remaining portion of the frosted material is exposed to form the surface frosted layer.

[0008] Preferably, the thickness of the surface abrasive layer is 0.1-1 mm, and the depth to which the abrasive material is embedded in the asphalt mortar is 0.6-0.8 times the particle size of the abrasive material; the abrasive material includes any one or more of corundum, quartz sand, manufactured sand, slag and steel slag.

[0009] In any of the above schemes, it is preferred that the thickness of the oil-rich asphalt surface layer is 3-5 cm; for open-graded PAC type asphalt mixtures, the asphalt-aggregate ratio is not less than 5.1%; for dense-graded AC type asphalt mixtures, the asphalt-aggregate ratio is not less than 5.1%; and for dense-graded SMA type asphalt mixtures, the asphalt-aggregate ratio is not less than 6.2%.

[0010] In any of the above embodiments, preferably, the particle size of the abrasive material is related to the thickness of the asphalt mortar. If the thickness of the asphalt mortar is < 0.375 mm, the particle size of the abrasive material is 0.3 mm or no abrasion is performed; if 0.375 mm ≤ the thickness of the asphalt mortar < 0.5 mm, the particle size of the abrasive material is 0.3 mm; if 0.5 mm ≤ the thickness of the asphalt mortar < 0.75 mm, the particle size of the abrasive material is a combination of 0.3 mm and 0.6 mm, and the mass ratio of the two is 1:2; if 0... If the thickness of the asphalt mortar is 75mm or less and less than 1.0mm, the particle size of the abrasive material should be 0.6mm. If the thickness of the asphalt mortar is 1.0mm or less and less than 1.475mm, the particle size of the abrasive material should be a combination of 0.6mm and 1.18mm, with a mass ratio of 1:2. If the thickness of the asphalt mortar is 1.475mm or less and less than 1.97mm, the particle size of the abrasive material should be 1.18mm. If the thickness of the asphalt mortar is ≥1.97mm, the particle size of the abrasive material should be 1.18mm or no abrasive should be applied.

[0011] In any of the above solutions, it is preferred that the particle size of the abrasive material is in the range of 0.3mm, 0.6mm and 1.18mm, that is, 0.3mm≤particle size<0.6mm, 0.6mm≤particle size<1.18mm, and 1.18mm≤particle size<2.36mm.

[0012] The present invention also provides a method for constructing a new asphalt pavement with a fine-textured finish, for laying any of the aforementioned fine-textured asphalt pavements, comprising the following steps in sequence:

[0013] Step 1: Select the particle size of the abrasive material according to the thickness of the asphalt mortar, and determine the amount of abrasive material to be applied based on laser texture scanning test and accelerated abrasion test;

[0014] Step 2: Use a paver to spread the oil-rich asphalt mixture on top of the asphalt intermediate layer to form the oil-rich asphalt surface layer;

[0015] Step 3: Install the automatic sandblasting machine on the front wheel bumper of the first steel-drum roller in the compaction unit responsible for initial compaction. Start the steel-drum roller and open the valve of the automatic sandblasting machine. The abrasive material is spread in the form of a material curtain above the rich asphalt surface layer. According to the set process, the abrasive material and the rich asphalt surface layer are simultaneously compacted in the first pass of initial compaction. During the first pass of compaction, the abrasive material is evenly spread above the newly laid rich asphalt surface layer. After the abrasive material is spread, the steel-drum roller immediately compacts it, causing part of the abrasive material to embed into the asphalt mortar of the rich asphalt surface layer, while the remaining part is exposed. During the retraction of the steel-drum roller after the first pass of compaction and during subsequent compaction processes, no more abrasive material is spread.

[0016] Step 4: Start the steel wheel roller and compact the abrasive material and the oil-rich asphalt surface layer simultaneously with the remaining passes of the initial compaction according to the set process to complete the paving of the abrasive asphalt pavement.

[0017] Step 5: Perform secondary and final compaction on the abrasive material and the oil-rich asphalt surface layer simultaneously according to the set process to ensure that the compaction degree of the oil-rich asphalt surface layer meets the design requirements.

[0018] Preferably, in step one, the particle size of the abrasive material is selected based on the thickness of the asphalt mortar, and the formula for calculating the thickness of the asphalt mortar is as follows: In the formula: H AM —Thickness of asphalt mortar, mm;

[0019] M – Asphalt usage, %;

[0020] ρ — density of asphalt, g / cm³ 3 ;

[0021] a, b, c, d, e, f, g, h — represent the percentage of aggregate mass passing through sieves with apertures of 19 mm, 4.75 mm, 2.36 mm, 1.18 mm, 0.6 mm, 0.3 mm, 0.15 mm, and 0.075 mm, respectively, in %.

[0022] In any of the above schemes, it is preferred that, in step one, the amount of abrasive material applied is determined based on laser texture scanning tests and accelerated abrasion tests, and the steps are included in sequence as follows:

[0023] Step (1): According to the design mix proportion of the rich oil asphalt surface layer asphalt mixture, five plate-shaped specimens are formed indoors. Then, the abrasive material is evenly spread on the surface of the five plate-shaped specimens according to the set spreading amount. Then, the five plate-shaped specimens are rolled and shaped using a molding machine. For the surface layer of open-graded asphalt mixture, the initial selection is 0.1 kg / m³. 2 0.25kg / m 2 0.4kg / m 2 0.55kg / m 2 and 0.8kg / m 2 For the top layer of dense-graded asphalt mixtures, the initial spreading rate is 1.0 kg / m³. 2 1.25kg / m 2 1.5kg / m 2 1.75kg / m 2 and 2.0kg / m 2 Five amounts of spreading;

[0024] Step (2): Use a laser texture analyzer to scan the surface texture of the plate-shaped specimen. After the texture elevation data is processed for bad pixels, tilt and offset errors, the texture elevation data with a wavelength greater than 0.5 mm is filtered out. The remaining data is used to calculate the micro-texture level between 0.06-0.5 mm. The amount of material to be spread corresponding to a micro-texture level of not less than 45 dB is taken as the minimum amount of abrasive material to be spread.

[0025] Step (3): Accelerated wear test was conducted on the five plate specimens respectively, and the relationship curve between the amount of abrasive and the wear value was plotted. The amount of abrasive material corresponding to the intersection of the starting tangent and the ending tangent in the relationship curve was taken as the maximum amount of abrasive material.

[0026] Step (4): When paving abrasive asphalt pavement, the amount of abrasive material to be spread can be selected between the minimum and maximum amount.

[0027] In any of the above schemes, preferably, in step two, when paving the rich oil asphalt surface layer, the paving temperature of the asphalt mixture is 155-190℃; in steps three and four, the spreading speed of the abrasive material is 2-4 km / h; in steps four and five, the abrasive material and the rich oil asphalt surface layer are simultaneously subjected to initial compaction, and the formula for calculating the number of compaction passes is as follows: In the formula,

[0028] N RC —The number of compaction passes for simultaneously initial compaction of the abrasive material and the oil-rich asphalt surface layer;

[0029] T RC — The compaction temperature at which the abrasive material and the rich oil asphalt surface layer are initially compacted simultaneously, i.e. the paving temperature of the rich oil asphalt surface layer asphalt mixture when the abrasive material is spread, ℃;

[0030] D RC —The ratio of the depth of the abrasive material embedded in the asphalt mortar to the particle size of the abrasive material, i.e., 0.6-0.8.

[0031] In this invention, the number of compaction passes for simultaneously initial compaction of the abrasive material and the oil-rich asphalt surface layer is related to the compaction temperature and compaction depth (i.e., the depth to which the abrasive material is embedded in the asphalt mortar). When calculating the number of compaction passes using the above formula, the calculation result is rounded up to the nearest integer. For example, if the calculation result is 2.1, it is rounded up to the nearest integer 3; if the calculation result is 3.3, it is rounded up to the nearest integer 4.

[0032] In this invention, the compaction depth is selected as follows: when the particle size of the abrasive material is 0.3mm, the depth of embedding of the abrasive material into the asphalt mortar is 0.6 times the particle size of the abrasive material; when the particle size of the abrasive material is a combination of 0.3mm and 0.6mm, 0.6mm, or 0.6mm and 1.18mm, the depth of embedding of the abrasive material into the asphalt mortar is 0.7 times the particle size of the abrasive material; when the particle size of the abrasive material is 1.18mm, the depth of embedding of the abrasive material into the asphalt mortar is 0.8 times the particle size of the abrasive material.

[0033] In any of the above schemes, it is preferred that in steps four and five, the initial compaction is carried out by static compaction, the weight of the steel wheel roller is 10-12t, the compaction speed is 2-4km / h, and all compaction passes are completed before the temperature of the asphalt mixture drops to 100℃.

[0034] In any of the above schemes, it is preferred that, in step six, the secondary compaction adopts a static compaction followed by a vibratory compaction method, with the steel wheel roller reciprocating 3-5 times at a compaction speed of 2-4 km / h and the steel wheel roller weighing 10-12t; the final compaction adopts a static compaction method, with the steel wheel roller reciprocating 1-2 times at a compaction speed of 2-4 km / h and the steel wheel roller weighing 10-12t.

[0035] In this invention, the particle size of the abrasive material is in the ranges of 0.3mm, 0.6mm, and 1.18mm, that is, 0.3mm ≤ particle size < 0.6mm, 0.6mm ≤ particle size < 1.18mm, and 1.18mm ≤ particle size < 2.36mm. For example, the particle size range of 0.6mm means that the abrasive material is obtained by passing it through a 1.18mm sieve and a 0.6mm sieve in sequence, resulting in an abrasive material with a particle size of 0.6mm ≤ particle size < 1.18mm.

[0036] The choice of abrasive material particle size is closely related to the thickness of the asphalt mortar. The embedding depth of the abrasive material in the asphalt mortar is 0.6-0.8 times the particle size of the abrasive material to ensure firm embedding and prevent large-scale detachment due to vehicle tire friction after traffic begins. However, it cannot be completely embedded in the asphalt mortar; if the abrasive material is not exposed, it will not achieve the effect of increasing micro-texture. Asphalt mortar is composed of asphalt, mineral powder, fine aggregates, and admixtures (such as fibers). The asphalt mortar coats the outer surface of the aggregates, rather than being distributed in the mixture as pure asphalt. In this invention, the thickness of the asphalt mortar is approximately 100 times the thickness of the asphalt film.

[0037] The pavers, steel wheel rollers, automatic sandblasting machines, laser texture analyzers, and other equipment used in this invention can be existing equipment, and there are no special requirements for the models; the laser texture scanning test and accelerated wear test can be carried out according to conventional operations; the thickness, materials, and construction of the asphalt intermediate layer, asphalt lower layer, and base course can adopt existing technologies.

[0038] The frosted asphalt pavement of this invention consists of a surface frosted layer, a rich asphalt top layer, an asphalt intermediate layer, an asphalt bottom layer, and a base layer. Compared to ordinary asphalt pavement, it includes a surface frosted layer. This surface frosted layer can consume excess asphalt while providing a rough surface, improving the anti-skid performance of the asphalt pavement in the initial stage of operation. This surface frosted layer is constructed simultaneously with the rich asphalt top layer; that is, after the rich asphalt top layer is newly laid, an automatic sandblasting machine is used to evenly spread the frosted material on the surface of the rich asphalt top layer, followed by compaction with a steel wheel roller, thus forming the frosted asphalt pavement. In other words, the frosted material is spread simultaneously with the rich asphalt top layer before the initial compaction. This invention solves the problem of insufficient early anti-skid performance in newly opened rich asphalt pavements due to excess asphalt covering the micro-texture of the pavement surface. This invention provides an effective technical solution to address the insufficient skid resistance of asphalt pavements in the early stages of road operation, addressing this issue during the construction phase. Specifically, it provides a method for applying a matte finish to newly paved asphalt pavements, specifying matting parameters including the matting material, particle size, and dosage, providing a reliable basis for those skilled in the art to select these parameters. This invention effectively ensures the skid resistance of asphalt pavements in the early stages of road operation and, from a skid resistance perspective, delays subsequent preventative maintenance, reducing the disruption of road maintenance to traffic, improving road safety, and reducing traffic accidents, thus demonstrating significant economic and social benefits.

[0039] The present invention provides a method for constructing a sanded asphalt pavement and a newly paved asphalt pavement, which has the following beneficial effects:

[0040] (1) The changes in the skid resistance of asphalt pavement after it is opened to traffic can be divided into three stages: The first stage is the early skid resistance improvement stage. In this stage, the asphalt mortar (or asphalt film) covers the micro-texture of the aggregate, so the skid resistance of the pavement is not fully utilized immediately after the road is opened to traffic. As the road is put into operation, the wear and tear of the asphalt mortar (or asphalt film) by vehicles exposes the micro-texture of the aggregate, thus improving the skid resistance to a certain extent. The second stage is the rapid decline stage of skid resistance. In this stage, the micro-texture of the aggregate is worn away by vehicle tires, and the texture decay leads to a rapid decrease in skid resistance. The third stage is the slow decline stage of skid resistance. In this stage, the micro-texture of the aggregate has been worn away, mainly resulting in the loss of macro-texture. It can be seen that in the first stage of the change in skid resistance, the asphalt mortar (or asphalt film) covers the micro-texture of the aggregate, so the skid resistance of the pavement is not fully utilized. This invention proposes to abrade the pavement by spreading abrasive material during the construction period, which effectively improves the skid resistance of the pavement in the early stage of road operation, thereby ensuring the safety of the road in the early stage of operation.

[0041] (2) In view of the problem that the excessive asphalt-aggregate ratio of oil-rich asphalt mixture further amplifies the effect of asphalt mortar (or asphalt film) on the micro-texture of aggregate, the present invention effectively supplements the micro-texture of the road surface in the early stage of traffic by spreading abrasive material on the road surface after the oil-rich asphalt mixture is laid, thus avoiding the problem of insufficient anti-skid performance in the early stage of traffic. At the same time, the abrasive material, particle size of abrasive material, and amount of abrasive material spread are limited, providing a reliable basis for those skilled in the art to select abrasive parameters.

[0042] (3) This invention proposes a method for selecting the particle size of the abrasive material and a method for determining the amount of abrasive material to be spread. When selecting the particle size of the abrasive material, if the particle size is too large, the abrasive material will be embedded in the asphalt mortar (or asphalt film) to a shallow depth, resulting in weak adhesion; if the particle size is too small, the abrasive material will easily overlap during the spreading process and will easily be completely embedded in the asphalt mortar (or asphalt film), resulting in an unsatisfactory effect on improving the micro-texture. These adverse factors will lead to the abrasive material falling off. When determining the amount of abrasive material to be spread, a dual control index is proposed. The minimum amount of abrasive material to be spread is defined as the amount of abrasive material to be spread when the micro-texture level between 0.06-0.5mm and the wavelength is not less than 45dB, ensuring the improvement effect on the micro-texture. The maximum amount of abrasive material to be spread is defined as the amount of abrasive material to be spread when the starting tangent and the ending tangent in the relationship curve intersect, avoiding the problem of excessive spreading leading to particle overlap and weak adhesion. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of a preferred embodiment of the abrasive asphalt pavement according to the present invention;

[0044] Figure 2 for Figure 1 A schematic diagram of the abrasive material embedded in asphalt mortar in the illustrated embodiment;

[0045] Figure 3 for Figure 1 The aggregate gradation composition diagram of the dense-graded SMA-13 ​​asphalt mixture in the embodiment shown;

[0046] Figure 4 for Figure 1 The process flow diagram of the sanding construction method for newly paved asphalt pavement in the embodiment shown;

[0047] Figure 5 for Figure 1 A comparison of the average structural depth of the plate-shaped specimens before and after sanding in the illustrated embodiment;

[0048] Figure 6 for Figure 1 The test results of various anti-slip properties of the frosted plate specimen in the illustrated embodiment after different abrasion cycles;

[0049] Figure 7 This is a mineral aggregate gradation diagram of a fine-graded SMA-13 ​​type asphalt mixture in another preferred embodiment of the fine-graded asphalt pavement and the fine-graded construction method for newly paved asphalt pavement according to the present invention.

[0050] Figure 8 for Figure 7 A comparison of the average structural depth of the plate-shaped specimens before and after sanding in the illustrated embodiment;

[0051] Figure 9 for Figure 7 The test results of various anti-slip properties of the frosted plate specimen in the illustrated embodiment after different abrasion cycles.

[0052] The diagram shows the following labels: 1-Surface sanding layer, 2-Oil-rich asphalt top layer, 3-Asphalt intermediate layer, 4-Asphalt bottom layer, 5-Base layer, 6-Aggregate, 7-Asphalt mortar, 8-Sanding material. Detailed Implementation

[0053] To further understand the invention, the following detailed description of the invention will be provided in conjunction with specific embodiments.

[0054] Example 1:

[0055] like Figure 1 and Figure 2 As shown, a preferred embodiment of the abrasive asphalt pavement of the present invention includes a five-layer structure, from top to bottom: a surface abrasive layer 1, an oil-rich asphalt top layer 2, an asphalt intermediate layer 3, an asphalt bottom layer 4, and a base layer 5; the surface abrasive layer 1 is paved with abrasive material 8, the oil-rich asphalt top layer 2 is paved with asphalt mixture, and the aggregate 6 in the asphalt mixture is coated with asphalt mortar 7; a portion of the abrasive material 8 is embedded in the asphalt mortar 7, and the remaining portion of the abrasive material 8 is exposed to form the surface abrasive layer 1.

[0056] The thickness of the surface abrasive layer is 0.3 mm, and the abrasive material is embedded in the asphalt mortar to a depth of 0.7 times the particle size of the abrasive material; the abrasive material is quartz sand. The thickness of the rich oil asphalt surface layer is 4 cm; a dense-graded SMA-13 ​​type asphalt mixture is used, with an asphalt-aggregate ratio of 6.6%, and the aggregate gradation composition is as follows: Figure 3 As shown.

[0057] The particle size of the abrasive material is related to the thickness of the asphalt mortar. Calculations show that the thickness of the asphalt mortar in this embodiment is 0.91 mm, which falls within the range of 0.75 mm ≤ asphalt mortar thickness < 1.0 mm. Therefore, the particle size of the abrasive material is selected to be 0.6 mm, i.e., 0.6 mm ≤ abrasive material particle size < 1.18 mm. When the particle size of the abrasive material is 0.6 mm, the embedding depth of the abrasive material into the asphalt mortar is 0.7 times the particle size of the abrasive material.

[0058] In this embodiment, the thickness of the surface frosted layer is 0.3 mm. The calculation method is as follows: when the particle size of the frosted material is 0.6 mm, the exposed size of the frosted material is 0.6 mm - 0.6 mm × 0.7 = 0.18 mm; when the particle size of the frosted material is 1.18 mm, the exposed size of the frosted material is 1.18 mm - 1.18 mm × 0.7 = 0.354 mm; the average of the two is the thickness of the surface frosted layer, which is approximately 0.3 mm.

[0059] like Figure 4 As shown, this embodiment also provides a method for applying a sandblasted finish to newly paved asphalt pavement, which includes the following steps in sequence:

[0060] Step 1: Select the particle size of the abrasive material according to the thickness of the asphalt mortar, and determine the amount of abrasive material to be applied based on laser texture scanning test and accelerated abrasion test;

[0061] Step 2: Use a paver to spread the oil-rich asphalt mixture on top of the asphalt intermediate layer to form the oil-rich asphalt surface layer;

[0062] Step 3: Install the automatic sandblasting machine on the front wheel bumper of the first steel-drum roller in the compaction unit responsible for initial compaction. Start the steel-drum roller and open the valve of the automatic sandblasting machine. The abrasive material is spread in the form of a material curtain above the rich asphalt surface layer. According to the set process, the abrasive material and the rich asphalt surface layer are simultaneously compacted in the first pass of initial compaction. During the first pass of compaction, the abrasive material is evenly spread above the newly laid rich asphalt surface layer. After the abrasive material is spread, the steel-drum roller immediately compacts it, causing part of the abrasive material to embed into the asphalt mortar of the rich asphalt surface layer, while the remaining part is exposed. During the retraction of the steel-drum roller after the first pass of compaction and during subsequent compaction processes, no more abrasive material is spread.

[0063] Step 4: Start the steel wheel roller and compact the abrasive material and the oil-rich asphalt surface layer simultaneously with the remaining passes of the initial compaction according to the set process to complete the paving of the abrasive asphalt pavement.

[0064] Step 5: Perform secondary and final compaction on the abrasive material and the oil-rich asphalt surface layer simultaneously according to the set process to ensure that the compaction degree of the oil-rich asphalt surface layer meets the design requirements.

[0065] In step one, the particle size of the abrasive material is selected based on the thickness of the asphalt mortar. The formula for calculating the thickness of the asphalt mortar is as follows: In the formula: H AM —Thickness of asphalt mortar, mm;

[0066] M – Asphalt usage, %;

[0067] ρ — density of asphalt, g / cm³ 3 ;

[0068] a, b, c, d, e, f, g, h — represent the percentage of aggregate mass passing through sieves with apertures of 19 mm, 4.75 mm, 2.36 mm, 1.18 mm, 0.6 mm, 0.3 mm, 0.15 mm, and 0.075 mm, respectively, in %.

[0069] In step one, the amount of abrasive material applied is determined based on laser texture scanning and accelerated abrasion tests, and includes the following steps in sequence:

[0070] Step (1): According to the design mix proportion of the rich oil asphalt surface layer asphalt mixture, five plate-shaped specimens are formed indoors. Then, the abrasive material is evenly spread on the surface of the five plate-shaped specimens according to the set spreading amount. Then, the five plate-shaped specimens are rolled and shaped using a molding machine. For the surface layer of dense-graded asphalt mixture, the initial selection is 1.0 kg / m³. 2 1.25kg / m 2 1.5kg / m 2 1.75kg / m 2 and 2.0kg / m 2 Five amounts of spreading;

[0071] Step (2): The surface texture of the plate-shaped specimen was scanned using a laser texture analyzer. After processing for bad pixels, tilt, and offset errors, the texture elevation data was filtered out, and the texture elevation data with a wavelength greater than 0.5 mm was removed. The remaining data was used to calculate the micro-texture level between 0.06 and 0.5 mm. The application amount corresponding to a micro-texture level of not less than 45 dB was taken as the minimum application amount of the abrasive material, and the result was determined to be 1.14 kg / m². 2 ;

[0072] Step (3): Accelerated abrasion tests were conducted on the five plate-shaped specimens, and the relationship curve between the amount of abrasive applied and the abrasion value was plotted. The amount of abrasive applied at the intersection of the tangent at the beginning and the tangent at the end of the curve was taken as the maximum amount of abrasive material applied, and the result was determined to be 1.46 kg / m³.2 ;

[0073] Step (4): When paving the abrasive asphalt pavement, the amount of abrasive material applied can be selected between the minimum and maximum application rates. In this embodiment, the average of the minimum and maximum application rates is taken as the optimal application rate, which is 1.30 kg / m². 2 .

[0074] In step two, the paving temperature of the asphalt mixture is 165℃ when laying the rich asphalt surface layer; in steps three and four, the spreading speed of the abrasive material is 3 km / h; in steps four and five, the abrasive material and the rich asphalt surface layer are simultaneously subjected to initial compaction, and the formula for calculating the number of compaction passes is as follows: In the formula,

[0075] N RC —The number of compaction passes for simultaneously initial compaction of the abrasive material and the oil-rich asphalt surface layer;

[0076] T RC — The compaction temperature at which the abrasive material and the rich oil asphalt surface layer are initially compacted simultaneously, i.e. the paving temperature of the rich oil asphalt surface layer asphalt mixture when the abrasive material is spread, ℃;

[0077] D RC — The ratio of the depth to which the abrasive material is embedded in the asphalt mortar to the particle size of the abrasive material.

[0078] In this embodiment, the number of rolling passes for the initial compaction of the abrasive material and the oil-rich asphalt surface layer is related to the rolling temperature and the rolling depth (i.e., the depth to which the abrasive material is embedded in the asphalt mortar). According to calculations, the number of rolling passes required for the initial compaction in this embodiment is four.

[0079] In steps four and five, the initial compaction is carried out using static compaction. The steel wheel roller weighs 12t and the rolling speed is 3km / h. All compaction passes are completed before the temperature of the asphalt mixture drops to 100℃.

[0080] In step six, the secondary compaction adopts a static compaction followed by a vibratory compaction method, with the steel wheel roller rolling back and forth 3-5 times (selected according to the compaction requirements of the rich asphalt surface layer), at a compaction speed of 3 km / h, and the steel wheel roller weighing 12t; the final compaction adopts a static compaction method, with the steel wheel roller rolling back and forth 1-2 times (selected according to the compaction requirements of the rich asphalt surface layer), at a compaction speed of 3 km / h, and the steel wheel roller weighing 12t.

[0081] The choice of abrasive material particle size is closely related to the thickness of the asphalt mortar. The abrasive material should be embedded in the asphalt mortar to a depth of 0.6-0.8 times its particle size. This ensures a firm embedding and prevents large areas from detaching due to tire friction after traffic begins. However, it should not be completely embedded in the asphalt mortar; if the abrasive material is not exposed, it will not enhance the micro-texture. Asphalt mortar is a mixture of asphalt, mineral powder, fine aggregates, and admixtures (such as fibers). The asphalt mortar coats the outer surface of the aggregates, rather than being distributed as pure asphalt within the mixture. In this embodiment, the thickness of the asphalt mortar is approximately 100 times the thickness of the asphalt film.

[0082] use Figure 3 The SMA-13 ​​asphalt mixture gradation shown is used to prepare several plate-shaped specimens with a length × width × height of 500mm × 500mm × 50mm, with 0.3% lignin fiber added (based on the mass of the asphalt mixture) according to a 6.6% asphalt-aggregate ratio. The abrasive plate-shaped specimens were prepared according to the parameters determined in this embodiment, including the particle size of the abrasive material, the amount of abrasive material applied, and the compaction process. Tests were conducted on both un-abrasive and abrasive plate-shaped specimens. A comparison of the average texture depth of the plate-shaped specimens before and after abrasion is shown in the figure below. Figure 5 As shown.

[0083] Depend on Figure 5 It can be seen that this embodiment uses abrasive material with a particle size of 0.6mm, and the spreading amount is relatively large at 1.30kg / m³. 2 However, since the particles of the abrasive material are small and mainly embedded in the asphalt mortar on the surface of coarse aggregate, the impact on the texture depth is relatively small. The average reduction in texture depth is only 7.1%. Therefore, the adverse effect of this embodiment on high-speed anti-skid performance is relatively small.

[0084] The frosted plate-shaped specimens prepared in this embodiment were subjected to indoor accelerated abrasion tests using an accelerated abrasion device. The BPN of the frosted plate-shaped specimens was measured after 0, 600, 1200, 1800, and 2400 abrasion cycles, respectively. 20 and C DF60 The test results of various anti-slip properties of the frosted plate specimens after different abrasion cycles are as follows: Figure 6 As shown in Figure C. SFC This is an indicator for actual road testing in engineering projects, which cannot be tested indoors. According to relevant research results, 200 cycles of accelerated wear using an accelerated wear device are equivalent to one month of actual road wear.

[0085] Depend on Figure 6 It can be seen that 2400 cycles of accelerated wear indoors is equivalent to the pendulum BPN value after one year of actual road traffic. 20 It still reaches 75, far exceeding the maintenance threshold of 45; dynamic friction coefficient C DF60It still reaches 0.70, maintaining high anti-skid performance. This is because within 3 months of opening to traffic, the abrasive material begins to gradually detach due to wear from vehicle tires. At this time, both the pendulum value and the dynamic friction coefficient decrease to a certain extent. However, within 3-12 months of opening to traffic, as the asphalt mortar covering the surface of the coarse aggregate gradually wears off, the surface texture of the coarse aggregate begins to be exposed. At this time, the friction coefficient of the road surface actually begins to increase.

[0086] This embodiment of the frosted asphalt pavement consists of a surface frosted layer, a rich asphalt top layer, an asphalt intermediate layer, an asphalt bottom layer, and a base layer. Compared to ordinary asphalt pavement, it includes an additional surface frosted layer. This surface frosted layer consumes excess asphalt and provides a rough surface, improving the anti-skid performance of the asphalt pavement in the initial stage of operation. This surface frosted layer is constructed simultaneously with the rich asphalt top layer; that is, after the rich asphalt top layer is newly laid, an automatic sandblasting machine is used to evenly spread the frosted material on the surface of the rich asphalt top layer, followed by compaction with a steel wheel roller to form the frosted asphalt pavement. This embodiment solves the problem of insufficient early anti-skid performance of rich asphalt pavements when they are first opened to traffic due to excess asphalt covering the micro-texture of the pavement. This embodiment effectively ensures the anti-skid performance of the asphalt pavement in the early stages of road operation and, from an anti-skid perspective, delays the subsequent preventative maintenance time of the asphalt pavement, reducing the interference of pavement maintenance on road traffic, improving road safety, and reducing the occurrence of traffic accidents, resulting in significant economic and social benefits.

[0087] The method for applying abrasive asphalt pavement and newly paved asphalt pavement in this embodiment has the following beneficial effects: In the first stage of the change in the anti-skid performance of asphalt pavement, the anti-skid performance of the pavement is not fully utilized because the asphalt mortar covers the micro-texture of the aggregate. This embodiment proposes to abrade the pavement by spreading abrasive material during the construction period, which effectively improves the anti-skid performance of the pavement in the early stage of road operation, thereby ensuring the safety of traffic in the early stage of road operation. Addressing the problem that an excessively high asphalt-aggregate ratio in oil-rich asphalt mixtures further amplifies the covering effect of asphalt mortar on the micro-texture of the aggregate, this embodiment applies abrasive material to the road surface immediately after the oil-rich asphalt mixture is laid. This effectively supplements the micro-texture of the road surface in the early stage of traffic operation, avoiding the problem of insufficient anti-skid performance in the early stage of traffic operation. At the same time, it limits the abrasive material, particle size, and amount of abrasive material applied, providing a reliable basis for those skilled in the art to select abrasive parameters.

[0088] Example 2:

[0089] According to another preferred embodiment of the present invention, the structure, grinding construction method, equipment used, technical principles, and beneficial effects of the ground asphalt pavement are basically the same as those in Embodiment 1, except that:

[0090] The thickness of the surface abrasive layer is 0.4 mm, and the abrasive material is embedded in the asphalt mortar to a depth of 0.7 times the particle size of the abrasive material; the abrasive material is quartz sand. The thickness of the rich oil asphalt surface layer is 5 cm; a dense-graded SMA-13 ​​type asphalt mixture is used, with an asphalt-aggregate ratio of 6.3%, and the aggregate gradation composition is as follows: Figure 7 As shown.

[0091] The particle size of the abrasive material is related to the thickness of the asphalt mortar. Calculations show that the asphalt mortar thickness in this embodiment is 1.15 mm, which falls within the range of 1.0 mm ≤ asphalt mortar thickness < 1.475 mm. Therefore, a combination of 0.6 mm and 1.18 mm particle sizes is selected for the abrasive material, with a mass ratio of 1:2. When the abrasive material uses a combination of 0.6 mm and 1.18 mm particle sizes, the embedding depth of the abrasive material into the asphalt mortar is 0.7 times the particle size of the abrasive material.

[0092] In step one, the thickness of the asphalt mortar was calculated to be 1.15 mm according to the formula; the minimum application rate of the abrasive material was determined to be 1.22 kg / m² based on laser texture scanning and accelerated abrasion tests. 2 The maximum spreading rate is 1.61 kg / m³. 2 The average of the two values ​​is taken as the optimal spreading amount in this embodiment, which is 1.42 kg / m². 2 .

[0093] In step two, the paving temperature of the asphalt mixture is 175℃ when laying the oil-rich asphalt surface layer; in steps three and four, the spreading speed of the abrasive material is 2km / h; in steps four and five, the abrasive material and the oil-rich asphalt surface layer are initially compacted simultaneously, and the number of compaction passes required for the initial compaction is three according to the calculation formula of the number of compaction passes.

[0094] In steps four and five, the initial compaction is carried out using static compaction. The steel wheel roller weighs 10t and the rolling speed is 2km / h. All compaction passes are completed before the temperature of the asphalt mixture drops to 100℃.

[0095] In step six, the secondary compaction adopts a static compaction followed by a vibratory compaction method, with the steel wheel roller rolling back and forth 3-5 times (selected according to the compaction requirements of the rich asphalt surface layer), the compaction speed is 2km / h, and the weight of the steel wheel roller is 10t; the final compaction adopts a static compaction method, with the steel wheel roller rolling back and forth 1-2 times (selected according to the compaction requirements of the rich asphalt surface layer), the compaction speed is 2km / h, and the weight of the steel wheel roller is 10t.

[0096] use Figure 7The SMA-13 ​​asphalt mixture gradation shown is used to prepare several plate-shaped specimens with a length × width × height of 500mm × 500mm × 50mm, with 0.3% lignin fiber added (based on the mass of the asphalt mixture) according to a 6.3% asphalt-aggregate ratio. The abrasive plate-shaped specimens were prepared according to the parameters determined in this embodiment, including the particle size of the abrasive material, the amount of abrasive material applied, and the compaction process. Tests were conducted on both un-abrasive and abrasive plate-shaped specimens. A comparison of the average texture depth of the plate-shaped specimens before and after abrasion is shown in the figure below. Figure 8 As shown.

[0097] Depend on Figure 8 It can be seen that this embodiment uses a combination of abrasive materials with particle sizes of 0.6mm and 1.18mm, and the spreading amount is relatively large at 1.42kg / m³. 2 However, since the particles of the abrasive material are small and mainly embedded in the asphalt mortar on the surface of coarse aggregate, the impact on the texture depth is relatively small. The average reduction in texture depth is only 12.2%. Therefore, the adverse effect of this embodiment on high-speed anti-skid performance is relatively small.

[0098] The frosted plate-shaped specimens prepared in this embodiment were subjected to indoor accelerated abrasion tests using an accelerated abrasion device. The BPN of the frosted plate-shaped specimens was measured after 0, 600, 1200, 1800, and 2400 abrasion cycles, respectively. 20 and C DF60 The test results of various anti-slip properties of the frosted plate specimens after different abrasion cycles are as follows: Figure 9 As shown in Figure C. SFC This is an indicator for actual road testing in engineering projects, which cannot be tested indoors. According to relevant research results, 200 cycles of accelerated wear using an accelerated wear device are equivalent to one month of actual road wear.

[0099] Depend on Figure 9 It can be seen that 2400 cycles of accelerated wear indoors is equivalent to the pendulum BPN value after one year of actual road traffic. 20 It still reaches 73, far exceeding the maintenance threshold of 45; dynamic friction coefficient C DF60 It still reaches 0.68, maintaining high anti-skid performance. This is because within 3 months of opening to traffic, the abrasive material begins to gradually detach due to vehicle tire wear, at which point both the pendulum value and dynamic friction coefficient decrease to some extent. Within 3-12 months of opening to traffic, the asphalt mortar covering the surface of the coarse aggregate gradually wears away. Due to the large thickness of the asphalt mortar, the surface texture of the coarse aggregate begins to be exposed, but not completely. At this time, although the friction coefficient of the road surface rebounds to some extent, it has not yet exceeded the initial value. With the continued wear over the next six months or so, the road surface friction coefficient will continue to rise and exceed the initial value.

[0100] The pavers, steel wheel rollers, automatic sandblasting machines, laser texture analyzers, and other equipment used in the above embodiments can be existing equipment, and there are no special requirements for the models; the laser texture scanning test and accelerated abrasion test can be conducted according to conventional operations; the thickness, materials, and construction of the asphalt intermediate layer, asphalt lower layer, and base layer can all adopt existing technologies. The raw materials used for paving the above-mentioned asphalt pavement were purchased from Beijing Municipal Road and Bridge Construction Materials Group Co., Ltd.

[0101] Special Note: The technical solution of this invention involves numerous parameters, and the synergistic effects between these parameters must be comprehensively considered to achieve the beneficial effects and significant progress of this invention. Furthermore, the value ranges of each parameter in the technical solution were obtained through extensive experimentation. For each parameter and the combinations thereof, the inventors have recorded a large amount of experimental data; however, due to space limitations, the specific experimental data is not disclosed here.

[0102] Those skilled in the art will readily understand that the abrasive asphalt pavement and the abrasive construction method for newly paved asphalt pavement of the present invention include any combination of the inventive content and specific embodiments described in the above specification and the various parts shown in the accompanying drawings. Due to space limitations and for the sake of brevity, not all of these combined solutions have been described. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for sanding newly paved asphalt pavement, characterized in that, The newly paved asphalt pavement comprises a five-layer structure, from top to bottom: a surface rough-textured layer, an oil-rich asphalt top layer, an asphalt intermediate layer, an asphalt bottom layer, and a base layer. The surface rough-textured layer is constructed from abrasive material, and the oil-rich asphalt top layer is constructed from asphalt mixture, with the aggregates in the asphalt mixture coated with asphalt mortar. A portion of the abrasive material is embedded in the asphalt mortar, while the remaining portion of the abrasive material is exposed to form the surface rough-textured layer. The particle size of the abrasive material is related to the thickness of the asphalt mortar: if the thickness of the asphalt mortar is <0.375mm, the particle size of the abrasive material is 0.3mm or no abrasion is performed; if 0.375mm ≤ asphalt mortar thickness <0.5mm, the particle size of the abrasive material is 0.3mm; if 0.5mm ≤ asphalt mortar thickness <0.75mm, the particle size of the abrasive material is a combination of 0.3mm and 0.6mm, with a mass ratio of 1:2; if 0.75mm ≤ asphalt mortar thickness <0.6mm, the particle size of the abrasive material is a combination of 0.3mm and 0.6mm, with a mass ratio of 1:2; if 0.75mm ≤ asphalt mortar thickness <0.375mm, the particle size of the abrasive material is 0.3mm or 0.6mm. If the mortar thickness is less than 1.0 mm, the abrasive material particle size is 0.6 mm. If the asphalt mortar thickness is between 1.0 mm and 1.475 mm, the abrasive material particle size is a combination of 0.6 mm and 1.18 mm, with a mass ratio of 1:

2. If the asphalt mortar thickness is between 1.475 mm and 1.97 mm, the abrasive material particle size is 1.18 mm. If the asphalt mortar thickness is ≥ 1.97 mm, the abrasive material particle size is 1.18 mm or no abrasive is applied. In step one, the amount of abrasive material applied is determined based on laser texture scanning and accelerated abrasion tests, and includes the following steps in sequence: Step (1): According to the design mix proportion of the rich oil asphalt surface layer asphalt mixture, five slab-shaped specimens are formed indoors. Then, the abrasive material is evenly spread on the surface of the five slab-shaped specimens according to the set spreading amount. Then, the five slab-shaped specimens are rolled and shaped using a molding machine. For the surface layer of open-graded asphalt mixture, the initial selection is 0.1 kg / m³. 2 0.25kg / m 2 0.4kg / m 2 0.55kg / m 2 and 0.8kg / m 2 For the top layer of dense-graded asphalt mixtures, the initial spreading rate is 1.0 kg / m³. 2 1.25kg / m 2 1.5kg / m 2 1.75kg / m 2 and 2.0kg / m 2 Five amounts of spreading; Step (2): Use a laser texture analyzer to scan the surface texture of the plate-shaped specimen. After the texture elevation data is processed for bad pixels, tilt and offset errors, the texture elevation data with a wavelength greater than 0.5 mm is filtered out. The remaining data is used to calculate the micro-texture level between 0.06-0.5 mm. The amount of material to be spread when the micro-texture level is not less than 45 dB is taken as the minimum amount of abrasive material to be spread. Step (3): Accelerated wear test was conducted on the five plate specimens respectively, and the relationship curve between the amount of abrasive and the wear value was plotted. The amount of abrasive material corresponding to the intersection of the starting tangent and the ending tangent in the relationship curve was taken as the maximum amount of abrasive material. Step (4): When paving the abrasive asphalt pavement, the amount of abrasive material to be spread should be selected between the minimum and maximum amount.

2. The method for sanding newly paved asphalt pavement according to claim 1, characterized in that, The thickness of the surface abrasive layer is 0.1-1mm, and the depth to which the abrasive material is embedded in the asphalt mortar is 0.6-0.8 times the particle size of the abrasive material; the abrasive material includes any one or more of corundum, quartz sand, manufactured sand, slag and steel slag.

3. The method for sanding newly paved asphalt pavement according to claim 2, characterized in that, The thickness of the oil-rich asphalt surface layer is 3-5 cm; for open-graded PAC type asphalt mixtures, the asphalt-aggregate ratio is not less than 5.1%; for dense-graded AC type asphalt mixtures, the asphalt-aggregate ratio is not less than 5.1%; for dense-graded SMA type asphalt mixtures, the asphalt-aggregate ratio is not less than 6.2%.

4. The method for sanding newly paved asphalt pavement according to claim 3, characterized in that, The abrasive material has particle sizes of 0.3mm, 0.6mm, and 1.18mm, i.e., 0.3mm ≤ particle size < 0.6mm, 0.6mm ≤ particle size < 1.18mm, and 1.18mm ≤ particle size < 2.36mm.

5. The method for sanding newly paved asphalt pavement according to claim 4, characterized in that, The sanding application method includes the following steps in sequence: Step 1: Simultaneously select the particle size of the abrasive material based on the thickness of the asphalt mortar; Step 2: Use a paver to spread the oil-rich asphalt mixture on top of the asphalt intermediate layer to form the oil-rich asphalt surface layer; Step 3: Install the automatic sandblasting machine on the front wheel bumper of the first steel-drum roller in the compaction unit responsible for initial compaction. Start the steel-drum roller and open the valve of the automatic sandblasting machine. The abrasive material is spread in the form of a material curtain above the rich asphalt surface layer. According to the set process, the abrasive material and the rich asphalt surface layer are simultaneously compacted in the first pass of initial compaction. During the first pass of compaction, the abrasive material is evenly spread above the newly laid rich asphalt surface layer. After the abrasive material is spread, the steel-drum roller immediately compacts it, causing part of the abrasive material to embed into the asphalt mortar of the rich asphalt surface layer, while the remaining part is exposed. During the retraction of the steel-drum roller after the first pass of compaction and during subsequent compaction processes, no more abrasive material is spread. Step 4: Start the steel wheel roller and compact the abrasive material and the oil-rich asphalt surface layer simultaneously with the remaining passes of the initial compaction according to the set process to complete the paving of the abrasive asphalt pavement. Step 5: Perform secondary and final compaction on the abrasive material and the oil-rich asphalt surface layer simultaneously according to the set process to ensure that the compaction degree of the oil-rich asphalt surface layer meets the design requirements.

6. The method for sanding newly paved asphalt pavement according to claim 5, characterized in that, In step one, the particle size of the abrasive material is selected based on the thickness of the asphalt mortar. The formula for calculating the thickness of the asphalt mortar is as follows: In the formula, —Thickness of asphalt mortar, mm; —Asphalt usage, % —Density of asphalt, g / cm³ 3 ; , , , , , , , —These represent the percentage of aggregate mass that passed through sieves with openings of 19mm, 4.75mm, 2.36mm, 1.18mm, 0.6mm, 0.3mm, 0.15mm, and 0.075mm, respectively.

7. The method for sanding newly paved asphalt pavement according to claim 6, characterized in that, In step two, the paving temperature of the asphalt mixture is 155-190℃ when laying the rich asphalt surface layer; in steps three and four, the spreading speed of the abrasive material is 2-4 km / h; in steps four and five, the abrasive material and the rich asphalt surface layer are simultaneously subjected to initial compaction, and the formula for calculating the number of compaction passes is as follows: In the formula, —The number of compaction passes for simultaneously initial compaction of the abrasive material and the oil-rich asphalt surface layer; — The compaction temperature at which the abrasive material and the rich oil asphalt surface layer are initially compacted simultaneously, i.e., the paving temperature of the rich oil asphalt surface layer asphalt mixture when the abrasive material is spread, ℃; —The ratio of the depth of the abrasive material embedded in the asphalt mortar to the particle size of the abrasive material, i.e., 0.6-0.

8.

8. The method for sanding newly paved asphalt pavement according to claim 7, characterized in that, In steps four and five, the initial compaction is carried out using static compaction. The steel wheel roller weighs 10-12t and the rolling speed is 2-4km / h. All compaction passes are completed before the temperature of the asphalt mixture drops to 100℃.

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