A rapid detection method and device for the pourability of large-void asphalt mixture

Abstract

The application discloses a kind of big gap asphalt mixture pourability rapid detection method and its detection device, it is by sealed test container with scale;The volume of slurry of target big gap asphalt mixture test piece in unit time is determined to determine the pourability of big gap asphalt mixture.The pourability provides reliable characterization data for the gradation design of semi-flexible pavement big gap asphalt mixture matrix;The detection device is simple in structure, and the adaptation range of device is wide, and can face laboratory and specific working environment.

Description

Technical Field

[0001] This invention belongs to the field of traffic engineering pavement, and more specifically, this invention relates to a rapid detection method and device for the injectability of large-void asphalt mixtures. Background Technology

[0002] To meet the demands of modern transportation development and overcome the rutting problem of asphalt pavements, early-strength grouted cement-asphalt composite pavements have emerged. This new technology refers to a cement-asphalt composite material formed by injecting special cement grout into a large-void matrix asphalt mixture. Studies have shown that its rutting resistance can be more than 20 times that of asphalt pavements, while its crack resistance and driving comfort are superior to cement concrete pavements, combining the advantages of both flexible and rigid pavements. The basic concept of the Marshall test was first proposed by Bruce Marshall of the Mississippi Highway Authority around 1939. The Marshall test is a test to determine the optimal asphalt-aggregate ratio of asphalt mixtures. The test process involves standard compaction of the specimen under specified temperature and humidity conditions, measuring the stability and flow value of the asphalt mixture, and after a series of calculations, plotting the relationship curves between the asphalt-aggregate ratio and stability, flow value, density, porosity, and saturation, finally determining the optimal asphalt-aggregate ratio of the asphalt mixture. In addition, early-strength grouting cement-asphalt composite pavement can be opened to traffic in a short period of time due to the use of special grouting materials. It can be widely used for rutting treatment in sections such as intersections and bus lanes, without the need for long-term maintenance, and has significant technical advantages and social benefits.

[0003] Therefore, whether the grout can fill the voids in the asphalt mixture matrix is ​​crucial for the quality control of semi-flexible materials. Grout fillability refers to the grout's fillability and its related properties to grouting quality. Grout fillability is used to determine whether the raw materials and gradation of the grout need adjustment to meet quality requirements; however, currently there are no testing indicators or methods for grout fillability.

[0004] The closest existing technology involves testing the void ratio of large-void asphalt mixtures according to the method described in JTG E20-2011, and indirectly determining groutability based on the void ratio. However, even with the same void ratio, the internal void structure and size differ between asphalt mixtures of different gradations. Furthermore, the fluidity of the grout also affects groutability. During the gradation design stage, it is impossible to predict the grouting fullness and grouting quality of the large-void asphalt mixture matrix using only void ratio data, thus hindering timely and effective control of the matrix asphalt mixture gradation.

[0005] Patent application CN201811114057.9 discloses a measuring device and evaluation method for the transverse permeability of asphalt mixtures. Using a self-designed asphalt mixture specimen permeability testing device, based on the water balance principle and employing a water volume control method, it evaluates the transverse permeability of asphalt mixture specimens and performs permeability testing on large-pore asphalt mixture slabs for drainage pavements. Patent application CN112067529A discloses a permeability testing device and method for permeable asphalt concrete, which can simultaneously measure the vertical and transverse permeability of permeable asphalt concrete. However, the specimen preparation for the above patents is cumbersome, making rapid testing based on experimental specimens impossible. Furthermore, these methods are only suitable for testing the permeability of water to materials and cannot be used to test the injectability of grout. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a rapid and accurate method for detecting the fillability of large-void asphalt mixture matrix.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a rapid detection method for the injectability of large-void asphalt mixtures is provided, comprising a graduated sealed test container; the injectability of large-void asphalt mixtures is determined by calculating the volume of slurry passing through the target large-void asphalt mixture specimen per unit time.

[0008] Specifically, the following steps are included:

[0009] S1: Real Marshall specimen tested by positive and negative impact; specimen height h (cm) measured using vernier calipers.

[0010] S2: Connect the sleeve to the test mold outside the Marshall specimen, and measure the inner diameter D (cm) of the sleeve with a vernier caliper; pour the grout into the sleeve, and record the time t (s) it takes for the grout in the sleeve to descend through the scale line or mark to the bottom fixed distance d (cm); the liquid used for testing is grout, water or other standard liquid.

[0011] S3: The groutability index of large-void asphalt mixture is the volume of grout passing through the large-void asphalt mixture specimen per unit time, V (cm3 / (cm*s)) (a correlation equation can be established between V and the porosity of the asphalt mixture specimen):

[0012]

[0013] The testing device for rapid testing of the injectability of large-void asphalt mixtures according to the present invention includes a Marshall mold, a sleeve, and a sealing part, wherein the Marshall mold is fixed to the inner wall of the bottom of the sleeve by snap-fit, and the sealing part is connected to the bottom of the sleeve.

[0014] Preferably, the sleeve is a cylinder without a top or top cap.

[0015] Preferably, the sleeve includes an upper sleeve, a lower sleeve, and a connecting sleeve; wherein, the upper sleeve is a cylinder with no top cap and a through hole at the bottom; the lower sleeve is a cylinder with a through hole at the top and no bottom cap; one end of the connecting sleeve is connected to the through hole of the upper sleeve, and the other end of the connecting sleeve is connected to the through hole of the lower sleeve.

[0016] Preferably, a valve is installed horizontally inside the connecting cylinder.

[0017] Preferably, the sealing part includes a baffle and a handle, the baffle and the handle are fixedly connected, and the sleeve is placed on the upper surface of the baffle.

[0018] Preferably, the sleeve is made of a transparent material, preferably plastic, glass or resin.

[0019] Preferably, the outer wall of the sleeve is provided with graduation lines.

[0020] Preferably, the outer wall of the upper sleeve is marked with markings.

[0021] The rapid detection method and device for the groutability of large-pore asphalt mixtures described in this invention are particularly suitable for detecting the groutability of large-pore asphalt mixture matrices. By determining its groutability, the gradation can be adjusted to ensure that the quality of the grout meets the actual requirements of the project.

[0022] Compared with the prior art, the solution of this invention has the following advantages:

[0023] 1. It can quickly and accurately detect the groutability of large-void asphalt mixture matrix. The groutability index comprehensively considers the influence of factors such as grout and void structure on the grouting quality on the basis of the original void ratio index. It provides reliable characterization data for the gradation design of large-void asphalt mixture matrix for semi-flexible pavement, and can effectively improve the quality of pavement engineering.

[0024] 2. This device has a simple structure and a wide range of applications, suitable for both laboratory and specific working environments. Attached Figure Description

[0025] The following is a brief explanation of the contents of each of the accompanying drawings and the markings in the drawings:

[0026] Figure 1 This is a schematic diagram of the integrated cylindrical sleeve of the present invention.

[0027] Figure 2 This is a schematic diagram of the upper and lower sleeve assembly of the present invention.

[0028] Figure 3 This is a schematic diagram of the sealing part of the present invention.

[0029] The markings in the diagram are: 1. Marshall trial mold; 2. Sleeve; 3. Valve; 4. Connecting sleeve; 5. Baffle; 6. Handle; 7. Scale line; 8. Marking line; 9. Upper sleeve; 10. Lower sleeve. Detailed Implementation

[0030] The following description, with reference to the accompanying drawings, further details the specific implementation of the present invention, including the shape and structure of each component, the relative positions and connections between the parts, the function and working principle of each part, the manufacturing process, and the operation and use methods, so as to help those skilled in the art to have a more complete, accurate, and in-depth understanding of the inventive concept and technical solution of the present invention.

[0031] like Figure 1 , Figure 2 and Figure 3 The testing device for a rapid testing method for the fillability of large-void asphalt mixtures includes a Marshall mold 1, a sleeve 2, and a sealing part. The Marshall mold 1 is fixed to the inner wall of the bottom of the sleeve 2 by snap-fit, and the sealing part is connected to the bottom of the sleeve 2.

[0032] like Figure 1 The sleeve 2 shown is a cylinder without a top or top cap, and the outer wall of the sleeve 2 is provided with scale lines 7.

[0033] like Figure 2 The sleeve shown includes an upper sleeve 9, a lower sleeve 10, and a connecting sleeve 4; wherein, the upper sleeve 9 is a cylinder without a top cover and with a through hole at the bottom; the lower sleeve 10 is a cylinder with a through hole at the top and without a bottom cover; one end of the connecting sleeve 4 is connected to the through hole of the upper sleeve 9, and the other end of the connecting sleeve 4 is connected to the through hole of the lower sleeve 10; a valve 3 is horizontally arranged inside the connecting sleeve 4; and a marking line 8 is provided on the outer wall of the upper sleeve 9.

[0034] like Figure 3 The sealing part shown includes a baffle 5 and a handle 6, with the baffle 5 and the handle 6 fixedly connected, and the sleeve 2 placed on the upper surface of the baffle 5.

[0035] The sleeves 2 in this invention are all made of transparent materials, preferably plastic, glass or resin.

[0036] Example 1:

[0037] The gradation of the large-void asphalt mixture is shown in Table 1. The Marshall specimen was compacted 50 times using both positive and negative impact methods. The height h of the Marshall specimen was 63.5 mm, and the distance d between the two graduation lines was 10 cm. The fluidity of the prepared slurry was 11.6 s. A straight sleeve with a height of 20 cm was placed on the Marshall mold. The slurry was poured into the sleeve, and the time t taken for the slurry to pass through the two graduation lines was recorded as 38 s. The sleeve diameter D was 101.3 mm.

[0038] Table 1 Gradation of Large-Porosity Asphalt Mixture

[0039] Sieve aperture size (mm) 16 13.2 9.5 4.75 2.36 1.18 0.6 0.3 0.15 0.075 Pass rate (%) 100 80 34 11 6 5 3 3 2 2

[0040] Example 2:

[0041] The gradation of the large-void asphalt mixture is shown in Table 1. The Marshall specimen was compacted 50 times using both positive and negative impact methods. The height h of the Marshall specimen was 63.6 mm, and the distance d between the two graduation lines was 10 cm. The fluidity of the prepared slurry was 12.4 s. A straight sleeve with a height of 20 cm was placed on the Marshall mold. A baffle was placed at the bottom of the Marshall mold, and the slurry was poured into the sleeve. The time t taken for the slurry to pass through the two graduation lines was recorded as 45 s. The sleeve diameter D was 101.3 mm.

[0042] Example 3:

[0043] The gradation of the large-void asphalt mixture is shown in Table 1. The Marshall specimen was compacted 50 times using both positive and negative impact methods. The height h of the Marshall specimen was 63.4 mm, and the distance d between the two graduation lines was 10 cm. The fluidity of the prepared slurry was 13.7 s. A straight sleeve with a height of 20 cm was placed on the Marshall mold, and the joint was sealed with transparent tape. The slurry was poured into the sleeve, and the time t taken for the slurry to pass through the two graduation lines was recorded as 72 s. The sleeve diameter D was 101.3 mm.

[0044] Example 4:

[0045] The gradation of the large-void asphalt mixture is shown in Table 1. Marshall specimens were compacted 50 times using both positive and negative methods. The specimen height was 64.2 mm, and the distance from the mark to the bottom was 10 cm. The prepared slurry flowability was 11.6 s. A sleeve with a connecting valve was placed on the Marshall mold. The connecting valve was closed, and the slurry was poured into the sleeve up to the mark. The connecting valve was then released, and the time taken for the slurry to travel from the mark to the bottom was recorded as 39 s. The sleeve diameter D was 101.3 mm.

[0046] Example 5:

[0047] The gradation of the large-void asphalt mixture is shown in Table 1. Marshall specimens were compacted 50 times using both positive and negative methods. The specimen height was 64 mm, and the distance from the mark to the bottom was 10 cm. The prepared slurry flowability was 12.4 s. A sleeve with a connecting valve was placed on the Marshall mold. The connecting valve was closed, and the slurry was poured into the sleeve up to the mark. The connecting valve was then released, and the time taken for the slurry to travel from the mark to the bottom was recorded as 47 s. The sleeve diameter D was 101.3 mm.

[0048] Example 6:

[0049] The gradation of the large-void asphalt mixture is shown in Table 1. Marshall specimens were compacted 50 times using both positive and negative methods. The height of the Marshall specimen was 63.8 mm, and the distance from the mark to the bottom was 10 cm. The fluidity of the prepared slurry was 13.7 s. A sleeve with a connecting valve was placed on the Marshall mold, and molten paraffin was dripped into the joint gap to seal it. The connecting valve was closed, and the slurry was poured into the sleeve up to the mark. The connecting valve was then released, and the time taken for the slurry to travel from the mark to the bottom was recorded as 73 s. The sleeve diameter D was 101.3 mm.

[0050] Table 2 Gradation of Large-Porosity Asphalt Mixture

[0051] Sieve aperture size (mm) 16 13.2 9.5 4.75 2.36 1.18 0.6 0.3 0.15 0.075 Pass rate (%) 100 52 29 8 4.5 4 2 2 2 2

[0052] Example 7:

[0053] The gradation of the large-void asphalt mixture is shown in Table 2. The Marshall specimen was compacted 50 times using both positive and negative methods. The specimen height was 64.8 mm, and the distance between the two graduation lines was 15 cm. The fluidity of the prepared slurry was 11.4 s. A straight sleeve with a height of 45 cm was placed on the Marshall mold. The slurry was poured into the sleeve, and the time taken for the slurry to pass through the two graduation lines was recorded as 58 s. The sleeve diameter D was 101 mm.

[0054] Example 8:

[0055] The gradation of the large-void asphalt mixture is shown in Table 2. The Marshall specimen was compacted 50 times using both positive and negative impact methods. The specimen height was 64.6 mm, and the distance between the two graduation lines was 15 cm. The fluidity of the prepared slurry was 12.1 s. A straight sleeve with a height of 45 cm was placed on the Marshall mold. The slurry was poured into the sleeve, and the time taken for the slurry to pass through the two graduation lines was recorded as 64 s. The sleeve diameter D was 101 mm.

[0056] Example 9:

[0057] The gradation of the large-void asphalt mixture is shown in Table 2. The Marshall specimen was compacted 50 times using both positive and negative methods. The specimen height was 64.9 mm, and the distance between the two graduation lines was 15 cm. The fluidity of the prepared slurry was 12.9 s. A straight sleeve with a height of 45 cm was placed on the Marshall mold. The slurry was poured into the sleeve, and the time taken for the slurry to pass through the two graduation lines was recorded as 78 s. The sleeve diameter D was 101 mm.

[0058] Example 10:

[0059] The gradation of the large-void asphalt mixture is shown in Table 2. The Marshall specimen was compacted 50 times using both positive and negative methods. The specimen height was 64.7 mm, and the distance between the two graduation lines was 15 cm. The fluidity of the prepared slurry was 11.4 s. A straight sleeve with a height of 45 cm was placed on the Marshall mold. The slurry was poured into the sleeve, and the time taken for the slurry to pass through the two graduation lines was recorded as 61 s. The sleeve diameter D was 101 mm.

[0060] Example 11:

[0061] The gradation of the large-void asphalt mixture is shown in Table 2. The Marshall specimen was compacted 50 times using both positive and negative impact methods. The specimen height was 64.2 mm, and the distance between the two graduation lines was 15 cm. The fluidity of the prepared slurry was 13.6 s. A straight sleeve with a height of 45 cm was placed on the Marshall mold. The slurry was poured into the sleeve, and the time taken for the slurry to pass through the two graduation lines was recorded as 89 s. The sleeve diameter D was 101 mm.

[0062] Example 12:

[0063] The gradation of the large-void asphalt mixture is shown in Table 2. The Marshall specimen was compacted 50 times using both positive and negative impact methods. The specimen height was 64.9 mm, and the distance between the two graduation lines was 15 cm. The fluidity of the prepared slurry was 15.4 s. A straight sleeve with a height of 45 cm was placed on the Marshall mold. The slurry was poured into the sleeve, and the time taken for the slurry to pass through the two graduation lines was recorded as 138 s. The sleeve diameter D was 101 mm.

[0064] Comparative Example 1:

[0065] The gradation of large-void asphalt mixture is shown in Table 1. Marshall specimens were subjected to 50 positive and negative impact compaction cycles to test the void ratio.

[0066] Comparative Example 2:

[0067] The gradation of large-void asphalt mixture is shown in Table 2. Marshall specimens were subjected to 50 positive and negative impact compaction cycles to test the void ratio.

[0068] The test results of the above experimental indicators are shown in Table 3.

[0069] Table 3 Experimental Data

[0070]

[0071]

[0072] As shown in Table 3, the porosity values ​​tested using traditional methods have different groutability properties depending on the type of grout.

[0073] As can be seen from the above embodiments and comparative experimental results, the present invention can more accurately evaluate the fillability of large-void asphalt mixture matrix in the gradation design stage.

[0074] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. A rapid test method for the fillability of large-void asphalt mixtures, characterized in that: Contains a graduated, sealed test container; The determination of the injectability of large-void asphalt mixtures by calculating the volume of slurry passing through a target large-void asphalt mixture specimen per unit time includes the following steps: S1: Positive impact Marshall specimen, measure the specimen height h with vernier calipers; S2: Connect the sleeve to the test mold outside the Marshall specimen, and measure the inner diameter D of the sleeve with a vernier caliper; pour the liquid into the sleeve, and record the time t it takes for the slurry in the sleeve to fall through the scale line or mark to the bottom fixed distance d; wherein the liquid used for testing is slurry, water or other standard liquid; S3: The groutability index of large-void asphalt mixture is the unit volume V of grout injected per unit time. The units for h, D, and d are cm, the unit for t is s, and the unit for V is cm. 3 / (cm*s).

2. The testing device for a rapid testing method of the groutability of large-void asphalt mixtures according to claim 1, characterized in that: It includes a Marshall mold, a sleeve, and a sealing part, wherein the Marshall mold is fixed to the inner wall of the bottom of the sleeve by snap-fit, and the sealing part is connected to the bottom of the sleeve.

3. A rapid testing device for the fillability of large-void asphalt mixtures according to claim 2, characterized in that, The sleeve is a cylinder without a cap at the top or bottom.

4. A rapid testing device for the fillability of large-void asphalt mixtures according to claim 2, characterized in that, The sleeve includes an upper sleeve, a lower sleeve, and a connecting sleeve; wherein, the upper sleeve is a cylinder with no top cap and a through hole at the bottom; the lower sleeve is a cylinder with a through hole at the top and no bottom cap; one end of the connecting sleeve is connected to the through hole of the upper sleeve, and the other end of the connecting sleeve is connected to the through hole of the lower sleeve.

5. A rapid testing device for the fillability of large-void asphalt mixtures according to claim 4, characterized in that, A valve is horizontally installed inside the connecting cylinder.

6. A rapid testing device for the fillability of large-void asphalt mixtures according to claim 2, characterized in that, The sealing part includes a baffle and a handle, with the baffle and handle fixedly connected, and the sleeve placed on the upper surface of the baffle.

7. A rapid testing device for the fillability of large-void asphalt mixtures according to claim 2, characterized in that, The sleeve is made of a transparent material, which can be one of plastic, glass or resin.

8. A rapid testing device for the fillability of large-void asphalt mixtures according to claim 3, characterized in that, The outer wall of the sleeve is provided with scale lines.

9. A rapid testing device for the fillability of large-void asphalt mixtures according to claim 4, characterized in that, The outer wall of the upper sleeve is marked with a line.

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