Method for measuring and calculating addition ratio of new hot in-place recycling asphalt mixture of asphalt pavement

Abstract

The invention discloses an asphalt pavement hot in-place recycling new asphalt mixture addition ratio measuring and calculating method, which comprises the following steps: S1, intermittently measuring the floating distance of an asphalt ground on a vehicle driving path by using a contact type floating distance measuring system, and obtaining and recording relevant parameters; s2, the compaction degree and the density of the old pavement are detected; s3, determining the milling depth and the thickness of the pavement after the new asphalt mixture is regenerated; s4, determining the compaction degree and density of the regenerated new asphalt mixture; and S5, calculating the mass of the old asphalt material after the old pavement is milled and the mass of the new asphalt mixture required by the new pavement of the road section, and calculating the addition ratio of the new asphalt mixture. The method can meet the requirement for accurate control of the mixing amount of the new asphalt mixture in the on-site hot in-place recycling construction process.

Description

Technical Field

[0001] The present invention belongs to the technical field of road maintenance, and particularly relates to a method for calculating the addition ratio of new asphalt mixture for in-situ hot recycling of asphalt pavement. Background Art

[0002] With the continuous increase in traffic volume and the increasing vehicle load, asphalt pavement is prone to diseases such as ruts during long-term use, seriously affecting the driving quality and safety performance of the road. The generation of ruts is mainly due to the plastic deformation of asphalt mixture under high temperature and heavy load, resulting in depressions on the road surface. When conducting in-situ hot recycling of asphalt pavement, in order to restore the original state of the road surface, an appropriate amount of new asphalt mixture must be added to fill these ruts. In addition, due to the lax quality control during the initial construction of some asphalt pavements, the pavement compaction degree is insufficient. To ensure that the compaction degree of the recycled pavement meets the design requirements, new asphalt mixture also needs to be added to enhance the compaction effect of the pavement. Therefore, during the in-situ hot recycling of asphalt pavement, the addition of new asphalt mixture is the key to restoring the good service performance of the road surface.

[0003] In the mix design of in-situ hot recycling of asphalt pavement, the incorporation amount of new asphalt mixture has a significant impact on the overall performance of the recycled asphalt mixture. Therefore, accurately determining the incorporation amount of new asphalt mixture is crucial for optimizing the mix design. However, during the actual construction process, after the new asphalt mixture is produced by the mixing plant, it needs to be transported to the site by transport vehicles for addition. If the incorporation amount is calculated inaccurately, it may lead to overproduction or underproduction of the new asphalt mixture, thereby causing waste of resources or a decline in construction efficiency. Therefore, accurately calculating the incorporation amount of new asphalt mixture is particularly important.

[0004] To address this problem, technicians have proposed various solutions, but most rely on using tools such as 3m straightedges to intermittently measure the rut depth of the old road surface and estimating the incorporation amount of new asphalt mixture through mathematical statistical methods. However, due to the irregular shape of the road surface ruts, this measurement method can only approximately estimate the geometric dimensions of the rut cross-section and the rut volume within a specific measuring point spacing, and cannot accurately reflect the true volume of the ruts. In addition, existing methods often ignore the influence of factors such as the compaction degree of the old road surface, the theoretical maximum density of the old road surface and new asphalt mixture, and the compaction degree of the recycled road surface on the calculation of the incorporation amount. Therefore, in practical applications, the incorporation amount of new asphalt mixture determined by existing methods often fails to achieve the ideal effect and has a large difference from the actual engineering requirements. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for calculating the addition ratio of new asphalt mixture for in-situ hot recycling of asphalt pavement, which can meet the precise control requirements of the incorporation amount of new asphalt mixture during the in-situ hot recycling construction process on site.

[0006] To achieve the above object, the present invention provides a method for calculating the addition ratio of new asphalt mixture for in-situ hot recycling of asphalt pavement, comprising the following steps:

[0007] S1. Intermittently measure the floating distance of the asphalt ground on the vehicle driving path by using a contact floating ranging system, the vehicle speed is v, and set the driving distance of the vehicle in one sampling period of the contact floating ranging system as L, and the width of a single lane for in-situ hot recycling construction is d; the height distance information of the current asphalt pavement cross-section obtained by each sampling of the contact floating ranging system is y i , the sampling length of a single contact floating ranging system is X, then the number of required floating ranging systems

[0008] where the sampling period is the time for the contact floating ranging system to sample from one end to the other end, and one sampling period is where γ is the lateral moving speed of the contact floating ranging system;

[0009] The rutting volume of the old asphalt pavement obtained by each contact floating ranging system in one sampling period is θ1 = f(y ε ) * L;

[0010] S2. Detect the compactness δ1 of the old pavement and the density ρ1 of the old pavement;

[0011] S3. Set the milling depth h1 and the thickness h2 of the pavement after the new asphalt mixture is recycled;

[0012] S4. Determine the compactness δ2 and density ρ2 of the new asphalt mixture after recycling;

[0013] S5. Calculate the mass of the old asphalt mixture after milling the old pavement and the mass of the new asphalt mixture required for the newly built pavement of this section Then the addition ratio of the new asphalt mixture

[0014] As a further solution of the present invention: The compactness δ1 of the old pavement is cored and tested in an evaluation section of 200 meters, and the number of cores is not less than 5.

[0015] As a further solution of the present invention: The density ρ1 of the old pavement is cored and tested in an evaluation section of 200 meters, and the number of cores is not less than 5.

[0016] As a further solution of the present invention: The compactness δ2 and density ρ2 of the new asphalt mixture after recycling are design values, and are determined by the vacuum method test.

[0017] As a further solution of the present invention: The contact floating ranging system includes:

[0018] Lateral guide rail;

[0019] A longitudinal floating profiling guide bar is driven by a servo motor to move horizontally on a transverse guide rail;

[0020] A data sensor is connected to the longitudinal floating profiling guide bar and is used to read the floating changes generated during the contact process between the longitudinal floating profiling guide bar and the ground, calculate the height fluctuations of the corresponding cross-section of the asphalt road, draw the contour map of the road cross-section in the height direction, and finally calculate the volume and mass of the old asphalt pavement.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] The contact type floating ranging system has a simple structure and is convenient to use and operate. By matching the measurement results with the formula calculation, the accurate addition amount of the new asphalt mixture can be obtained, thereby improving the efficiency of the in-situ hot recycling project of the asphalt pavement and avoiding energy waste at the same time. Description of the Drawings

[0023] Figure 1 This is the contact type floating ranging system in the present invention;

[0024] Figure 2 This is the contour map of the cross-section height obtained after the old road surface is collected by the present invention;

[0025] Figure 3 This is the driving distance of the vehicle in one sampling period of the present invention.

[0026] In the figure, 1 is the transverse guide rail, and 2 is the longitudinal floating profiling guide bar. Detailed Embodiments

[0027] The present invention will be further described below through embodiments.

[0028] As Figures 1 to 3 shown, a method for calculating the addition ratio of new asphalt mixture for in-situ hot recycling of asphalt pavement includes the following steps:

[0029] S1. Intermittently measure the floating distance of the asphalt ground on the vehicle driving path by using the contact type floating ranging system, the vehicle speed is v, and set the driving distance of the vehicle in one sampling period of the contact type floating ranging system as L, and the width of the single lane for in-situ hot recycling construction is d; the contact type floating ranging system obtains the height distance information of the current asphalt pavement cross-section as y each time it samples i , the sampling length of a single contact type floating ranging system is X, then the number of required floating ranging systems

[0030] where the sampling period is the time for the contact type floating ranging system to sample from one end to the other end, and one sampling period is where γ is the horizontal moving speed of the contact type floating ranging system;

[0031] For each contact floating ranging system, the rut volume of the old asphalt pavement obtained in one sampling period is θ1 = f(y ε ) * L;

[0032] S2. Detect the compaction degree δ1 of the old pavement and the density ρ1 of the old pavement;

[0033] S3. Set the milling depth h1 and the thickness h2 of the pavement after the regeneration of the new asphalt mixture;

[0034] S4. Determine the compaction degree δ2 and the density ρ2 of the pavement after the regeneration of the new asphalt mixture;

[0035] S5. Calculate the mass of the old asphalt material after milling the old pavement and the mass of the new asphalt mixture required for the newly built pavement of this section Then the addition ratio of the new asphalt mixture

[0036] Furthermore, the compaction degree δ1 of the old pavement is cored and tested in an evaluation section of 200 meters, and the number of cores is not less than 5.

[0037] Furthermore, the density ρ1 of the old pavement is cored and tested in an evaluation section of 200 meters, and the number of cores is not less than 5.

[0038] Furthermore, the compaction degree δ2 and the density ρ2 of the pavement after the regeneration of the new asphalt mixture are design values and are determined by the vacuum method test.

[0039] Furthermore, the contact floating ranging system includes:

[0040] Transverse guide rail 1;

[0041] Longitudinal floating profiling guide rod 2, which is driven by a servo motor (not shown in the figure) to move horizontally on the transverse guide rail 1;

[0042] Data sensor (not shown in the figure), which is connected to the longitudinal floating profiling guide rod 2 and is used to read the floating changes generated during the contact process between the longitudinal floating profiling guide rod 2 and the ground, calculate the height fluctuation value of the corresponding cross-section of the asphalt road, draw the contour map of the road cross-section in the height direction, and finally calculate the volume and mass of the old asphalt pavement.

[0043] When the present invention is specifically implemented:

[0044] 1) The vehicle starts, and the vehicle-mounted controller obtains the current vehicle speed v of the vehicle in real time; at the same time, the contact floating ranging system starts, such as Figure 1The floating ranging system shown moves from one end of the system to the other end, denoted as a sampling period \(t\). The sampling length of a single contact floating ranging system is \(X\), and the driving distance of the vehicle in one sampling period of the contact floating ranging system is set as \(L\). The width of a single lane for in-situ hot recycling construction is \(d\), and the height distance information of the current asphalt pavement cross-section is obtained by repeated sampling of reciprocating motion as \(y\). i ;

[0045] The rut volume of the old asphalt pavement obtained by each contact floating ranging system in one sampling period is \(\theta_1 = f(y ε )\times L(1);

[0046] In formula (1), \(f(y n )\) represents the cross-sectional area formed by ruts within one sampling period of the contact floating ranging device, and the calculation formula is

[0047] In formula (2), \(x\) represents the sampling interval distance of the contact floating ranging system, and the calculation formula is \(\varepsilon\) represents the number of samples in one sampling period of a single contact floating ranging system, and the calculation formula is where \(\gamma\) is the lateral moving speed of the contact floating ranging system, and \(v\) is the sampling frequency of the contact floating ranging system;

[0048] One sampling period of a single contact floating ranging system is

[0049] The driving distance \(L\) of the vehicle in one sampling period of the contact floating ranging system is

[0050] The number of contact floating ranging systems is

[0051] Then the mass of the old asphalt material after milling the old pavement in one sampling period is \(m_1 = n\theta_1\delta_1\rho_1(8)\), where \(\delta_1\) is the initial compaction degree of the old pavement, and \(\rho_1\) is the initial density of the old pavement;

[0052] Substituting formulas (1)-(7) into (8) gives

[0053] The mass of the new asphalt mixture required for the newly constructed pavement of this section in one sampling period is \(m_2\), then where \(h_2\) is the thickness of the pavement after recycling the new asphalt mixture, \(\delta_2\) is the compaction degree of the new asphalt mixture after recycling, and \(\rho_2\) is the density of the new asphalt mixture after recycling;

[0054] Then the addition ratio of the new asphalt mixture for the newly constructed pavement in one sampling period is:

[0055]

[0056] Among them, the vehicle speed v and the height distance information y i are obtained in real time. The initial compaction degree δ1 and density ρ1 of the old road surface are test values, and the compaction degree δ2, density ρ2, and thickness h2 of the new asphalt mixture after regeneration are design values. The sampling frequency η and sampling length X of the contact floating ranging system are set values.

Claims

1. A method for calculating the addition ratio of new asphalt mixture in in-situ hot recycling of asphalt pavement, characterized in that, It includes the following steps: S1. Intermittently measure the floating distance of the asphalt ground on the vehicle driving path by using a contact floating ranging system. The vehicle speed is v, and set the driving distance of the vehicle in one sampling period of the contact floating ranging system as L, and the width of a single lane for in-situ hot recycling construction is d; each time the contact floating ranging system samples, obtain the height distance information y on the current asphalt pavement cross-section i , the sampling length of a single contact floating ranging system is X, then the number of required floating ranging systems where the sampling period is the time for the contact floating ranging system to sample from one end to the other end, and one sampling period is where γ is the lateral moving speed of the contact floating ranging system; For each contact floating ranging system, the rut volume of the old asphalt pavement obtained in one sampling period is θ1 = f(y ε ) * L; S2. Detect the compaction degree δ1 and density ρ1 of the old road surface; S3. Set the milling depth h1 and the thickness h2 of the road surface after the regeneration of the new asphalt mixture; S4. Determine the compaction degree δ2 and density ρ2 of the new asphalt mixture after regeneration; S5. Calculate the mass of the old asphalt material after milling the old road surface and the mass of the new asphalt mixture required for the newly constructed road surface of this section Then the addition ratio of the new asphalt mixture 2. The method for calculating the addition ratio of new asphalt mixture in in-situ hot recycling of asphalt pavement according to claim 1, characterized in that, The compaction degree δ1 of the old road surface is cored and tested in an evaluation section of 200 meters, and the number of cores is not less than 5.

3. A method for calculating the addition ratio of new asphalt mixture in in-situ hot recycling of asphalt pavement according to claim 1, characterized in that, The density ρ1 of the old road surface is cored and tested in an evaluation section of 200 meters, and the number of cores is not less than 5.

4. A method for calculating the addition ratio of new asphalt mixture in in-situ hot recycling of asphalt pavement according to claim 1, characterized in that, The compaction degree δ2 and density ρ2 of the new asphalt mixture after regeneration are design values and are determined by the vacuum method test.

5. A method for calculating the addition ratio of new asphalt mixture in in-situ hot recycling of asphalt pavement according to any one of claims 1-4, characterized in that, The contact type floating ranging system includes: A transverse guide rail (1); A longitudinal floating profiling guide rod (2), which is driven by a servo motor to move horizontally on the transverse guide rail (1); A data sensor, which is connected to the longitudinal floating profiling guide rod (2) and is used to read the floating changes generated during the contact between the longitudinal floating profiling guide rod (2) and the ground, calculate the height fluctuation value of the corresponding cross-section asphalt road, draw the contour map of the road cross-section in the height direction, and finally calculate the volume and mass of the old asphalt road surface.

Images