CN113626986B - Asphalt pavement modulus gradient determination method and device and electronic equipment - Google Patents
Asphalt pavement modulus gradient determination method and device and electronic equipment Download PDFInfo
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Abstract
The invention relates to a method and a device for determining modulus gradient of an asphalt pavement, electronic equipment and a computer readable storage medium, wherein the method for determining modulus gradient of the asphalt pavement comprises the following steps: obtaining a transverse strain value, a vertical strain value and a corner of a pavement core sample test piece to obtain a fitting formula; planning and solving the modulus gradient model parameters of the asphalt pavement and the ratio of the top dynamic modulus to the bottom dynamic modulus of the test piece through the fitting formula to obtain the modulus gradient model parameters of the asphalt pavement and the initial ratio of the top dynamic modulus to the bottom dynamic modulus of the test piece; acquiring a dynamic modulus main curve, and acquiring top surface and bottom surface dynamic modulus under the conditions of set temperature and frequency according to the dynamic modulus main curve; and obtaining the modulus gradient of the asphalt pavement under the conditions of set temperature and frequency according to the modulus gradient model parameters of the asphalt pavement and the dynamic moduli of the top surface and the bottom surface. The method for determining the modulus gradient of the asphalt pavement disclosed by the invention realizes the determination of the modulus gradient of the asphalt pavement.
Description
Technical Field
The invention relates to the technical field of asphalt pavement evaluation, in particular to an asphalt pavement modulus gradient determination method, an asphalt pavement modulus gradient determination device, electronic equipment and a computer readable storage medium.
Background
During service, under the action of environmental factors such as temperature, ultraviolet rays, oxygen concentration and the like, asphalt in the asphalt pavement and oxygen in air undergo chemical reaction, and the properties undergo a series of changes, so that the asphalt pavement is aged. The aged asphalt pavement is hardened and embrittled, the durability is reduced, and fatigue cracking is more easily generated. In the aging process, oxygen in the air is firstly subjected to chemical reaction with the asphalt mixture on the surface of the asphalt pavement, and then is subjected to chemical reaction with the asphalt mixture in the asphalt pavement through the gaps. Because more time is needed for oxygen in the air to diffuse through the interconnected gaps into the deep part of the pavement, the oxygen concentration in the deep part of the pavement structure is lower, and the aging rate is slower, so that the non-uniform aging phenomenon of the asphalt pavement occurs along the depth direction.
The dynamic modulus of the asphalt mixture has a correlation with the aging and damage degree, and the higher the aging degree of the asphalt mixture is, the larger the dynamic modulus value is. The dynamic modulus of the aged asphalt pavement changes along the depth direction of the pavement, so that the modulus of the asphalt pavement is nonuniform. By researching the non-uniformity of the modulus of the aged asphalt pavement, the non-uniform aging phenomenon of the asphalt pavement can be represented. Meanwhile, the dynamic modulus gradient of the asphalt mixture is an important parameter in the design and evaluation of asphalt pavement, and can be applied to the mechanical response analysis of asphalt pavement. By using the analysis result of the mechanical response, the phenomena of permanent deformation, fatigue cracking and the like of the asphalt pavement can be estimated, so that the asphalt pavement is designed and evaluated, and the road engineering construction service is provided. However, in the current stage, when the asphalt pavement is designed and evaluated, the influence of the non-uniform aging effect on the dynamic modulus parameter of the asphalt pavement is often ignored, and the modulus of each structural layer is considered to be uniform, so that the analysis result is different from the actual service condition of the pavement. Whereas the prior art does little solution for determining the modulus gradient of asphalt pavement.
Disclosure of Invention
In view of the foregoing, it would be desirable to provide a method, apparatus, electronic device, and computer-readable storage medium for determining a modulus gradient of an asphalt pavement.
In order to achieve the above object, the present invention provides a method for determining a modulus gradient of an asphalt pavement, comprising:
obtaining a transverse strain value, a vertical strain value and a corner of a pavement core sample test piece, and fitting the transverse strain value, the vertical strain value and the corner to obtain a fitting formula;
planning and solving the modulus gradient model parameters of the asphalt pavement and the ratio of the top dynamic modulus to the bottom dynamic modulus of the test piece through the fitting formula to obtain the modulus gradient model parameters of the asphalt pavement and the initial ratio of the top dynamic modulus to the bottom dynamic modulus of the test piece;
acquiring a dynamic modulus main curve according to the modulus gradient model parameters of the asphalt pavement and the initial ratio of the top dynamic modulus and the bottom dynamic modulus of the test piece, and acquiring the top surface dynamic modulus and the bottom surface dynamic modulus under the set temperature and frequency conditions according to the dynamic modulus main curve;
and obtaining the modulus gradient of the asphalt pavement under the conditions of set temperature and frequency according to the modulus gradient model parameters of the asphalt pavement and the dynamic moduli of the top surface and the bottom surface.
Further, fitting the transverse strain value, the vertical strain value and the rotation angle to obtain a fitting formula, which specifically comprises: fitting the transverse strain value, the vertical strain value and the rotation angle to obtain a fitting formula
Wherein,for parameters->L is the side length of the cross section, d is the thickness of the test piece, t is the loading time, and F is m (t)、G m (t)、H m (t) is the transverse strain value, the vertical strain value and the rotation angle, l d/2 The height of the top surface of the test piece after deformation is l -d/2 The height of the bottom surface of the test piece after deformation.
Further, the method for planning and solving the modulus gradient model parameter of the asphalt pavement and the ratio of the top dynamic modulus to the bottom dynamic modulus of the test piece through the fitting formula specifically comprises the following steps: carrying out planning solution on the asphalt pavement modulus gradient model parameter n and the initial ratio k of the top and bottom dynamic moduli of the test piece by using the fitting formula and the planning formula, wherein the planning formula is that
Wherein,
further, a dynamic modulus main curve is obtained according to the modulus gradient model parameter of the asphalt pavement and the initial ratio of the top dynamic modulus and the bottom dynamic modulus of the test piece, and the method specifically comprises the following steps: and acquiring dynamic moduli of the bottom surface, the middle part and the top surface of the test piece, and acquiring a dynamic modulus main curve according to the asphalt pavement modulus gradient model parameters, the initial ratio of the dynamic moduli of the top and the bottom of the test piece and the dynamic moduli of the bottom surface, the middle part and the top surface of the test piece.
Further, acquiring dynamic moduli of the bottom surface, the middle part and the top surface of the test piece, and acquiring a dynamic modulus main curve according to the parameter of the asphalt pavement modulus gradient model, the initial ratio of the dynamic moduli of the top and the bottom of the test piece and the dynamic moduli of the bottom surface, the middle part and the top surface of the test piece, wherein the dynamic modulus main curve specifically comprises:
acquiring dynamic modulus of the bottom surface, the middle part and the top surface of the test piece by using a dynamic modulus formula, and acquiring a dynamic modulus main curve according to the modulus gradient model parameter of the asphalt pavement, the initial ratio of the dynamic modulus of the top part and the bottom part of the test piece, the dynamic modulus of the bottom surface, the middle part and the top surface of the test piece and the dynamic modulus main curve formula, wherein the dynamic modulus formula is as follows
Wherein E is -d/2 * (omega) is the dynamic modulus of the bottom surface of the test piece,for the dynamic modulus of the top surface of the test piece>The dynamic modulus of the middle part of the test piece is represented by n, the modulus gradient model parameter of the asphalt pavement, k is the initial ratio of the dynamic modulus of the top and the bottom of the test piece, w is the frequency, and J' -d/2 (ω)、J″ -d/2 (omega) is the real and imaginary parts of creep compliance, respectively, the dynamic modulus principal curve formula is
Wherein E is * (omega) is dynamic modulus, omega is loading frequency, delta is dynamic modulus minimum, alpha is difference of ordinate of upper and lower asymptotes of main curve, beta, gamma, lambda is shape parameter, alpha T Is a factor of-Wen Yiwei.
Further, the method for determining the modulus gradient of the asphalt pavement further comprises the step of obtaining a time-Wen Yiwei factor through a time-Wen Yiwei factor formula, wherein the time-Wen Yiwei factor formula is as followsWherein C is 1 、C 2 Respectively fitting parameters, t is the test temperature, t 0 For reference temperature, a T Is a factor of-Wen Yiwei.
Further, according to the modulus gradient model parameters of the asphalt pavement, the top surface and the bottom surface dynamic modulus, obtaining the modulus gradient of the asphalt pavement under the conditions of set temperature and frequency, specifically comprising:
obtaining the modulus gradient of the asphalt pavement under the conditions of set temperature and frequency according to the modulus gradient model parameters of the asphalt pavement, the dynamic modulus of the top surface and the bottom surface and the modulus gradient model formula, wherein the modulus gradient model formula is as follows
Wherein E (z) is a dynamic modulus value at the road surface depth z, E d/2 For the surface modulus of the test piece, E -d/2 The modulus of the bottom surface of the test piece, d is the thickness of the test piece, n is a model parameter, and k is 1 The test ratio of the dynamic modulus at the top and bottom of the test piece is shown.
The invention also provides a device for determining the modulus gradient of the asphalt pavement, which comprises a test piece data processing module, a planning solving module, a dynamic modulus acquisition module and a modulus gradient determining module;
the test piece data processing module is used for acquiring a transverse strain value, a vertical strain value and a corner of the pavement core sample test piece, and fitting the transverse strain value, the vertical strain value and the corner to obtain a fitting formula;
the planning and solving module is used for planning and solving the modulus gradient model parameter of the asphalt pavement and the ratio of the top dynamic modulus and the bottom dynamic modulus of the test piece through the fitting formula to obtain the initial ratio of the modulus gradient model parameter of the asphalt pavement and the top dynamic modulus and the bottom dynamic modulus of the test piece;
the dynamic modulus acquisition module is used for acquiring a dynamic modulus main curve according to the parameter of the asphalt pavement modulus gradient model and the initial ratio of the dynamic moduli at the top and the bottom of the test piece, and acquiring the top surface dynamic modulus and the bottom surface dynamic modulus under the conditions of set temperature and frequency according to the dynamic modulus main curve;
the modulus gradient determining module is used for obtaining the modulus gradient of the asphalt pavement under the conditions of set temperature and frequency according to the modulus gradient model parameters of the asphalt pavement and the dynamic moduli of the top surface and the bottom surface.
The invention also provides electronic equipment, which comprises a memory and a processor, wherein the memory is stored with a computer program, and the computer program realizes the method for determining the modulus gradient of the asphalt pavement according to any technical scheme when being executed by the processor.
The present invention also provides a computer-readable storage medium having stored thereon a computer program which, when executed by a processor, implements a method for determining a modulus gradient of an asphalt pavement according to any of the above-described aspects.
The beneficial effects of adopting the embodiment are as follows: fitting the transverse strain value, the vertical strain value and the corner by acquiring the transverse strain value, the vertical strain value and the corner of the pavement core sample test piece to obtain a fitting formula; planning and solving the modulus gradient model parameters of the asphalt pavement and the ratio of the top dynamic modulus to the bottom dynamic modulus of the test piece through the fitting formula to obtain the modulus gradient model parameters of the asphalt pavement and the initial ratio of the top dynamic modulus to the bottom dynamic modulus of the test piece; acquiring a dynamic modulus main curve according to the modulus gradient model parameters of the asphalt pavement and the initial ratio of the top dynamic modulus and the bottom dynamic modulus of the test piece, and acquiring the top surface dynamic modulus and the bottom surface dynamic modulus under the set temperature and frequency conditions according to the dynamic modulus main curve; obtaining the modulus gradient of the asphalt pavement under the conditions of set temperature and frequency according to the modulus gradient model parameters of the asphalt pavement and the dynamic moduli of the top surface and the bottom surface; the determination of the modulus gradient of the asphalt pavement is realized.
Drawings
FIG. 1 is a schematic flow chart of an embodiment of a method for determining modulus gradient of an asphalt pavement according to the present invention;
fig. 2 is a schematic diagram of cutting an integral pavement core sample according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of a test piece cutting process according to an embodiment of the present invention;
FIG. 4 is a diagram illustrating strain measurement according to an embodiment of the present invention;
FIG. 5 is a schematic diagram showing the acquisition of strain at different positions of a test piece according to the embodiment of the present invention along with the change of loading time;
FIG. 6 is a schematic diagram of a dynamic modulus main curve provided by an embodiment of the present invention;
FIG. 7 is a schematic representation of modulus gradients provided by embodiments of the present invention;
fig. 8 is a block diagram of an apparatus for determining a modulus gradient of an asphalt pavement according to an embodiment of the present invention.
Detailed Description
Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form a part hereof, and together with the description serve to explain the principles of the invention, and are not intended to limit the scope of the invention.
In one embodiment of the present invention, a method for determining a modulus gradient of an asphalt pavement is disclosed, and the method for determining a modulus gradient of an asphalt pavement includes:
step S1, obtaining a transverse strain value, a vertical strain value and a corner of a pavement core sample test piece, and fitting the transverse strain value, the vertical strain value and the corner to obtain a fitting formula;
s2, planning and solving the parameters of the asphalt pavement modulus gradient model and the ratio of the top dynamic modulus to the bottom dynamic modulus of the test piece through the fitting formula to obtain the parameters of the asphalt pavement modulus gradient model and the initial ratio of the top dynamic modulus to the bottom dynamic modulus of the test piece;
s3, acquiring a dynamic modulus main curve according to the modulus gradient model parameter of the asphalt pavement and the initial ratio of the top dynamic modulus and the bottom dynamic modulus of the test piece, and acquiring the top surface dynamic modulus and the bottom surface dynamic modulus under the conditions of set temperature and frequency according to the dynamic modulus main curve;
and S4, obtaining the modulus gradient of the asphalt pavement under the conditions of set temperature and frequency according to the modulus gradient model parameters of the asphalt pavement and the dynamic moduli of the top surface and the bottom surface.
In one embodiment, a field core sample (the diameter of the core sample can be 15 cm) is drilled at the road shoulder of the asphalt pavement, the core sample structure comprises a pavement asphalt mixture surface layer and a part of base layer, and the service time of the pavement is considered as the aging time of the pavement core sample; cutting the whole pavement core sample, and separating the upper surface layer, the middle surface layer and the lower surface layer of the pavement with different asphalt mixture types, wherein the cutting schematic diagram of the whole pavement core sample is shown in fig. 2.
Cutting a pavement core sample cylinder test piece with the diameter of 15cm by adopting a cutting saw, and cutting the test piece into a cuboid test piece with the length of 100mm, the width of 100mm and the thickness of 40-60mm, wherein the cutting process is mainly divided into the following three steps, as shown in figure 3, the rough upper surface of the pavement core sample is subjected to grinding treatment, the loss of the thickness of the test piece is reduced as much as possible in the process, and the upper surface and the lower surface of the ground test piece are flat, so that the stress of the surface of the test piece is uniform in the test; cutting off the base layer along the boundary line of each structural layer of the core sample, and cutting and separating the upper, middle and lower layers; the cylindrical test pieces of each structural layer were cut into rectangular test pieces having a cross section of 100mm×100mm along the cross section.
In another embodiment, 6 groups of LVDTs are mounted on the surface of the test piece and are used for measuring the strain at different positions of the test piece during the test, and a strain measurement schematic diagram is shown in fig. 4. LVDT (Linear Displacement sensor) on the front side and the rear side in the vertical direction are used for testing vertical strain of the top surface and the bottom surface of a test piece, LVDT on the other two sides in the 2 groups in the vertical direction are used for measuring strain of the middle of the test piece, LVDT on the horizontal direction are used for measuring transverse deformation of the test piece, gauge length of the LVDT in the vertical direction is 70mm, and gauge length of the LVDT in the horizontal direction is the thickness of the test piece.
A Material Tester (MTS) is adopted to carry out uniaxial compression creep test, the test temperatures are respectively 5 ℃, 20 ℃ and 35 ℃, the test temperatures are sequentially carried out from low temperature to high temperature, and before the corresponding temperature test is carried out, the test piece is required to be subjected to health maintenance in an environment box for 4 hours so as to ensure that the internal temperature of the test piece reaches balance. In order to ensure that the test piece is in a linear viscoelastic phase during loading, a suitable loading force is determined by a exploratory test prior to testing, so that the total strain generated by the test piece during testing does not exceed 150 mu epsilon. Three parallel tests were performed on each test piece, and a schematic diagram of the collection of strain at different positions of the test piece according to the change of loading time was shown in fig. 5. Taking the average value of the three results for subsequent analysis; each set of tests was spaced 15 minutes apart to ensure that the test pieces were fully recovered from the viscoelastic strain experienced. The transverse strain value, the vertical strain value and the corner of the pavement core sample test piece can be obtained through the method.
As a preferred embodiment, fitting the transverse strain value, the vertical strain value and the rotation angle to obtain a fitting formula specifically includes: fitting the transverse strain value, the vertical strain value and the rotation angle to obtain a fitting formula
Wherein,for parameters->L is the side length of the cross section, d is the thickness of the test piece, t is the loading time, and F is m (t)、G m (t)、H m (t) is the transverse strain value, the vertical strain value and the rotation angle, l d/2 The height of the top surface of the test piece after deformation is l -d/2 The height of the bottom surface of the test piece after deformation.
In a specific embodiment, the transverse strain value, the vertical strain value and the rotation angle are fitted to obtain a fitting formula
Wherein,is a model parameter (fitting parameter), t is a loading time, s.
As a preferred embodiment, the method for planning and solving the modulus gradient model parameter of the asphalt pavement and the ratio of the top dynamic modulus and the bottom dynamic modulus of the test piece through the fitting formula specifically comprises the following steps: carrying out planning solution on the asphalt pavement modulus gradient model parameter n and the initial ratio k of the top and bottom dynamic moduli of the test piece by using the fitting formula and the planning formula, wherein the planning formula is that
Wherein,l is the side length of the cross section, d is the thickness of the test piece, < >>
As a preferred embodiment, the method for obtaining the dynamic modulus main curve according to the asphalt pavement modulus gradient model parameter and the initial ratio of the top and bottom dynamic moduli of the test piece specifically comprises the following steps: and acquiring dynamic moduli of the bottom surface, the middle part and the top surface of the test piece, and acquiring a dynamic modulus main curve according to the asphalt pavement modulus gradient model parameters, the initial ratio of the dynamic moduli of the top and the bottom of the test piece and the dynamic moduli of the bottom surface, the middle part and the top surface of the test piece.
As a preferred embodiment, the dynamic modulus of the bottom surface, the middle part and the top surface of the test piece are obtained, and the dynamic modulus main curve is obtained according to the modulus gradient model parameter of the asphalt pavement, the initial ratio of the dynamic modulus of the top and the bottom of the test piece and the dynamic modulus of the bottom surface, the middle part and the top surface of the test piece, which specifically comprises the following steps:
acquiring dynamic modulus of the bottom surface, the middle part and the top surface of the test piece by using a dynamic modulus formula, and acquiring a dynamic modulus main curve according to the modulus gradient model parameter of the asphalt pavement, the initial ratio of the dynamic modulus of the top part and the bottom part of the test piece, the dynamic modulus of the bottom surface, the middle part and the top surface of the test piece and the dynamic modulus main curve formula, wherein the dynamic modulus formula is as follows
Wherein E is -d/2 * (omega) is the dynamic modulus of the bottom surface of the test piece,for the dynamic modulus of the top surface of the test piece>The dynamic modulus of the middle part of the test piece is represented by n, the modulus gradient model parameter of the asphalt pavement, k is the initial ratio of the dynamic modulus of the top and the bottom of the test piece, w is the frequency, and J' -d/2 (ω)、J″ -d/2 (omega) is the real and imaginary parts of creep compliance, respectively, the dynamic modulus principal curve formula is
Wherein E is * (omega) is dynamic modulus, omega is loading frequency, delta is dynamic modulus minimum, alpha is difference of ordinate of upper and lower asymptotes of main curve, beta, gamma, lambda is shape parameter, alpha T Is a factor of-Wen Yiwei.
In one embodiment, the loading frequencyJ′ -d/2 (ω)、J″ -d/2 (ω) is the real and imaginary parts of the creep compliance,
as a preferred embodiment, the asphalt pavement modulus gradient determination method further comprises the step of obtaining a time-Wen Yiwei factor through a time-Wen Yiwei factor formula, wherein the time-Wen Yiwei factor formula is as followsWherein C is 1 、C 2 Respectively fitting parameters, t is the test temperature, t 0 For reference temperature, a T Is a factor of-Wen Yiwei.
During pavement design and evaluation, the dynamic modulus at 20 ℃ and 10Hz is generally adopted, so that the dynamic modulus of the asphalt pavement in a wider frequency range is determined by drawing a dynamic modulus main curve, and the change trend of the dynamic modulus of the asphalt pavement in a corresponding frequency along with the depth of the pavement is obtained, thereby providing a basis for the subsequent analysis of the mechanical response condition of the asphalt pavement in long-term service under the action of vehicle load. Drawing a dynamic modulus main curve, wherein the dynamic modulus main curve is shown in the following formula;
wherein E is * (ω) is dynamic modulus, MPa; omega is the loading frequency, rad/s; delta is the minimum value of dynamic modulus and MPa; alpha is the difference value of the ordinate of the upper and lower asymptotes of the main curve and MPa; beta, gamma and lambda are shape parameters; alpha T Is a time-Wen Yiwei factor, calculated by the following formula;
wherein C is 1 、C 2 Fitting parameters; t is the test temperature, DEG C; t is t 0 For reference temperature, DEG C
As a preferred embodiment, obtaining the asphalt pavement modulus gradient under the set temperature and frequency conditions according to the asphalt pavement modulus gradient model parameters and the top surface and bottom surface dynamic moduli specifically comprises:
obtaining the modulus gradient of the asphalt pavement under the conditions of set temperature and frequency according to the modulus gradient model parameters of the asphalt pavement, the dynamic modulus of the top surface and the bottom surface and the modulus gradient model formula, wherein the modulus gradient model formula is as follows
Wherein E (z) is a dynamic modulus value at the road surface depth z, E d/2 For the surface modulus of the test piece, E -d/2 The modulus of the bottom surface of the test piece, d is the thickness of the test piece, n is a model parameter, and k is 1 The test ratio of the dynamic modulus at the top and bottom of the test piece is shown.
In one embodiment, uniaxial compression tests are performed on the pavement core sample upper, middle and lower test pieces to determine n and k and the dynamic moduli E of the bottom, middle and top surfaces of the test pieces -d/2 、E 0 、E d/2 The method comprises the steps of carrying out a first treatment on the surface of the By the formulaAnd determining the change of the dynamic modulus of the upper, middle and lower layers of the pavement along with the depth, thereby obtaining the change trend of the dynamic modulus of the whole asphalt surface layer along with the depth.
In another embodiment, depending on the Hubei section of the Beijing Kong Australian highway, the construction is carried out in 2002, the coring time is 2018, the service time of the pavement during coring is 16 years, the aging time of a core sample at the road shoulder is 16 years, the pavement core sample comprises an upper layer, a middle layer and a lower layer, the pavement structure of the Hubei section of the Beijing Kong Australian highway is a super-wave-12.5 type structure with the thickness of 4cm on the upper layer, the middle layer is an AC-20I type structure with the thickness of 6cm, and the lower layer is an AC-20S type structure with the thickness of 6 cm. The sizes of test pieces of the upper, middle and lower layers of the actual core sample are respectively 100mm long by 100mm wide by 35mm high, 56mm and 56mm, wherein the sizes of the test pieces of the upper, middle and lower layers are 3.5cm, 5.6cm and 5.6 cm; the change of strain with time at 5 ℃, 20 ℃, 35 ℃ in the top, middle, bottom and transverse directions of the test piece under a constant load was measured by a uniaxial compression creep test, and is shown in fig. 3. The top surface, the middle part and the bottom surface of the test piece are different in strain, so that the material performance of the asphalt pavement at different depths is different, the top surface strain is minimum, the bottom surface strain is maximum, the dynamic modulus of the test piece is maximum at the top surface, and the bottom surface is minimum, so that the dynamic modulus of the test piece is unevenly distributed along the depth direction due to the uneven aging phenomenon, and the modulus gradient phenomenon exists.
Fitting the top surface, the middle part, the bottom surface, the transverse strain and the change condition of the corner of the test piece along with the loading time to determine model parameters, thereby determining the dynamic modulus of the bottom surface, the middle part and the top surface of each structural layer within the range of 0.004rad/s-0.01 rad/s; according to the result of the pavement modulus gradient deduction, the dynamic modulus of the upper layer, the middle layer and the lower layer of the asphalt pavement can be determined to take curves along with the change of depth under each frequency, wherein the dynamic modulus of each structural layer with the ratio of 0.01rad/s is as follows,for middle level->For the lower layer->To obtain the dynamic modulus in a wider frequency range, drawing a dynamic modulus main curve, wherein the dynamic modulus main curve is shown in fig. 6, and the dynamic modulus main curve parameters of each structural layer are obtained as shown in table 1;
TABLE 1
In the process of pavement design and evaluation, the dynamic modulus at 20 ℃ and 10Hz is adopted, and the modulus gradient condition of the asphalt pavement at the frequency can be determined according to the dynamic modulus main curve, as shown in table 2;
TABLE 2
From the relevant parameters in Table 2, the dynamic modulus trend with depth of the asphalt pavement at 20 ℃ and 10Hz can be plotted as shown in the figure. By testing the modulus non-uniformity of the asphalt pavement, the modulus gradient phenomenon of the asphalt pavement can be determined, wherein the modulus gradient phenomenon is shown in a schematic diagram in fig. 7, and the modulus gradient phenomenon is shown in an upper layer, a middle layer and a lower layer after the asphalt pavement is aged for 16 years.
The embodiment of the invention provides a device for determining modulus gradient of an asphalt pavement, which is structurally characterized in that the device comprises a test piece data processing module 1, a planning solving module 2, a dynamic modulus obtaining module 3 and a modulus gradient determining module 4 as shown in fig. 8;
the test piece data processing module 1 is used for obtaining a transverse strain value, a vertical strain value and a corner of a pavement core sample test piece, and fitting the transverse strain value, the vertical strain value and the corner to obtain a fitting formula;
the planning and solving module 2 is used for planning and solving the modulus gradient model parameter of the asphalt pavement and the ratio of the top and bottom dynamic moduli of the test piece through the fitting formula to obtain the initial ratio of the modulus gradient model parameter of the asphalt pavement and the top and bottom dynamic moduli of the test piece;
the dynamic modulus acquisition module 3 is used for acquiring a dynamic modulus main curve according to the parameter of the asphalt pavement modulus gradient model and the initial ratio of the dynamic moduli at the top and the bottom of the test piece, and acquiring the top surface dynamic modulus and the bottom surface dynamic modulus under the conditions of set temperature and frequency according to the dynamic modulus main curve;
the modulus gradient determining module 4 is configured to obtain a modulus gradient of the asphalt pavement under the conditions of a set temperature and a set frequency according to the modulus gradient model parameter of the asphalt pavement and the dynamic moduli of the top surface and the bottom surface.
An embodiment of the present invention provides an electronic device, including a memory and a processor, where the memory stores a computer program, and when the computer program is executed by the processor, the method for determining a modulus gradient of an asphalt pavement according to any one of the above embodiments is implemented.
An embodiment of the present invention provides a computer-readable storage medium having stored thereon a computer program which, when executed by a processor, implements a method including determining a modulus gradient of an asphalt pavement according to any of the above embodiments.
The invention discloses a method, a device, electronic equipment and a computer readable storage medium for determining modulus gradient of an asphalt pavement, wherein a fitting formula is obtained by obtaining a transverse strain value, a vertical strain value and a corner of a pavement core sample test piece and fitting the transverse strain value, the vertical strain value and the corner; planning and solving the modulus gradient model parameters of the asphalt pavement and the ratio of the top dynamic modulus to the bottom dynamic modulus of the test piece through the fitting formula to obtain the modulus gradient model parameters of the asphalt pavement and the initial ratio of the top dynamic modulus to the bottom dynamic modulus of the test piece; acquiring a dynamic modulus main curve according to the modulus gradient model parameters of the asphalt pavement and the initial ratio of the top dynamic modulus and the bottom dynamic modulus of the test piece, and acquiring the top surface dynamic modulus and the bottom surface dynamic modulus under the set temperature and frequency conditions according to the dynamic modulus main curve; obtaining the modulus gradient of the asphalt pavement under the conditions of set temperature and frequency according to the modulus gradient model parameters of the asphalt pavement and the dynamic moduli of the top surface and the bottom surface; the determination of the modulus gradient of the asphalt pavement is realized.
The asphalt pavement modulus gradient determined by the technical scheme of the invention can represent the non-uniform aging phenomenon of the asphalt pavement after long-term service, and the pavement evaluation and design work can be perfected by determining the non-uniform performance of the pavement dynamic modulus after long-term aging, so that the asphalt pavement modulus gradient has great significance for road engineering construction.
Those skilled in the art will appreciate that all or part of the flow of the methods of the embodiments described above may be accomplished by way of a computer program to instruct associated hardware, where the program may be stored on a computer readable storage medium. Wherein the computer readable storage medium is a magnetic disk, an optical disk, a read-only memory or a random access memory, etc.
The present invention is not limited to the above-mentioned embodiments, and any changes or substitutions that can be easily understood by those skilled in the art within the technical scope of the present invention are intended to be included in the scope of the present invention.
Claims (7)
1. A method for determining a modulus gradient of an asphalt pavement, comprising:
obtaining a transverse strain value, a vertical strain value and a corner of a pavement core sample test piece, and fitting the transverse strain value, the vertical strain value and the corner to obtain a fitting formula;
planning and solving the modulus gradient model parameters of the asphalt pavement and the ratio of the top dynamic modulus to the bottom dynamic modulus of the test piece through the fitting formula to obtain the modulus gradient model parameters of the asphalt pavement and the initial ratio of the top dynamic modulus to the bottom dynamic modulus of the test piece;
acquiring a dynamic modulus main curve according to the modulus gradient model parameters of the asphalt pavement and the initial ratio of the top dynamic modulus and the bottom dynamic modulus of the test piece, and acquiring the top surface dynamic modulus and the bottom surface dynamic modulus under the set temperature and frequency conditions according to the dynamic modulus main curve;
obtaining the modulus gradient of the asphalt pavement under the conditions of set temperature and frequency according to the modulus gradient model parameters of the asphalt pavement and the dynamic moduli of the top surface and the bottom surface;
wherein, the fitting formula is:
wherein,for parameters->，LFor the side length of the cross section,dthe thickness of the test piece is given by the thickness of the test piece,tfor loading time, the ∈>、/>、/>Respectively a transverse strain value, a vertical strain value and a corner,>is the height of the top surface of the test piece after deformation, +.>The height of the bottom surface of the deformed test piece;
planning and solving the modulus gradient model parameter of the asphalt pavement and the ratio of the top dynamic modulus and the bottom dynamic modulus of the test piece through the fitting formula, wherein the method specifically comprises the following steps: carrying out planning solution on the asphalt pavement modulus gradient model parameter n and the initial ratio k of the top and bottom dynamic moduli of the test piece by using the fitting formula and the planning formula, wherein the planning formula is that
Wherein,，/>，/>，/>；
acquiring dynamic modulus of the bottom surface, the middle part and the top surface of the test piece, and acquiring a dynamic modulus main curve according to the modulus gradient model parameter of the asphalt pavement, the initial ratio of the dynamic modulus of the top and the bottom of the test piece and the dynamic modulus of the bottom surface, the middle part and the top surface of the test piece, wherein the dynamic modulus main curve specifically comprises the following steps:
acquiring dynamic modulus of the bottom surface, the middle part and the top surface of the test piece by using a dynamic modulus formula, and acquiring a dynamic modulus main curve according to the modulus gradient model parameter of the asphalt pavement, the initial ratio of the dynamic modulus of the top part and the bottom part of the test piece, the dynamic modulus of the bottom surface, the middle part and the top surface of the test piece and the dynamic modulus main curve formula, wherein the dynamic modulus formula is as follows
Wherein,for the dynamic modulus of the bottom surface of the test piece,/>For the dynamic modulus of the top surface of the test piece>Is the dynamic modulus of the middle part of the test piece,nis a modulus gradient model parameter of the asphalt pavement,kthe initial ratio of the top and bottom dynamic moduli of the test piece,the dynamic modulus main curve formula is that
Wherein,for dynamic modulus>In order to load the frequency of the signal,δfor the dynamic modulus minimum value,αis the difference of the ordinate of the upper and lower asymptotes of the main curve,β、γ、λfor shape parameters +.>Is a factor of-Wen Yiwei.
2. The method for determining the modulus gradient of the asphalt pavement according to claim 1, wherein the step of obtaining the main dynamic modulus curve according to the modulus gradient model parameter of the asphalt pavement and the initial ratio of the top dynamic modulus to the bottom dynamic modulus of the test piece comprises the following steps: and acquiring dynamic moduli of the bottom surface, the middle part and the top surface of the test piece, and acquiring a dynamic modulus main curve according to the asphalt pavement modulus gradient model parameters, the initial ratio of the dynamic moduli of the top and the bottom of the test piece and the dynamic moduli of the bottom surface, the middle part and the top surface of the test piece.
3. The method of claim 1, further comprising obtaining a time-Wen Yiwei factor from a time-Wen Yiwei factor formula, the time-Wen Yiwei factor formula beingWherein, the method comprises the steps of, wherein,C 1 、C 2 the parameters are respectively the fitting parameters of the method,tin order to test the temperature of the test piece,t 0 for reference temperature->Is a factor of-Wen Yiwei.
4. The method for determining the modulus gradient of the asphalt pavement according to claim 1, wherein the obtaining the modulus gradient of the asphalt pavement under the condition of set temperature and frequency according to the modulus gradient model parameter of the asphalt pavement, the top surface dynamic modulus and the bottom surface dynamic modulus comprises the following steps:
obtaining the modulus gradient of the asphalt pavement under the conditions of set temperature and frequency according to the modulus gradient model parameters of the asphalt pavement, the dynamic modulus of the top surface and the bottom surface and the modulus gradient model formula, wherein the modulus gradient model formula is as follows:
wherein,E(z) is the dynamic modulus value at road depth z,E d/2 the modulus of the surface of the test piece,E -d/2 is the modulus of the bottom surface of the test piece,dthe thickness of the test piece is given by the thickness of the test piece,nas a parameter of the model, it is possible to provide,k 1 the test ratio of the dynamic modulus at the top and bottom of the test piece is shown.
5. The device for determining the modulus gradient of the asphalt pavement is characterized by comprising a test piece data processing module, a planning solving module, a dynamic modulus obtaining module and a modulus gradient determining module;
the test piece data processing module is used for acquiring a transverse strain value, a vertical strain value and a corner of the pavement core sample test piece, and fitting the transverse strain value, the vertical strain value and the corner to obtain a fitting formula;
the planning and solving module is used for planning and solving the modulus gradient model parameter of the asphalt pavement and the ratio of the top dynamic modulus and the bottom dynamic modulus of the test piece through the fitting formula to obtain the initial ratio of the modulus gradient model parameter of the asphalt pavement and the top dynamic modulus and the bottom dynamic modulus of the test piece;
the dynamic modulus acquisition module is used for acquiring a dynamic modulus main curve according to the parameter of the asphalt pavement modulus gradient model and the initial ratio of the dynamic moduli at the top and the bottom of the test piece, and acquiring the top surface dynamic modulus and the bottom surface dynamic modulus under the conditions of set temperature and frequency according to the dynamic modulus main curve;
the modulus gradient determining module is used for obtaining the modulus gradient of the asphalt pavement under the conditions of set temperature and frequency according to the modulus gradient model parameters of the asphalt pavement and the dynamic moduli of the top surface and the bottom surface;
wherein, the fitting formula is:
wherein,for parameters->，LFor the side length of the cross section,dthe thickness of the test piece is given by the thickness of the test piece,tfor loading time, the ∈>、/>、/>Respectively a transverse strain value, a vertical strain value and a corner,>is the height of the top surface of the test piece after deformation, +.>The height of the bottom surface of the deformed test piece;
planning and solving the modulus gradient model parameter of the asphalt pavement and the ratio of the top dynamic modulus and the bottom dynamic modulus of the test piece through the fitting formula, wherein the method specifically comprises the following steps: carrying out planning solution on the asphalt pavement modulus gradient model parameter n and the initial ratio k of the top and bottom dynamic moduli of the test piece by using the fitting formula and the planning formula, wherein the planning formula is that
Wherein,，/>，/>，/>；
acquiring dynamic modulus of the bottom surface, the middle part and the top surface of the test piece, and acquiring a dynamic modulus main curve according to the modulus gradient model parameter of the asphalt pavement, the initial ratio of the dynamic modulus of the top and the bottom of the test piece and the dynamic modulus of the bottom surface, the middle part and the top surface of the test piece, wherein the dynamic modulus main curve specifically comprises the following steps:
acquiring dynamic modulus of the bottom surface, the middle part and the top surface of the test piece by using a dynamic modulus formula, and acquiring a dynamic modulus main curve according to the modulus gradient model parameter of the asphalt pavement, the initial ratio of the dynamic modulus of the top part and the bottom part of the test piece, the dynamic modulus of the bottom surface, the middle part and the top surface of the test piece and the dynamic modulus main curve formula, wherein the dynamic modulus formula is as follows
Wherein,for the dynamic modulus of the bottom surface of the test piece,/>For the dynamic modulus of the top surface of the test piece>Is the dynamic modulus of the middle part of the test piece,nis a modulus gradient model parameter of the asphalt pavement,kthe initial ratio of the top and bottom dynamic moduli of the test piece,wfor frequency +.>The dynamic modulus main curve formula is that
Wherein,for dynamic modulus>In order to load the frequency of the signal,δfor the dynamic modulus minimum value,αis the difference of the ordinate of the upper and lower asymptotes of the main curve,β、γ、λfor shape parameters +.>Is a factor of-Wen Yiwei.
6. An electronic device comprising a memory and a processor, the memory having stored thereon a computer program which, when executed by the processor, implements the method comprising determining the modulus gradient of an asphalt pavement as defined in any one of claims 1-4.
7. A computer-readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the method comprising determining the modulus gradient of an asphalt pavement according to any one of claims 1-4.
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