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CN-122020235-A - Early warning method for concentrated burst period of fatigue cracks of semi-rigid base asphalt pavement

CN122020235ACN 122020235 ACN122020235 ACN 122020235ACN-122020235-A

Abstract

The invention discloses an early warning method for a concentrated burst period of fatigue cracks of a semi-rigid base asphalt pavement, which comprises the following steps of judging a macroscopic development stage of a transverse crack based on the structural type and service life of a target pavement, identifying a road section in the gentle development stage of relatively slow crack expansion rate as a potential risk section, detecting the crack density of the road section in the gentle development stage, calculating the total length of the crack in a unit area as a crack surface density index, comparing the index with a preset first-level threshold value to primarily evaluate the development degree of the macroscopic crack, selecting a representative crack position on the road section to drill an asphalt surface core sample, extracting an asphalt mortar material of an upper layer, testing complex shear modulus and a phase angle through a rheological test, calculating a microcrack early warning index reflecting the fatigue performance of the material based on the complex shear modulus and the phase angle, dividing the microcrack early warning index into different early warning grades according to the numerical range of the microcrack early warning index, and formulating a differential pavement detection frequency, a coring period or engineering strategy for different early warning grades and crack densities according to the comparison result of the crack surface density index and the preset threshold value, and is suitable for a complex fitting practice model of a large-scale maintenance network.

Inventors

  • JIANG JIWANG
  • NI FUJIAN
  • XU DUO
  • LAI XIAOFENG
  • ZHENG JUNQIU
  • DING ZIHAO
  • FAN YUNLONG
  • ZHANG ZHANMING

Assignees

  • 东南大学

Dates

Publication Date
20260512
Application Date
20251215

Claims (10)

  1. 1. The early warning method for the concentrated burst period of the fatigue crack of the semi-rigid base asphalt pavement is characterized by comprising the following steps of: (1) Judging the macroscopic development stage of the transverse crack based on the structure type and service life of the target pavement, and identifying the road section in the gentle development stage with relatively slow crack expansion rate as a potential risk section; (2) Detecting the crack density of a road section in a gentle development stage, calculating the total length of the crack in a unit area as a crack surface density index, and comparing the index with a preset first-level threshold value to primarily evaluate the development degree of the macroscopic crack; (3) Drilling an asphalt surface layer core sample at a representative crack position of a road section, extracting an asphalt mortar material of an upper layer, testing complex shear modulus and phase angle through a rheological test, and calculating a microcrack early warning index reflecting the fatigue performance of the material based on the complex shear modulus and the phase angle; (4) Dividing the microcrack early warning index into different early warning grades according to the numerical range of the microcrack early warning index, and then formulating different pavement detection frequencies, coring periods or maintenance engineering strategies according to the comparison result of the crack surface density index and the preset threshold value in the step (2) aiming at different early warning grade and crack density combinations.
  2. 2. The method for early warning of a concentrated burst period of fatigue cracks of a semi-rigid base asphalt pavement according to claim 1, wherein in the step (1), the macroscopic development stage comprises an initial stage of small number of cracks and slow growth, a rapid development stage of rapid increase of the number of cracks, a gentle development stage of slow crack expansion rate, and a secondary acceleration stage of rapid crack expansion again until concentrated burst.
  3. 3. The method for early warning of concentrated burst of fatigue cracks of a semi-rigid base asphalt pavement according to claim 2, wherein the stage is judged by matching the service life of the pavement with a key time node preset based on a structure type, wherein the key time node comprises a first node for identifying a gradual development stage and a second node for identifying a secondary acceleration development stage.
  4. 4. The method for early warning of a concentrated burst period of fatigue cracks of a semi-rigid base asphalt pavement according to claim 1, wherein in the step (2), the crack surface density index comprehensively considers the lengths of transverse cracks, longitudinal cracks and strip repairs.
  5. 5. The method for early warning of a concentrated burst period of fatigue cracks of a semi-rigid base asphalt pavement according to claim 1, wherein in the step (2), a preset first-level threshold is used for defining whether the crack development enters a precursor state of secondary accelerated development.
  6. 6. The method for early warning the concentrated burst period of the fatigue cracks of the semi-rigid base asphalt pavement according to claim 1, wherein in the step (3), the early warning index of the microcracks is obtained by squaring the product of the complex shearing modulus and the sine value of the phase angle, namely the measured complex shearing modulus G * value and the phase angle delta value, and the square of G * sin delta is calculated and used as a key index reflecting the scale fatigue performance of the in-service asphalt pavement mortar and used for early warning the crack development.
  7. 7. The method for warning the concentrated burst period of fatigue cracks of a semi-rigid base asphalt pavement according to claim 1, wherein in the step (4), the warning level of the microcrack warning index is defined by comparing the value with a preset second level threshold interval.
  8. 8. The method for early warning the concentrated burst period of fatigue cracks of a semi-rigid base asphalt pavement according to claim 1, wherein in the step (4), the differentiation strategy is that measures for maintaining a conventional detection frequency and prolonging a coring period, improving the detection frequency and implementing annual coring or starting structural stability assessment are respectively taken according to different microcrack early warning index grades to determine a repair scheme when the crack surface density is lower than a first-stage threshold, and measures for implementing preventive maintenance and starting structural stability assessment to determine the repair scheme or formulating a large repair scheme are respectively taken according to different microcrack early warning index grades when the crack surface density reaches or exceeds the first-stage threshold.
  9. 9. An electronic device comprising a memory and a processor, the memory storing a computer program, the processor implementing the steps of the method of claims 1-8 when the program is executed.
  10. 10. A computer readable storage medium, characterized in that a computer program is stored, which program, when being executed by a processor, carries out the steps of the method according to claims 1-8.

Description

Early warning method for concentrated burst period of fatigue cracks of semi-rigid base asphalt pavement Technical Field The invention relates to the technical field of road engineering, in particular to a method for early warning of a concentrated burst period of fatigue cracks of a semi-rigid base asphalt pavement. Background Cracks are one of the most representative structural hazards of semi-rigid base asphalt pavement. If scientific identification and active intervention cannot be carried out at the initial stage of crack evolution, the fatigue damage accumulation of the structural layer is accelerated, the service life of the pavement is obviously shortened, and the later maintenance difficulty and the social cost are increased. Although the road surface detection technology is continuously advanced in recent years, the automatic inspection equipment and evaluation indexes are widely applied, the current early warning and maintenance decision system aiming at crack diseases still has the following key bottlenecks: (1) The disease identification is delayed, the perception capability of an evolution process is lacking, the existing detection means focuses on apparent forms (such as length, width and density) of the crack, the current situation of the disease is recorded in a static snapshot mode, and the dynamic evolution rule from crack initiation to macroscopic expansion of the crack cannot be captured. The maintenance decision is often based on the centralized manifestation of diseases, and prospective intervention is difficult to realize. (2) The evaluation dimension is single, and the material performance degradation mechanism is ignored, namely the main stream maintenance evaluation depends on road table detection indexes such as PCI, TCS and the like, and the indexes are convenient to quantify, but can not reflect the mechanical property degradation of the asphalt surface layer material caused by aging and fatigue. Because the damage state of the material scale is not included in the early warning system, the judgment of the crack explosion risk lacks a physical basis, and the maintenance measures are often disjointed with the actual disease mechanism. (3) Early warning and response are disjoint, and a hierarchical response mechanism is lacking, namely, even if part of road sections are identified as high risks, the existing flow lacks a differential response strategy based on risk grades. Or excessively relying on empirical 'one-cut' maintenance to cause resource waste, or delaying the intervention time due to lack of a definite threshold value and missing the optimal prevention window. The above problems together lead to passive cycling of the traditional curing mode into discovery, i.e. deterioration, repair, i.e. rework. Disclosure of Invention The invention aims to provide an early warning method for a concentrated burst period of fatigue cracks of a semi-rigid base asphalt pavement, which can accurately early warn in different development stages of the pavement cracks by combining the crack development stages, the crack surface density (SFD) and the microcrack early warning index (MCI), identify potential crack development risks in advance and formulate a differentiated maintenance strategy to solve the problems in the background technology. The technical scheme is that the early warning method for the concentrated burst period of the fatigue crack of the semi-rigid base asphalt pavement comprises the following steps: (1) Judging the macroscopic development stage of the transverse crack based on the structure type and service life of the target pavement, and identifying the road section in the gentle development stage with relatively slow crack expansion rate as a potential risk section; (2) Detecting the crack density of a road section in a gentle development stage, calculating the total length of the crack in a unit area as a crack surface density index, and comparing the index with a preset first-level threshold value to primarily evaluate the development degree of the macroscopic crack; (3) Drilling an asphalt surface layer core sample at a representative crack position of a road section, extracting an asphalt mortar material of an upper layer, testing complex shear modulus and phase angle through a rheological test, and calculating a microcrack early warning index reflecting the fatigue performance of the material based on the complex shear modulus and the phase angle; (4) Dividing the microcrack early warning index into different early warning grades according to the numerical range of the microcrack early warning index, and then formulating different pavement detection frequencies, coring periods or maintenance engineering strategies according to the comparison result of the crack surface density index and the preset threshold value in the step (2) aiming at different early warning grade and crack density combinations. Further, in the step (1), the macroscopic development stage inclu