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³¤°²´óѧѧ±¨£¨×ÔÈ»¿Æѧ°æ£©[ISSN:1006-6977/CN:61-1281/TN]

Issue:

2021Äê4ÆÚ

Page:

11-20

Research Field:

µÀ·¹¤³Ì

Publishing date:

Info

Title:

Research on invisible structure integrity damages of asphalt pavement

Author(s):

FU Junª¬ª©1; 2ªª;  LI Zhongª²jieª¬1;  YANG Rongª²qiª¬1;  JIA Daª²weiª¬1;  DING Qingª²junª¬2

£¨1. School of Transportation, Wuhan University of Technology, Wuhan 430070, Hubei, China; 2. State Keyª¤Laboratory of Silicate Building Materials, Wuhan University of Technology, Wuhan 430070, Hubei, China)

Keywords:

road engineering;  asphalt pavement;  invisible structure integrity;  direct parameter;  indirect parameter;  macroª²meso crossª²scale simulation

PACS:

-

DOI:

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Abstract:

In order to explore the early performance evolution mechanism of asphalt pavement in service state, by defining the basic concept of invisible structure integrity of asphalt pavement, the invisible failure of asphalt pavement was evaluated from the perspective of the micro interface parameter performance and the chaotic evolution of subcritical cracks. The interface thickness ª«Dª«, elastic modulus ª«Eª« and strength ª«Fª« of the meso interface transition zone between asphalt and aggregate were considered as the direct parameters of invisible structure integrity and normalized to study the meso effect of direct parameter changes on asphalt pavement decay. The indirect parameter ª«Jª« at the mesoª²scale crack tip was used to determine the critical state of decay acceleration and crack instability growth. In the analysis of practical example, the asphalt mixture in mesoª²scale was simplified as threeª²phase composite materials composed of coarse aggregate, asphalt mortar and interface. Based on the mechanism of crossª²scale analysis and the displacement transfer method of subª²model, the macroª²meso finite element model was established. Considering the meso mechanical response of asphalt pavement under 500 cycles of axle load, four meso regions were selected. After initial normalization, the threshold values of single parameter ª«£ÛD£Ýª¬¡äª« and ª«£ÛF£Ýª¬¡äª« were 20%, and the threshold value of ª«£ÛE£Ýª¬¡äª« was 10%. If the threshold value exceeds the single limit value, the interface performance will be affected. The relevant examples realized process of mesoª²crack initiation and dynamic evolution, and provided a pre factor for indirect parameter ª«Jª«ª²integral evaluation of invisible structural integrity. The results show that when the direct parameter change £Û¦¤ª«Zª«£Ýª¬¡ä over 15%, the interface will produce invisible failure, even if the coupling effect of direct and indirect parameters is not considered, the single parameter exceeding the limit will directly affect the ¦¤ª«Zª« failure, and the ¦¤ª«Zª« failure severity is affected by the superposition of various parameters. The fracture toughness ª«Jª«ª­C is negatively correlated with the direct parameter ¦¤ª«Zª«. ¡¼JP2¡½When the ¦¤ª«Zª« overrun increases from 5.32% to ª©28.51%ªª, the ª«Jª«ª­C decreases from 1.725 to 0.724 kJ/mª¬2. With the aggravation of invisible structure failure, the interface performance of asphalt mixture decreases, and its fracture toughness decreases accordingly. Based on the double criterions, influence effects of direct and indirect parameters can be preliminarily revealed, which can provide support for the invisible structure integrity failure assessment of asphalt pavement. The study can provide reference for early failure inflection point determination and preventive maintenance of asphalt pavement. 1 tab, 11 figs, 27 refs.

References:

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Memo:

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Common functions

Last Update: 2021-08-12