| Asphalt pavements under the application of repeated vehicle loading and the effect of external environment for a long period of time may exhibit various forms of pavement disease.As one of the main disease form,the cracking disease will cause serious damage to the continuity and integrity of the pavement structure.It is very necessary to carry out the study on cracking propagation characteristics of asphalt pavement with typical cracks under temperature load and moving load for it can reveal the cracking behavior of asphalt pavement more deeply,and it can also provide technical support of pavement design and maintenance for engineers.In this paper,the asphalt pavements with single transverse temperature crack,with double transverse surface cracks and with longitudinal and transverse double cracks were taken as the research objects,and the cracking propagation characteristics of the pavements mentioned above under the influences of various factors were studied in depth.The main research works are as follows:(1)Based on the finite element model of asphalt pavement with temperature crack,the cracking propagation characteristics of surface crack in 24 hours of two cold waves under temperature load was analyzed,also the characterization of cracking propagation in typical temperature field under moving load was studied,the cracking propagation resistance of two top surface materials SMA-13 and AC-13 were compared on the basis of them.(2)The finite element model of asphalt pavement with double surface cracks was established aiming at the cracking propagation characteristics of double Top-Down surface cracks.The interference effect of crack spacing D on the expansion of double surface cracks under moving load was studied emphatically,and the influences of pavement structure type(semi-rigid base asphalt pavement,inverted asphalt pavement,and the compound asphalt pavement),interface contact condition between top surface and mid surface,and the speed of moving load on the propagation of surface crack were discussed as well.(3)Reference to the common cracking form of semi-rigid base asphalt pavement,the finite element model of semi-rigid base asphalt pavement with longitudinal surface crack and transverse reflection crack on base layer was established.The influences of crack spacing and the depth of reflection crack on cracking propagation were analyzed,and based on the fatigue fracture mechanics theory,the fracture fatigue life of surface crack under different vehicle loads were calculated.To provide theoretical support for prevention of reflection cracking,the calculation and analysis of the treatment measures for reflection crack were carried out. |
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