| With the rapid development of Expressway in China,"12th Five-Year" plan of national highway mileage has been completed."13th Five-Year" period,China's transportation development is in support of a comprehensive well-off society in the crucial period,optimize the network layout of the critical period,quality and efficiency upgrading transformation enter a new stage of modernization.In the road construction of our country,the asphalt road occupies a large proportion.The improvement of the performance and service life of asphalt road are focussed,and also become the focus of the research work.Asphalt pavement is mainly paved with asphalt mixture.The performance of asphalt mixture will determine the advantages and disadvantages of asphalt pavement.Asphalt mixture is composed of asphalt and mineral aggregate and fillers,and the performance of each component determines the final performance of asphalt mixture.Asphalt mortar,as the dispersed phase in the asphalt mixture structure system,can well fill the skeleton void,and provide enough bonding strength for the mixture,which is an important part of the road performance of the asphalt mixture.This paper will study the damage healing performance of asphalt mortar by using the digital speckle correlation technique combined with the bending damage healing test.Considering several factors affecting the damage healing of asphalt pavement,the main influencing factors of the damage healing of asphalt mortar are determined by the orthogonal design method.The damage and healing degree of asphalt mortar are evaluated according to the index of fracture mechanics,and the healing degree of asphalt mortar is analyzed.Asphalt mortar single damnification orthogonal test showed that the fracture toughness of Jc asphalt mortar as healing index has reliable effect,the healing of fracture toughness index under different influence factors of healing more sensitive based on the analysis of the asphalt mortar can damage energy dissipation in the healing process and healing.Compared with the healing time,healing temperature and damage degree,the aging degree had more significant influence on the healing degree of two kinds of asphalt mortar,and the aging degree was the main factor affecting the healing degree.With the increase of the number of wound healing,the healing of asphalt mortar after long-term aging degree decreased significantly,two kinds of asphalt mortar healing showed: no aging> the short-term aging > long-term aging trend,with the deepening of aging,two kinds of asphalt mortar healing degree decreased gradually;the effect of aging on the healing effect of asphalt mortar obviously,paving pavement should be reasonable control and use of the process of aging.Asphalt mortar Multidamage self-healing test found: multiple injury self-healing test after healing significantly decreased of two asphalt mortar and asphalt mortar,the healing of a bigger drop;after three injury healing after SBS modified asphalt mortar healing degree is obviously higher than the matrix asphalt mortar,indicated that SBS modified with the increase of the number of asphalt mortar damage healing ability,on the road during the service has better healing ability.Based on digital speckle correlation method,asphalt mortar damnification test has two stages.In the first stage of healing,the healing value is larger and healing rate is faster.The healing degree of the second stage is greatly reduced,and the healing rate is slowed down obviously tends to be stable.Long after the aging test of two kinds of asphalt mortar specimens the union is the biggest,the long-term aging of asphalt mortar on the single damage healing degree has great influence,the main reason is the long-term aging makes the internal precipitation of asphalt asphalt mortar,leading to the increase of the surface viscosity,thereby increasing the healing effect of the first stage.The surface micro morphology observation of asphalt mortar specimens is observed.After aging,the matrix asphalt mortar has a deeper surface color than the SBS modified asphalt mortar,and the surface asphalt of the matrix asphalt mortar is more precipitated,which plays an important role in the healing of the asphalt mortar.Compared with the matrix asphalt mortar,the surface of SBS modified asphalt mortar is more smooth after aging,and the surface morphology of SBS modified asphalt mortar is smaller before and after aging.Compared the short-term aging of two kinds of asphalt mortar surface morphology,cracks appeared on the surface of SBS modified mortar,and no obvious cracks appeared on the surface of matrix asphalt mortar.Short term aging has greater impact on the surface morphology of SBS modified asphalt mortar. |
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