Research on Low-temperature Cracking Characteristics of Buton Rock Asphalt Concrete Based on Microscopic Scale
In order to describe the low-temperature characteristics and crack development law of Buton rock asphalt in more detail,the crack extension process of Buton rock asphalt concrete specimens in low-temperature bending damage tests was observed and analyzed at a fine scale by using the digital image correlation(DIC)technique.The formation and extension of cracks,as well as the changes in displacement and strain at the tip of the cracks in the specimens,were captured during the loading process.The results show that:(1)from the DIC displacement nephogram,cracks start to sprout from the bottom of the beam specimen,and as loading proceeds,the displacement of the specimen's scattering spots increases in the horizontal direction on both sides,the scattering area narrows in the mid-span region,and the tip of the scattering area appears,and the cracks begin to extend upwards,and the rate of change of the scattering spot displacements decreases until cracks are extended to dam-age;(2)from the strain nephogram,it can be seen that there are tensile and compressive strains in both horizontal and vertical directions,in the initial stage,multiple small tensile regions appeared at the bottom of the specimen,giving rise to several small cracks,and the tensile region converges and increases,with the increase in loading,the symmetrical tensile strain on both sides moves towards the middle of the span,the range of bottom compressive strain increases rapidly,and cracks continue to expand until the damage;(3)the final crack length under the same conditions in descending order is:SBS modified asphalt,Buton rock asphalt,and matrix asphalt,and the crack damage loading time in descending order is:SBS modified asphalt,Buton rock asphalt,and matrix asphalt,indicating that the low-temperature inhibition macro-cracking performance of Buton rock asphalt is better than that of matrix asphalt.
mesoscalebuton rock asphaltasphalt mixturelow temperature characteristics
万方数据
维普
