Influence Of Environmental Factors On The Properties Of Rubber-modified Asphalt And Its Mixture

By the end of 2021,my country’s expressway mileage will be 169,100 kilometers,ranking first in the world.However,the asphalt pavement is affected by external environmental factors such as moisture,ultraviolet light and thermal oxygen,resulting in the decline of the road performance of the pavement,which has attracted more and more attention.Therefore,based on the actual humid and hot complex climatic conditions in southern my country,and considering the wide application of rubber-modified asphalt pavement,this paper adopts the environmental factor simulation method based on moisture,ultraviolet light,thermal oxygen,water-light combination and water-heat combination.Modified asphalt,rubber-modified asphalt mixture and interface properties were studied.This research is of great significance to put forward technical measures to improve the early disease of actual rubber-modified asphalt pavement in southern China and prolong its service life.In this paper,the high and low temperature properties of rubber modified asphalt under the action of moisture,ultraviolet light,thermal oxygen,water-light combination and water-heat combination environmental factors were studied through conventional index tests and dynamic shear rheological tests.The behavior of its high and low temperature performance affected by environmental factors is explained.The results show that the rutting factor of the water-light combination decreases with the increase of the test temperature,while the phase angle increases with the increase of the test temperature and the increase becomes slower.The rutting factor increases with the development of the water-heat combination and the increase is mainly reflected in the initial stage,while the phase angle increases with the increase of the test temperature and the increase slows down;LMS%,D value under the influence of various environmental factors And the Mp value increases gradient with the influence of environmental factors,and LMS%has a good correlation with its softening point and ductility.Then,the interface properties of rubber-modified asphalt and aggregate under various environmental factors are studied.The results show that with the increase of the number of freeze-thaw cycles/ultraviolet light irradiation time/film heating time,the thickness of the asphalt film decreases gradually,the spalling rate increases gradually and the increase becomes slow.With the increase of water-light combination time,the thickness of the asphalt film gradually decreased,and the increase of the spalling rate tended to increase compared with that under the action of ultraviolet light,but the increase was smaller.With the prolongation of water-heat combination time,the spalling rate increased significantly and slowed down compared with thermal aging.Finally,the high temperature performance,low temperature performance,anti-skid performance and anti-loose performance of the mixture under various environmental factors were studied,and compared with the rubber-modified asphalt.The results show that with the increase of UV irradiation time,the dynamic stability and rutting depth of rubber-modified asphalt mixtures decrease,but both tend to be stable.With the extension of the heating time of the film,the dynamic stability and rutting depth of the rubber-modified asphalt mixture increased and decreased respectively,but both tended to be stable;thermal oxygen can significantly reduce the anti-loose properties of the mixture;moisture can promote the effect of ultraviolet light on mixing The effect of high temperature properties of materials.The maximum flexural-tensile strain of the mixture decreases with the prolongation of the combined action time of water-light and converges with the action of ultraviolet light,while the stiffness modulus increases with the prolongation of the combined action time of water-light and increases with the action of UV light.Convergence of time prolongation and ultraviolet light action;moisture can effectively promote the weakening effect of ultraviolet light on the anti-slip properties of the mixture;moisture promotes the weakening of the anti-loose properties of the mixture by ultraviolet light.High temperature water can promote the effect of thermal oxygen on the high temperature properties of the mixture;the maximum flexural tensile strain and stiffness modulus of the mixture both decrease with the prolongation of water-heat combined action time,and the effect of heat on the properties converges with the prolongation of the action time;High temperature water can effectively promote the weakening effect of thermal oxygen on the anti-slip and anti-loose properties of the mixture.