Study On High Temperature Properties Of Foamed Asphalt Warm Mix SAC-20

Warm mix asphalt(Warm Mix Asphalt)technology is to reduce the viscosity of asphalt through certain measures to realize asphalt mixture mixing construction at low temperature,thus saving a lot of energy consumption in the asphalt mixture mixing,transportation and paving process,reduce the gas harm to health and the pollution of the environment.Pavement performance is very important for asphalt pavement,and high temperature performance is the most important.Innovative academician Sha Qinglin put forward a series of SAC gradation design method to optimize the gradation design of asphalt mixture,the SAC series of asphalt mixture than other mixture engineering cost and other characteristics of gap has a smaller and cheaper rate.In this paper,the high temperature performance of SAC-20 two asphalt mixture was studied by combining the technology of water foaming asphalt warm mix and SAC asphalt mixture.Through the indoor water foaming asphalt and using orthogonal test,expansion rate and half-life of two evaluation indexes to find 70 matrix asphalt foaming conditions: best foaming temperature is 160 DEG C,foaming water content 2%,foaming temperature is 20 c..The viscosity temperature variation of Brookfield Viscometer test of foam asphalt,the temperature is low,the foam asphalt viscosity ratio 70 matrix asphalt viscosity,water foamed asphalt viscosity reducing effect is obvious;when the temperature rises,the foam asphalt viscosity and 70 asphalt viscosity gradually tended to be consistent,the asphalt viscosity reducing effect no significant.The optimal compaction temperature of foam asphalt mixture is 135.By reference to the general hot mix SAC gradation design method,the mixture ratio design of foam asphalt warm mix SAC-20 was successfully completed,and the physical and mechanical indexes of mixture of warm mix SAC-20 were designed to meet the requirements.Permanent deformation tests,through repeated loading of three axis high temperature.The results show that the high temperature foam warm mix asphalt SAC-20 mixture and SAC-20 mixture of hot mix anti deformation ability quite,and the high temperature is better than that of ordinary hot mix AC-20 mixture anti deformation ability.Analysis of the mechanics of warm mix SAC-20 mixture constitutive model,and are fitted using high temperature three axis repeated loading test data,the mechanical model of fitting parameters of mixture,deformation of warm mix SAC-20 established prediction model.Three dimensional curve of high temperature permanent deformation of warm mix SAC-20 mixture was drawn.Through the rutting test of asphalt mixture,it is confirmed that the high-temperature stability of foamed asphalt warm mix SAC-20 mixture is slightly inferior to that of hot mix SAC-20 asphalt mixture.The results show that there is a high correlation between the high temperature deformation test and rutting test of three axis repeated loading,and it can be used to establish and modify the high temperature permanent deformation model of warm mix SAC-20 mixture by using the data of three axis repeated loading test.Through the research of this paper,it is confirmed that the high temperature performance of foamed asphalt warm mix SAC-20 is equal to that of ordinary hot mix SAC-20.