Study On Dynamic Modulus Of Recycled Asphalt Mixture In Cold Region

With the gradual development of China’s economy,the demand for highway construction is increasing.The advantage of asphalt pavement performance makes asphalt pavement become the most widely used road material.At the same time,it also brings problems of resource and environmental pollution.The reuse of waste asphalt mixture is an effective solution to reduce resource waste and environmental pollution.Therefore,the application of recycled asphalt mixture in the paving of new roads is the general trend.Through Superpave 19 regenerated asphalt mixture design,compared with the traditional Marshall design method,the advantages and disadvantages of the two design methods were analyzed,and then the regenerated asphalt mixture with different content was formed by two design methods.The influence factors of dynamic modulus of recycled asphalt mixture and the influence of dosage on dynamic modulus were studied.With repeated loading method as a basic method for dynamic modulus test,using DTS multi-function testing machine as a test tool,and with reference to our country "highway engineering asphalt and asphalt mixture test procedures",added the test temperature 20 ℃ as cold and dynamic modulus characteristic test temperature.dynamic modulus and static modulus specimens were prepared.The test results were obtained through the test,and the test results were sorted out and analyzed.The test results show that the increase of the content of old materials will increase the dynamic modulus and the static modulus,and have a greater impact on the dynamic modulus,resulting in an increase in the rotor-stator ratio.Test temperature and frequency of applied load have great influence on dynamic modulus,and the effect of temperature is more obvious.Compared with two mixture design methods,Superpave design method has better dynamic performance than Marshall design method.In the end,principal dynamic modulus curves of recycled asphalt mixtures and normal mixtures with different contents were established by fitting parameters of sigmosumo function and using time temperature equivalence principle.The established main curve can show the change rule of dynamic modulus in the whole range,which is of great significance to the research on the dynamic performance of recycled asphalt mixture.