Research And Application Of Asphalt Content Detection Considering Aggregate Segregation

With the rapid development of highway in our country,the early damage appear frequently in asphalt pavement.The construction quality problems are the key to early damage,therefore it is important to control construction quality of asphalt pavement.The asphalt content plays a important role in the controlling system of construction quality of asphalt pavement.The asphalt content directly influences the mechanical properties of the mixture.To control the asphalt content in the certain range of optimum asphalt content is premise of reducing early damages and improving the serviceability and durability of asphalt pavement.It is very important to measure asphalt content accurately and rapidly,which can provide effective data for evaluation systemof construction quality and scientific payment.The paper systematic studied on asphalt content in the controlling system of construction quality of asphalt pavement.The main method to test asphalt content is combustion furnace method which has advantage of easy operation,high-precision and no pollution to the environment.Firstly,This paper carry out the research of combustion furnace method,and put forward improved calibration process based on the composition analysis of the displayed mass loss of combustion furnace method.Researching the effect of the mineral aggregate types on the mass loss rate and analyzing the variation of aggregate graduation use the improved calibration process.The variation of aggregate graduation has a very important influence on the testing result of asphalt content for the same asphalt mixture.The more coarse aggregates the sample has,the smaller testing result of asphalt content is,vice versa.From estimating oil-stone ratio by specific surface area,the article analyzing the effect of aggregate gradation on asphalt content,establishing linear relationship between key sieves(4.75mm?2.36mm)and oil-stone ratio by combustion test of sampling of simulating gradation segregation.On the based of laboratory study,the paper proposed the method of testing asphalt content which considered the aggregate segregation.Combined with the construction of middle course in a road of Chao-hui freeway,the paper respectively research the effect of aggregate segregation on the asphalt content of asphalt mixture which is sampled from thebackfield and the back of paver.The study provides a more reasonable research approach for detection of asphalt content index,and has a very important significance to evaluate asphalt content which represent the construction quality of asphalt pavement.