Gradation Segregation Control in Asphalt Pavement Construction

Abstract

The segregation of gradation is believed to be one of the main causes of the premature pavement deteriorations. Much of unqualified aggregates used in asphalt pavement construction result in the segregation of gradation. The traditional aggregate handling method has the defects of poor quality in processing and low rate of qualified aggregate in result in highway construction in china. The beginning of the study is from more than 30 sections of the asphalt pavement construction, in which the sieve sizes for aggregate processing and the variation of aggregate gradation is under investigation. Found and used a set of standardized screens for aggregate processing on a large scale processing. The key of the gradation segregation control in asphalt pavement construction is the quality control of the aggregate processing, is pointed out. The relationship between the sieve sizes for aggregate handling and the standard sieve sizes which should be controlled; the relationship between the aggregate specifications and the screens for aggregate processing; and the relationship between the sort of mix and the aggregate specifications, is put forward. With application of the new aggregate processing method, almost all variation factor percent passing key controlled sieves is smaller than 2.6%. The mean surface texture depth measured from 229 inspection sites is 1.03 mm and the maximum variation factor of the texture depth is only 2.7%. The authors believe that the standardized aggregate processing technique reported in this paper is the most effective means to reduce asphalt pavement segregation and may open a new era in the realm of aggregate processing for highway constructions in China.