Research on a Laboratory Technique to Prepare a Rejuvenating Composite Seal and Test Its Long-Term Water Stability

Abstract

A rejuvenating composite seal (RCS) consists of a chip seal and a micro-surfacing (MS). There are two reasons for RCS’s poor application effect in China and less frequent application than that of MS: first, the material amount of a composite seal is determined largely based upon experience and lacks a theoretical basis; and second, the composite seal cannot achieve the expected service life. The objective of this study is to determine an appropriate technique to prepare RCS in the laboratory and verify its long-term water stability. Based on an improved sweep test, a method to determine the rate at which to apply the rejuvenating emulsified asphalt used in a chip seal was established. Through the wet track abrasion test and the loaded wheel test, the proper proportion of materials in the MS mix was determined. The material dosage and technique to prepare the RCS was determined by the matrix analysis method based on a multitarget orthogonal test, and its long-term water stability was determined by immersion and freeze-thawing. The results showed that the material dosage of the chip seal was quantitatively determined by an improved sweeping test, the preparation process and material dosage of the composite seal were quantitatively determined by matrix analysis, and the resulting composite seal had reasonable structure and good comprehensive performance. The findings of this paper can provide theoretical guidance for the promotion and application of composite seals in China.