Effects of aggregate shape on the macrotexture and performance of chip seal: a laboratory study

Abstract

Chip seal is an efficient maintenance strategy for bituminous pavements, with aggregate shape significantly impacting its embedment and performance, but there is limited quantification of its effects. Using the Aggregate Image Measurement System II (AIMS-II) for shape classification, this study investigated the influence of aggregate shape on chip seal's macrotexture and performance through a series of tests, including 3D laser scanning test, aggregate coverage test, skid resistance test, and sweep test, employing response surface methodology (RSM) for quantification. Results indicated that an abundance of flat aggregates deteriorates surface quality by increasing roughness and altering texture spacing, recommending their proportion be kept under 10%. Conversely, elongated aggregates enhance performance by enriching texture depth and sharpening surface peaks. Spearman rank correlation analysis identified the arithmetic mean peak curvature (S_pc) and the root mean square height (S_q) as reliable measures for evaluating skid resistance and aggregate retention of chip seals, respectively.

GRAPHICAL ABSTRACT

KEYWORDS:

• Chip seal
• Aggregate shape
• Response surface methodology
• Macrotexture
• Surface performance

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research is supported by the National Key Research and Development Program of China (No. 2021YFB2601000), the National Natural Science Foundation of China (NSFC) (No. 52078048) and the Fundamental Research Funds for the Central Universities, CHD (300102212708).