Gradation Design and Optimization of Mineral Aggregates for a Highway Project in Central America

DOI

10.2991/978-94-6463-902-5_9How to use a DOI?

Keywords

Uperpave; Asphalt mixture; Gradation optimization; SAC

Abstract

In response to the environmental characteristics of the tropical rainforest climate in Central America, where the annual rainfall reaches 4,000 mm, this study systematically establishes control points and restricted zones for mineral aggregate gradation in strict accordance with Superpave specifications and the Costa Rican Highway and Bridge Design and Construction Code CR2010. The gradation curve is optimized by integrating Mr. Sha Qinglin’s design philosophy of SAC coarse aggregate gap-graded asphalt concrete, which emphasizes the critical role of the 4.75 mm particle size as the boundary between coarse and fine aggregates. Through experiments with five preset gradation curves, the study investigates the fundamental laws governing the relationship between gradation selection and variations in key volumetric indices of asphalt mixtures, including void ratio (VV), voids in mineral aggregate (VMA), and voids filled with asphalt (VFA).Experimental results reveal that 3–6 mm aggregates significantly interfere with the formation of the coarse aggregate skeleton, while the passing rate of 0.075 mm particles directly affects pavement void ratio and water permeability. The study further identifies that the interference between aggregate particles and asphalt mortar significantly influences the structural stability of the mixture. Based on these findings, a Superpave-19 asphalt mixture gradation design is proposed, featuring optimized proportions of 16–22 mm, 10–16 mm, and 0–3 mm aggregates to balance skeleton formation and mortar filling. This design not only meets the climatic requirements of tropical rainforest regions but also minimizes segregation risks, offering a practical reference for similar highway projects in analogous climatic zones.

Copyright

© 2025 The Author(s)

Open Access

Open Access This chapter is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/), which permits any noncommercial use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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TY  - CONF
AU  - Canhui Xiao
AU  - Jianbao Fu
AU  - Yucheng Ding
AU  - Huaijin Xu
PY  - 2025
DA  - 2025/12/16
TI  - Gradation Design and Optimization of Mineral Aggregates for a Highway Project in Central America
BT  - Proceedings of the 2025 7th International Conference on Civil Engineering, Environment Resources and Energy Materials (CCESEM 2025)
PB  - Atlantis Press
SP  - 80
EP  - 90
SN  - 2352-5401
UR  - https://doi.org/10.2991/978-94-6463-902-5_9
DO  - 10.2991/978-94-6463-902-5_9
ID  - Xiao2025
ER  -