Open Access

ARTICLE

Optimization Study on Crack Resistance of Coarse-Grained Dense-Graded Asphalt Mixtures Based on Scaled Laboratory Testing

Rui Chen¹, Jian Qing^2,3, Xuan Cheng⁴, Ang Fu¹, Xinquan Xu^2,3,*
1 Dongguan Road and Bridge Investment and Construction Co., Ltd., Dongguan, China
2 Guangdong Hualu Transportation Technology Co., Ltd., Guangzhou, China
3 Guangdong Jiaoke Technology R&D Co., Ltd., Guangzhou, China
4 China Highway Engineering Consulting Group Co., Ltd., Beijing, China
* Corresponding Author: Xinquan Xu. Email:

Structural Durability & Health Monitoring https://doi.org/10.32604/sdhm.2026.087049

Received 09 June 2026; Accepted 18 August 2026; Published online 07 September 2026

Abstract

To address the current issues of insufficient crack resistance and limited applicability of asphalt pavement stress-absorbing layers, this study focuses on coarse-grained dense-graded asphalt mixtures and proposes an optimization scheme based on the CAVF (Coarse Aggregate Volume Fraction) gradation design method, systematically exploring its crack resistance and engineering suitability. The research selected three types of binders: SBS-modified asphalt, SH-V-modified asphalt, and ultra-high-viscosity-modified asphalt. Semi-circular bending tests determined the optimal asphalt-aggregate ratios of 5.2%, 5.5%, and 6.0%, respectively. Under these ratios, the mixture forms a dense skeletal structure, achieving a balance between shear and crack resistance. Routine indoor tests show: SH-V-modified mixture achieves Marshall stability of 11.90 kN and rutting stability of 6363 times/mm, with the best high-temperature rutting resistance, but the maximum low-temperature flexural tensile strain is 1956.6 με, indicating weaker crack resistance; ultra-high viscosity mixture has a maximum low-temperature flexural tensile strain of 2113.4 με, with outstanding deformation and crack resistance, but its stability is only 9.60 kN, making rutting resistance relatively insufficient; SBS mixture has average performance across all aspects, balancing basic crack resistance and rutting resistance. Indoor scaling tests simulating 0.7 MPa wheel pressure and bottom hollow conditions show significant differences in crack development and fatigue life among the three types of mixtures. The main crack in SH-V-modified mixture is an oblique crack, about 5.5 mm long, with the longest fatigue life reaching 4500 cycles, capable of withstanding long-term heavy loads; SBS mixture has main cracks nearly vertical, about 2.5 mm long, with the shortest fatigue life at only 3000 cycles; ultra-high viscosity mixture has crack length and fatigue life between the two. In summary, this study clarifies the performance advantages and applicable scenarios of different types of coarse-grained asphalt mixtures, providing precise technical support for the selection of stress absorption layer materials in heavy-load sections and old cement pavement white-to-black projects.

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Keywords

Coarse-grained dense-graded asphalt mixture; stress-absorbing layer; CAVF gradation design method; scaled laboratory testing; crack resistance

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