DING L T, ZHANG K X, ZHANG M Y,et al.Gradation composition design of ultra-thin overlay mixture based on GB5 theory[J].Journal of Henan Polytechnic University(Natural Science) ,2026,45(5):188-196.

doi:10.16186/j.cnki.1673-9787.2024030008

Received:2024/03/04

Revised:2024/08/07

Published:2026-07-24

Gradation composition design of ultra-thin overlay mixture based on GB5 theory

Ding Longting1, Zhang Kaixing2, Zhang Mengyuan1, Shen Quanjun1, Wang Xuancang3, Zhou Bo3

1.Innovation Research Institute， Shandong Hi-speed Group Co.， Ltd.， Jinan  250001， Shandong， China；2.Zhonggong Gaoke Maintenance Technology Co.， Ltd.， Beijing  100095， China；3.School of Highway， Chang’an University， Xi’an  710064， Shaanxi， China

Abstract: Objectives As one of the most widely used preventive maintenance techniques for pavements， ultra-thin overlays provide favorable conditions for safe and smooth traffic operation. To address the issues of insufficient compactability and poor durability of ultra-thin overlays， a new gradation design method was proposed for ultra-thin overlay mixtures.  Methods Based on the aggregate interlocking theory， a GB5 gradation design method for ultra-thin overlays was developed using a three-line equation approach. A gradation design procedure was established， and the rationality of the gradation was verified using the Bailey method. The compactability， pavement performance， and surface functional durability of the proposed mixture were compared with those of mixtures designed using conventional mix design methods.  Results Compared with conventional gradations， the asphalt mixture designed using the GB5 method exhibited a reduced compaction energy index （CEI） and a slightly higher compaction rate （K）， indicating improved compactability. The high- and low-temperature performance was significantly enhanced， with increases in high-temperature stability （10.6%）， low-temperature failure strain （19.6%）， residual stability （3.9%）， and freeze–thaw splitting strength （3.7%）， while stiffness modulus decreased by 23.7%. Water stability showed a slight improvement. Regarding surface functional durability， after 30，000 abrasion cycles， the mass loss rate of the conventional gradation was approximately 4.4% higher than that of the GB5 gradation. The texture depth under different abrasion cycles was also higher for the GB5 mixture， indicating better surface functional durability. Conclusions The proposed GB5 gradation design method improves the durability and surface functionality of ultra-thin overlays， providing a new approach for gradation design and offering valuable guidance for related research.

Key words:road engineering;ultra-thin overlay;GB5 theory;gradation design;pavement performance;surface functional durability