Exploring creep and recovery behavior of hot mix asphalt field cores with multi-sequenced repeated load test

Authors：Dong, Niya; Wang, Duanyi; Zhang, Shaowei; Chen, Zhaojie; Liang, Haixiu^*; Ni, Fujian; Yu, Jiangmiao; Yu, Huayang

Source：CONSTRUCTION AND BUILDING MATERIALS, 2021, 279: 122435.

DOI：10.1016/j.conbuildmat.2021.122435

• Multi-sequenced repeated load test
• Strain response
• Resilient modulus
• Non-recoverable compliance
• Percent recovery

Rutting is known as a major distress in hot-mix asphalt (HMA) pavements. In order to fully characterize the creep and recovery behaviors of HMA mixes under varying loading conditions at high temperatures, a newly modified multi-sequenced repeated load test with a greatly improved sampling rate of 500 in a second was developed and performed on HMA field cores. Various indicators, including maximum strain, recovered strain, un-recovered strain, resilient modulus (M-r), non-recoverable creep compliance (J(nr)), and percent recovery (R%) were proposed to investigate the visco-elastic properties of asphalt mixture. The stress-dependencies of these indicators were analyzed, besides, the correlation and ANOVA analyses were also conducted. Based on the analysis results, it is found that all analyzed indicators except M-r show significant stress-dependency; the vast majority of strain can be recovered (R > 99%), and an increased stress plays a negative role in recovery behavior. The facts indicate that only in a wider stress domain can the visco-elastic characteristics of HMA mixes be fully understood, furthermore, J(nr) and R are superior to other indicators in statistically differentiating the viscous and elastic properties of different asphalt mixtures, respectively.