Frost resistance and service life prediction of recycled aggregate concrete (RAC) under flexural fatigue damage

As a road material, recycled aggregate concrete (RAC) offers advantages in terms of resource reuse and environmental sustainability. However, in cold regions, concrete pavements are often subjected to flexural fatigue loads from vehicular traffic. In order to fill the current gap in research on the...

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Veröffentlicht in:Construction & building materials 2025-01, Vol.458, p.139787, Article 139787
Hauptverfasser: Yu, Zhengxing, Hou, Yongli, Zhu, Jincai, Tian, Yafeng
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Sprache:eng
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Zusammenfassung:As a road material, recycled aggregate concrete (RAC) offers advantages in terms of resource reuse and environmental sustainability. However, in cold regions, concrete pavements are often subjected to flexural fatigue loads from vehicular traffic. In order to fill the current gap in research on the frost resistance of RAC after flexural fatigue damage, this study investigated the effects of recycled coarse aggregate (RCA) replacement rate and flexural fatigue loading on the frost resistance of RAC. The results show that the relative dynamic modulus of elasticity of RAC exhibits a two-stage characteristic of ‘plunge-smooth’ as the number of fatigue cycles increases. With the increase in the number of freeze-thaw cycles (FTCs), the mass loss rate of RAC specimens increased and the relative dynamic modulus of elasticity decreased. Applying an appropriate amount of flexural fatigue can suppress the increase in mass loss rate and the decay of dynamic modulus under FTCs, thus improving the frost resistance of RAC. In particular, the porosity of R25 and R100 samples decreased by 0.33 % and 0.36 %, respectively, after applying 10,000 flexural fatigue cycles, suggesting that flexural fatigue loading contributes to the compaction and refinement of the RAC structure, which improves its frost resistance. In addition, considering the replacement rate of RCA and the number of fatigue cycles, an entropy generation model (EGM) for RAC was developed, which achieved high predictive accuracy, surpassing second-level standards, providing a scientific basis for the use of RAC structures in cold regions. •Increasing the RCA replacement rate accelerates RAC deterioration under FTCs.•Optimal flexural fatigue loads mitigate RAC specimen degradation during FTCs.•Pore structure analysis of the frost resistance mechanism of RAC under fatigue damage.•An EGM-based predictive model for RAC service life with enhanced accuracy.
ISSN:0950-0618
DOI:10.1016/j.conbuildmat.2024.139787