ORIGINAL ARTICLE Mechanical and durability properties of concrete subjected to early-age freeze–thaw cycles Dongyun Liu . Yongming Tu . Pan Shi . Gabriel Sas . Lennart Elfgren Received: 7 March 2021 / Accepted: 6 October 2021 / Published online: 4 November 2021 Ó RILEM 2021 Abstract Early-age frost damage to concrete used in winter construction or in cold environments negatively affects the development of the hydration process and the performance of the concrete, thereby reducing the service life of the building structure. Experimental research was carried out to investigate the compressive strength, resistance to chloride penetration and resistance to freeze–thaw of concrete specimens subjected to early- age freeze–thaw cycles (E-FTCs). The effects that different pre-curing times of concrete and mineral admixtures have on the properties of early-age frost- affected concrete were also analyzed. Results show that the earlier the freeze–thaw cycles (FTCs), the poorer the later-age performance. Later-age water-curing cannot completely restore the damage that E-FTCs do to concrete. In the same conditions used in this study, the effects of E-FTCs on later-age mechanical and durability properties of ordinary Portland cement concrete (OPC) are small. The incorporation of fly ash significantly reduces the resistance to freeze–thaw of concrete during early-age and later-age. The presence of silica fumes has an adverse effect on the later-age resistance to freeze– thaw. In general, the recovery percentage of later-age durability indexes of concrete subjected to E-FTCs is lower than that of compressive strength. For concrete subjected to E-FTCs, it is more important to ensure the recovery of later-age durability. Keywords Early-age freeze–thaw cycles Á Pre- curing time Á Fly ash Á Silica fume Á Resistance to freeze–thaw Abbreviations E-FTC Early-age freeze–thaw cycle OPC Ordinary Portland cement concrete FA Fly ash SF Silica fume FAC Fly ash concrete SFC Silica fume concrete MLR Mass loss rate RDM Relative dynamic modulus of elasticity DF Durability factor FTC Freeze–thaw cycle RP Recovery percentage D. Liu Á Y. Tu (&) Á P. Shi Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education, School of Civil Engineering, Southeast University, 211189 Nanjing, People’s Republic of China e-mail: tuyongming@seu.edu.cn; yongming.tu@ltu.se D. Liu Á Y. Tu Á G. Sas Á L. Elfgren Division of Structural and Fire Engineering, Department of Civil, Environmental and Natural Resources Engineering, Lulea ˚ University of Technology, SE 97187 Lulea ˚, Sweden Y. Tu National Engineering Research Center for Prestressing Technology, Southeast University, 211189 Nanjing, People’s Republic of China G. Sas SINTEF Narvik AS, 8517 Narvik, Norway Materials and Structures (2021) 54:211 https://doi.org/10.1617/s11527-021-01802-x