TY - JOUR A1 - Vanoutrive, Hanne A1 - van den Heede, Philip A1 - Alderete, Natalia A1 - Andrade, Carmen A1 - Bansal, Tushar A1 - Camões, Aires A1 - Cizer, Özlem A1 - de Belie, Nele A1 - Ducman, Vilma A1 - Etxeberria, Miren A1 - Frederickx, Lander A1 - Grengg, Cyrill A1 - Ignjatović, Ivan A1 - Ling, Tung-Chai A1 - Liu, Zhiyuan A1 - Garcia-Lodeiro, Inés A1 - Lothenbach, Barbara A1 - Medina Martinez, César A1 - Sanchez-Montero, Javier A1 - Olonade, Kolawole A1 - Palomo, Angel A1 - Phung, Quoc Tri A1 - Rebolledo, Nuria A1 - Sakoparnig, Marlene A1 - Sideris, Kosmas A1 - Thiel, Charlotte A1 - Visalakshi, Talakokula A1 - Vollpracht, Anya A1 - von Greve-Dierfeld, Stefanie A1 - Wei, Jinxin A1 - Wu, Bei A1 - Zając, Maciej A1 - Zhao, Zengfeng A1 - Gruyaert, Elke T1 - Report of RILEM TC 281-CCC: outcomes of a round robin on the resistance to accelerated carbonation of Portland, Portland-fly ash and blast-furnace blended cements JF - Materials and Structures N2 - Many (inter)national standards exist to evaluate the resistance of mortar and concrete to carbonation. When a carbonation coefficient is used for performance comparison of mixtures or service life prediction, the applied boundary conditions during curing, preconditioning and carbonation play a crucial role, specifically when using latent hydraulic or pozzolanic supplementary cementitious materials (SCMs). An extensive interlaboratory test (ILT) with twenty two participating laboratories was set up in the framework of RILEM TC 281-CCC 'Carbonation of Concrete with SCMs'. The carbonation depths and coefficients determined by following several (inter)national standards for three cement types (CEM I, CEM II/B-V, CEM III/B) both on mortar and concrete scale were statistically compared. The outcomes of this study showed that the carbonation rate based on the carbonation depths after 91 days exposure, compared to 56 days or less exposure duration, best approximates the slope of the linear regression and those 91 days carbonation depths can therefore be considered as a good estimate of the potential resistance to carbonation. All standards evaluated in this study ranked the three cement types in the same order of carbonation resistance. Unfortunately, large variations within and between laboratories complicate to draw clear conclusions regarding the effect of sample pre-conditioning and carbonation exposure conditions on the carbonation performance of the specimens tested. Nevertheless, it was identified that fresh and hardened state properties alone cannot be used to infer carbonation resistance of the mortars or concretes tested. It was also found that sealed curing results in larger carbonation depths compared to water curing. However, when water curing was reduced from 28 to 3 or 7 days, higher carbonation depths compared to sealed curing were observed. This increase is more pronounced for CEM I compared to CEM III mixes. The variation between laboratories is larger than the potential effect of raising the CO2 concentration from 1 to 4%. Finally, concrete, for which the aggregate-to-cement factor was increased by 1.79 in comparison with mortar, had a carbonation coefficient 1.18 times the one of mortar. Supplementary Information The online version contains supplementary material available at 10.1617/s11527-022-01927-7. Y1 - 2022 U6 - https://doi.org/10.1617/s11527-022-01927-7 VL - 55 IS - 3 SP - 1 EP - 29 PB - Springer ER -