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

Hanne Vanoutrive, Philip Van den Heede, Natalia Alderete, Carmen Andrade, Tushar Bansal, Aires Camoes, Özlem Cizer, Nele De Belie, Vilma Ducman, Miren Etxeberria, Lander Frederickx, Cyrill Grengg, Ivan Ignjatovic, Tung-Chai Ling, Zhiyuan Liu, Inés Garcia-Lodeiro, Barbara Lothenbach, Cesar Medina Martinez, Javier Sanchez-Montero, Kolawole OlonadeAngel Palomo, Quoc Tri Phung, Nuria Rebolledo, Marlene Sakoparnig, Kosmas Sideris, Charlotte Thiel, Talakokula Visalakshi, Anya Vollpracht, Stefanie von Greve-Dierfeld, Jinxin Wei, Bei Wu, Maciej Zajac, Zengfeng Zhao, Elke Gruyaert

Research outputpeer-review


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.
Original languageEnglish
Article number99
Pages (from-to)1-29
Number of pages29
JournalMaterials and Structures
StatePublished - 4 Apr 2022

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