Hanne Vanoutrive, Philip Van den Heede, Natalia Alderete, Carmen Andrade, Tushar Bansal, Aires Camões, Özlem Cizer, Nele De Belie, Vilma Ducman, Miren Etxeberria, Lander Frederickx, Cyrill Grengg, Ivan Ignjatović, Tung-Chai Ling, Zhiyuan Liu, Inés Garcia-Lodeiro, Barbara Lothenbach, César Medina Martinez, Javier Sanchez-Montero, Kolawole Olonade, Angel 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 Zając, Zengfeng Zhao, Elke Gruyaert, Universitat Politècnica de Catalunya. Departament d'Enginyeria Civil i Ambiental, and Universitat Politècnica de Catalunya. ATEM - Anàlisi i Tecnologia d'Estructures i Materials
The final publication is available at Springer via http://dx.doi.org/10.1617/s11527-022-01927-7 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. The authors would like to thank HeidelbergCement AG for the supplied cements and the chemical and physical analysis. H. Vanoutrive has received internal funding from KU Leuven which made this interlaboratory study possible. P. Van den Heede, N. Alderete and Z. Liu are funded by the Research Foundation—Flanders (FWO) (project No. G062720N, 12ZG820N and G0F3619N). The financial support of FWO is gratefully acknowledged. Peer Reviewed This report has been prepared by members of the working groups 1 and 2 within a framework of RILEM TC 281-CCC ‘‘Carbonation of concrete with supplementary cementitious materials’’ and further reviewed and approved by all members of the RILEM TC 281-CCC. TC Membership Chair: Prof. Nele De Belie. Deputy Chair: Prof. Susan Bernal Lopez. Members: Natalia Alderete, Carmen Andrade, Ueli Angst, Tushar Bansal, Ve´ronique Baroghel-Bouny, Muhammed P.a. Basheer, Nele De Belie, Susan Bernal Lopez, Hans D. Beushausen, Leon Black, Aires Camöes, Servando Chincho´n-Paya, Özlem Cizer, Gisela Paola Cordoba, Martin Cyr, Patrick Dangla, Yuvaraj Dhandapani, Katja Dombrowski-Daube, Vilma Ducman, Yogarajah Elakneswaran, Jan Elsen, Juan Manuel Etcheverry, Miren Etxeberria, Ana Maria Fernandez-Jimenez, Lander Frederickx, Isabel Fuencisla Saez del Bosque, Cassandre Le Galliard, Ine`s Garcia Lodeiro, Daniel Geddes, Christoph Gehlen, Mette Geiker, Guoqing Geng, Bahman Ghiassi, Gregor Gluth, Cyrill Grengg, Elke Gruyaert, R. Doug Hooton, Bruno Huet, Andres Idiart, Ivan Ignjatovic, Kei-Ichi Imamoto, Shiju Joseph, Siham Kamali-Bernard, Antonis Kanellopoulos, Xinyuan Ke, Sylvia Kessler, Heejeong Kim, Arto Ko¨lio¨, Juan Li, Ning Li, Tung Chai Ling, Qing-Feng Liu, Zhiyuan Liu, Barabare Lothenbach, Isabel Martins, Jose´-Fernando Martirena-Hernandez, César Medina Martinez, Fabrizio Moro, Shishir Mundra, Marija Nedeljkovic, Kolawole A. Olonade, José Pacheco, Christian Paglia, Angel Paloma, Ravi Patel, Janez Perko, Quoc Tri Phung, John L. Provis, Francisca Puertas, Nuria Rebolledo, Marlene Sakoparnig, Javier Sancez Montero, Francesco Santoro, Sriram Pradeep Saridhe, Karen Scrivener, Marijana Serdar, Zhenguo Shi, Kosmas K. Sideris, Ruben Snellings, Matteo Stefanoni, Charlotte Thiel, Karl-Christian Thienel, Michael D.A. Thomas, Ilda Tole, Luca Valentini, Philip Van den Heede, Hanne Vanoutrive, Yury Andre´s Villagran Zaccardi, Talakokula Visalakshi, Anya Vollpracht, Stefanie Von Greve-Dierfeld, Brant Walkley, Fazhou Wang, Ling Wang, Jinxin Wei, Lia Weiler, Bei Wu, Yan Yao, Guang Ye, Maciej Zaja˛c, Zengfeng Zhao, Semion Zhutovsky. Hanne Vanoutrive and Philip Van den Heede have contributed equally to this work.