@article{VanoutriveAldereteDeBelieetal., author = {Vanoutrive, Hanne and Alderete, Natalia and De Belie, Nele and Etxeberria, Miren and Grengg, Cyrill and Ignjatović, Ivan and Ling, Tung-Chai and Liu, Zhiyuan and Garcia-Lodeiro, In{\´e}s and Medina Mart{\´i}nez, C{\´e}sar and Sanchez, Javier and Palomo, Angel and Rebolledo, Nuria and Sakoparnig, Marlene and Sideris, Kosmas and Thiel, Charlotte and Van den Heede, Philip and Vollpracht, Anya and von Greve-Dierfeld, Stefanie and Wei, Jinxin and Zając, Maciej and Gruyaert, Elke}, title = {Report of RILEM TC 281-CCC: outcomes of a round robin on the resistance to natural carbonation of Portland, Portland-fly ash and blast-furnace cements and its relation to accelerated carbonation}, series = {Materials and Structures}, volume = {57}, journal = {Materials and Structures}, number = {9}, publisher = {Springer Science and Business Media}, issn = {1359-5997}, doi = {10.1617/s11527-024-02464-1}, abstract = {Numerous (inter)national standards are in place for assessing the resistance to carbonation of mortar and concrete. Within the framework of RILEM TC 281-CCC 'Carbonation of Concrete with SCMs,' an extensive interlaboratory test campaign (ILT) involving twenty-two participating laboratories worldwide was initiated to compare natural carbonation of concrete and mortar with three different cement types (Portland cement (CEM I), Portland-fly ash cement (CEM II/B-V) and blast-furnace cement (CEM III/B)) and investigate its relation to accelerated carbonation as reported in Vanoutrive et al. (Mater Struct 55:1-29, 2022). It could be concluded that ranking of cement types was analogous between accelerated and natural carbonation methods. Environmental parameters have an important effect on the carbonation rate, however, differences between the mean carbonation rates originating from indoor and sheltered outdoor natural exposure with different exposure conditions and curing regimes were insignificant for each considered cement type. This is caused by the scatter related to carbonation testing among different laboratories. Nevertheless, results showed that a natural exposure period of at least one year is essential to reach a constant carbonation rate over time. For both natural and accelerated carbonation, the carbonation rate increased by 18\% when the aggregate-to-cement ratio increased by 1.79 (concrete versus mortar). This correlation seems insensitive to binder type and exposure method. Finally, the best correlation between natural and accelerated carbonation was found for EN 12390-10 (specifically natural indoor exposure) and EN 12390-12 (accelerated exposure) when only test methods performed by more than one laboratory were considered.}, language = {en} } @article{BernalDhandapaniElakneswaranetal., author = {Bernal, Susan A. and Dhandapani, Yuvaraj and Elakneswaran, Yogarajah and Gluth, Gregor J. G. and Gruyaert, Elke and Juenger, Maria C. G. and Lothenbach, Barbara and Olonade, Kolawole Adisa and Sakoparnig, Marlene and Shi, Zhenguo and Thiel, Charlotte and van den Heede, Philip and Vanoutrive, Hanne and Von Greve-Dierfeld, Stefanie and De Belie, Nele and Provis, John L.}, title = {Report of RILEM TC 281-CCC: A critical review of the standardised testing methods to determine carbonation resistance of concrete}, series = {Materials and Structures}, volume = {57}, journal = {Materials and Structures}, number = {8}, publisher = {Springer}, issn = {0025-5432}, doi = {10.1617/s11527-024-02424-9}, pages = {31}, abstract = {The chemical reaction between CO2 and a blended Portland cement concrete, referred to as carbonation, can lead to reduced performance, particularly when concrete is exposed to elevated levels of CO2 (i.e., accelerated carbonation conditions). When slight changes in concrete mix designs or testing conditions are adopted, conflicting carbonation results are often reported. The RILEM TC 281-CCC 'Carbonation of Concrete with Supplementary Cementitious Materials' has conducted a critical analysis of the standardised testing methodologies that are currently applied to determine carbonation resistance of concrete in different regions. There are at least 17 different standards or recommendations being actively used for this purpose, with significant differences in sample curing, pre-conditioning, carbonation exposure conditions, and methods used for determination of carbonation depth after exposure. These differences strongly influence the carbonation depths recorded and the carbonation coefficient values calculated. Considering the importance of accurately determining carbonation potential of concrete, not just for predicting their durability performance, but also for determining the amount of CO2 that concrete can re-absorb during or after its service life, it is imperative to recognise the applicability and limitations of the results obtained from different tests. This will enable researchers and practitioners to adopt the most appropriate testing methodologies to evaluate carbonation resistance, depending on the purpose of the conclusions derived from such testing (e. g. materials selection, service life prediction, CO2 capture potential).}, language = {en} } @article{VandenHeedeThielDeBelie, author = {Van den Heede, Philip and Thiel, Charlotte and De Belie, Nele}, title = {Natural and accelerated carbonation behaviour of high-volume fly ash (HVFA) mortar: Effects on internal moisture, microstructure and carbonated phase proportioning}, series = {Cement and Concrete Composites}, volume = {113}, journal = {Cement and Concrete Composites}, number = {October}, publisher = {Elsevier}, doi = {10.1016/j.cemconcomp.2020.103713}, abstract = {Binders with large portions of carbon-intensive Portland cement replaced by supplementary cementitious materials (e.g. fly ash) are more susceptible to carbonation mainly due to their lower CO2 buffering capacity. This conclusion is usually drawn from accelerated experiments at elevated CO2 levels involving processes that seriously differ from natural carbonation. The resulting presence of H2O reactant in the pore system and the carbonated microstructure itself may be very different. In this paper, these phenomena were investigated for High-Volume Fly Ash (HVFA) mortar via carbonation tests at ±0.04\% CO2 (natural carbonation), 1\% CO2 and 10\% CO2. Internal humidity sensor monitoring and 1H NMR relaxometry revealed the highest water vapour and liquid water contents after carbonation at 10\% CO2. Carbonation at 10\% CO2 results in a coarser pore structure than carbonation at 1\% CO2, and this probably due to a higher degree of C-S-H carbonation.}, language = {en} } @article{VonGreveDierfeldLothenbachVollprachtetal., author = {Von Greve-Dierfeld, Stefanie and Lothenbach, Barbara and Vollpracht, Anya and Wu, Bei and Huet, Bruno and Andrade, Carmen and Medina, C{\´e}sar and Thiel, Charlotte and Gruyaert, Elke and Vanoutrive, Hanne and Del Sa{\´e}z Bosque, Isabel F. and Ignjatovic, Ivan and Elsen, Jan and Provis, John L. and Scrivener, Karen and Thienel, Karl-Christian and Sideris, Kosmas and Zajac, Maciej and Alderete, Natalia and Cizer, {\"O}zlem and Van den Heede, Philip and Hooton, Robert Douglas and Kamali-Bernard, Siham and Bernal, Susan A. and Zhao, Zengfeng and Shi, Zhenguo and De Belie, Nele}, title = {Understanding the carbonation of concrete with supplementary cementitious materials}, series = {Materials and Structures}, volume = {53}, journal = {Materials and Structures}, publisher = {Springer Nature}, doi = {10.1617/s11527-020-01558-w}, pages = {1 -- 34}, abstract = {Blended cements, where Portland cement clinker is partially replaced by supplementary cementitious materials (SCMs), provide the most feasible route for reducing carbon dioxide emissions associated with concrete production. However, lowering the clinker content can lead to an increasing risk of neutralisation of the concrete pore solution and potential reinforcement corrosion due to carbonation. carbonation of concrete with SCMs differs from carbonation of concrete solely based on Portland cement (PC). This is a consequence of the differences in the hydrate phase assemblage and pore solution chemistry, as well as the pore structure and transport properties, when varying the binder composition, age and curing conditions of the concretes. The carbonation mechanism and kinetics also depend on the saturation degree of the concrete and CO2 partial pressure which in turn depends on exposure conditions (e.g. relative humidity, volume, and duration of water in contact with the concrete surface and temperature conditions). This in turn influence the microstructural changes identified upon carbonation. This literature review, prepared by members of RILEM technical committee 281-CCC carbonation of concrete with supplementary cementitious materials, working groups 1 and 2, elucidates the effect of numerous SCM characteristics, exposure environments and curing conditions on the carbonation mechanism, kinetics and structural alterations in cementitious systems containing SCMs.}, language = {en} } @article{VanoutriveVandenHeedeAldereteetal., author = {Vanoutrive, Hanne and Van den Heede, Philip and Alderete, Natalia and Andrade, Carmen and Bansal, Tushar and Cam{\~o}es, Aires and Cizer, {\"O}zlem and De Belie, Nele and Ducman, Vilma and Etxeberria, Miren and Frederickx, Lander and Grengg, Cyrill and Ignjatović, Ivan and Ling, Tung-Chai and Liu, Zhiyuan and Garcia-Lodeiro, In{\´e}s and Lothenbach, Barbara and Medina Martinez, C{\´e}sar and Sanchez-Montero, Javier and Olonade, Kolawole Adisa and Palomo, Angel and Phung, Quoc Tri and Rebolledo, Nuria and Sakoparnig, Marlene and Sideris, Kosmas and Thiel, Charlotte and Visalakshi, Talakokula and Vollpracht, Anya and Von Greve-Dierfeld, Stefanie and Wei, Jinxin and Wu, Bei and Zając, Maciej and Zhao, Zengfeng and Gruyaert, Elke}, title = {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}, series = {Materials and Structures}, volume = {55}, journal = {Materials and Structures}, number = {3}, publisher = {Springer}, doi = {10.1617/s11527-022-01927-7}, pages = {1 -- 29}, abstract = {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.}, language = {en} }