TY - CHAP A1 - Hansen, Kurt Kielsgaard A1 - Lataste, Jean-François A1 - Nilsson, Lars-Olof A1 - Thiel, Charlotte A1 - Michel, Alexander T1 - Specimen or Core; In the Laboratory T2 - Methods of Measuring Moisture in Building Materials and Structures : State-of-the-Art Report of the RILEM Technical Committee 248-MMB N2 - When also the sides, of a specimen or a core from a structure, are available during the moisture measurement procedure numerous techniques are applicable compared with when only the exposed surface is available. Y1 - 2018 U6 - https://doi.org/10.1007/978-3-319-74231-1_24 SP - 221 EP - 228 PB - Springer ER - 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 - TY - JOUR A1 - Olsson, Nilla A1 - Abdul Wahid, Fatmawati A1 - Nilsson, Lars-Olof A1 - Thiel, Charlotte A1 - Wong, Hong S. A1 - Baroghel-Bouny, Véronique T1 - Wick action in mature mortars with binary cements containing slag or silica fume - The relation between chloride and moisture transport properties under non-saturated conditions JF - Cement and Concrete Research N2 - Moisture and ionic transport under non-saturated condition is an important, but poorly understood transport phenomena particularly for mature systems containing supplementary cementitious materials. This paper investigates the moisture and chloride profiles of 3-year old mortars containing Portland cement (OPC), slag and silica fume (SF) after long-term (30–48 months) wick action exposure in 1.09 M NaCl solution. Moisture profiles were measured with ¹H NMR relaxometry and chloride profiles with microXRF. The measured profiles were discussed in relation to moisture dependent material properties such as chloride diffusion coefficients, moisture diffusion coefficients, and desorption isotherms. Results show that the combination of different cementitious materials, e.g. the cementitious binder, is the key factor affecting chloride penetration depth. The cementitious binder also strongly affects chloride diffusion coefficient, moisture diffusion coefficient and chloride binding properties, which are all important parameters for the prediction of chloride ingress. KW - Chloride KW - Durability KW - Long-Term Performance KW - Microstructure KW - Transport properties Y1 - 2018 U6 - https://doi.org/10.1016/j.cemconres.2018.06.006 VL - 111 IS - September SP - 94 EP - 103 PB - Elsevier ER - TY - CHAP A1 - Lataste, Jean-François A1 - Thiel, Charlotte A1 - Franzoni, Elisa T1 - Electrical Resistance T2 - Methods of Measuring Moisture in Building Materials and Structures N2 - Electrical resistance is the ability for a material to impede the flow of electrical current. The resistance (R) is expressed in ohm (Ohm), its inverse is the conductance (C) is expressed in siemens (S). The resistance is function of geometry of tested body and measurement device. So one generally prefers the resistivity (ρΩ) expressed in ohm-meter (Ohm·m), or its inverse the conductivity (σ) in siemens per meter (S/m), representing the intrinsic material’s property. Y1 - 2018 U6 - https://doi.org/10.1007/978-3-319-74231-1_8 SP - 55 EP - 66 PB - Springer ER - TY - CHAP A1 - Hansen, Kurt Kielsgaard A1 - Lataste, Jean-François A1 - Thiel, Charlotte T1 - ND-Methods - From a Surface T2 - Methods of Measuring Moisture in Building Materials and Structures N2 - A complicated application is to measure a moisture distribution with depth from a surface non-destructively. Only a few methods are suitable for such a case. KW - Complicated Applications KW - Electrical Resistivity Tomography KW - Gray Straight Line KW - Integral Moisture Content KW - Resistivity Distribution Model Y1 - 2018 U6 - https://doi.org/10.1007/978-3-319-74231-1_21 SP - 193 EP - 198 PB - Springer ER - TY - CHAP A1 - Thiel, Charlotte A1 - Beddoe, Robin E. T1 - Investigating the role of moisture on concrete carbonation using single-sided H-NMR T2 - International RILEM Conference on Materials, Systems and Structures in Civil Engineering 2016 - Conference segment on Moisture in Materials and Structures, 22-24 August 2016, Lyngby, Denmark N2 - Accelerated test methods are commonly used in order to predict concrete carbonation in natural concentrations. Here, specimens are carbonated at high CO 2 concentrations at a specified temperature and relative humidity. However, the transfer of laboratory results to field behaviour remains difficult because CO 2 transport is affected by the original moisture content of the specimens and additional moisture formed by the carbonation reaction. Therefore knowledge on moisture transport and content during carbonation is required. Specimens made with Ordinary Portland cement and a water/cement ratio 0.50 were exposed to 0.05, 2 and 10 vol.% CO 2 for 28 days. Single-sided NMR moisture profiles were determined before, during and after carbonation. It is shown that moisture content increases due to carbonation at high CO 2 10 %) in the beginning of the exposure. An increase in capillary pore water in front and behind the carbonation front could be observed even after 28d. During natural carbonation moisture changes are mainly due to the change in porosity produced by the carbonation reactions. It is shown that changes in phase composition and thus porosity dominate the carbonation process in cement-based materials. Therefore, the suitability of high CO 2 concentrations is limited for an accelerated test that reflects field condition. Single-sided 1 H NMR proved to be a valuable tool to investigate moisture transport in concrete non-destructively. Y1 - 2016 SN - 978-2-35158-171-1 SP - 261 EP - 268 PB - RILEM Publications S.A.R.L. ER - TY - CHAP A1 - Thiel, Charlotte A1 - Stengel, Thorsten T1 - Nachhaltigkeitsaspekte von Oberbauweisen aus Asphalt und Beton T2 - 10. Münchener Baustoffseminar GRIFFIG - LEISE - DAUERHAFT, Asphalt und Beton im Straßenbau, 10, 2012, München Y1 - 2012 ER - TY - CHAP A1 - Thiel, Charlotte A1 - Haynack, Alexander A1 - Geyer, Sebastian A1 - Gehlen, Christoph A1 - Braun, Alexander ED - Pereira, Eduardo B. ED - Barros, Joaquim A. O. ED - Figueiredo, Fabio P. T1 - CarboDB-Open Access Database for Concrete Carbonation T2 - Proceedings of the 3rd RILEM Spring Convention and Conference (RSCC 2020), Volume 1: Strategies for a Resilient Built Environment, March 9-14, 2020, Guimarães, Portugal N2 - Sustainable service life design of reinforced concrete structures relies on accurate input values. However, in the field of carbonation induced corrosion some input parameters and statistical distributions still need to be validated for worldwide climate conditions. Furthermore, many well-published literature data is not considered due to different storage conditions. At the suggestion of CEN/TC 104/SC1/WG1 the database “CarboDB” was created providing open access to extensive information on concrete carbonation under different storage conditions. The natural carbonation coefficient as well as the minimum concrete cover can be calculated for chosen situations. CarboDB provides reliable data on concrete carbonation in order to increase existing knowledge on concrete carbonation. The database is available online at http://carbodb.bgu.tum.de//. By registration further contribution is possible and appreciated. New insights can be gained by merging several sources. For natural carbonation, testing only up to 140 days underestimates the carbonation progress of concretes with limestone fillers and high amount of ground granulated blast furnace slag. KW - Carbonation KW - Service life design KW - Data management KW - Compliance testing KW - Supplementary cementicious materials Y1 - 2021 SN - 978-3-030-76547-7 U6 - https://doi.org/10.1007/978-3-030-76547-7_8 SP - 79 EP - 90 PB - Springer International Publishing CY - Cham ER - TY - JOUR A1 - van den Heede, Philip A1 - Thiel, Charlotte A1 - de Belie, Nele T1 - Natural and accelerated carbonation behaviour of high-volume fly ash (HVFA) mortar: Effects on internal moisture, microstructure and carbonated phase proportioning JF - Cement and Concrete Composites N2 - 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. KW - 1H NMR relaxometry KW - Carbonation KW - Mercury intrusion porosimetry KW - Moisture sensors KW - Multi-ring electrodes KW - Thermogravimetric analysis Y1 - 2020 U6 - https://doi.org/10.1016/j.cemconcomp.2020.103713 VL - 113 IS - October PB - Elsevier ER - TY - CHAP A1 - Thiel, Charlotte A1 - Lowke, Dirk A1 - Gehlen, Christoph T1 - Effect of minimum temperature, salt and moisture content on concrete under freeze-thaw deicing salt attack T2 - ICDC 2012 : International Congress on Durability of Concrete; Trondheim, Norway, 18-21 June 2012 N2 - While in the field of reinforcement corrosion service life prediction is well-established, there is still need for a user-friendly design model in the field of freeze-thaw deicing salt attack. This attack is one of the major causes of damage to concrete structures in cold climates. The degree of moisture during the first freeze-thaw-cycles exceeds moisture saturation by capillary suction and diffusion. When a critical degree of saturation is reached before freezing damage occurs immediately. As a consequence, depending on the concrete resistance (e.g. pore structure of the concrete) and the severeness of the freeze-thaw load (e.g. minimum temperature, moisture offer and salt concentration), a certain number of freeze-thaw cycles is needed before damage occurs (initial phase). The main exposure parameters influencing the initial phase as well as the subsequent evolution of damage (deterioration phase) are the minimum temperature as well as the salt and moisture content. These factors were determined by single-sided NMR, gravimetry and mercury intrusion porosimetry respectively. Three different concrete compositions were exposed to freeze-thaw deicing salt load at different minimum temperatures. To investigate the influence of the initial moisture content concrete specimens were continuously exposed to freeze-thaw load while other specimens from the same batch were exposed to alternating freeze-thaw exposure with intermediate dry periods. It was found that the minimum temperature and intermediate dry periods had a significant influence on the initial phase as well as on the degradation phase. In addition, higher chloride content in the near-surface concrete reduced the scaling rate. The chloride content under freeze-thaw exposure with 3% NaCl solution in laboratory significantly exceeded typical contents due to capillary suction and diffusion. Increasing the minimum temperature increased the chloride content. The investigations form the basis for service life prediction of concrete towards freeze-thaw deicing salt attack. KW - freeze-thaw deicing salt attack KW - moisture movement Y1 - 2012 U6 - https://doi.org/10.13140/2.1.3243.9367 PB - Norwegian Concrete Association ER -