TY - CONF A1 - Nikoonasab, Ali A1 - Müller, Thoralf A1 - Gluth, Gregor T1 - Study of steel behavior in synthetic pore solutions of GGBFS-containing cements using EIS N2 - Steel corrosion in sulfide-containing solutions presents a challenge in a number of environments and appli¬cations, such as the kraft process, the oil and gas industry, and reinforced concrete structures. In concrete, sulfides are introduced by ground granulated blast-furnace slag (GGBFS), which is a widespread component of standard cements and which can also be utilized in the production of alkali-activated materials (AAMs). However, a knowledge gap exists concerning the compositions of pore solutions in GGBFS-containing cements, especially regarding sulfur and its various species and understanding how these sulfur species affect the surface layer and the corrosion behavior of steel in such environments. The present study employed electrochemical impedance spec¬tros-copy to study the behavior of steel in synthetic solutions representing GGBFS-containing cements and AAMs. The electrochemical behavior of steel in sulfide-containing solutions differs from that observed in ordinary Portland cement solutions, generally exhibiting lower open circuit potentials and polarization resistances in the former environments. This suggests that the criteria or standards used to assess the probability of steel corrosion in Portland cement concrete are not applicable to GGBFS-containing concrete due to differences of their pore solution compositions. T2 - International Workshop on Impedance Spectroscopy – IWIS 2024 CY - Chemnitz, Germany DA - 24.09.2024 KW - Cement KW - Ground granulated blast-furnace slag KW - Sulfide KW - Steel corrosion KW - Impedance spectroscopy PY - 2024 DO - https://doi.org/10.1109/IWIS63047.2024.10847235 SP - 44 EP - 48 PB - IEEE AN - OPUS4-61221 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nikoonasab, Ali A1 - Licht, M. A1 - Weiler, L. A1 - Achenbach, R. A1 - Raupach, M. A1 - Gluth, Gregor T1 - Pore solution compositions and redox potentials of ground granulated blast furnace slag-containing cement pastes N2 - The pore solutions of hardened ground granulated blast furnace slag (GGBFS)-containing cements differ from the pore solutions of other cements with effects on reinforcement corrosion, application of electrochemical methods and immobilisation of radioactive waste. In the present study, the pore solutions of seven different GGBFS-containing cements (alkali-activated slag, alkali-activated slag/fly ash blends, hybrid alkaline cement (HAC), CEM III/C and CEM III/B) were extracted and their elemental and sulfate concentration, pH, redox potential and conductivity were determined; a Portland cement (CEM I) pore solution was analysed analogously. The silicon and aluminium concentrations of the alkali-activated cements increased with fly ash fraction, reaching values up to 5 mM and 10 mM, respectively, and thus were considerably higher than those of the standard cements. The redox potentials of the pore solutions of the GGBFS-containing cements were in the range from −100 mV to –500 mV vs Ag/AgCl, that is considerably lower than that of the Portland cement (8–20 mV vs Ag/AgCl), with the value depending on the GGBFS fraction and whether the cements were alkali-activated or not. These results indicate that the effects of reduced sulfur species from GGBFS in cements are more pronounced in alkali-activated materials, including HAC, and increase with GGBFS fraction. KW - Alkali-activated materials KW - Ground granulated blast furnace slag KW - Sulfide KW - Redox potential KW - Pore solution PY - 2026 DO - https://doi.org/10.1680/jadcr.25.00041 SN - 1751-7605 SN - 0951-7197 VL - 38 IS - 4 SP - 238 EP - 249 PB - Emerald CY - Leeds AN - OPUS4-64619 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bernal, S. A. A1 - Angst, U. M. A1 - Provis, J. L. A1 - Thiel, C. A1 - Gluth, Gregor A1 - Villagran-Zaccardi, Y. A1 - De Belie, N. T1 - Recommendation of RILEM TC 281-CCC: RILEM CPC-18R1—guideline for measuring the carbonation depth of hardened concrete using a pH indicator solution N2 - This recommendation provides a procedure for determining the carbonation depth on the surface of concrete by applying a pH indicator. This includes definitions of carbonation, carbonation depth and carbonation front, as well as descriptions of the different pH indicator solutions that can be used. Recommendations for testing laboratory-prepared specimens and those obtained from concrete structures are also given. This involves guidelines for sample preparation and/or extraction, CO2 exposure duration, carbonation depth determination and reporting of results. A section on data interpretation is also provided, as carbonation results are used for determining durability of concrete, as well as a criterion for materials selection or for carbon uptake calculations. The new Recommendation CPC-18R1 is intended to supersede the former RILEM recommendation CPC-18, particularly when prescribed as the preferred method for evaluating and reporting carbonation depths. KW - Carbonation KW - Concrete KW - pH indicator KW - Phenolphthalein KW - Testing PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-656191 DO - https://doi.org/10.1617/s11527-026-02966-0 SN - 1359-5997 SN - 1871-6873 VL - 59 IS - 3 SP - 1 EP - 11 PB - Springer Nature AN - OPUS4-65619 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Herbst, Tristan A1 - Gluth, Gregor A1 - Rübner, Katrin A1 - Kühne, Hans-Carsten T1 - SCM: living up to the standard N2 - European and Germany regulations demand an elaborate waste management to save natural resources, reduce waste volumes deposited at landfills and enhance sustainable development by recycling of various residues. Research into the use of these materials in the construction sector and other fields is a positive step forward in achieving these objectives. BAM shares its latest findings. PY - 2012 SN - 0959-6038 IS - September SP - 115 EP - 117 PB - Holbrook & Son CY - Dorking AN - OPUS4-30409 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -