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Povzetek: The phase assemblage evolution of binders with novel supplementary cementitious materials (SCMS) during exposure to adverse environments needs to be quantified to accelerate their adoption, and further optimize binder formulation. As such, the interaction between chloride and cementitious matrices with novel SCMs needs to be quantified. The goal of workgroup 2 of RILEM TC EBD-298 is to assess the methods used to quantify chloride binding. This state-of-the-art report reviews the standardized and novel methods to measure chloride binding through an average content (acid/water soluble) or a specific bound content per phase (XRD, TGA, SEM–EDS, …). Each method is presented with respect to our current understanding of chloride binding and speciation in cementitious materials. The discussion around the purpose, use and reporting of each method highlights the gaps limiting the comparison between studies, in particular the lack of standard protocol, and complementary characterization. This review is the groundwork for a “cookbook” of experimental workflows to investigate chloride binding in modern cementitious binders.
Ključne besede: cement, chloride, supplementary cementitious materials, CSMs
Objavljeno v DiRROS: 12.01.2026; Ogledov: 214; Prenosov: 87
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Povzetek: We investigate the interactions and modifications induced by low-energy electron beam irradiation in beamsensitive materials, with crystalline gold trichloride (AuCl3) as a model system. Employing scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS) in an operando setup, we investigated surface and bulk transformations as a function of irradiation time (0–1080 s) and accelerating voltage (1–30 kV). Irreversible structural changes were observed both on the surface and within the bulk of the AuCl3 crystal. Surface analysis revealed the formation and growth of µm-sized vertically oriented carbon nanopillars, with voltage-dependent growth dynamics governed by backscattered (BSE) and secondary electrons (SE). At the same time, the bulk of the AuCl3 decomposed under carbon pillars, forming Au nanoparticles and near-surface voids whose size and spatial distribution correlated with the energy deposition profiles. The observed morphological and chemical alterations pose a significant obstacle to accurate chemical composition analyses by energy-dispersive X-ray spectroscopy (EDS) and suggest a narrow operating window for conducting reliable SEM analysis.
Ključne besede: beam sensitive materials, electron beam interactions, electron radiation, gold chloride, carbon deposition
Objavljeno v DiRROS: 29.09.2025; Ogledov: 419; Prenosov: 200
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Povzetek: This dataset supports the tables and figures in the article Effect of sulfide in a 0.2 M NaCl solution on copper and pre-oxidized copper in oxic conditions Effect of sulfide in a 0.2 M NaCl solution on copper and pre-oxidized copper in oxic conditions (https://doi.org/10.1016/j.surfin.2025.107387). The data set contains experimental data for copper and pre-oxidized copper samples exposed to chloride solution (0.2 M Cl–) with different sulfide concentrations (5·10–6 M SH– and 1·10–4 M SH–) at room temperature (22 ± 2 °C) and elevated temperature (60 °C). Corrosion potential was monitored over a period of 24 hours. After 24 h immersion, electrochemical impedance spectroscopy was performed to observe the properties of the surface film formed on the copper and the pre-oxidized copper. The dataset also includes images of pre-oxidized samples after 24 hours immersion in different solutions, original Raman spectra and Raman images, XPS data and images data from the scanning electron microscope and images of cross-section of samples. The dataset was also used for the model of corroding system (Figure 13)
Ključne besede: copper, pre-oxidized copper, chloride and sulfide environment, electrochemical properties, surface characterization, Raman, cyclic voltammetry
Objavljeno v DiRROS: 11.08.2025; Ogledov: 662; Prenosov: 412
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Povzetek: Background Benzalkonium chloride (BAC) is one of the most common ingredients of the disinfectants. It is commonly detected in surface and wastewaters where it can interact with the residues of pharmaceuticals that are also common wastewater pollutants. Among the latter, the residues of antineoplastic drugs are of particular concern as recent studies showed that they can induce adverse effect in aquatic organisms at environmentally relevant concentrations. Methods Ecotoxicity of BAC as an individual compound and in a binary mixture with an antineoplastic drug 5-fluorouracil (5-FU) was determined towards alga Pseudokirchneriella subcapitata, a representative of primary producers. The toxicity of the BAC+5-FU binary mixture was predicted by the two basic models: concentration addition (CA) and independent action (IA), and compared to the experimentally determined toxicity. Additionally combination index (CI) was calculated to determine the type of interaction. Results After 72 h exposure to BAC a concentration dependent growth inhibition of P. subcapitata was observed with an EC50 0.255 mg/L. Comparing the predicted no effect concentration to the measured concentrations in the surface waters indicate that BAC at current applications and occurrence in aquatic environment may affect algal populations. The measured toxicity of the mixture was higher from the predicted and calculated CI confirmed synergistic effect on the inhibition of algal growth, at least at EC50 concentration. The observed synergism may have impact on the overall toxicity of wastewaters, whereas it is less likely for general environments because the concentrations of 5-FU are several orders of magnitude lower from its predicted no effect concentration. Discussion These results indicate that combined effects of mixtures of disinfectants and antineoplastic drugs should be considered in particular when dealing with environmental risk assessment as well as the management of municipal and hospital wastewaters.
Ključne besede: ecotoxicity, benzalkonium chloride, algae, 5-fluorouracil, synergistic inhibition
Objavljeno v DiRROS: 24.07.2024; Ogledov: 1050; Prenosov: 768
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Povzetek: Many standardised durability testing methods have been developed for Portland cement-based concretes, but require validation to determine whether they are also applicable to alkali-activated materials. To address this question, RILEM TC 247-DTA "Durability Testing of Alkali-Activated Materials" carried out round robin testing of carbonation and chloride penetration test methods, applied to five different alkali-activated concretes based on fly ash, blast furnace slag or metakaolin. The methods appeared overall to demonstrate an intrinsic precision comparable to their precision when applied to conventional concretes. The ranking of test outcomes for pairs of concretes of similar binder chemistry was satisfactory, but rankings were not always reliable when comparing alkali-activated concretes based on different precursors. Accelerated carbonation testing gave similar results for fly ash-based and blast furnace slag-based alkali-activated concretes, whereas natural carbonation testing did not. Carbonation of concrete specimens was observed to have occurred already during curing, which has implications for extrapolation of carbonation testing results to longer service life periods. Accelerated chloride penetration testing according to NT BUILD 443 ranked the tested concretes consistently, while this was not the case for the rapid chloride migration test. Both of these chloride penetration testing methods exhibited comparatively low precision when applied to blast furnace slag-based concretes which are more resistant to chloride ingress than the other materials tested.
Ključne besede: alkali-activated materials (AAM), carbonatization, chloride penetration, Rilem TC, durability
Objavljeno v DiRROS: 17.08.2023; Ogledov: 2832; Prenosov: 1137
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