1. Characterization of the substrates from two cultural-heritage sites and a preparation of model substratesSabina Dolenec, Vilma Ducman, Snezana B. Vučetić, Edo Velkavrh, Miroslava Radeka, Jonjaua Ranogajec, 2014, izvirni znanstveni članek Povzetek: In this study the microstructural characteristics of the materials selected from two cultural-heritage sites (the Dornava Manor, Slovenia, and the Bač Fortress, Serbia) and of the model samples - the control and aged ones - were investigated. The samples were characterized by means of mercury intrusion porosimetry (MIP) and total-specific-area analysis (BET). A good agreement was achieved between the samples of the brick and mortar from the Bač Fortress,or the samples of the natural stone and render from the Dornava Manor, and the corresponding model samples.
Ključne besede: materials, microstructure, brick, natural stone, mortar, frost resistance
Objavljeno v DiRROS: 26.09.2025; Ogledov: 374; Prenosov: 170
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2. Characteristics of lightweight aggregate concrete interfacial transition zoneVesna Milovanović, Vilma Ducman, Miroslava Radeka, 2014, izvirni znanstveni članek Povzetek: The paper presents the characteristics of the interfacial zone between the lightweight aggregate produced on the basis of waste materials and binder matrix with the application of the methods SEM, EDS and the Vickers micro hardness test. On the basis of the SEM and EDS analysis, as well as the criteria for the atomic ratio of elements which compose some products of hydration, we can gain insight into the dominant composition of the interfacial zone. The values of the Vickers micro hardness test for four kinds of tested concrete after seven days of hydration is impossible to correlate with the composition of the interfacial zone in reliable way, whereas after twenty eight days the differences in values are insignificant.
Ključne besede: lightweight aggregate, waste material, interfacial zone
Objavljeno v DiRROS: 26.09.2025; Ogledov: 306; Prenosov: 167
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3. Aggregates obtained by alkali activation of fly ash : the effect of granulation, pelletization methods and curing regimesOgnjen Lj. Rudić, Vilma Ducman, Mirjana Malešev, Vlastimir Radonjanin, Suzana Draganić, Slobodan Šupić, Miroslava Radeka, 2019, izvirni znanstveni članek Povzetek: This paper presents results regarding the phase composition, microstructure and textural properties of two types of aggregates, which were prepared via crushing or pelletization of alkali-activated Class F fly ash and cured under different conditions. The alkali activator was the same for aggregate products, containing an alkaline solution consisting of 8 M NaOH and Na-silicate (8 M NaOH/Na-silicate = 1:2.5 mass ratio). The aforementioned properties were influenced by two different preparation procedures combined with varying curing regimes (under normal conditions at 20 %C, RH 40%60% for 28 and 120 days and under an accelerated regime, at 65 %C for 5 days). Aggregates were characterized using X-ray diffraction (XRD), Fourier-transform transmission infrared spectroscopy (FTIR), back scattered electron microscopy with energy dispersive spectrometer (BSE-EDS) analyses and mercury intrusion porosimetry (MIP). The results showed noteworthy structural and textural diversities between the two types of aggregate. The method of preparation and curing regime affected the formation of the N-A-S-H structure and the texture of the alkali-activated fly ash product, with the crushing method giving an advantage
Ključne besede: alkali activation, agregat, FTIR
Objavljeno v DiRROS: 14.09.2023; Ogledov: 1290; Prenosov: 835
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