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Iskalni niz: "avtor" (Ana Mladenovič) .

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1.
Origins of architectural heritage: the resources and variety of natural stones in Slovenia
Sabina Dolenec, Nina Žbona, Boštjan Rožič, Mojca Bedjanič, Snježana Miletić, Matevž Novak, Ana Mladenovič, 2026, izvirni znanstveni članek

Povzetek: The distinct geological variation of Slovene’s territory, which includes all three major types of natural stone (sedimentary, igneous and metamorphic), offers an ample selection of building and art materials to be chosen based on their properties and/or aesthetic appearance. The tectonic diversity of the area caused some difficulties in extracting some of the natural stones, resulting in quarries being abandoned for economic and spatial reasons, but some beautiful examples of the use of lasting value in both construction and art still persist. Examples include the abandoned quarries of Pohorje marble and Podpeč limestone, where extraction has been documented from as early as the Roman times, with the latter also designated as a Global Heritage Stone Resource. The Pohorje mountains are an area of granodiorite as well as green cizlakite, the latter being Slovenian endemic. Furthermore, the Kras (Karst) region is one of the most interesting areas containing natural stone reserves in Slovenia, with a large variety of Cretaceous shallow-water limestones. All of these are abandoned, with the two natural stone quarries still operating being associated with the presence of rudist biostromes and bioherms, which are responsible for the aesthetic appearance of these natural stones. It is also characteristic of Slovenia to use a variety of local rocks, such as sandstone, conglomerate, breccia, shale and tuff, to give character to vernacular architecture. Some of the quarries are designated and protected as valuable natural features or natural monument, while several buildings decorated with Slovene natural stones are declared as cultural monuments of local or national importance or included in the UNESCO World Heritage List. This paper presents the most significant Slovene quarries of natural stones that have been used in architectural heritage, the mineralogical and physical-mechanical characteristics of these stones, as well as examples of their use in monuments.
Ključne besede: Slovenian quarries, natural stone, stone monuments, cizlakite, Kras (Karst) quarry region
Objavljeno v DiRROS: 29.07.2026; Ogledov: 149; Prenosov: 48
.pdf Celotno besedilo (3,63 MB)

2.
Multi-scale X-ray techniques for assessing recycled concrete aggregate : from XRPD analysis of leftover cement in recycled aggregates to micro-CT imaging of concrete microstructure
A. Bisciotti, Lucia Mancini, Alberto Viani, Vesna Zalar Serjun, Ana Mladenovič, Giuseppe Cruciani, 2025, izvirni znanstveni članek

Povzetek: The content of leftover cement paste is a crucial parameter for determining recycled aggregates quality. Various methods assess this, including wet techniques (acid dissolution, chemical degradation, water absorption), physical approaches (freeze-thaw cycles, mechanical shredding, oven-dried density, thermal disaggregation), and spectroscopic or microscopy analyses. However, these methods often lack accuracy, are time-consuming, or depend on operator skill. A novel X-ray Powder Diffraction and Rietveld quantitative phase analysis approach is introduced to improve measurements precision. Results are compared with multi-scale analyses (microscopy, Xray computed tomography, mechanical testing) on recycled aggregate concrete specimens. Findings highlight a strong correlation between leftover cement paste content and key concrete properties, including microstructure, hydration products, and mechanical performance. This study confirms that leftover cement paste content is a decisive factor in recycled concrete aggregate properties, and that the proposed method offers a rapid and reliable approach to control this parameter.
Ključne besede: recycled concrete aggregate, leftover cement paste, CDW, X-ray diffraction, microstructure
Objavljeno v DiRROS: 27.08.2025; Ogledov: 962; Prenosov: 626
.pdf Celotno besedilo (8,35 MB)
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Recycled red mud as an useful geotechnical material
Primož Pavšič, Marija Đurić, Mateja Košir, Alenka Mauko Pranjić, Ana Mladenovič, Primož Oprčkal, Sara Seršen, Vesna Zalar Serjun, 2024, objavljeni znanstveni prispevek na konferenci

Povzetek: Red mud (RM) is an extractive waste from Bayer process in alumina production. The most conventional methods of RM disposal are tailing dams, or dry storage,both of which raiseenvironmental concerns due to the high alkalinity of RMandthe presence and leaching of potentially hazardous elements (PTEs).Due to its fine-grained nature and poor mechanical properties, as well as leaching of potentially hazardous substances, RM cannot be used by itself. Properties of the RM can be improved, by mixing it with hydraulic or pozzolanic binders, such as calcareous ashes or steelmaking slag, to produce mechanically stable and durable composites for earthworks. On the other hand, RMcan also serve as an immobilization additive for remediation of contaminated soils.Two different approaches for useful utilization of RMare presented based on results of laboratory research and a real case study, opening of new possibilities for conserving natural resources and reducing environmental hazards of RM deposits.
Ključne besede: red mud, recycling, geotechnical composites, environment
Objavljeno v DiRROS: 30.10.2024; Ogledov: 1444; Prenosov: 1478
.pdf Celotno besedilo (8,18 MB)
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5.
Comparison of the mineralogy and microstructure of EAF stainless steel slags with reference to the cooling treatment
Mojca Loncnar, Ana Mladenovič, Marija Zupančič, Peter Bukovec, 2017, izvirni znanstveni članek

Povzetek: TIn the present study the differences in the mineralogical composition and microstructure of various types of EAF stainless steel (EAF S) slag with regard to the cooling treatment, the operation practice in an EAF (electric arc furnace) and environmental ageing reactions were evaluated. It was shown that the mineralogy of the investigated EAF S slags varied from one slag to another, depending on the quality of the produced stainless steel. The production process of the treated steel also has a strong influence on the mineralogy of the slags. The conditions during water cooling treatment were not sufficient to prevent the crystallization of primary mineral phases, which occurs predominantly in air-cooled EAF S slags, probably due to the high basicity of the investigated slags. However, the water cooling treatment of hot slag leads to the absence of γ-CaSiO 4 and the formation of secondary mineral phases predominantly calcite, portlandite, ettringite, calcium aluminate hydrate and calcium silicate hydrate. It has been shown that during the environmental ageing test (down-flow column test) secondary mineral phases were formed, which were the same as those formed during the water cooling treatment.
Ključne besede: electric arc furnace stainless steel slag, cooling path, microstructure, mineralogy
Objavljeno v DiRROS: 14.08.2024; Ogledov: 1421; Prenosov: 821
.pdf Celotno besedilo (3,74 MB)
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6.
Heavy metal signature and environmental assessment of nearshore sediments: Port of Koper (Northern Adriatic Sea)
Nastja Rogan Šmuc, Matej Dolenec, Sabina Dolenec, Ana Mladenovič, 2018, izvirni znanstveni članek

Povzetek: Heavy metal abundance and potential environmental risks are reported for surface sediments (n = 21) from the Port of Koper area, Republic of Slovenia. The enrichment factor (EF) indicates minor enrichment in arsenic (As), cadmium (Cd), copper (Cu), molybdenum (Mo), lead (Pb), antimony (Sb), and zinc (Zn), moderately to severely enriched with nickel (Ni). The trace metal chemistries, in the context of sediment quality guidelines (SQG), imply adverse threshold effect concentrations (TEC) and probable effect concentrations (PEC), for Ni only. Sediment sequential leaching experiments demonstrated that the majority of heavy metals were of natural lithogenic origin and low bioavailability. The heavy metals’ potential for “Risk Assessment Code” values exhibited no or low anthropogenic environmental burden, with the exception of Mo.
Ključne besede: port sediments, heavy metals, chemical speciation, risk assessment, Northem Adriatic Sea
Objavljeno v DiRROS: 12.12.2023; Ogledov: 2284; Prenosov: 1095
.pdf Celotno besedilo (6,88 MB)
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7.
Mining waste in circular economy - legislative aspect
Senko Pličanič, Ana Mladenovič, Alenka Mauko Pranjić, Petra Vrhovnik, 2020, izvirni znanstveni članek

Povzetek: One of the common European commitments is a transition towards a green circular economy in which waste is not discarded and considered to be just an environmental problem, but should be recognized as an important potential source of raw materials for industry. In a priority order in waste management activities, introduced by the Waste Directive in 2012, recycling is set just behind the waste prevention and reuse. Many types of waste can be recycled, the most perspective being construction, industrial and mining wastes. The latter are produced and disposed of at mine sites during the excavation and processing of ore and are extremely perspective due to large quantities and remaining of different metals, however still underutilized, with low recycling rate. Many mining wastes are inert and do not releases contaminants into environment, however, some of them are problematic and even require monitoring. Reprocessing of these wastes, which include beneficiation and sequential extraction of valuable metals in the first phase and recycling of residues in both structural and civil engineering in the second phase establishes a zero waste model with several benefits for economy, environment and society. Out of the South-East European countries, North Macedonia has great potential to establish this model. As a consequence of long mining tradition and abundant ore resources, there are many mining and metallurgical tailings, on the other hand vivid economy and numerous sinks for use of recycled materials in construction sector can accommodate these quantities. However, there are open questions in terms of administrative procedures and legislation. What are those obstacles that accompany the smooth establishment of the proposed model from a legislative point of view? This paper deals with the situation in North Macedonia, in terms of opportunities, legislative options and the need to adopt new legislation, taking also into account the current problems in this field in Europe.
Ključne besede: circular economy, zero-waste approach, mining waste, construction sector, legislation, krožno gospodarstvo, pristop ničelnega odpadka, rudarski odpadki, gradbeništvo, zakonodaja
Objavljeno v DiRROS: 04.12.2023; Ogledov: 2191; Prenosov: 982
.pdf Celotno besedilo (435,68 KB)
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8.
Detoxified spent pot lining from aluminum production as (alumino-)silicate source for composite cement and autoclaved aerated concrete
Arne Peys, Mateja Košir, Ruben Snellings, Ana Mladenovič, Liesbeth Horckmans, 2021, izvirni znanstveni članek

Povzetek: New sources of supplementary cementitious materials (SCMs) are needed to meet the future demand. A potential new source of SCM is spent pot lining, a residue from aluminum production. The present work showed that the refined aluminosilicate part of spent pot lining (SPL) has a moderate chemical reactivity in a cementitious system measured in the R3 calorimetry test, comparable to commercially used coal fly ash. The reaction of SPL led to the consumption of Ca(OH)2 in a cement paste beyond 7 days after mixing. At 28 and 90 days a significant contribution to strength development was therefore observed, reaching a relative strength, which is similar to composite cements with coal fly ash. At early age a retardation of the cement hydration is caused by the SPL, which should most likely be associated with the presence of trace amounts of NH3. The spent pot lining is also investigated as silica source for autoclaved aerated concrete blocks. The replacement of quartz by spent pot lining did not show an adverse effect on the strength-density relation of the lightweight blocks up to 50 wt% quartz substitution. Overall, spent pot lining can be used in small replacement volumes (30 wt%) as SCM or as replacement of quartz (50 wt%) in autoclaved aerated concrete blocks.
Ključne besede: spent pot lining, construction materials, recycling, autoclaved aerated conctrte, supplementary cementitious material
Objavljeno v DiRROS: 04.12.2023; Ogledov: 1951; Prenosov: 946
.pdf Celotno besedilo (15,66 MB)
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9.
Izgradnja lizimetrov za preučevanje izpiranja potencionalno nevarnih snovi iz gradbenih proizvodov
Janez Turk, Janko Urbanc, Ana Mladenovič, Alenka Sešek Pavlin, Primož Oprčkal, Karmen Fifer Bizjak, Barbara Likar, Marko Brodnik, Nina Mali, 2020, izvirni znanstveni članek

Povzetek: Z uporabo recikliranih odpadkov v gradbeništvu nadomeščamo naravne materiale in s tem vzpostavljamo krožno gospodarstvo na lokalnem nivoju. Pomemben vidik je tudi ohranjanje naravnih virov. To je še posebno pereče pri zemeljskih delih (npr. zasipih in nasipih), kjer prihaja do velike porabe materialov. Geotehnični kompoziti iz recikliranih materialov, v primerjavi z naravnimi agregati ali zemljinami, lahko vsebujejo višje celotne koncentracije potencialno nevarnih snovi (težke kovine, klorid, sulfat, fluorid, organska onesnaževala itd.). Pogoj za uporabo takšnih kompozitov je, da so v njih potencialno nevarne snovi imobilizirane in da so zato iz kemijskega vidika trajno inertni. Možni vplivi na okolje, predvsem prenos različnih potencialno nevarnih snovi iz kompozitov v tla oziroma vodonosnik, so običajno ovrednoteni na laboratorijski ravni, medtem ko je njihovo obnašanje v dejanskem okolju slabo proučeno. Zato se pojavljajo zahteve po razvoju občutljivih, zanesljivih in cenovno ter časovno učinkovitih orodij za določitev masnih tokov potencialno nevarnih snovi iz gradbenih proizvodov, na primer geotehničnih kompozitov, pod vplivi različnih okoljskih dejavnikov. V članku predstavljamo postopek vzpostavitve terenskega laboratorija na osnovi sistema "pan" lizimetrov, za zbiranje izcednih voda iz zasipov, ki so bili izdelani iz geotehničnih kompozitov iz recikliranih materialov. Lizimetre smo konstruirali in izvedli tako, da je njihova izgradnja cenovno ugodna, hkrati pa so po svojih dimenzijah dovolj veliki, da reprezentativno odražajo procese v zgrajenih geotehničnih zasipih. Pridobljeni podatki o količini in parametrih izcedne vode bodo služili kot osnova za določanje vodne bilance in za študij imobilizacije potencialno nevarnih snovi v kompozitih. Hkrati bodo uporabljeni kot vhodni podatki za geokemijski numerični model, s katerim bomo simulirali transport potencialno nevarnih snovi, sproščenih iz preučevanih kompozitov, v različnih tipih vodonosnikov (npr. medzrnski in razpoklinski).
Ključne besede: lizimeter, izlužek, okoljski monitoring, geotehnični zasip, odpadki
Objavljeno v DiRROS: 12.09.2023; Ogledov: 3460; Prenosov: 1124
.pdf Celotno besedilo (2,46 MB)
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10.
Remediation of contaminated soil by red mud and paper ash
Primož Oprčkal, Ana Mladenovič, Nina Zupančič, Janez Ščančar, Radmila Milačič Ščančar, Vesna Zalar Serjun, 2020, izvirni znanstveni članek

Povzetek: Remediation of contaminated soil can be performed by using various techniques, which must be adequately tailored for each specific case. The aim of this research is to critically evaluate the potential use of red mud and paper ash and a combination of the two as immobilization additives for the remediation of contaminated soil from one of the most polluted sites in Slovenia. The proposed procedure involves the preparation of geotechnical composites made from contaminated soil and mixed with 25 wt% of immobilization additives and an optimal quantity of water to achieve consistency, at which maximum compaction according to the Proctor Compaction Test procedure can be achieved. The results reveal a positive, time-dependent trend for the immobilization of potentially toxic elements in the composite with paper ash, because of the formation of the new hydration products with potentially toxic elements. In a composite containing only red mud, potentially toxic elements were immobilized by sorption mechanisms with no general time-dependent trends. The composite with a combination of additives demonstrates the remediation characteristics of both red mud and paper ash. Using this approach excavated contaminated soil, red mud and paper ash can be successfully recycled in the proposed composites, which can be beneficially used in situ for rehabilitation of contaminated sites. Nevertheless, mobilization of some potentially toxic elements at high pHs may represent a limiting factor and has to be taken into the consideration when a combination of red mud and paper ash is used as immobilization additive.
Ključne besede: red mud, paper ash, contaminated soil, potentially toxic elements, geotechnical composites
Objavljeno v DiRROS: 31.08.2023; Ogledov: 2756; Prenosov: 1803
.pdf Celotno besedilo (2,28 MB)
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