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Query: "fulltext" AND "organization" (Slovenian National Building and Civil Engineering Institute) .

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1.
Diketopyrrolopyrrole pigment core@multi-layer ▫$SiO_2$▫ shell with improved photochemical stability
Erika Švara Fabjan, Zineb Saghi, Paul A. Midgley, Mojca Otoničar, Goran Dražić, Miran Gaberšček, Andrijana Sever Škapin, 2018, original scientific article

Abstract: A model organic pigment (diketopyrrolopyrrole) is encapsulated by a silica coating in order to improve its photochemical stability. Unlike in previous works where single-layer silica coatings were used for similar purposes, we here propose creation of a multi-layer silica shell synthesized via in-situ sol-gel method, which should significantly improve the homogeneity and thus the protection ability of the coating. This is done by repeating the basic two-step process (pigment surface modification and silica encapsulation) several times, creating the final protective shell in a layer-by-layer fashion. The compositional and structural properties of the prepared coatings is studied using Fourier-transform infrared spectroscopy, differential thermal and thermogravimetric analysis, nitrogen adsorption measurements and transmission electron microscopy. Photochemical stability of non-encapsulated and encapsulated pigment particles is evaluated via the so-called fast-irradiation method. Various correlations between the essential coating properties, such as thickness, porosity, SiO2 content, and the corresponding photochemical stability of the samples are established and discussed in detail. As a whole, our results confirm the basic hypothesis, that multiple-layered silica shells show improved pigment protection ability in comparison to the single-layer coatings.
Keywords: organic pigments, silica coating, encapsulation, morphology, photocemical stability
Published in DiRROS: 27.03.2024; Views: 23; Downloads: 9
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2.
Lessons learned from the monitoring of retaining structures, built in demanding geotechnical conditions in Slovenia
Pavel Žvanut, Janko Logar, 2019, published scientific conference contribution

Abstract: A typical retaining structure built with large-diameter bored piles in soft clastic rock, and sup-ported by pre-stressed permanent ground anchors, is discussed. Step-by-step back analyses were performed. A simplified geological structure was first used in the analyses, together with a simple Mohr-Coulomb model. The results were compared with more complex analyses using a Hardening Soil model and a more detailed geological structure. Much better results were obtained with the use of the HS model, which is more suitable for the modelling of rock of such a type, but even with the use of the MC model the final results were quite good, making the use of the observational method attractive for engineers.
Keywords: geotechnics, gretaining structures, bored piles, numerical modelling, finite element method, observational method
Published in DiRROS: 27.03.2024; Views: 29; Downloads: 7
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3.
Modelling of traffic load effects in the assessment of existing road bridges
Dominik Skokandić, Ana Mandić Ivanković, Aleš Žnidarič, Mladen Srbić, 2019, review article

Abstract: Traffic load models used for the design of new bridges are based on conservative assumptions and have not been proven efficient for assessing safety of existing bridges. In the case of existing bridges, it is reasonable to use load models that are based on bridge weigh-in-motion data which, in addition to axle loads and spacing of bridge-crossing vehicles, provide information on bridge behaviour under traffic load. This paper provides an overview of traffic load models, as well as guidelines on the use of weigh-in-motion data when assessing condition of existing road bridges.
Keywords: prometna obtežba, tehtanje vozil med vožnjo, mostni WIM, ocenjevanje stanja, obstoječi mostovi, traffic load, weigh-in-motion, bridge WIM, condition assessment, existing bridges
Published in DiRROS: 27.03.2024; Views: 27; Downloads: 10
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4.
Validation of the recycled backfill material for the landslide stabilization at a railway line
Karmen Fifer Bizjak, Barbara Likar, 2024, original scientific article

Abstract: In mountain areas landslides many times endanger safety of transport infrastructures, and these must be stabilized with retaining wall structures. In this paper the validation of a new composite as a backfill material for landslide stabilization with a large scale demo retaining wall is presented. The new composite was made from residues of paper industry, which uses for its production deinking process. New composite was validated with the laboratory tests, construction of small demo sites and at the end with a large demo retaining wall structure with a length of 50 m. It was concluded that the paper sludge ash and the paper sludge are in proportion 70:30, compacted on the optimal water content and maximum dry density, reached sufficient uniaxial compressive and shear strength. However, the composite's hydration processes required the definition of an optimal time between the composite mixing and installation. In 2019, the retaining wall structure from the new composite was successfully built. The large demo structure is an example of the knowledge transfer from the laboratory to the construction site, in which composite and installing technology could be verified.
Keywords: landslides, recycled backfill material, paper sludge ash, geotechnical composite, railway line, recycled material, environment
Published in DiRROS: 26.03.2024; Views: 38; Downloads: 19
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5.
The challenge of integrating Life Cycle Assessment in the building design process - a systematic literature review of BIM-LCA workflows
Tajda Potrč Obrecht, Martin Röck, Endrit Hoxha, Alexander Passer, 2019, published scientific conference contribution

Abstract: To foster sustainable development in construction sectors, environmental impacts need to be reduced dramatically. The Life Cycle Assessment (LCA) technique is the most firmly established methodology used to quantify these environmental impacts and, therefore, has been applied with increasing frequency to assess the environmental performance of buildings. To effectively improve a building's environmental performance, an integration of LCA in the design process is required. This can be achieved by coupling LCA with digital design tools, e.g., Building Information Modelling (BIM). To identify the pro and cons of streamlining the integration of LCA and BIM, a comprehensive Systematic Literature Review (SLR) was performed. We identified more than 50 relevant BIM-LCA case studies and analysed the applied BIM-LCA workflows in detail. In most of the studies reviewed, the LCA has been applied in an early design stage. The authors primarily used LCA tools and manual or semi-automatic methods to exchange data between BIM models. In most cases, contemporary BIM-LCA workflows utilized conventional spreadsheets (e.g., Excel worksheets). However, the results of the analysis show that an automated link between LCA and BIM can be achieved if certain challenges are overcome. By automating exchange of information between BIM and LCA tools and improving the reliability of this process, the LCA application can be streamlined in design practice and, hence, the necessary improvements of the environmental performance of buildings can be supported.
Keywords: building information modelling, life cycle assessment, systematic Literature Review
Published in DiRROS: 18.03.2024; Views: 54; Downloads: 38
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6.
Weathering effects on cellulose acetate microplastics from discarded cigarette butts
Branka Mušič, Andrijana Sever Škapin, 2024, published scientific conference contribution (invited lecture)

Abstract: Cellulose acetate, commonly used in cigarette filters, poses environmental concerns due to its questionable (bio)degradability and prevalent presence in nature. This study compares the weathering effects on two types of cigarette filters: traditional and newer filters used in heated tobacco devices (HTP). Microplastics were derived from used cigarette parts and then subjected to artificial aging. Analytical techniques (Thermogravimetry-Differential Scanning Calorimetry TG/DSC, Fourier-Transform Infrared Spectroscopic Analysis (FTIR)) and loose bulk density measurements were employed pre- and post-aging cellulose acetate of both types of samples. Despite increasing evidence influencing European Union (EU) directives on tobacco product disposal, there's a lack of systematic analysis on the weathering impact, especially concerning the touted environmental benefits of newer filters. Results indicate decreased particle size in cellulose acetate filters post-aging. Variances were observed in thermal behavior, yet FTIR spectra remained unchanged.
Keywords: cellulose acetate, cigarette filters, microplastics, artificial weathering, polymer degradation
Published in DiRROS: 12.03.2024; Views: 84; Downloads: 80
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7.
Green transition in slovenian building and civil engineering industry : 10 years of research on alkali-activated materials and alkali-activated foams
Barbara Horvat, Branka Mušič, 2024, published scientific conference contribution (invited lecture)

Abstract: The building and civil engineering industry yearly causes more than 40% of man-made CO2 and consumes raw materials for two-thirds of Mont Everest. To decrease the carbon footprint and consumption of raw materials, alkali-activated materials (AAMs) are researched as an alternative to conventional building and civil engineering products like cements, mortar, and ceramics. Ideally, locally available waste materials are used as ingredients: (i) as precursors that react with alkali and form an aluminosilicate network, and (ii) as fillers that get permanently encapsulated and safely stored in AAMs. The addition of gas bubbles and lightweight fillers transforms AAMs into alkali-activated foams and alkali-activated lightweight materials that have the potential to be used as thermal and acoustic insulation materials. Although AAMs are researched worldwide, this review focuses on the state-of-the-art localised solely to Slovenia, particularly on the materials and curing procedures used, as well as on the scientific contribution of the basic research. Besides, the year 2024 marks 10 years of research on alkali activation of raw and waste inorganic materials in Slovenia.
Keywords: secondary raw material, alkali-activated material, alkali-activated foams, alkali, circular economy, microwave irradiation, mechanical strength
Published in DiRROS: 12.03.2024; Views: 71; Downloads: 64
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8.
Influence of ammonium polyphosphates and 2,4,6-triamino-1,3,5-triazine on the mechanical-physical properties of polyurethane and alkali-activated materials
Branka Mušič, Barbara Horvat, 2024, published scientific conference contribution

Abstract: In building constructions, the tendency towards an ever-better material directs us to composite materials. In this work, we prepared an organic-organic and organic-inorganic composite material by incorporating fire retardants, ammonium polyphosphates, and 2,4,6-triamino-1,3,5-triazine, into a polyurethane network and an aluminosilicate network (ASN) of alkali-activated material. Polyurethane foams (PUR) are well-known materials that, due to their properties, such as low weight-to-strength ratio, low electrical and thermal conductivity, flexibility, and relatively simple preparation process, are used in various industries, also in the construction industry, e.g., for thermal insulation of windows and doors or fixing and sealing joinery. Opposite, the ASN of alkali-activated metakaolin, successfully paves the way for new applications, such as high-temperature protection. In this paper, these interactive properties of prepared composites are studied using thermal testing and mechanical analysis. It was found that inhibitors significantly increase the fire resistance of PUR systems while they slightly reduce the mechanical properties. Incorporating polymer flame retardant into ASN in building products, such as façade panels , can decrease the mechanical properties but can offer the non-flammable building envelope not get heated from burning surroundings, i.e., not becoming a convection heat source, but rather represent a fire-distinguisher for flammable materials.
Keywords: flame retardants, polyurethane, alkali activated material, metakaolin, microwave irradiation, mechanical strength
Published in DiRROS: 12.03.2024; Views: 67; Downloads: 31
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9.
Waste rubber incorporated in the alkali-activated metakaolin’s aluminosilicate network enhanced by microwave irradiation
Barbara Horvat, Branka Mušič, 2024, published scientific conference contribution

Abstract: Building materials represent the possibility of prolonging the life of waste materials. The key is to ensure that the products are suitable for their function. So we activated metakaolin with the alkaline Na-silicate solution in the ratio that ensures the prevention of efflorescence and high mechanical strength (Horvat and Ducman, 2019). As the waste material (to be incorporated in the aluminosilicate network (ASN) of the alkali-activated metakaolin) ground waste rubber from electric cables was used in the preselected mass ratios. Its inclusion in products, like paving stones, can reduce stiffness, improve durability, dampen vibrations, and reduce road noise. The mechanical strengths of test samples with rubber present on the active surface or slightly below were higher compared to samples where rubber was encapsulated throughout the volume. Compressive strength was higher when samples were irradiated with low powers of microwaves while irradiation with higher powers led to the foaming of alkali-activated slurry. The encapsulation quality of the ground rubber was evaluated by SEM while the chemical influence on ASN was determined by EDS, FTIR, and XRD. Slipperiness change on the active surface of pavement stones proved that the addition of the ground rubber enhanced the walking safety of the product.
Keywords: secondary raw material, alkali activated material, waste rubber, metakaolin, encapsulation of organic in inorganic material, microwave irradiation, mechanical strength
Published in DiRROS: 12.03.2024; Views: 60; Downloads: 31
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10.
Final report on the RIS Intership implementation
Anže Tesovnik, 2023, treatise, preliminary study, study

Keywords: alkalijsko aktivirani materiali, odpadni materiali, mehanske trdnosti
Published in DiRROS: 11.03.2024; Views: 78; Downloads: 0
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