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Abstract: 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.
Keywords: circular economy, zero-waste approach, mining waste, construction sector, legislation, krožno gospodarstvo, pristop ničelnega odpadka, rudarski odpadki, gradbeništvo, zakonodaja
Published in DiRROS: 04.12.2023; Views: 225; Downloads: 131
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Abstract: Cestne povezave morajo biti odporne proti podnebnim in prometnim obremenitvam, intervali vzdrževanja asfaltnih vozišč pa čim daljši. Zato naftna industrija razvija vedno bolj odporne bitumne za cestogradnjo, hkrati pa se uveljavljajo nove preiskave, s katerimi lahko obnašanje bitumnom celovito ovrednotimo. Za karakterizacijo s polimeri modificiranih bitumnov (PmB) osnovne preiskave trdote in zmehčišča, ki se že dolga leta uporabljajo, ne zadoščajo. Zato se določajo tudi reološke karakteristike. Za karakterizacijo se uporablja dinamični strižni reometer, s katerim v kontroliranih pogojih napetosti in deformacij na majhnih vzorcih bitumna določamo viskoelastične in plastične lastnosti vzorcev bitumna. V prispevku so prikazani rezultati osnovnih in reoloških preiskav s polimeri modificiranih bitumnov različnih trdnostnih razredov, ki se uporabljajo v slovenskem prostoru.
Keywords: s polimeri modificiran bitumen, reologija, DSR, MSCRT
Published in DiRROS: 04.12.2023; Views: 246; Downloads: 104
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Abstract: Raw materials are of great importance for humankind as they enable the development of technology, drive industry and economy, and overall the lifestyle we know today. The paper is addressing the topic of interactive learning about the mineral raw materials, i.e. metals and non-metals. Due to population growth and consequently in-creased global demand for raw materials, there is a need to educate younger generations about the raw materials and their properties and origin, so they would know from an early age where the mineral products they use come from and how purchase decisions affect the social environments of people who live in countries with resources exploitation.Todayʼs trends in mining are oriented towards more sustainable exploitation and management, taking into account the economic, social and environmental aspects. An example of such is exploitation of secondary raw materials from tail-ings and heaps. But in some countries, mining is stuck in the past, using obsolete technologies causing increased pol-lution and strongly present linear economy approaches of take-use-dispose attitudes or even unethical approaches, such as children being exploited as a cheap workforce, people being abducted, tortured and even killed over minerals (min-erals being exploited in such way are called blood or conflict minerals). Further, due to the potential negative impacts on health and safety, due to the emissions in air, water and surface disturbance, the public perception of mining is still perceived as negative in most cases. School curriculums most often lack description of current situations in the global mining. Therefore, within the EIT RawMaterials BRIEFCASE and 3D BRIEFCASE projects the project partners provide the comprehensive view of the issues of todayʼs mining and use of raw materials. The paper presents the description of both projects and the non-conventional teaching methods - the hands-on and digital tools for pupils and teachers, i.e. the briefcases, the "Briefcase of mineral applications" game, workshops and the supporting materials. The main objective of projects is to raise the pupils awareness about the utility and indispensability of minerals and mining and the consequences of their uses and production systems, which would increasein the long term the awareness about the social and environmental consequences of raw material production.
Keywords: raw materials, mining, pupils and students, non-conventional teaching tools, BRIEFCASE, 3D BRIEFCASE, curricular planning, EIT RawMaterials
Published in DiRROS: 04.12.2023; Views: 245; Downloads: 111
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Abstract: Pod vplivi prometnih obremenitev in okoljskih vplivov se kakovost vozišč stalno slabša. Z uporabo modificiranega švicarskega indeksa MSI lahko ocenimo in spremljajmo staranje vozišča, sposobnost zagotavljanja njegove funkcije pa lahko opredelimo z izgubo uporabnosti vozišča. Prispevek podaja predlog nove modelne funkcije za opredelitev staranja vozišča oziroma njegove izgube uporabnosti na osnovi vizualne ocene stanja vozišča (MSI) in določitev njegove navidezne starosti glede na predlagani model staranja vozišč.
Keywords: vozišče, ocena stanja, MSI, model
Published in DiRROS: 04.12.2023; Views: 197; Downloads: 107
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Abstract: This paper presents results from an experimental assessment of glued-in rods in cross laminated timber (CLT). For the purposes of the study more than 60 pull-pull tests were performed, where the specimens varied in terms of bonded-in length (from 80 to 400 mm), rod diameter (16-24 mm) and rod-to-grain angle (parallel and perpendicular). Several different failure modes that are not common for other applications of glued-in rods (e.g., a failure between CLT layers) were obtained for the analysed CLT specimens. It was found that these failure mechanisms can substantially influence the obtained ultimate tension loads. At the end, the experimental results were compared with empirical and semi-empirical equations for estimating the pull-out strength of glued-in rods in structural timber and glulam. The comparison showed that most of the existing equations overestimate the ultimate tension loads for specimens with the rod parallel to the grain and underestimate the ultimate tension load for specimens with the rod perpendicular to the grain. The results vary because the possible CLT failure modes were not included in previous studies. Further studies are proposed to improve the equations for glued-in rods in CLT.
Keywords: glued-in rods, cross laminated timber (CLT), pull-pull experiment, glued-in length, rod-to-grain angle, failure mechanisms in CLT
Published in DiRROS: 29.11.2023; Views: 225; Downloads: 179
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