{"?xml":{"@version":"1.0"},"edm:RDF":{"@xmlns:dc":"http://purl.org/dc/elements/1.1/","@xmlns:edm":"http://www.europeana.eu/schemas/edm/","@xmlns:wgs84_pos":"http://www.w3.org/2003/01/geo/wgs84_pos","@xmlns:foaf":"http://xmlns.com/foaf/0.1/","@xmlns:rdaGr2":"http://rdvocab.info/ElementsGr2","@xmlns:oai":"http://www.openarchives.org/OAI/2.0/","@xmlns:owl":"http://www.w3.org/2002/07/owl#","@xmlns:rdf":"http://www.w3.org/1999/02/22-rdf-syntax-ns#","@xmlns:ore":"http://www.openarchives.org/ore/terms/","@xmlns:skos":"http://www.w3.org/2004/02/skos/core#","@xmlns:dcterms":"http://purl.org/dc/terms/","edm:WebResource":[{"@rdf:about":"http://www.dlib.si/stream/URN:NBN:SI:doc-DUDB4JQX/ca3d5ca8-2f69-4697-a8bb-40dcf1bd1e09/HTML","dcterms:extent":"45 KB"},{"@rdf:about":"http://www.dlib.si/stream/URN:NBN:SI:doc-DUDB4JQX/4d5e160a-c4fe-4fd7-96a1-31e606d6cb58/PDF","dcterms:extent":"400 KB"},{"@rdf:about":"http://www.dlib.si/stream/URN:NBN:SI:doc-DUDB4JQX/c9d2730a-5bf2-429f-b717-cb02b1c644d1/TEXT","dcterms:extent":"32 KB"}],"edm:TimeSpan":{"@rdf:about":"1951-2026","edm:begin":{"@xml:lang":"en","#text":"1951"},"edm:end":{"@xml:lang":"en","#text":"2026"}},"edm:ProvidedCHO":{"@rdf:about":"URN:NBN:SI:doc-DUDB4JQX","dcterms:isPartOf":[{"@rdf:resource":"https://www.dlib.si/details/URN:NBN:SI:spr-OE4S1HGI"},{"@xml:lang":"sl","#text":"Gradbeni vestnik"}],"dcterms:issued":"2009","dc:creator":"Trtnik, Gregor","dc:format":[{"@xml:lang":"sl","#text":"letnik:58"},{"@xml:lang":"sl","#text":"številka:7"},{"@xml:lang":"sl","#text":"str. 180-187"}],"dc:identifier":["ISSN:0017-2774","COBISSID:787294","URN:URN:NBN:SI:doc-DUDB4JQX"],"dc:language":"sl","dc:publisher":{"@xml:lang":"sl","#text":"Zveza društev gradbenih inženirjev in tehnikov Slovenije"},"dc:subject":[{"@xml:lang":"sl","#text":"cement"},{"@xml:lang":"sl","#text":"preiskava materiala"},{"@xml:lang":"sl","#text":"ultrazvočne meritve"},{"@xml:lang":"sl","#text":"ultrazvočne metode"},{"@xml:lang":"sl","#text":"veziva"}],"dcterms:temporal":{"@rdf:resource":"1951-2026"},"dc:title":{"@xml:lang":"sl","#text":"Uporaba ultrazvočne metode za oceno vezanja materialov s cementnih vezivom| The use of ultrasonic method to esstimate the setting time of cement based materials|"},"dc:description":[{"@xml:lang":"sl","#text":"In this paper, the possibility of using two different ultrasonic (US) methodsto estimate the initial setting time of different cement based materials is briefly discussed. In the case of different concrete mixtures, an ultrasonic wave trans- mission method (USWT) is analyzed and in the case of pure cement pastes, both the USWT and an ultrasonic wave reflection (USWR) methods as well as their combina- tion are discussed. It was found out that in the case of the USWT method, the initial setting time of an arbitrary concrete and cement paste mixtures can be estimated very accurately from the time of the first inflection point of the corresponding velocity (Vp) - time curve. In the case of pure cement pastes, the initial setting time can be also estimated by the time, when the shear wave reflection coefficient (dr) starts to increase rapidly. As an addition, the end of the first phase of the corresponding vp drcurve can be used to define the initial setting process of cement pastes. Repro- ducibility of both methods is shown and statistical analysis of the estimation of the initial setting time of cement pastes with the ultrasonic wave transmission method is discussed"},{"@xml:lang":"sl","#text":"V prispevku je prikazana možnost uporabe dveh različnih neporušnih ultrazvočnih (UZ) metod za oceno začetka vezanja različnih materialov s cementnim vezivom. V primeru betonskih mešanic je bila uporabljena metoda prehoda vzdolžnih UZ-valov, v primeru čistih cementnih past pa metoda prehoda vzdolžnih UZ-valov, metoda odboja strižnih UZ-valov in kombinacija obeh uporabljenih UZ-metod. Pokazano je, da lahko ob pravilni interpretaciji rezultatov z obema metodama korektno ocenimo začetek vezanja različnih materialov s cementnim vezivom. Tako v primeru betonskih mešanic kot v primeru čistih cementih past začetni čas vezanja poljubne mešanice zadovoljivo ocenimo s časom pojava prve prevojne točke no krivulji hitrosti prehoda vzdolžnih UZ-valov (Vp) s časom, v primeru čistih cementnih past pa lahko začetek vezanja ocenimo tudi s časom, pri katerem začne vrednost strižnega odbojnega koeficienta (dr) intenzivno naraščati, oz. s koncem prvega območja na ustreznih diagramih Vp-dr. Prikazana je ponovljivost obeh metod in statistična analiza zanesljivosti ocene začetka vezanja cementnih past z metodo prehoda vzdolžnih UZ-valov"}],"edm:type":"TEXT","dc:type":[{"@xml:lang":"sl","#text":"znanstveno časopisje"},{"@xml:lang":"en","#text":"journals"},{"@rdf:resource":"http://www.wikidata.org/entity/Q361785"}]},"ore:Aggregation":{"@rdf:about":"http://www.dlib.si/?URN=URN:NBN:SI:doc-DUDB4JQX","edm:aggregatedCHO":{"@rdf:resource":"URN:NBN:SI:doc-DUDB4JQX"},"edm:isShownBy":{"@rdf:resource":"http://www.dlib.si/stream/URN:NBN:SI:doc-DUDB4JQX/4d5e160a-c4fe-4fd7-96a1-31e606d6cb58/PDF"},"edm:rights":{"@rdf:resource":"http://creativecommons.org/licenses/by-nc-sa/4.0/"},"edm:provider":"Slovenian National E-content Aggregator","edm:intermediateProvider":{"@xml:lang":"en","#text":"National and University Library of Slovenia"},"edm:dataProvider":{"@xml:lang":"sl","#text":"Zveza društev gradbenih inženirjev in tehnikov Slovenije"},"edm:object":{"@rdf:resource":"http://www.dlib.si/streamdb/URN:NBN:SI:doc-DUDB4JQX/maxi/edm"},"edm:isShownAt":{"@rdf:resource":"http://www.dlib.si/details/URN:NBN:SI:doc-DUDB4JQX"}}}}