Korelacija med ultrazvočnimi meritvami in meritvami električne prevodnosti cementnih past v zgodnjem hidratacijskem obdobju : magistrsko delo

Vogrič, Nina (author), Planinc, Igor (mentor), Trtnik, Gregor (comentor)

V magistrski nalogi smo z dvema naprednima neporušnima metodama spremljali razvoj strukture materiala s cementnim vezivom (MCV) v zgodnjem hidratacijskem obdobju. Osnovni namen dela je na osnovi lastnih eksperimentalnih preiskav analizirati možnost uporabe metode prehoda vzdolžnih ultrazvočnih (UZ) valov ter metode merjenja električne prevodnosti za zasledovanje hidratacijskega procesa ter procesa vezanja in strjevanja MCV. V primeru uporabe ultrazvočne tehnike sta bili analizirani dve metodi, in sicer metoda merjenja hitrosti prehoda vzdolžnih ultrazvočnih valov ter metoda analize celotnega spektra vzdolžnih UZ valov. Hkrati z obema neporušnima metodama smo merili tudi spreminjanje temperature znotraj MCV med procesom hidratacije. Glavni znanstveni doprinos magistrske naloge poleg potrditve možnosti uporabe obeh uporabljenih metod za določitev začetka in konca vezanja MCV predstavlja korelacija rezultatov, dobljenih z obema uporabljenima neporušnima tehnikama, ter analiza možnosti uporabe obeh metod za določitev dveh pomembnih mejnikov v procesu formiranja strukture MCV, tj. perkolacije trdne faze in deperkolacije faze (z vodo nasičenih) por. Ugotovili smo, da lahko s kombinacijo rezultatov obeh uporabljenih neporušnih metod natančno in enolično določimo omenjene fundamentalne fenomene, ki nastopijo v procesu zgodnjega formiranja strukture MCV. Obe uporabljeni merilni tehniki sta različno občutljivi na različne fenomene, ki se pojavijo v zgodnjem obdobju formiranja strukture MCV, posamezne karakteristične točke v tem procesu pa se pojavijo pri enakih časih ne glede na vrsto uporabljene metode. Ugotovljena je enolična zveza med rezultati obeh uporabljenih merilnih tehnik, ki je neodvisna od sestave cementnih past. Omenjene ugotovitve so pomembne za razvoj novih merilnih tehnik določanja različnih fenomenov v razvoju strukture MCV ter za izboljšanje razumevanja tega procesa.

• Language: Slovenian
• Keywords: gradbeništvo, magistrska dela, cementni materiali, hidratacija, formiranje strukture, ultrazvočne meritve, konduktivnost, vezanje, strjevanje, perkolacija, deperkolacija
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FGG - Faculty of Civil and Geodetic Engineering
• Place of publishing: Ljubljana
• Publisher: [N. Vogrič]
• Year: 2016
• Number of pages: XIV, 61 str.
• PID: 20.500.12556/RUL-87621
• UDC: 624.07:691.54(497.4)(043)
• COBISS.SI-ID: 7837281
• Publication date in RUL: 09.12.2016

VOGRIČ, Nina, 2016, Korelacija med ultrazvočnimi meritvami in meritvami električne prevodnosti cementnih past v zgodnjem hidratacijskem obdobju : magistrsko delo [online]. Master’s thesis. Ljubljana : N. Vogrič. [Accessed 17 May 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=87621

Secondary language

• Language: English
• Title: Correlation between ultrasonic and electrical conductivity measurements on early age cement pastes

Abstract

In this thesis, two advanced non-destructive methods were used to monitor the formation of the structure within cement based materials (CBM) at early ages. The main objective of this work has been to determine the possibility of using an ultrasonic wave transmission method and an electric conductivity method to monitor the hydration process and to determine setting and hardening periods of CBM based on our own experimental research. Two methods have been used in the scope of ultrasonic method, namely ultrasonic wave transmission method and frequency spectrum of ultrasonic waves method. Simultaneously with both mentioned methods, the temperature within the CBM during hydration process has also been measured. In addition to the confirmation of the ability to monitor initial and final setting and hardening times of CBM with both non-destructive methods, the main scientific contribution of the thesis comprises the correlation of results from both used non-destructive methods along with the analysis of possible use of these methods to determine two very important milestones in microstructure development of BCM, which are percolation of solid phase and depercolation of porosity phase. We came to the conclusion that the combination of both methods enables accurate and inevitable determination of those fundamental phenomena that occur at early ages of the formation of the structure of CBM. Both methods have shown different sensitivity to these phenomena, however important milestones occur at the same time regardless of the used method. A unique relation between both methods has been identified, regardless of cement pastes’ composition. These findings are important for the development of the advanced measuring techniques intended for the research of structure development within CBM and to improve the understanding of the process.

• Keywords: civil engineering, master of science thesis, cement based materials, hydration, formation of structure, ultrasonic measurements, conductivity, setting, hardening, percolation, depercolation