Infrardeča termografija kot metoda zaznavanja segregacije samozgoščevalnega betona

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Jezik:	Slovenski jezik
Leto izida:	2013
Izvor:	Ljubljana
Tipologija:	2.11 - Diplomsko delo
Organizacija:	UL FGG - Fakulteta za gradbeništvo in geodezijo
Založnik:	[K. Jazbec]
UDK:	691.3(497.4)(043.2)
COBISS:	6446945
Št. ogledov:	2381
Št. prenosov:	712
Ocena:	0 (0 glasov)
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Sekundarni jezik:	Angleški jezik
Sekundarni naslov:	Infrared thermography as method for detection of self-compacting concrete segregation
Sekundarni povzetek:	In the thesis the capability of using infrared thermography for the detection of segregation in laboratory specimens made from self-compacting concretes is analyzed with respect to the mixture properties. In the introduction the physical basis of infrared thermography is presented as well as the composition and operation of an infrared camera. Moreover, the applications of infrared thermography in civil engineering and related fields are outlined together with the common data processing approaches. In addition, the properties of self-compacting concrete are briefly presented. In the experimental part, the construction of specimens from different concrete mixtures is described. The thesis focuses on the capability of using both active and passive thermography for the estimation of the properties of hardened concrete, i.e. for the detection of possible segregation of the concrete mixture, as well as for the evaluation of its density and porosity. For the preparation of two series of specimens three different aggregates were used; two lightweight (with high and low density) and one normal weight aggregate. On the specimens from the first series (controlled conditions for segregation) a sensitivity analysis of the performance of IR thermography for the detection of segregation was carried out with respect to the different data processing approaches. Phase and thermal images were found to yield the best results. However, for good thermal images, ideally uniform heating and homogeneous specimen surface is required. With the second series of specimens (segregation simulated by more fluid concrete mixture), the efficiency of phase images was additionally confirmed. In the framework of the thesis a comparison between specimens made from lightweight concrete of different densities was additionally carried out. Lightweight specimen of higher density was found to have lower thermal diffusivity. As an example of segregation detection with passive thermography, the concrete hydratation heat was exploited as heating source. It was shown that after the removal of the framework the amount of the released heat was too low to enable segregation detection. However, on a simple concrete plate we demonstrated that thermography is capable of detecting individual steps of concrete hydratation.
Sekundarne ključne besede:	graduation thesis;civil engineering;self-compacting concrete;segregation;nondestructive testing;thermography;infrared camera;heat transfer;thermal image;phase image;
Vrsta datoteke:	application/pdf
Vrsta dela (COBISS):	Diplomsko delo
Komentar na gradivo:	Univ. v Ljubljani, Fak. za gradbeništvo in geodezijo
Strani:	XVIII, 73 str.
Vrsta dela (ePrints):	thesis
Naslov (ePrints):	Infrared thermography as method for detection of self-compacting concrete segregation
Ključne besede (ePrints):	samozgoščevalni beton;segregacija;neporušne preiskave;termografija;termokamera;prenos toplote;temperaturna slika;fazna slika
Ključne besede (ePrints, sekundarni jezik):	self-compacting concrete;segregation;nondestructive testing;thermography;infrared camera;heat transfer;thermal image;phase image
Povzetek (ePrints):	V diplomski nalogi smo s pomočjo infrardeče termografije analizirali sposobnost zaznavanja segregacije v laboratorijskih preizkušancih iz samozgoščevalnega betona v odvisnosti od lastnosti mešanice. V uvodnem delu so predstavljene fizikalne osnove infrardeče termografije, osnove sestave in delovanja termokamere, uporaba termografije v gradbeništvu in sorodnih področjih ter najpogostejši načini obdelave podatkov pri termografiji. Strnjeno so opisane tudi lastnosti samozgoščevalnega betona. V eksperimentalnem delu je opisana priprava preizkušancev iz različnih betonskih mešanic. V okviru diplomske naloge nas je zanimala sposobnost uporabe tako aktivne kot pasivne termografije za oceno lastnosti strjenega betona, tj. za zaznavanje možne segregacije betonske mešanice, kot tudi za oceno gostote in poroznosti le-te. Za pripravo dveh serij preizkušancev smo uporabili tri različne agregate; dva lahka agregata (nizke in visoke gostote) in navadni agregat. V okviru prve serije preizkušancev, kjer so bili pogoji segregacije kontrolirani, je bila narejena občutljivostna analiza termografske metode za zaznavanje segregacije v odvisnosti od načina obdelave podatkov. Ugotovljeno je bilo, da nam z najboljšimi rezultati postrežejo fazne ter temperaturne slike, vendar slednje le v primeru idealno enakomernega segrevanja in homogene površine. Z drugo serijo preizkušancev, kjer smo segregacijo simulirali z bolj tekočo betonsko mešanico, smo učinkovitost faznih slik dodatno potrdili. V nalogi smo dodatno primerjali tudi preizkušance iz lahkega agregata različnih gostot in ugotovili, da ima preizkušanec iz lahkega agregata večje gostote manjšo termično difuzivnost. Kot primer zaznave segregacije s pasivno termografijo, smo kot vir toplote izkoristili hidratacijsko toploto betona in ugotovili, da je količina sproščene toplote po razopaženju že premajhna za zaznavo le-te. Na preprostem primeru plošče pa smo pokazali, da lahko s termografijo lepo zaznamo posamezne faze hidratacije betona.
Povzetek (ePrints, sekundarni jezik):	In the thesis the capability of using infrared thermography for the detection of segregation in laboratory specimens made from self-compacting concretes is analyzed with respect to the mixture properties. In the introduction the physical basis of infrared thermography is presented as well as the composition and operation of an infrared camera. Moreover, the applications of infrared thermography in civil engineering and related fields are outlined together with the common data processing approaches. In addition, the properties of self-compacting concrete are briefly presented. In the experimental part, the construction of specimens from different concrete mixtures is described. The thesis focuses on the capability of using both active and passive thermography for the estimation of the properties of hardened concrete, i.e. for the detection of possible segregation of the concrete mixture, as well as for the evaluation of its density and porosity. For the preparation of two series of specimens three different aggregates were used; two lightweight (with high and low density) and one normal weight aggregate. On the specimens from the first series (controlled conditions for segregation) a sensitivity analysis of the performance of IR thermography for the detection of segregation was carried out with respect to the different data processing approaches. Phase and thermal images were found to yield the best results. However, for good thermal images, ideally uniform heating and homogeneous specimen surface is required. With the second series of specimens (segregation simulated by more fluid concrete mixture), the efficiency of phase images was additionally confirmed. In the framework of the thesis a comparison between specimens made from lightweight concrete of different densities was additionally carried out. Lightweight specimen of higher density was found to have lower thermal diffusivity. As an example of segregation detection with passive thermography, the concrete hydratation heat was exploited as heating source. It was shown that after the removal of the framework the amount of the released heat was too low to enable segregation detection. However, on a simple concrete plate we demonstrated that thermography is capable of detecting individual steps of concrete hydratation.
Ključne besede (ePrints, sekundarni jezik):	self-compacting concrete;segregation;nondestructive testing;thermography;infrared camera;heat transfer;thermal image;phase image
ID:	8313084