Sekundarni jezik: |
Angleški jezik |
Sekundarni naslov: |
Assessment of stability of fresh scc with electrical conductivity method |
Sekundarni povzetek: |
In diploma work we were trying to establish the behaviour of self-compacting concrete during mixing, casting and during setting of the concrete in moulds. Self-compacting concrete mixtures must be handled extra carefully during mixing and casting otherwise instabilities might easily occur, which is reflected in segregation. Therefore, in formwork of experimental work we put four pairs of electrodes at four different levels of specially prepared moulds to monitor the behaviour of samples. Stability of two different mixtures with the same water-to-cement ratio was being monitored with electrical conductivity method. First mixture was composed from cement CEM II/A-M (LL-S) 42,5R, limestone filler and crushed limestone assembled from four different fractions, while the second mixture was composed of cement CEM II/A-S 42,5R, limestone filler and natural river gravel assembled from three fractions. For each concrete mixture six specimens were prepared. Three of them were cast in the moulds homogenously and three where consolidated with a help of internal vibrator in order to assure segregation and different electro conductivity at different levels of the mould. At the end we cut the concrete samples to check them visually and make the comparison to the results, gained by electrical conductivity method. Additionally to this test, we carried out also slump-flow test on fresh concrete mixtures, we determined initial and final setting times during concrete mixtures setting, as well as we tested compressive strength of hardened concrete mixtures. |
Sekundarne ključne besede: |
graduation thesis;electrical conductivity;self-compacting concrete;segregation;concrete mixtures setting;estimation of stability;homogeneity;compressive strenght; |
Vrsta datoteke: |
application/pdf |
Vrsta dela (COBISS): |
Diplomsko delo |
Komentar na gradivo: |
Univ. v Ljubljani, Fak. za gradbeništvo in geodezijo |
Strani: |
XI, 67 str. |
Vrsta dela (ePrints): |
thesis |
Naslov (ePrints): |
Assessment of stability of fresh scc with electrical conductivity |
Ključne besede (ePrints): |
električna prevodnost;samozgoščevalni beton;segregacija;vezanje betona;ocena stabilnosti;homogenost;tlačna trdnost |
Ključne besede (ePrints, sekundarni jezik): |
electrical conductivity;self-compacting concrete;segregation;concrete mixtures setting;estimation of stability;homogeneity;compressive strength |
Povzetek (ePrints): |
V diplomski nalogi smo poskušali ugotoviti obnašanje samozgoščevalnih betonov med pripravo, vgradnjo v kalupe in med vezanjem v kalupih. Samozgoščevalni betoni so betoni, pri katerih je treba biti še posebej pozoren pri njihovi pripravi in vgradnji, saj lahko hitro pride do nestabilnosti, ki se kaže v segregaciji. Zato smo spremljali njihovo obnašanje v posebej pripravljenih kalupih, na katerih so bili pritrjeni štirje pari elektrod v štirih različnih višinah kalupa. Z metodo električne prevodnosti smo preverjali stabilnost dveh različnih samozgoščevalnih betonskih mešanic z enakim vodocementnim razmerjem. Prva mešanica je vsebovala cement CEM II/A-M (LL-S) 42,5R, drobljen apnenčev agregat in apnenčevo moko, druga mešanica pa cement CEM II/A-S 42,5R, rečni prod in apnenčevo moko. Pri vsaki izmed mešanic smo pripravili po šest preskušancev. Tri preskušance vsake izmed mešanic smo v kalupe vgradili homogeno, tri preskušance pa smo namerno zvibrirali z vibracijsko iglo, kar naj bi povzročilo segregacijo in s tem različno prevodnost na različnih višinah vzorcev v kalupu. Na koncu smo strjene vzorce prerezali po višini kalupa tako, da smo lahko opravili še vizualno oceno prerezanih vzorcev in jih primerjali z rezultati, ki smo jih dobili pri oceni stabilnosti z metodo električne prevodnosti. Dodatno smo opravili še preiskave razleza s posedom na svežih betonskih mešanicah, določili začetek in konec vezanja med vezanjem betonskih mešanic ter preskusili tlačno trdnost strjenega betona. |
Povzetek (ePrints, sekundarni jezik): |
In diploma work we were trying to establish the behaviour of self-compacting concrete during mixing, casting and during setting of the concrete in moulds. Self-compacting concrete mixtures must be handled extra carefully during mixing and casting otherwise instabilities might easily occur, which is reflected in segregation. Therefore, in formwork of experimental work we put four pairs of electrodes at four different levels of specially prepared moulds to monitor the behaviour of samples. Stability of two different mixtures with the same water-to-cement ratio was being monitored with electrical conductivity method. First mixture was composed from cement CEM II/A-M (LL-S) 42,5R, limestone filler and crushed limestone assembled from four different fractions, while the second mixture was composed of cement CEM II/A-S 42,5R, limestone filler and natural river gravel assembled from three fractions. For each concrete mixture six specimens were prepared. Three of them were cast in the moulds homogenously and three where consolidated with a help of internal vibrator in order to assure segregation and different electro conductivity at different levels of the mould. At the end we cut the concrete samples to check them visually and make the comparison to the results, gained by electrical conductivity method. Additionally to this test, we carried out also slump-flow test on fresh concrete mixtures, we determined initial and final setting times during concrete mixtures setting, as well as we tested compressive strength of hardened concrete mixtures. |
Ključne besede (ePrints, sekundarni jezik): |
electrical conductivity;self-compacting concrete;segregation;concrete mixtures setting;estimation of stability;homogeneity;compressive strength |
ID: |
8311994 |