Razvoj CEM metode za oceno reoloških lastnosti svežega betona
V sklopu diplomske naloge smo opravili preiskave, katerih glavni namen je bil razviti oziroma modificirati metode za projektiranje sestave ekvivalentnih malt iz sestave betonov. Optimalna metoda formulacije naj bi se določila na podlagi preiskav razleza in reoloških lastnosti določenih z reometrom ConTec Viscometer 5. Na podlagi sestav betonov, ki so bile določene in preskušene v okviru drugih diplomskih nalog, smo sestavili pet etalonskih mešanic referenčnih malt, ki smo jih nato modificirali z namenom, da ugotovimo, če se reološkim lastnostim betona res najbolj približa tista mešanica malte, ki je bila iz tega betona izpeljana ali je ustreznejša katera od modificiranih malta. Vse mešanice so bile sestavljene iz vode, agregata, cementa in dodatkov. Voda in agregat se pri maltah nista spreminjala, uporabili pa smo dve različni vrsti cementa. Pri štirih mešanicah smo del cementa nadomestili z mineralnima dodatkoma mikrosiliko in žlindro, kar se tiče kemijskih dodatkov, pa smo uporabili superplastifikator in aerant. Največ pozornosti smo namenili preiskavi z razlezom, ki nam je predstavljala osnovo za oceno reoloških lastnosti ekvivalentnih maltnih mešanic, ki smo jih nato primerjali z betoni in ugotavljali korelacije. Na podlagi podobnosti razlezov smo v nadaljevanju primerjali tudi reološke parametre malt in betonov, ki smo jih dobili z reometrom ConTec Viscometer 5.
The main purpose of the research work in framework of this thesis was the development or modification of CEM ("concrete equivalent method") for the design of equivalent mortar composition from concrete composition. The optimal formulation method should be determined based on the flow table test and rheological characteristics obtained by ConTec Viscometer 5. Based on the composition of concretes designed and tested in the framework of other diploma works we designed five reference mortar mixtures, which were later modified. We wanted to find out whether the reference mortar mixture is the best mixture to estimate the rheological properties of concrete or one of modified mixtures could be a better choice. All mixtures were composed of water, aggregate, cement and additives. The type of water and aggregate were the same for all mortars and we used two types of cement. In four mixtures we substituted part of the cement with mineral additive, microsilica or slag. As chemical admixtures we selected superplasticizer and air entraining agent. We focused on the results of flow table test, which represented the basis for the estimation of rheological characteristics of the equivalent mortar mixtures; these were later compared with the results obtained on concretes and correlations were made. Finally, based on the similar flow values we also compared rheological parameters of mortars and concretes acquired with the rheometer ConTec Viscometer 5.
2012
2015-07-10 10:18:03
1060
gradbeništvo, diplomska dela, VSŠ, OG-MK, svež beton, sveža malta, pričakovan razlez, CEM metoda, reologija svežih cementnih mešanic
graduation thesis, civil engineering, fresh concrete, fresh mortar, expected flow value, CEM method, rheology of fresh cement mixtures
mb11
[B. Hren]
Blaž
Hren
70
Violeta
Bokan-Bosiljkov
991
Andraž
Hočevar
994
UDK
4
691.32(043.2)
COBISS_ID
3
6031201
GRV023_Hren.pdf
2877826
Predstavitvena datoteka
2017-04-30 11:08:06