MODELING AND ANALYSIS OF RHEOLOGICAL INDICATORS OF SELF-COMPACTING LIGHTWEIGHT CONCRETE TO INCREASE THEIR PROCESSABILITY
Journal Title: Збірник наукових праць Українського державного університету залізничного транспорту - Year 2018, Vol 178, Issue 12
Abstract
In this paper we propose way to improve the technological performance of self-compacting concrete based on lightweight expanded clay aggregate by control of rheological parameters of their cement matrix by purposeful modifying of additives’ functional groups and microfine mineral filler using analytical methods of computer materials science. The aim of the study was to ensure in such mixtures an increased plasticity and high stability, which can allow them to retain their high mobility and solve the problem of displacing grains of lightweight aggregate. During the analyze the results of rheometry of the investigated solution mixtures the most appropriate model describing their rheological behavior has been determined. The effect on the rheological parameters of the self-compacting lightweight concrete mixes (viscosity coefficient and yield point) of a finely dispersed fly ash excipient, a carboxylate superplasticizer, and a stabilizer additive was established. It has been shown that the adding of a plasticizing additive and fly ash in an amount of up to 15% significantly reduces the flow index, which provides an increase in the viscosity coefficient, increasing the plasticity of the mixture, and an increase in the resistance of the liquid phase of the solution to the pressure of floating at a lower density aggregate grain is achieved by adding fly ash, sealing cement matrix, and stabilizer additives up to 0.035%. This approach of analyze of monofactorial dependencies of variable factors’ influence on coefficients of rheological behavior models allows to solve the main problem when using concrete on lightweight aggregate – crowding out expanded clay grains by solution liquid phase – with providing the necessary fluidity (workability, passing and filling ability, flowability) and maintaining high stability (structure viscosity, segregation resistance). As a result of the analysis of the theoretical and practical data obtained, it was assumed that balancing between the coefficients k and τ0, it is theoretically possible to obtain a concrete mixture on a self-compacting lightweight aggregate, ensuring its mobility and homogeneity.
Authors and Affiliations
Maksym Ostryzniuk, Svitlana Savchenko, Sergіi Gedulyan, Nadіia Antoniuk
Keywords
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- EP ID EP396531
- DOI 10.18664/1994-7852. 178.2018.139009
- Views 77
- Downloads 0
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