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
Related Articles
- EP ID EP396531
- DOI 10.18664/1994-7852. 178.2018.139009
- Views 98
- Downloads 0
EXPERIENCE GAINED DURING EXAMINATION OF ELECTROMAGNETIC COMPATIBILITY BETWEEN ROLLING STOCK AND AXLE COUNTERS
Axle counters are more and more often applied in train detection systems. The wheel sensor is a main part of each axle counter system. In parallel, more and more complex railway vehicles, especially traction ones, are a...
REPAIR AND RECONSTRUCTION OF FACADES OF HISTORICAL BUILDINGS OF KHARKOV CITY
The article is devoted to the issue of repair and restoration of facades of historical buildings on the example of the city of Kharkov. The analysis of the latest researches and publications devoted to this issue is carr...
NUMERICAL INVESTIGATIONS OF DYNAMIC TRANSVERSE FORCES IN CURVES, IN THE ZONES OF RAILS VARIETIES
The purpose of the work is to identify, by numerical methods, the causes of intensive lateral wear of rails and other bounces of the track in curves of small radius. The research has been carried out for the most mass ty...
PROSPECTS IMPROVING THE EFFICIENCY OF THE RAILWAY PASSENGER SECTOR OF HIGH SPEED TRANSPORTATIONS
As a result of the conducted research it can be concluded that in Ukraine only speeding up of passenger transportation is gaining momentum. The analytical foundations of statistical transport epicycles remain valid also...
A MATHEMATICAL MODELING OF AC ELECTRIC LOCOMOTIVE WITH ACTIVE CONVERTER IN TRACTION
One of the ways to increase the power factor of AC electric locomotives with DC traction motors is the use of converters on fully controlled semiconductor devices — active current source rectifiers. However, the modes of...