The high-quality decorative and artistic fiber-reinforced concrete was made in SPSUACE
On June 25, 2018 the graduate of the Faculty of Civil Engineering of Saint-Petersburg State University of Architecture and Civil Engineering Aida Akhmedshina defended her Master's thesis dedicated to the creation of high-quality decorative and artistic fiber-reinforced concrete. The Supervisor of the work was Doctor of Technical Science, Professor, the Head of the Department of Technology of Building Materials and Metrology of SPSUACE Yury Vladimirovich Pukharenko.
The relevance of the theme is due to the need to preserve the cultural heritage and improve the architectural expressiveness of new buildings, primarily of St. Petersburg, as well as in other cities of Russia, because the atmospheric influence adversely affect first the external decoration of buildings and then the load-bearing building structures. Prevention of the penetration of negative factors into the interior of the structure lies more on the facing layer of the structure. The solution of the problem is in the development and use of durable, reliable, possessing architectural expressiveness of materials, allowing to reduce the time and quantity of capital and reconstruction works.
A. Akhmedshina analyzed the available results of obtaining high-quality concrete for the last 20 years both in Russia and abroad; determined effective raw materials components, including reinforcing fibers and by-products of production; developed the compositions and investigated the physical and mechanical properties of high-strength fine-dispersed fiber-reinforced concrete; has developed techniques and ways of creating artistic expressiveness of the material.
The researcher came to the conclusion that when deepening into the microstructure of concrete, the use of highly active cement is required when normalizing the tricalcium aluminate C3A. At the same time, low water-cement ratio gives high strength of concrete and, in turn, requires high flow of plasticizer.
The results of the experiments have a nonlinear character of the dependence "strength – coefficient of volume reinforcement", which is confirmed by previously published works at the Department of Technology of Building Materials and Metrology of SPSUACE.
At a low reinforcement factor from 0 to 0.2% vol. fibers are considerably removed from each other and do not give the strength increase. They are a filler of irregular shape (l >> b), capable of reducing its strength due to its anisotropy. In the range from 0.2 to 0.5% by volume, joint work of the fibers forms zones of concentrated reinforcement with increased density and prevents the opening of cracks, significantly increasing the physical-mechanical parameters. With a further increase in the number of reinforcing fibers, their concentration reaches a limiting value – the thickness of the matrix layer is not enough to impregnate the entire volume of the fiber, the adhesion worsens and the processes of cracking begin.
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Партнёр:
Санкт-Петербургский государственный архитектурно-строительный университет