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Eco-efficient blended cements with high volume supplementary cementitious materials

Sanytsky Myroslav, Kropyvnytska Tetiana, Ivashchyshyn Hanna, Rykhlitska Оksana

Budownictwo i Architektura

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2019

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Vol. 18, nr 4

5--14

EN

The ways of reducing CO2 emissions in the cement industry were analysed for the purposes of implementation of the low carbon development strategy. The optimal solution to this problem is the technologically optimised blended cements with high volume of supplementary cementitious materials of various genesis and fineness. The design of eco-friendly blended cements was achieved by a synergistic combination of the main constituents such as granulated blast furnace slag, superfine zeolite, fly ash and limestone, as well as by optimisation of the their granulometric composition, taking into account their bimodal particle size distribution by volume and surface area. Moreover, the article presents the technical, environmental and economic benefits of using eco-efficient blended cements.

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Inclusion of construction and demolition waste as a coarse aggregate and a cement addition in structural concrete design

Cantero B., Sáez del Bosque I. F., Matías A., Sánchez de Rojas M. I., Medina C.

Archives of Civil and Mechanical Engineering

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2019

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Vol. 19, no. 4

1338--1352

EN

Dissociating economic growth from the use of natural resources is imperative to the sustainable development of the construction industry. The use of secondary raw materials by processing and managing construction and demolition waste (C&DW) is one of the major challenges to transition to a circular economy. This study assessed the effect of simulta- neously using cement additioned with the ceramic (fired clay-based) fraction of C&DW and recycled mixed aggregate (RMA) in concrete manufacture by analysing fresh concrete workability, density and air content and hardened concrete compressive, flexural and splitting tensile strength. Regression and variance analyses were run on the findings to determine the effect of RMA and cement type and their interaction on the dependent variables. The percentage of RMA was observed to be the most significant determinant for concrete density and air content. Early age compressive strength was impacted by cement type, although strength in the later age materials was comparable to that of concrete manufactured with conventional cement. The combined effect of cement type and percent- age of RMA appeared to have no significant effect on tensile or flexural strength. On the contrary, the differences observed in these properties were due to the separate effect of each factor. The findings showed that the use of cement containing C&DW additions and up to 50% RMA did not substantially compromise concrete performance.

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Particle size characterisation of SCMs by mercury intrusion porosimetry

Klemm A. J., Wiggins D. E.

Fizyka Budowli w Teorii i Praktyce

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2017

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T. 9, nr 1

5--12

EN

Mercury intrusion porosimetry (MIP) is widely used for the microstructural characterisation of porous solids. Comparatively few studies have employed the technique to characterise the size of particles within powdered samples. The present study uses the MIP technique to characterise the particle sizes of contemporary supplementary cementitious materials (SCMs), and in particular uses the technique to present particle size distributions, rather than a single mean size. Representivity of the technique for known limitations of non-spherical and porous particles are checked using the Scanning Electron Microscope. The findings indicate that the MIP affords a good approximation of particle sizes, including distributions, of spherical and non-spherical particles. The technique was also found to provide reasonable accuracy for estimating the particle sizes of highly porous particles, where distinction between inter-particle and intra-particle porosity was made.

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Sustainable concretes containing supplementary cementitious materials

Rusyn B., Sanytsky M., Szymanska J., Geviuk I.

Budownictwo o Zoptymalizowanym Potencjale Energetycznym

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2012

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nr 1(9)

95--102

EN

This paper is devoted to the most important developments in the field of sustainable concrete production and evaluates various approaches. In the global context of cost reduction and CO2 constraints, producers are striving to lower the cement content in concrete. Limits are set by regional and global availability of appropriate materials. The use of supplementary cementitious materials (SCMs), where no additional clinkering process is involved, leads to a significant reduction in CO2 emissions per ton of cementitious materials (grinding, mixing and transport of concrete use less energy compared to the clinkering process) and also provides the utilization of by-products from industrial manufacturing processes. Such new materials might be able to play a significant role as main cement constituents in the future.

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Artykuł dotyczy oceny produkcji zrównoważonych betonów zawierających dodatkowe składniki wiążące. Obecnie na całym świecie dąży się do zmniejszeniu kosztów i ograniczenia emisji CO2, dlatego też celem producentów jest obniżenie zawartości cementu w betonach. Działania te wynikają z konieczności dostosowania się do narzuconych limitów emisji CO2 oraz z faktu kurczenia się zasobów odpowiednich materiałów do produkcji cementu. Zastosowanie dodatkowych składników wiążących, które można pozyskać bez kosztownego procesu wypalania klinkieru, prowadzi do znaczącej redukcji emisji CO2, przypadającej na tonę wyprodukowanego spoiwa cementowego. Obniża to także koszty związane z mieleniem, oraz umożliwia wykorzystanie ubocznych produktów procesów przemysłowych do wytworzenia materiałów wiążących. Nowe materiały mają szansę stać się głównymi składnikami cementów przyszłości.