An Investigation of the Mechanical and Physical Characteristics of Cement Paste Incorporating Different Air Entraining Agents using X-ray Micro-Computed Tomography
Autor: | Mohamed Abd Elrahman, Pawel Sikora, Sang-Yeop Chung, Mohamed E. El Madawy, Stanisław Majer, Osama Youssf |
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Přispěvatelé: | Technische Universität Berlin, Elrahman, Mohamed Abd, El Madawy, Mohamed E, Chung, Sang-Yeop, Majer, Stanisław, Youssf, Osama, Sikora, Pawel |
Jazyk: | angličtina |
Rok vydání: | 2020 |
Předmět: |
Materials science
General Chemical Engineering air entraining agents 0211 other engineering and technologies 02 engineering and technology micro-CT micro-ct Inorganic Chemistry Thermal insulation pores 021105 building & construction aluminum powder lcsh:QD901-999 General Materials Science Composite material Porosity Cement Structural material business.industry lightweight cement paste 021001 nanoscience & nanotechnology Condensed Matter Physics Microstructure compressive strength Compressive strength Fly ash thermal insulation ddc:621 Air entrainment hollow microspheres lcsh:Crystallography 621 Angewandte Physik 0210 nano-technology business |
Zdroj: | Crystals, Vol 10, Iss 1, p 23 (2020) Crystals Volume 10 Issue 1 |
ISSN: | 2073-4352 |
Popis: | Improving the thermal insulation properties of cement-based materials is the key to reducing energy loss and consumption in buildings. Lightweight cement-based composites can be used efficiently for this purpose, as a structural material with load bearing ability or as a non-structural one for thermal insulation. In this research, lightweight cement pastes containing fly ash and cement were prepared and tested. In these mixes, three different techniques for producing air voids inside the cement paste were used through the incorporation of aluminum powder (AL), air entraining agent (AA), and hollow microspheres (AS). Several experiments were carried out in order to examine the structural and physical characteristics of the cement composites, including dry density, compressive strength, porosity and absorption. A Hot Disk device was used to evaluate the thermal conductivity of different cement composites. In addition, X-ray micro-computed tomography (micro-CT) was adopted to investigate the microstructure of the air-entrained cement pastes and the spatial distribution of the voids inside pastes without destroying the specimens. The experimental results obtained showed that AS specimens with admixture of hollow microspheres can improve the compressive strength of cement composites compared to other air entraining admixtures at the same density level. It was also confirmed that the incorporation of aluminum powder creates large voids, which have a negative effect on specimens&rsquo strength and absorption. |
Databáze: | OpenAIRE |
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