| Autor: |
Samouh, Hamza, Ishikawa, Shunsuke, Kontani, Osamu, Murakami, Kenta, Nishimoto, Shoji, Suzuki, Kiyoteru, Maruyama, Ippei |
| Zdroj: |
Materials & Structures; Dec2021, Vol. 54 Issue 6, p1-16, 16p |
| Abstrakt: |
A good durability of concrete under nuclear conditions is essential for the safe operating of nuclear powerplants. In this case, concrete is generally exposed to a relatively high range of temperature compared to ordinary situations, and the understanding of its thermomechanical behavior becomes required for a fair safety assessment. To achieve this objective, the thermomechanical behavior of the concrete components should be understood. Among these components, this paper focuses on aggregates due to their high proportion in concrete and the high heterogeneity. A granite sample is selected, and it is composed of quartz, plagioclase, K-feldspar, biotite and some minor phases of muscovite, zircon, chlorite, and fluorite. The CTE according to three orthogonal directions is measured and small difference is observed. According to the XRCT examination, the samples do not show any visible cracks. However, some voids surrounding heavy phases are detected before the heating process. To identify these heavy phases, SEM–EDS is used, and some micro cracks have been detected and linked to biotite and pargasite. The numerical estimation of the average of the high and low bounds underestimates the CTE compared to the experimental value. It is consistent with the pre-damaged state providing a higher strain for an equivalent thermic stress. Two-phase model composed from an inclusion inside a predominant phase is used to calculate the hydrostatic pressure. The combinations giving high pressure allow to identify the zones of weakness in the granite. It also shows a higher probability of cracking for the biotite and pargasite inclusions inside quartz. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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