Thermo-mechanical properties of Penly reactor envelope at temperatures up to 200°C

Autor: T. Nürnbergerová, I. Janotka
Rok vydání: 1999
Předmět:
Zdroj: Materials and Structures. 32:719-726
ISSN: 1871-6873
1359-5997
DOI: 10.1007/bf02905068
Popis: This paper reports on an experimental investigation conducted to study the effects of high temperatures of up to 200°C on the phase composition, pore structure development and physico-mechanical properties of concrete at the PENLY nuclear power plant (France). The concrete specimens were manufactured under laboratory conditions from identical materials used at the construction site in PENLY, and then stored at 20°C/100% R.H. for 28 days and exposed to temperatures of 40°C, 60°C, 100°C, 200°C, and 20°C/60%R.H., respectively. Test results revealed that an intense structural integrity degradation of PENLY concrete occurs between 100°C and 200°C due both to a loss of water bound in hydrated cement minerals and to subsequent air void formation. This phenomenon is related to an increase in the median pore radius and total porosity values, as well as to a decrease in the dynamic and static moduli of PENLY concrete. The reduction in volume of the hydrate phase is believed to be the reason behind the rapid expansion, over a short time interval, due to a time-limited moistening of the specimen by released water with a sudden rise in temperature, followed by a stabilised period of shrinkage and creep.
Databáze: OpenAIRE
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