Effect of Temperature and Age of Concrete on Strength – Porosity Relation

The compressive strengths of unsealed samples of concrete at the age of 180 days and have been measured at temperatures 20 °C, 300 °C, 600 °C and 900 °C. All of tests were performed for cold material. We compared our results with those obtained in [10] for the same type of concrete (age 28, resp. 90 days and measured at temperature ranging from 20 °C to 280 °C). Dependencies of compressive strength and porosity were correlated together and compared for the samples of age 28, 90 and 180 days. Behaviour of concrete of the age 90, resp. 180 days confirms generally accepted hypothesis that with increasing porosity strength of the concrete decreases. It has to be stressed out, howerer, that concrete samples of the age 28 days exhibit totally opposite dependency.

Effect of Thermal Cycling on the Strength and Texture of Concrete for Nuclear Safety Structures

The effect of thermal cycling (freezing and thawing) on the texture and strength of two types of concrete is studied: 1. Concrete used for a containment structure at NPP Temelín (Czech Republic) - so-called TEMELÍN concrete.2. Highly resistant PENLY concrete, which was used as a standard because of its high quality, proved by the research carried out in a European Commission project. The results for the two samples of concrete are compared

Effect of Thermal Cycling on the Strength and Texture of Concrete for Nuclear Safety Structures

The effect of thermal cycling (freezing and thawing) on the texture and strength of two types of concrete is studied: 1. Concrete used for a containment structure at NPP Temelín (Czech Republic) - so-called TEMELÍN concrete.2. Highly resistant PENLY concrete, which was used as a standard because of its high quality, proved by the research carried out in a European Commission project. The results for the two samples of concrete are compared