HYGRIC AND THERMAL PROPERTIES OF HPC FOR CONCRETE CONTAINMENTS OF NUCLEAR POWER PLANTS

Thermal conductivity, specific heat and linear thermal expansion coefficient are measured in the temperature range from 100°C to 800°C and in the moisture range from dry material to saturation water content. Linear hygric expansion coefficient is measured in the whole moisture range from dry material to full water saturation. Moisture diffusivity is measured as a function of temperature up to 80°C, and the effects of high-temperature exposure up to 800°C and freeze/thaw cycles on its value are studied. In order to analyze the observed changes in moisture diffusivity and thermal parameters, thermal analysis and visual analysis are performed. As the main reason for these changes, the crack formation is identified. Particularly, the magnitude of variations of moisture diffusivity is found to be affected by the quality of aggregates rather than by the quality of cement. High quality quartzitic aggregates with very low porosity and very good mechanical properties perform much better than other, more porous siliceous aggregates such as opal, and than the calcareous aggregates such as chalk.

• INTRODUCTION

• METHODS FOR MEASURING HYGRIC AND THERMAL PROPERTIES

• MATERIAL SAMPLES

• EXPERIMENTAL RESULTS

• DISCUSSION

• CONCLUSIONS

• ACKNOWLEDGEMENTS

• REFERENCES