| Autor: |
Chikako Fujiyama, Ryojiro Kato |
| Rok vydání: |
2017 |
| Předmět: |
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| Zdroj: |
High Tech Concrete: Where Technology and Engineering Meet ISBN: 9783319594705 |
| DOI: |
10.1007/978-3-319-59471-2_170 |
| Popis: |
The strain rate dependent responses of concrete mortar and cement paste cylinders were investigated using uniaxial compression tests with high and low loading rates. The influence of the cracking process was focused on first. Pre-cracked specimens of concrete and mortar were examined. The results suggested that the influence of the cracking process is possibly more dominant than the influence of the water content. The movement of water through micro-pores of a matrix was focused on next. The water inside the mortar specimens was controlled by temperature. The specimens were frozen to temperatures between approximately −20 to −197 °C by using ice, dry ice, and liquid nitrogen. A special device for thermal insulation during loading was developed for this study. The strengths of the most specimens were magnified at high strain rates, although the movement of water through micro-pores was partially prevented by the freezing of pore water. The results indicated that the movement of free water in the micro-pores of the matrix did not always dominate the strain rate effect of the mortar. Lastly, the specimens made of cement paste were examined in order to examine the influence of interfacial transition zones (ITZ) around the aggregates. The results suggested that the existence of the ITZs discouraged strain rate effects because ITZs dispersed the initiation of micro cracks. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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