Micro- and Macro-scale Mechanical Properties of Meta-cherts as Concrete Aggregates
Koki Maekawa, Wei Wang, Hamza Samouh, Shunsuke Ishikawa, Osamu Kontani, Takahiro Ohkubo, Kenta Murakami, Kiyoteru Suzuki, Ippei Maruyama
https://doi.org/10.3151/jact.21.284

アルカリ骨材反応や中性子照射、コンクリートの強度評価の観点から、骨材の物理的評価が重要です。この観点において各鉱物の強度、ヤング率等の物性の他、鉱物グレインの粒界の強度が重要になります。また、既存の骨材の内部のひび割れや欠陥部、再析出部分と堆積部分、熱変性部分の違いなどの評価も大事です。これらの検討を可能とする微小試験体を用いた直接引張試験方法を提案しました。

This paper presents the measurement of the tensile strength, Young’s modulus, and linear coefficient of thermal expansion in a meta-chert. Two areas are targeted in this aggregate ? a white area where quartz grains are densely compacted and a gray area where the quartz grains are coarser. The macro- and micro-scale data are compared. Young’s modulus is not significantly different between macro-scale compression and micro-scale tension loading in the white region. Macro-scale splitting and micro-scale direct tensile strengths exhibit similar bimodal behavior due to the failure mechanisms of these two distinct areas. The macro- and micro-scale coefficients of thermal expansion are similar for the gray region, reflecting the quartz nature. Conversely, the micro-scale coefficient of thermal expansion of the white area shows a different behavior.