22. Some Experiments on Thermal Shock Fracture of Rocks

Abstract

Thermal shock resistance and thermal strain are examined experimentally on basaltic rocks: thermal strain was created in the sample, cylindrical in shape having a coaxially drilled inner hole, by suddenly pouring hot molten metal into its inner hole. It was observed that the thermal strain (tensile) measured on the outer surface of the sample increases with the increase in the temperature of the poured metal. When the thermal strain reached the critical strain, fracture was observed. The temperature of the poured metal when it causes a fracture was in the present case about 800℃ onwards.|玄武岩の熱衝撃抵抗および熱歪を実験的に調べた.熱歪は,円筒状内孔を有する玄武岩柱に,種々の温度の熔融金属を注入して生ぜしめられた.標本表面に発生する引つ張り歪みは,ストレーンゲージによつて測定されたが,注入金属の温度とともに増大することが観られた.また破壊を起す場合の金属温度はほぼ800℃以上であつた.800℃以上の温度差を有する高温岩漿が,地層岩石内に突然注入した場合には,熱衝撃破壊の発生が予想される