Limits on the use of the heavy liquid extraction method

摘要

The heavy liquid extraction method (HLE) was recently introduced as a technique to extract concrete pore water using a centrifuge. Lumps of crushed and water-saturated concrete are placed in a centrifuge vessel and covered with chloroform. The differential pressure applied to the concrete by the rotation of the centrifuge displaces the concrete pore liquid, and it can then be found on top of the concrete. A study was conducted in order to test the method and explore its limitations. Concrete with three different w/c ratios (0.4, 0.5 and 0.7) aged 3 months and cement contents of 450 kg/m~3, 400 kg/m~3 and 370 kg/m~3 was cast for the study. Additionally, lumps of a 3-year-old concrete with a w/c ratio of 0.7 were used.