2018 Volume 72 Issue 1 Pages 173-180
Mercury intrusion porosimetry has been widely used as a method to measure the pore structure of cementitious materials, but considering the influence on the environment, a method that does not use mercury is required. Also, in the mercury intrusion porosimetry, the sample is dried before measurement, so the measurement result indicates the pore structure of the dried sample. Therefore, a thermoporometry method can be proposed as a method not requiring the use of mercury and drying process of specimen. The thermoporometry method estimates the porosity from the amount of heat generated during the freezing and thawing of water in the pore. So far, the authors have measured with a small size of sample, but in this study the thermoporometry method was applied to the bulk sample. As a result, peaks which could not be measured with a small size of sample could be detected. And it was clarified that blending blast furnace slag forms finer pore structure of hardened cement paste. Therefore, transport properties of hardened cement paste with BFS was improved. It was also clarified that the diffusion of chloride ions in hardened cement paste depends on the pore volume of 6nm or more.
