2019 Volume 73 Issue 1 Pages 407-412
Cr（Ⅵ） elution in improved volcanic coarse-grained soil with cement-based solidifying material, is often higher than the permissible limit under soil environmental standards of JAPAN. This is because the soil contains allophane in soil clay fraction, which inhibits the hydration of cement-based solidifying material. It is necessary to select a better ground improvement material according to the content of allophane in the soils. A method is presented to rapidly measure the content of allophane on site. Allophane test （active aluminum test） was performed using simulated soils with adjusted allophane content. Color analysis was performed on the image data of allophane test. The contents of allophane was accurately estimated from RGB values by color analysis. This method was verified using scoria in eastern Shizuoka prefecture and kuroboku soil （andosols） in Kumamoto prefecture. The soils evaluated were well estimated.
