Abstract
Approximately 200 million cubic meters of debris have deposited due to pyroclastic flow activity in the surrounding area of Unzendake between May 1991 and February 1995. One extremely good way of using this debris is to mix it with cement to make soil cement for use as an ordinary building construction material.
So, in order to clarify the properties of soil cement made with the pyroclastic flow debris, its usability as a construction material, and the economic feasibility of its use, on-site test construction were carried out. The test construction were done for three mixing methods: plant mixing, back hoe mixing with cement milk at place, and back hoe mixing with cement powder at place.
The results reveal that if the cement is about 8 %, compressive strength between 5 × 106Pa and 8 × 106Pa is obtained. The results also demonstrate that the back hoe mixing with cement powder at place is suitable for fast small-scale work and the plant mixing method is appropriate for preparing large quantities of high quality soil cement.
