Characteristics of SHIRASU Concrete
-Based on Contents in the Manual established by Kagoshima Prefectural Office-
By K. Takewaka
Concrete Journal, Vol.45, No.2, Feb. 2007
- Synopsis
- Shirasu concrete is defined as a concrete using Shirasu as fine aggregate entirely. Shirasu is a name of the pyroclastic flow deposits called in the southern part of Kyushu Island, Japan, where the huge volume of it accumulates. As Shirasu taken from the deposits shows a sandy state, examination was performed continuously to use it as the fine aggregate for the past approximately 20 years. Especially in a latter half of 1990's, it came to be a noteworthy material that should be examined as the substitute for sea sand more practically, because collection regulation of sea sand started to be carried out from the viewpoint of environmental protection. Consequently, Kagoshima prefectural office established the "Manual for design and construction of the concrete used Shirasu as fine aggregate (draft)" in January 2006. In this paper, characteristics of Shirasu concrete, its mixture design method and the matters that require attention in the execution are briefly outlined based on the contents of the Manual, and they are followed by the introduction of some activities for practical use of Shirasu concrete in Kagoshima prefecture with the future prospects.
- Keywords:
- Shirasu concrete, Shirasu, Pyroclastic flow deposits, Manual for design and construction, Examples of practical use
