Development of new pozzolan using `Shirasu' particles as concrete admixture
Takewaka Koji
Abstract:From author's previous study, it was considered that fine particles of `Shirasu' which is one of pyroclastic flow deposits would cause the pozzolanic reaction. Purposes of this study are clarification of the pozzolanic reaction on Shirasu and determination of manufacturing condition as concrete admixture. In this study, the mortars are made by several types of Shirasu blended cement. And the following results are obtained; (1) Using the Shirasu particles having 90% or more of glass contents and crushed at the fineness condition of 5000 cm2/g or more, same workability as on normal cement mortar and same strength as on fly-ash cement mortar could be secured on this Shirasu blended cement mortar. (2) The pozzolanic reaction having the Shirasu particles in the mortar could be clarified by using the chemical analysis methods, such as differential thermal analysis, scanning electron microscope and X-ray analysis. Key Words:Shirasu, pyroclastic flow deposits, concrete admixture, fineness of particle, glass content, strength of mortar, chemical analysis