| Research Abstract |
In this investigation, cementitious materials, such as blast furnace slag, fly ash and silica fume, were globally estimated from the viewpoint of high performance concrete. In addition, as another materials, volcanic ash was investigated for utilization of concrete.
To reduce unit powder content of high fluidity concrete by controlling powder's particle size distribution, the ranges of viscosity and yield value of mortar to be part of concrete, which satisfy the high fluidity, nonsegregating property and passability between steel bars, were clarified. And the physical characters of powser, which can satisfy the ranges with the minimum unit powder content, were clarified. Besed on the results, new cementitious powder which can produce high fluidity concrete with low unit powder content was presented.
Investigations were planned to make clear that relationship between size distribution of powders and rheological properties (yield value and viscosity) of mortar which have direct effects upon properties of high fluidity coucrete. As the results of this study, they were found that yield value of mortar is influenced by n-value of the Rosin-Rammler which is the main factor of amount of excess water in mortar, and that viscosity of mortar is influenced by blaine surface area, which it is reason of the effect obtained by combining absorption of superplasticizer and thickness of water film.
|
