モルタルの流動性におよぼす骨材中のモンモリロナイトの影響 Influence of Montmorillonite in Aggregate on Fluidity of Mortar
It is well known that the aggregate containing montmorillonite suppresses the flowability and accelerates the setting of concrete. In this study, the influence of such aggregate on the early hydration of cement was investigated and the mechanism of flow loss of fresh mortar was discussed.<BR>The fine aggregate containing montmorillonite used in this study shows a remarkable adsorption of OH<SUP>-</SUP> and K<SUP>+</SUP> ions. Immediately after the mixing, the saturation degree of Ca (OH) <SUB>2</SUB> in liquid phase of mortar was extremely depressed by using this aggregate. Consequently, the initial hydration of interstitial phase was accelerated and the monosulphate hydrate formed with ettringite. After that, the saturation degree of Ca (OH) <SUB>2</SUB> increased rapidly and the monosulphate hydrate was converted to the ettringite. It is considered that the remarkable flow loss of the mortar using this aggregate after one hour is due to the rapid conversion of monosulphate hydrate to the ettringite with large cohesive energy.
- 無機マテリアル : セッコウ・石灰・セメント・地球環境の科学 = Inorganic materials
無機マテリアル : セッコウ・石灰・セメント・地球環境の科学 = Inorganic materials 4(267), 93-100, 1997-03
The Society of Inorganic Materials, Japan