マグネシウムを固溶した三カルシウムアルミネートおよびアウインの合成とセッコウ共存下での水和

抄録

In order to lower the basicity of soil quality stabilizer on hydration, substitution of Ca²⁺ ion with Mg²⁺ ion in C₃A and Hauyne which form Ettringite, a major hydration phase of cement type soil stabilizer, on hydration and hydration characteristics of substituted products were examined. The substitution of Ca²⁺ ion with Mg²⁺ ion in the framework of C₃A and Hauyne was confirmed by change of XRD patterns of products and the substituted amounts were estimated to be within 0.4 and 0.5 mol, respectively. The Mg-substituted C₃A and Hauyne were found to be effective to lower the pH value upon hydration. Ettringite which formed from both solid solutions was considered to contain also Mg²⁺ ion in the framework up to about 0.3 mol. In the course of hydration in the system of [(3-x) CaO·xMgO] ·Al₂O₃+3CaSO₄, considerable expansion of body was observed and products showed low compressibility. On the other hand, products did not expand much on hydration and showed high compressibility in the case of [(3-y) CaO·yMgO] ·3Al₂O₃·CaSO₄+2CaSO₄.