Effects of Minerals on the Dissolvable Ion Concentration and pH Value of Hardened Cement
The influence of grinded blast furnace slag (GBFS), high-calcium fly ash (HF), desulfurized gypsum (DG) and Na2SO4 (NS) on dissolvable ion Moore concentration and pH value of hardened cement is researched. In liquor with hardened cement powder, the dissolvable ion Moore concentration of Mg, Si or Al is according to each ion content in raw materials of cement paste. In materials system of cement-slag-HF, NS reduces the ion Moore concentration of Al and increases that of Mg or Si. PH value of hardened cement is mostly controlled by dissolvable Ca ion Moore concentration in the material system of cement-BBFS-HF. Alkali metal ions, which is introduced with additional materials, effect pH value more remarkably than the dissolvable Ca ion Moore concentration. PH value of hardened cement decreases a little if 50% cement is replaced by same weight of GBFS and HF. HF can reduce pH value more seriously than GBFS. DG enhances S and Ca ion Moore concentration, and decreases pH value of hardened cement.
H. B. Zhu et al., "Effects of Minerals on the Dissolvable Ion Concentration and pH Value of Hardened Cement", Advanced Materials Research, Vols. 261-263, pp. 270-274, 2011