Eco-cement is made from municipal waste incinerator ash, which contains much amount of Al
2O
3 and Cl
-. Consequently Eco-cement contains much more amount of interstitial phase and Cl
- than OPC. Although 20 to 40 mass% of Cl
- in Eco-cement dissolved into free water within 3 hours, Cl
- concentration decreased rapidly after that. In the case that Cl
- content in cement was adjusted to 0.1 mass% by NaCl, almost all of Cl
- in free water was bound as Friedel's salt in mortar with Eco-cement, OPC and Blastfurnace Slag Cement. The value of [Cl
-/OH
-] molar ratio of free water in each mortar was under 0.6 at 28 days, so steel corrosion is likely not to occur. In the case that Cl
- content was increased to 1.0 mass%, Eco-cement bound more amounts of Cl
- than other cements by producing much amount of Friedel's salt. Remained Cl
- in free water, which was not bound as Friedel's salt was sorbed in hydrates such as C-S-H.
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