フッ素含有非晶質カルシウムアルミネート-ポルトランドセメント-セッコウ系の水和

抄録

The hydrauric properties have been investigated, when amorphous 3CaO-3Al₂O₃-CaF₂ and CaSO₄ were used as the rapid hardening admixture for portland cement. The hydration process, the strength development and the expansion properties were remarkably influenced by the amounts of added amorphous 3CaO-3Al₂O₃-CaF₂ and CaSO₄.
The hydration of alite was delayed owing to a coating of hydration products. The dense coating of Al (OH) 3 gel might be formed on the surface of alite particles, because of the lower ratio of CaO to Al₂O₃ in amorphous 3CaO-3Al₂O₃-CaF₂ than in C₂AH₈, the principal crystalline product.
The retadation of alite hydration became more significant, when larger amount of amorphous 3CaO-3Al₂O₃-CaF₂ was added. It was concluded that the ratio of amorphous 3CaO-3Al₂O₃ CaF₂ to CaSO₄ should be about 0.5 in order to obtain proper rapid hardening admixture.