Effects of the particle sizes of expansive clinker on strength-expansion characteristics of type K expansive cements

✍ Scribed by M.D. Cohen; C.W. Richards

• Publisher: Elsevier Science
• Year: 1982
• Tongue: English
• Weight: 530 KB
• Volume: 12
• Category: Article
• ISSN: 0008-8846
• DOI: 10.1016/0008-8846(82)90034-5

✦ Synopsis

In tests conducted on blended Type K expansive cements, it was observed that in fine blends, the main expanding particles (C4A3~) and sulfates deplete faster compared to identical coarser blends because the fine blends have a larger number of expansive sites. This can decrease the expansion time and susceptibility to abnormal behavior, i.e. "double-curvature expansion" and "strength-drop" phenomena. Observations suggest that the mechanism of formation of ettringite crystals is topochemical.

A la suite des tests conduits sur les m~]anges de ciments expansifs de Type K, on a observ~ q'avec les melanges fins les principales J particules expans~ves (C4A~S) et les sulfates se redulsent plus rapidement compares aux m~langes identiques mais plus granuleux, parce que les melanges fins ont un plus grand nombre d'emplacements expansifs. Ceci peut diminuer le temps d'expansion et ~galement la susceptlb+llte de creer un comportement anormal c est-a-dlre des ph~nomenes de "dilatation ~ double courbure" et de "perte de force".

Les observations suggerent que le mecanlsme de formation de cristaux ettringite est topochimique.