Effect of temperature on sulphate adsorption/desorption by tricalcium silicate hydrates

✍ Scribed by Yan Fu; Ping Xie; Ping Gu; J.J. Beaudoin

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 358 KB
• Volume: 24
• Category: Article
• ISSN: 0008-8846
• DOI: 10.1016/0008-8846(94)90156-2

✦ Synopsis

Sulphate adsorption from internal sources was studied in hydrating systems containing C-S-H gel and gypsum with respect to delayed ettringite formation. The influence of C3A addition on sulphate desorption was also investigated. Research indicates that C-S-H gel will adsorb sulphate faster at high temperature resulting in quick depletion of the gypsum phase in C-S-H -gypsum mixtures. Sulphate adsorbed at high temperature is desorbed more slowly than that adsorbed at normal temperature. Slower release of sulphate from an internal sulphate source may be a critical condition for delayed ettringite formation in high temperature cured Portland cement paste.