Evaluation of calcium hydroxide contents in pozzolanic cement pastes by a chemical extraction method

✍ Scribed by Kritsada Sisomphon; Lutz Franke

• Publisher: Elsevier Science
• Year: 2011
• Tongue: English
• Weight: 308 KB
• Volume: 25
• Category: Article
• ISSN: 0950-0618
• DOI: 10.1016/j.conbuildmat.2010.06.039

✦ Synopsis

The aim of the study is to investigate the calcium hydroxide (Ca(OH) 2 ) contents in pozzolanic cement pastes analyzed by the chemical extraction method and thermal analysis (DTA/TG). The second part of the study involves the carbonation of pozzolanic cement pastes and its influence on Ca(OH) 2 reduction. The Ca(OH) 2 contents in cement pastes after being subjected to accelerated carbonation were investigated by a chemical extraction method and compared to those values from DTA/TG analysis. The experimental results show that the chemical method reveals overall results comparable to those from DTA/TG analysis. However, in case of pastes containing high amounts of mineral admixtures or pastes subjected to carbonation which contain very low Ca(OH) 2 , only the chemical method yields precise reliable results by showing the pseudo-negative contents.