Quantitative distribution of sulfate between phases in Portland cements

• 作 者: MaYing;YangSha;JueshiQian;
• 机 构: College of Materials Science and Engineering, Chongqing University, Chongqing 400045, China
• 出 处: The 14th International Congress on the Chemistry of Cement (
• 发表日期: 2015年期

　　Sulfate in Portland cement which occurs as many various phases mainly comes from clinker and added gypsum,and also less of it from admixtures and additives.Quantitative distributions of sulfate between phases in Portland cements and clinkers in relation to composition are exhibited.Sixty works cements and 20 works clinkers and 10 laboratory clinkers which have a wide range of chemical composition were used.Two procedures, 50% ethanol (volume/volume) and saturated soda methods for measuring the distribution of sulfates are described.The results show in Portland cement clinkers easy soluble sulfates dissolved at short minutes are mainly present as alkali sulfates, but other soluble sulfates except alkali sulfates in a relatively large proportion occur in Portland cements.Gypsum occupies 60% to 90% of total SO3 content in Portland cements.The distribution of sulfates in Portland cements has much difference with in clinkers, which calls an attention for wider understanding of the sulfate phases in cements and provides a reference for cement application.