{"title":"Physical Properties and Hydration Behavior of 3CaO⋅Al2O3 Composition by Quenching after Fusion","authors":"N. Tsuyuki, H. Otake, Tsugio Miyakawa, J. Kasai","doi":"10.2109/JCERSJ1950.94.1091_636","DOIUrl":null,"url":null,"abstract":"The melt of 3CaO⋅Al2O3 (G-C3A) composition in the presence of a small amount of SiO2 was synthesized by rapid quenching after fusion. Furthermore, the physical properties and the hydration behavior of G-C3A were investigated. G-C3A results in a lowering of lattice constant, a decrease of specific gravity and an increase of free CaO compared with C3A. The hydration was not completed even on 10 days curing, and 3CaO⋅Al2O3⋅6H2O hydrate grew very slowly. It is thought that Al(OH)4- eluted from G-C3A is remarkably depressed against Ca2+. The molar ratio (CaO/Al2O3) in case of G-C3A was given 2.7 after 10 days curing but closely approached to 1.0 after 6 hours curing in case of C3A. Namely, as glass phase is formed on G-C3A surface, the strain occurs in inner layer. Therefore, it is difficult to elute Al(OH)4- by breaking -Al-O-Al- bonds. Although the elution of Al(OH)4- by NaOH is considerable, the growth of the hydrate cannot be expected because of depression of the elution of Ca2+. The results of surface analysis by ESCA showed that the binding energy of inner shell electron of Ca, Al, and Si combined with O (oxygen) in G-C3A is 0.7-0.8eV higher than C3A. Consequently, as the elution of Ca2+ and Al(OH)4- is depressed, the hydration reaction becomes inactive.","PeriodicalId":17274,"journal":{"name":"Journal of the Ceramic Association, Japan","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of the Ceramic Association, Japan","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.2109/JCERSJ1950.94.1091_636","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
The melt of 3CaO⋅Al2O3 (G-C3A) composition in the presence of a small amount of SiO2 was synthesized by rapid quenching after fusion. Furthermore, the physical properties and the hydration behavior of G-C3A were investigated. G-C3A results in a lowering of lattice constant, a decrease of specific gravity and an increase of free CaO compared with C3A. The hydration was not completed even on 10 days curing, and 3CaO⋅Al2O3⋅6H2O hydrate grew very slowly. It is thought that Al(OH)4- eluted from G-C3A is remarkably depressed against Ca2+. The molar ratio (CaO/Al2O3) in case of G-C3A was given 2.7 after 10 days curing but closely approached to 1.0 after 6 hours curing in case of C3A. Namely, as glass phase is formed on G-C3A surface, the strain occurs in inner layer. Therefore, it is difficult to elute Al(OH)4- by breaking -Al-O-Al- bonds. Although the elution of Al(OH)4- by NaOH is considerable, the growth of the hydrate cannot be expected because of depression of the elution of Ca2+. The results of surface analysis by ESCA showed that the binding energy of inner shell electron of Ca, Al, and Si combined with O (oxygen) in G-C3A is 0.7-0.8eV higher than C3A. Consequently, as the elution of Ca2+ and Al(OH)4- is depressed, the hydration reaction becomes inactive.
在少量SiO2的存在下,采用快速淬火的方法合成3CaO⋅Al2O3 (G-C3A)成分的熔体。进一步研究了G-C3A的物理性质和水化行为。与C3A相比,G-C3A降低了晶格常数,降低了比重,增加了游离CaO。固化10 d水化未完成,3CaO⋅Al2O3⋅6H2O水合物生长缓慢。从G-C3A中洗脱的Al(OH)4-被认为对Ca2+有明显的抑制作用。G-C3A的摩尔比(CaO/Al2O3)在固化10天后为2.7,而C3A在固化6小时后接近1.0。即当G-C3A表面形成玻璃相时,应变发生在内层。因此,通过破坏-Al- o -Al-键来洗脱Al(OH)4-是困难的。虽然NaOH对Al(OH)4-的洗脱作用是相当大的,但由于Ca2+的洗脱作用受到抑制,水合物的生长不能预期。ESCA表面分析结果表明,G-C3A中Ca、Al和Si与O(氧)结合的内壳电子结合能比C3A高0.7-0.8eV。因此,由于Ca2+和Al(OH)4-的洗脱被抑制,水合反应变得不活跃。