Effect of SO3 on the alkali compounds of portland cement clinker
1951; US government; Volume: 47; Issue: 5 Linguagem: Inglês
10.6028/jres.047.042
ISSN2376-5305
Autores Tópico(s)Innovative concrete reinforcement materials
ResumoThis investiga tion ShOWR t!lat the compound Na20.8CaO.3Ah03,whi ch is known io bp one of t h e form s in which N azO may occur in por t lan d cem ent clin ke r.!, is unstll,ble at clinkering tem p eratures in thc pres(')nce of 803.This compound rea cts wit h b 0 3 to form N a28 0 .and 3CaO .AI20 3. Any excess of Na20 wi ll remain as Na20.8CaO.3Ah03,become a constituent of the clinker glass, or enter into SOlid .solu tion with one of tbe other clinker components.I n cl inker compositionE containinf!; bot h soda and potash together wit h 80 " an a lka lisulfate phase is produced t hat contai ns hoth of the alkalies.For molecular ratios H zOi 8 0 a greater t h an uni ty, a preferential reap-tion of the 8 0 3 with K 2 0 is indicated.Empirical relationships between t h e alkali('s and t he 803 of the cement mixture indicate that t he al kalies fi rst combine wit h t h e 8 0 3 in t he approximate molec ular rlttio K20/N a~0 = 3 t o t Ile extent that t he compositio n limits of the mixture p ermit.The composition of t he a lkalisu lfate phase for mi-•tures of var.ving soda-potash contellis with H 20 /803 molocu lar ratios equal to 1, 2, and 3 h ave been determined .Equat ions are d evcloped for calculatin g the ~lppr ox im ate com position of the a lkal i sulfaLe awl t he potential phase co mposition of cl ink crtype m ixt u res having other R l O/R 0 3 ratios.
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