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The role of C-S-H and temperature in delayed ettringite formation



Title: The role of C-S-H and temperature in delayed ettringite formation
Author(s): R. Barbarulo, H. Peycelon, S. Prené
Paper category : conference
Book title: International RILEM Workshop on Internal Sulfate Attack and Delayed Ettringite Formation
Editor(s): K. Scrivener and J. Skalny
Print-ISBN: 2-912143-44-6
e-ISBN: 2912143802
Publisher: RILEM Publications SARL
Publication year: 2004
Pages: 155 - 166
Total Pages: 12
Nb references: 16
Language: English


Abstract: The equilibriums between C-S-H and sulfate and between C-S-H and ettringite were studied at 20 and 85°C. Sulfate sorption on C-S-H depends on the Ca/Si ratio of the C-S-H, and not on temperature. When temperature increases, ettringite dissolves, releasing sulfate in solution and increasing the quantity of sulfate bound to the C-S-H. When a system initially equilibrated at 85°C is put at 20°C, the system goes toward the 20°C equilibrium in about one month. The interaction between C-S-H and sulfate could be modeled by a surface complexation reaction. This allowed calculating the supersaturation of the solution relative to ettringite, showing that high crystallization pressures could be exerted by ettringite after a "C-S-H + ettringite" system has been submitted to a cooling from 85 to 20°C.


Online publication: 2002-09-07
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/2912143802.010