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Experimental data on the alkalinity evolution of the pore solution in concrete affected by alkali-silica reaction



Title: Experimental data on the alkalinity evolution of the pore solution in concrete affected by alkali-silica reaction
Author(s): Patrice Rivard, Marc-André Bérubé, Jean-Pierre Ollivier, Gérard Ballivy
Paper category : conference
Book title: International RILEM Symposium on Concrete Science and Engineering: A Tribute to Arnon Bentur
Editor(s): J. Weiss, K. Kovler, J. Marchand, and S. Mindess
Print-ISBN: None
e-ISBN: 2912143926
Publisher: RILEM Publications SARL
Publication year: 2004
Nb references: 18
Language: English


Abstract: The alkalinity of the concrete pore solution was analyzed at different period of time in order to determine the minimal concentration that would stop alkali-silica reaction. The test specimens were kept over water at 38°C as the length and mass variations were periodically monitored. The pore solution was expressed from prisms at different ages. The water at the bottom of the pails was also analyzed. Also, several concrete cores taken from a dam suffering from ASR were tested for residual expansion in the same storage condition and pore solution was expressed after storage. Results showed that the alkali concentration in all mixture was found to decrease with time, which was mainly due to the leaching. After 52 weeks, the alkali loss ranged from 12 to 25% of the original Na2Oe content of the concrete, depending on the mixture proportioning and the aggregate type. This means that residual expansion performed on concrete core might be underestimated due to the leaching of alkalis. Other testing showed that a cycle of drying/rewetting reduces the alkali concentration measured on expressed pore solution from 20 to 40%. The expansion on both laboratory prisms and dam core stopped at an alkalinity [Na+K] of about 220 mmol/l.


Online publication: 2004-03-25
Classification: Expansive Reactions
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/2912143926.065