Leaching Lithium

Project ID: 1938
Principal Investigator: John Robertson
Research Topic: Condition Assessment
Funded Fiscal Years: 2014, 2015 and 2016
Keywords: lithium, leaching lithium, alkali silica reaction, presoaked lightweight aggregates

Research Question

Alkali silica reaction (ASR) still has the potential to severely damage the Bureau of Reclamation's concrete structures. ASR is a form of concrete deterioration caused by a reaction between alkalies in the cement used in concrete and certain types of aggregates. The reaction was discovered in the 1930s, and methods were developed to prevent the reaction from damaging concrete structures. Those methods were principally to limit the amount of alakalies in the cement used in the concrete and to use non-reactivce aggregates.
However, these methods are no longer as effective as they were once considered. This is due to a couple of factors - the lack of economically available high quality aggregate sources and the increase in alkali content in cement due to energy use issues. It seems ASR will always be around some areas of the country, and will likely start to be more of a problem in the foreseeable future. Fortunately, a solution has been found that has the potential to reduce or eliminate ASR in new concrete structures. Lithium is that solution. In fact, we had two projects within
the last year where reactive aggregates were proposed for use in the concrete mixture that used lithium to mitigate the reaction.
When added to concrete lithium chemically mitigates the formation of ASR, thus maintaining durability and increasing service life. One concern with using lithium to mitigate ASR is leaching of the lithium by water out of
the concrete. If the lithium were to leach out of the concrete, over time the concrete would be at risk of suffering from ASR, then expanding and developing cracks. Knowing the long term leaching characteristics would help us determine if lithium is a viable solution for ASR mitigation for concrete exposed to water.

Need and Benefit

Funding for these tasks would help in the decision process of whether to allow the use of lithium in a water containing structure. This knowledge is required in order for us to design our structures that are located in areas
with ASR problems.
There are substantial questions about the effectiveness of the use of lithium in concrete or concrete repair applications to mitigate ASR.

Contributing Partners

Contact the Principal Investigator for information about partners.

Research Products

Bureau of Reclamation Review

The following documents were reviewed by experts in fields relating to this project's study and findings. The results were determined to be achieved using valid means.

Leaching Lithium (final, PDF, 1.6MB)
By Katie Bartojay
Publication completed on September 30, 2016

There are at least 22 Reclamation dams that have been effected by alkali-silica reaction (ASR). Once ASR has begun, there are limited methods available to stop the reaction. Lithium based admixtures can be used in new construction or applied to existing structures to mitigate ASR. Lithium salts in concrete have been studied in the laboratory since the 1950s. There are a limited amount of long-term studies on structures containing lithium-based admixtures. Most of the field implementations has been in transportation infrastructure (pavements, bridges, etc.) and not in hydraulic structures. Many of Reclamation's structures are in contact with constantly flowing water. This research investigates the short term (8 months) effect of running water on concrete containing lithium-nitrate admixtures (a) introduced as a surface treatment on cured concrete and (b) intermixed in the fresh concrete .

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Last Updated: 6/22/20