| Abstract: | Expansion measurements, chemical analysis and petrography have been undertaken to assess a possible side‐effect of using strongly alkaline additives (lithium hydroxide or sodium hydroxide) in encapsulating mortars used to promote the activity of sacrificial zinc anodes employed for galvanic cathodic protection of steel in concrete. Very high concentrations of lithium hydroxide in the encapsulating mortars were found to cause no deleterious expansion associated with alkali‐silica reaction (ASR) in surrounding “model” concrete specimens even when the latter contained aggregate of known susceptibility to ASR and a near‐threshold level of intrinsic alkalinity. Encapsulating mortars formulated with an equivalent molarity of sodium hydroxide, however, were found to induce significant expansion due to ASR in similar specimens. |
