Methods of limiting hydroxyl ion concentrations or their effects in concrete pore solutions to interfere with alkali silica reaction

Abstract

Methods of reducing hydroxyl ions in concrete pore solutions are provided. Such methods are useful in providing resistance to gels which form in concrete due to the alkali-silica (ASR) reaction. The methods comprise adding a salt or mixture thereof to the concrete, in aqueous or solid form, the salt or salt mixture having cations higher in valence than the anions. The methods also comprise adding an acidic phosphate or a silicon-containing alkoxide to the concrete. The methods further comprise resisting and/or inhibiting ASR in airfield runway concrete pore solutions by applying a soluble salt or a mixture of soluble salts in solution or a deicing salt mixture in situ to the runway concrete. All of the above methods are useful in reducing hydroxyl ions in concrete. Such methods can be used to resist ASR in fresh concrete, in concrete that is setting, or in hardened concrete.