Accelerator admixture

摘要

An accelerator composition for use with sprayed cementitious compositions, which is an aqueous solution or dispersion of a blend of the essential Components 1-3 Component 1-aluminium sulphate Component 2-at least one of an alkanolamine and an alkylene diamine or triamine Component 3-hydrofluoric acid optionally with at least one of Components 4-7, with the proviso that at least one of Component 4 or Component 5 be present: Component 4-at least one of sodium hydroxide, potassium hydroxide, lithium hydroxide, magnesium hydroxide, lithium carbonate, sodium carbonate, potassium carbonate, magnesium carbonate, sodium sulphate, potassium sulphate, magnesium sulphate and lithium sulphate; Component 5-C₁-C₁₀ aliphatic mono- and dicarboxylic acids and their metal salts; Component 6-aluminium hydroxide; Component 7-at least one of phosphoric acid and phosphorous acid. The accelerators have excellent long-term stability and work well with "difficult" cements, such as some Japanese OPCs.