Alkali-free setting and hardening accelerator

Described are setting and hardening accelerators for hydraulic binders and said binder comprising compositions that are free of alkali metals and chlorides. The setting and hardening accelerators comprise, as main component, water-soluble fluoride comprising aluminum salts and water-soluble sulfate comprising aluminum salts, as well as optionally complexing agents and/or amines. In comparison with alkaline accelerators, said mixtures result in an essential shortening of the setting time and a fast development of compressive strengths.