General provisions for early-strength agents and early-strength water-reducing agents

① in concrete projects, the following early strength agents can be used; chloride salts, sulfates, organic amines, and formates. ② early-strength and early-strength water-reducing agent can be used for steam-cured concrete and construction under normal temperature, low temperature and negative temperature (the minimum temperature shall not be lower than 5℃) concrete projects with early strength…