All-solid waste concrete expansive agent and preparation method thereof

The invention belongs to the technical field of expansive agents, and particularly relates to an all-solid waste concrete expansive agent and a preparation method thereof. Wherein the expanding agent comprises the following components in percentage by mass: 60-70% of carbide slag, 3-8% of aluminum ash, 0-5% of Bayer process red mud and 25-35% of desulfurized gypsum. The preparation method of the expanding agent comprises the following steps: pulping, proportioning, making a filter cake, granulating, calcining and grinding to obtain a finished product. The all-solid waste concrete expansive agent can overcome the defects that in the prior art, clinker calcination of a concrete expansive agent consumes high-quality limestone resources, a large amount of greenhouse gas CO2 is discharged, and the ecological environment is damaged; according to the method, the problems of land occupation, environment pollution and serious pollution to surrounding underground water, soil, air and ecological environment caused by st