To provide a method for producing an aggregate having a specific gravity in oven dried condition of 1.5-2.0, high strength and low water absorbability by using a small amount of an additive and composition controlling agents comprising silica and/or alumina and controlling calcia content in the fired aggregate, and to provide the artificial lightweight aggregate obtained by this method.
The method for producing the artificial lightweight aggregate comprises mixing incinerated ash obtained from waste with a caking additive, a foaming agent, a reducing agent and, as a composition controlling agent, at least one of silica or alumina, then, after pulverizing the obtained mixture, adding water, forming and firing the formed body. Furthermore, the formed body is fired after drying and kneading. The calcium content in the fired aggregate of the formed body does not exceed 16 wt.% expressed in terms of oxide. The suitable foaming agent is at least one of iron oxide or silicon carbide and the suitable reducing agent is carbonaceous material. The artificial lightweight aggregate is obtained by the method mentioned above and has a specific gravity is oven dried condition of 1.5-2.0, a uniaxial compressive fracture load of ≥50 kgf and a water-absorbability of ≤10%.
NAGANAMI TAKESHI
KAGAKUI ATSUSHI
KAWAMOTO KOJI
