Abstract: A method of destroying a brittle body by molding around an elastic tube or an elastic tube in which is inserted a plastic wire or a heat-fusible member for defining a charging hole where the member or tube is partly exposed at the surface of the brittle body, and, after pulling out the elastic tube or fusing the heat-fusible member, an expandable splitting agent capable of expanding by hydration is charged into the charging hole and subjected to hydration-expansion to destroy the brittle body. In another form, a water-impermeable film enclosing an expandable splitting agent capable of expanding by hydration therein is previously buried in a brittle body in a relation partly exposed at the surface of the brittle body, and, after aperturing the exposed end of the water-impermeable film, the expandable splitting agent is subjected to hydration-expansion to destroy the brittle body.

Abstract: An expansive demolition agent prepared by crushing a clinker for manufacturing powdered expansive demolition agent obtained by sintering, which is capable of hydrating and expanding in a hole drilled in a brittle material to demolish the brittle material, the maximum particle diameter of the agent being one-third or less the diameter of the hole, and containing 10% or less of fine particles having a particle diameter of 0.3 mm or less.

Abstract: An improved finely pulverized expansive cement additive which causes the cement mortar or concrete mixed therewith to bear increased chemical prestressing property, the clinker of said additive substantially consisting of alite crystals containing fine crystals of calcium oxide therein and a phase substantially consisting of optic-microscopically amorphous calcium sulfate in which said alite crystals are dispersed.