Onoda Cement Co., Ltd.

Other

Shiro Ishii

Toshio Kawano

Hachiro Kubota

Koichi Soeda

Toshiharu Hida

Koretoshi Hitotsuya

Takaaki Katayama

Jyunichiro Migita

Junichiro Migita

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.

Method of destroying a brittle body by hydration expansion

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.

Expansive demolition agent

A demolition agent which acts by means of expansive stress generated upon hydration and which is prepared by calcining limestone at 1300.degree. to 1600.degree. C. to produce a hard-burned quick lime whose crystal sizes are 10 to 100 micron, pulverizing the resulting hard-burned quick lime to 1500 to 5000 cm.sup.2 /g (Blaine), mixing 5 to 70 parts by weight of a hydraulic material to 30 to 95 parts by weight of the hard-burned quick lime and furthermore adding 0.1 to 5 parts by weight of an admixture comprising a water reducing agent to 100 parts by weight of the mixture of the powdery hard-burned quick lime and the hydraulic material. The demolition agent is used as an aqueous slurry. The slurry is filled into holes of a brittle material to demolish the brittle material by means of expansive stress generated upon hydration.

Demolition agent, its preparation and its use

The present demolition agent for brittle materials is prepared by pulverizing a clinker which is obtained by mixing a calcareous material, a siliceous material and gypsum at the molar ratio of CaO/SiO.sub.2 =5.0-14.4 and CaSO.sub.4 /SiO.sub.2 =0.13-1.19 and burning the mixture under an oxidizing atmosphere to 1350.degree.-1550.degree. C. The main components of the clinker thus obtained consist of 24-65% by weight of 3CaO. SiO.sub.2 crystals, 30-60% by weight of CaO crystalline particles and 5-17% by weight of CaSO.sub.4, wherein more than 50% by weight of said CaO crystalline particles is included in the large 3CaO.SiO.sub.2 crystals grown. The present demolition agent is used to break brittle materials by means of the expansive stress of aqueous slurry of the demolition agent poured into the hole of the brittle materials.

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Zushi, Japan

Shiro Ishii