A refractory composition is formed by preparing a set retarded fresh cementitious composition formed from a class C fly ash, a set retardant such as boric acid, and an alkali activator such as an alkali metal citrate salt, and contacting the set-retarded fresh cementitious composition with a pH regulator, such as an alkali metal hydroxide or alkali metal carbonate. The set retarded mixture provides workability and avoids equipment fouling caused by premature setting, while the alkali activator provides rapid setting when desired. The cementitious composition is shaped into a brick, panel, slab, concrete fire log, or the like and allowed to harden. The hardened cementitious composition can be heated to form a dried cementitious composition, and further heated to produce a high strength refractory composition. Fibers and/or aggregates may be included.

A refractory composition is formed by preparing a set retarded fresh cementitious composition formed from a class C fly ash, a set retardant such as boric acid, and an alkali activator such as an alkali metal citrate salt, and contacting the set-retarded fresh cementitious composition with a pH regulator, such as an alkali metal hydroxide or alkali metal carbonate. The set retarded mixture provides workability and avoids equipment fouling caused by premature setting, while the alkali activator provides rapid setting when desired. The cementitious composition is shaped into a brick, panel, slab, concrete fire log, or the like and allowed to harden. The hardened cementitious composition can be heated to form a dried cementitious composition, and further heated to produce a high strength refractory composition. Fibers and/or aggregates may be included.

A thermistor sintered body has a thickness in a range of 1 ?m to 100 ?m and an area in a range of 1 mm.sup.2 to 10 mm.sup.2, and is composed of a single body of a sintered body having a composition of NiMn.sub.2O.sub.4. This thermistor sintered body can be manufactured by a first step of dropping a raw material liquid RL onto a surface of a substrate rotatably supported, a second step of rotating the substrate with the dropped raw material liquid RL and spreading the raw material liquid RL, a third step of forming a sintered body having the composition of NiMn.sub.2O.sub.4 on the surface of the substrate by heating and holding the raw material liquid RL and the substrate on which the raw material liquid RL has been placed, and a fourth step of separating the sintered body from the substrate.

A thermistor sintered body has a thickness in a range of 1 ?m to 100 ?m and an area in a range of 1 mm.sup.2 to 10 mm.sup.2, and is composed of a single body of a sintered body having a composition of NiMn.sub.2O.sub.4. This thermistor sintered body can be manufactured by a first step of dropping a raw material liquid RL onto a surface of a substrate rotatably supported, a second step of rotating the substrate with the dropped raw material liquid RL and spreading the raw material liquid RL, a third step of forming a sintered body having the composition of NiMn.sub.2O.sub.4 on the surface of the substrate by heating and holding the raw material liquid RL and the substrate on which the raw material liquid RL has been placed, and a fourth step of separating the sintered body from the substrate.

A method of fabricating an impregnated fiber assembly, the method including introducing a first suspension including a first powder of solid particles into an inside volume defined by an inside face of a first fiber texture of hollow shape placed in a mold, an outer face of the first fiber texture being present facing a wall of the mold; using a centrifugal force to impregnate the first fiber texture with the first suspension by rotating the mold; after impregnating the first texture, positioning a second fiber texture on the inside face of the first fiber texture to obtain a fiber assembly; introducing a second suspension including a second powder of solid particles into the inside volume after putting the second fiber texture into position; and using a centrifugal force to impregnate the second fiber texture with the second suspension by rotating the mold to obtain an impregnated fiber assembly.

A method of fabricating an impregnated fiber assembly, the method including introducing a first suspension including a first powder of solid particles into an inside volume defined by an inside face of a first fiber texture of hollow shape placed in a mold, an outer face of the first fiber texture being present facing a wall of the mold; using a centrifugal force to impregnate the first fiber texture with the first suspension by rotating the mold; after impregnating the first texture, positioning a second fiber texture on the inside face of the first fiber texture to obtain a fiber assembly; introducing a second suspension including a second powder of solid particles into the inside volume after putting the second fiber texture into position; and using a centrifugal force to impregnate the second fiber texture with the second suspension by rotating the mold to obtain an impregnated fiber assembly.

The present invention discloses a centrifugal intelligent construction device for excavating concrete structure: a push-type excavation equipment, excavating rocks and soil, and collecting crushed stones, sand, soil, and water; a centrifugal screening equipment, performing centrifugal screening and classification collection on the collected crushed stones, sand, soil, and water; the intelligent batching equipment, which matches the classified crushed stones, sand, soil, and water according to their quality and fineness, adding cementitious materials, auxiliary materials, additives, and activators, and mixing them to obtain a mixed wet material; a centrifugal printing equipment, pumping and extruding the mixed wet materials, and using a centrifugal rotating outer cylinder to print and compact them into dense shape; an intelligent reinforcement equipment, integrating reinforcements between the layers of printed concrete strips by using the wall mounted laying, positioning and inserting reinforcements inside the printed concrete strips during the centrifugal printing process to form an integrated reinforced concrete structure. The device can achieve the additive and intelligent construction of closed concrete structures in underground, underwater, and extreme construction environments, solving the technical dilemma of insufficient engineering application scope of open additive manufacturing technology.

The present invention discloses a centrifugal intelligent construction device for excavating concrete structure: a push-type excavation equipment, excavating rocks and soil, and collecting crushed stones, sand, soil, and water; a centrifugal screening equipment, performing centrifugal screening and classification collection on the collected crushed stones, sand, soil, and water; the intelligent batching equipment, which matches the classified crushed stones, sand, soil, and water according to their quality and fineness, adding cementitious materials, auxiliary materials, additives, and activators, and mixing them to obtain a mixed wet material; a centrifugal printing equipment, pumping and extruding the mixed wet materials, and using a centrifugal rotating outer cylinder to print and compact them into dense shape; an intelligent reinforcement equipment, integrating reinforcements between the layers of printed concrete strips by using the wall mounted laying, positioning and inserting reinforcements inside the printed concrete strips during the centrifugal printing process to form an integrated reinforced concrete structure. The device can achieve the additive and intelligent construction of closed concrete structures in underground, underwater, and extreme construction environments, solving the technical dilemma of insufficient engineering application scope of open additive manufacturing technology.

A concrete cap molding device for molding concrete caps for posts includes a clamshell mold, which is selectively hingable between open and closed configurations. In the closed configuration, the clamshell mold has a top, in which an orifice is centrally positioned, a bottom, which is open, a sidewall extending between the top and the bottom, and a circular cross-sectional profile when viewed from the bottom or the top. Handles are attached to the clamshell mold and can be grasped in hands of a user, enabling the user to position the clamshell mold around a post that protrudes from a mound of concrete, to close the clamshell mold, and to rotate or oscillate the clamshell mold, concurrently with motivating the clamshell mold into the mound of concrete to mold the mound of concrete into a concrete cap around the post.

A concrete cap molding device for molding concrete caps for posts includes a clamshell mold, which is selectively hingable between open and closed configurations. In the closed configuration, the clamshell mold has a top, in which an orifice is centrally positioned, a bottom, which is open, a sidewall extending between the top and the bottom, and a circular cross-sectional profile when viewed from the bottom or the top. Handles are attached to the clamshell mold and can be grasped in hands of a user, enabling the user to position the clamshell mold around a post that protrudes from a mound of concrete, to close the clamshell mold, and to rotate or oscillate the clamshell mold, concurrently with motivating the clamshell mold into the mound of concrete to mold the mound of concrete into a concrete cap around the post.