Takenaka Corporation

Takemoto Yushi Kabushiki Kaisha

Petoca, Ltd.

Mitsubishi Materials Corporation

Sanyo Chemical Industries, Ltd.

Takenaka Komuten Co., Ltd.

Keihin Ryoko Concrete Ind. Corp.

Keihin Ryoko Concrete Industry Corporation

Takemoto Oil and Fat Corporation

Toshio Yonezawa

Mitsuo Kinoshita

Kenrou Mitsui

Shinji Tamaki

Yoshikazu Nagata

Katsumi Takano

Sadatoshi Ohno

Masarou Kojima

Masaki Iwata

Junichi Ida

Mitsuo Sato

Hideyuki Nakajima

Masahiro Iida

Yasushi Katsuta

Kazuhide Saitou

Tadahiro Kakizawa

Keishirou Okamoto

Koichi Ito

Yasuhiko Yoshioka

Hayao Aoyagi

Tsuneo Yamamoto

Kunio Yanagibashi

Toshihide Shimono

Takashi Iwashimizu

Hisatsugu Yoshida

Etsurou Asakura

Tooru Okuno

Makoto Nakazima

Eiji Sato

Junji Inagaki

Yousaku Ikeo

Kazumasa Inoue

Toyoji Miura

Tomonori Yoshida

Kunio Sakaue

Tetsuo Nakase

Toru Okuno

Kenzo Kitazawa

Ken-ichi Mase

Yasuyuki Saito

Takao Kono

Tetsuo Oura

Kenro Mitsui

Soil cement slurry is produced by mixing blast-furnace slag fine particles with a specified fineness and Portland cement at a specified ratio to prepare blast-furnace slag cement and using a specified amount of slurry composition for ground improvement including this blast-furnace slag cement with water and an admixture per 1 mof ground. The admixture contains specified amounts of a hardening accelerator, a defoamer and a fluidizer.

Method of producing soil cement slurry

A multi-functional admixture for concrete, having improved fluidity for providing hardened materials with improved early strength, smaller shrinkage rate, improved resistance against freezing and thawing action and slower carbonation speed, contains a specified kind of graft copolymer and/or its salt, a specified kind of (poly)alkyleneglycol monoalkyl ether and a specified kind of organic phosphate at specified ratios.

Multi-functional admixtures for concrete

A high-strength hydraulic cement composition contains cement, fine aggregates, coarse aggregates, water and a specified admixture and has a unit amount of water in the range of 120-185 kg/m. Water and the cement are contained at a ratio of 20-40% and the admixture is contained in the amount of 0.1-3.0 weight parts per 100 weight parts of the cement. The admixture is one or more selected from reaction mixtures obtained by specified two processes and partially or completely neutralized substances obtained from such a reaction mixture through these two processes and also a specified third process. The specified two processes include initiating a radical copolymerization process of a radical polymerizable monomer mixture containing maleic anhydride and a monomer of a specified kind in a non-aqueous system in the presence of a non-aqueous radical initiator and stopping the radical copolymerization reaction in its midst while the inversion rate of polymerization is at a specified level by adding water to the reaction system to thereby obtain a reaction mixture. The specified third process is for partially or completely neutralizing the reaction mixture.

High-strength hydraulic cement compositions

An ultra high-strength hydraulic cement composition contains a binder, fine aggregates, coarse aggregates, an antifoaming agent, water and a specified admixture and has a unit amount of the binder in the range of 480-1800 kg/m. Water and the binder are contained at a ratio of 10-25% and the admixture is contained in the amount of 0.2-3.5 weight parts per 100 weight parts of the binder. The binder may be cement or a mixture of cement and a microscopic powder admixture. The admixture is one or more selected from reaction mixtures obtained by specified two processes and partially or completely neutralized substances obtained from such a reaction mixture through these two processes and also a specified third process. The specified two processes include initiating a radical copolymerization process of a radical polymerizable monomer mixture containing maleic anhydride and a monomer of a specified kind in a non-aqueous system in the presence of a non-aqueous radical initiator and stopping the radical copolymerization reaction in its midst while the inversion rate of polymerization is at a specified level by adding water to the reaction system to thereby obtain a reaction mixture. The specified third process is for partially or completely neutralizing the reaction mixture.

Ultra high-strength hydraulic cement compositions

There are here disclosed carbon fibers for reinforcement of cement which are obtained by applying, onto the surfaces of carbon fibers, esters of oleic acid and aliphatic monovalent alcohols, esters of oleyl alcohol and monovalent fatty acids, polyoxyalkylene bisphenol ethers or polyether esters as sizing agents, and a cement composite material having a bending strength of 300 kgf/cm.sup.2 or more which contains cut carbon fibers having a fiber length of 10 to 50 mm at a mixing volume ratio of the cut carbon fibers to the cement matrix in the range of 1 to 5%. According to the present invention, there are provided the carbon fibers for reinforcement of cement which have excellent adhesive properties to the cement, good process passage properties through a direct spray gun and good bundling properties and which are suitable for a direct spray method, and the cement composite material using the carbon fibers and having high bending strength.

Carbon fibers for reinforcement of cement and cement composite material

Carbon fiber rovings for reinforcement of concrete are here disclosed which are obtained by sizing, with a sizing agent, strands each consisting of 100 to 1,000 monofilaments of mesophase pitch-based carbon fibers, and then bundling the thus sized 5 to 100 strands into one roving.

Carbon fiber rovings for reinforcement of concrete

The hydraulic substance according to the present invention comprises a certain amount of solid particles A (such as portland cement and mixed cement comprising portland cement), an average diameter thereof is 5 to 50 .mu.m, and solid particles B (such as silica fume comprising amorphous silica), an average diameter thereof is less than 1/5 of the particles A, and the particles B have such characteristic that they cohere to the surfaces of the particles A in water, and the quantity of the particles B is arranged such that they cover at least to make a single layer over the whole or part of surfaces of the particles A to cover whole or part of surfaces of particles A with particles B at least with a single layer, and the quantity of the water is arranged such that it is less than 60% of the total amount of the particles A and particles B.

Hydraulic substance with water stable particle coating

Apparatus for feeding ultrafine powder in quantitative batch operation

Ultra high-strength hydraulic cement compositions with extremely low water-to-cement ratio of 10-30% and having high fluidity and improved capability of preventing slump loss, from which high-quality ultra high-strength hardened concrete and mortar can be obtained with superior workability, contain a binder composed of cement or a mixture of cement and a microscopic powder admixture, aggregates, water and a cement dispersion agent composed of water-soluble vinyl copolymers obtained by aqueous solution radical polymerization of five specified kinds of monomers at a ratio within a specified range The unit content of the binder is 400-1300kg/m.sup.3, the water-to-binder ratio is 10-30% and the content of cement dispersion agent is 0.1-2.0 weight parts for 100 weight parts of the binder.

A pressure water absorption inhibitor for lightweight aggregates which comprises an aqueous dispersion of a polymeric substance having a viscosity which permits the aqueous dispersion to enter the fine pores in the surface layer of a lightweight aggregate and which dispersion is capable of being thickened to a viscosity of not less than 50 times the viscosity before thickening by elevation of the pH.

Suppression of pressure water absorption of lightweight aggregate by

Growing community of inventors

Inzai, Japan

Toshio Yonezawa