Petoca, Ltd.

Takenaka Corporation

Katsumi Takano

Toshio Yonezawa

Yoshikazu Nagata

Sadatoshi Ohno

Masaki Iwata

Junichi Ida

Hideyuki Nakajima

Yasushi Katsuta

Tadahiro Kakizawa

Minoru Takabatake

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

A specific sizing agent comprising as the main component an adduct of mono- or poly-cyclic phenol with alkylene oxide is applied in a specified amount to the surface of a high-strength and high-elasticity carbon fiber or a precursor fiber thereof and then dried to prepare a reinforcing carbon fiber according to the present invention, which is then preformed into a fiber arrangement, impregnated with a precursor of matrix carbon, and carbonized to produce a high-strength and high-elasticity carbon-carbon composite material.

Reinforcing carbon fiber and process for producing carbon-carbon

Growing community of inventors

Ibaraki-ken, Japan

Katsumi Takano