Abstract: Polyolefin resin fibers for cement reinforcement which have hydrophilicity imparted thereto and show excellent adhesion to cement matrices. The fibers are ones which have been formed from a polypropylene resin by spinning and have undergone a surface modification treatment selected from oxidation treatment and fluorination treatment so that the fiber surface has an index of wetting of 38 dyn/cm or higher. The polypropylene resin fibers for cement reinforcement, when used in the application or placing of various mortars or concretes, give cement moldings improved in flexural toughness, such as flexural strength and impact strength.

Abstract: Deformed fiber which is either a long fiber prepared by such a manner that plural parallel yarns are unified by formation of connecting parts at appropriate intervals on the longitudinal direction of yarn or particularly a short fiber prepared by cutting the above wherein the plural parallel yarns of filaments are spun from a thermoplastic resin for obtaining the deformed fiber which is effective as pile yarn or gas permeating woven fabric having a specific shape or as fiber for reinforcement of cement for improving tensile strength, bending strength, shock resistance, crack resistance, etc. of molded cement product by improving the working ability and reinforcing property as a result of compounding the short fiber prepared by cutting the deformed fiber with hydraulic substance such as concrete or mortar as a material for public works or buildings.