Title: Fabrication andProperties for a New Carbon Fiber Reinforced Cement Product

Author(s): T. Ando, H. Sakai, K. Takahashi, T. Hoshijima, M. Awata, and S. Oka

Publication: Symposium Paper

Volume: 124

Issue:

Appears on pages(s): 39-60

Keywords: carbon fibers; cladding; durability; fiberboard; flexural strength; fiber reinforced concretes; mixers; mixing; production methods; workability; tensile strength; tests; Materials Research

DOI: 10.14359/2239

Date: 9/1/1990

Abstract:
The fabrication, properties, and application of carbon fiber reinforced cement (CFRC) product made of coal tar pitch-based high-performance carbon fiber are presented. The experiments were conducted by mixing the chopped carbon fiber strands with cement and sand to obtain CFRC. The mixing test results revealed that this type of carbon fiber disperses quickly and uniformly in ordinary mortar. No special type of mixer is required. To optimize the characteristics of CFRC, experimental analysis was conducted on batches made in a mortar mixer regarding the fiber properties and mix proportion. The relationships of these parameters to the mechanical properties were examined. It was revealed that the parameters determining the apparent viscosity F (flow index) of CFRC slurries are fiber diameter í1, filament number n, specific surface area S, and fiber volume fraction Vf. It was also revealed that the parameters determining the strength of the hardened body were fiber tensile strength TS and Vf. The flexural strength of the 20 mm thick CFRC is about 3 to 4 times greater than that of plain mortar. This CFRC is also stronger and more durable than other FRC under the same conditions. High productivity, light weight, and weatherability characterize this new CFRC. These characteristics being appreciated, precast CFRC products have been increasingly used in construction in Japan. Some detailed descriptions of the practical applications are also made.