ABSTRACT
Mechanical characteristics of chopped fiber reinforced cement composites (FRC) reinforced with four types of new fibers, namely, PAN-based high tension type (PAN-HT) and pitch-based general purpose type (pitch-GP) carbon fibers, aramid fiber and alkali-resistant glass fiber were examined for various fiber contents and aspect ratios by bending, compressive and tensile tests. Their mechanical chracteristics are compared and evaluated under common experimental conditions. It was found that tensile and flexural characteristics of each FRC are greatly improved by the increase in fiber content and aspect ratio Fiber effective coefficient which determines the effectiveness of fiber reinforcment in tensile strength of each FRC by composition law has the tendency of monotonous decrease with the increase in fiber content and aspect ratio. Under the same fiber content and aspect ratio conditions it shows the smallest values in PAN-HT carbon fiber and the greatest values in pitch-GP carbon fiber, which is the tendency in inverse proportion to the tensile strength of each fiber. Under the same matrix and fiber content conditions, PAN-HT carbon chopped fiber reinforced cement composite (PAN-CFRC) has the very high flexural strength and high elasticity, but have the very low toughness. Aramid chopped fiber reinforced cement composite (AFRC) shows the toughest characteristics, but has rather low flexural strength and elastic range. Pitch-GP carbon chopped fiber reinforced cement composite (Pitch-CFRC) and alkali-resistant glass chopped fiber reinforced cement composite (GFRC) have the flexural characteristics good for building materials of general performance with the normal strength and toughness.
