Flexural behavior of carbon fiber-reinforced concrete beams under impact loading: Fid-Bau Portal

Flexural behavior of carbon fiber-reinforced concrete beams under impact loading

Wang, Zhuoran / Ma, Gang / Ma, Zhihong / Zhang, Yu

Abstract The flexural behavior of carbon fiber-reinforced concrete (CFRC) beams under impact loading was studied herein. A modified molding process was proposed for manufacturing CFRC beams to achieve the uniform dispersion of 20-mm long carbon fibers in the concrete matrix. Different fiber volume fractions and impact velocities were considered. Their effects on the tensile and compressive strain, distribution of vertical displacement and acceleration, energy absorption, and dynamic increase factor (DIF) were analyzed to investigate the mechanical properties. The results indicated that the CFRC beams with 0.35% fiber content absorbed the highest energy (about 2.3 times that of beams without fibers). Based on the approximate linear distribution of inertial force along CFRC beams, an equation was deduced to calculate the generalized inertial force. The results indicated that the DIF increased with strain rate, and an empirical equation was proposed to describe the strain rate effect.

Graphical abstract Display Omitted

Highlights • A modified molding process is proposed for manufacturing CFRC to achieve the uniform dispersion of 20 mm long carbon fibers. • Under impact loading, the energy absorption of CFRC beams is superior to that of beams without fibers. • The strain curves are divided into three phases as a whole to characterized the impact fracture behavior of CFRC beams. • An equation is deduced to calculate the generalized inertial force. • An empirical equation is proposed to describe the relationship between strain rate and dynamic increase factor.