Chopped carbon fibre reinforcement in high-strength concrete: Flexural characteristics

Abstract

In this study, the flexural behaviour of high-strength concrete was tested with chopped carbon fibres that were 30 mm long and added in amounts of 0.2%, 0.4%, 0.6%, 0.8%, and 1%. Thirty-six prisms were evaluated experimentally for flexural strength at 28 days using an ultrasonic pulse velocity test and a flexural testing machine. X-ray diffraction and linear regression analysis were carried out to characterise crystalline material and linear correlation amongst different mixes. Increasing the number of carbon fibres in high-strength concrete led to unexpected and innovative findings, such as lower pulse velocities and improved flexural characteristics up to an optimum dosage point. In SEM images of chopped carbon fibres, debonding was the most prevalent cause of failure.