The impact resistance and mechanical properties of the reinforced self-compacting concrete incorporating recycled CFRP fiber with different lengths and dosages

The present paper investigates the feasibility of using recycled CFRP fibers in self-compacting concrete. The fresh and hardened properties of the reinforced self-compacting concrete were assessed, considering different fiber volume fractions of 0.5%, 1%, 1.5%, and 2% along with different fiber lengths of 10, 20, and 30 mm. The fresh state properties of the reinforced mix compositions were evaluated in terms of flowability and viscosity. Moreover, the hardened properties of specimens were obtained by using the ultrasonic pulse velocity, compressive strength, flexural strength, and impact resistance. To characterize mechanical properties and impact resistance, 130 specimens were experimentally tested. Back-scattered electron (BSE) images and elemental maps were used to identify crystalline structure of the cement-based matrix. Moreover, energy-dispersive X-ray spectroscopy (EDX) employed to determine the qualitative or semi-quantitative chemical compositions of the cementitious mix composition. The surface morphology and topography of the embedded CFRP fibers in the cement-based matrix were characterized by scanning electron microscope (SEM) and atomic force microscope (AFM) images, respectively. Regarding the obtained large experimental database, an analytical analysis was executed by using linear regression analysis to correlate the impact and mechanical properties of the reinforced self compacting concrete, considering different contents and lengths of recycled carbon fiber. The results showed that increasing recycled carbon fiber volume fraction and length enhances mechanical properties and impact resistance of the reinforced mix compositions, while reduces the workability. (C) 2016 Elsevier Ltd. All rights reserved.