Pukotine od savijanja u gredama od betona ojačanog vlaknima s armaturnim šipkama od vlaknima ojačanog polimera

Abstract

There are several reasons why civil and structural engineers may need to use FRP reinforcement (fibre reinforced polymer) in concrete. The primary reason is durability, but other reasons include electromagnetic neutrality, high strength, and lightweight. The use of fibre-reinforced polymer composites, as replacement for steel reinforcement in concrete structures, is a widespread practice in many countries. The unique characteristic of FRP as a material not susceptible to corrosion makes it particularly suitable in a variety of situations. Due to generally low elastic modulus and poor bond, the use of FRP results in larger crack widths, especially when beams are reinforced with GFRP bars. The aim of this research is to use fibre-reinforced concrete (FRC) in order to reduce crack widths. The paper provides results for 16 beams (three samples per set for GFRP and two samples per set for steel reinforcement) tested under four point bending. Based on the applied methodology, the existing codes are reviewed, compared and modified, so as to enable their calibration in accordance with appropriate results.