Load Deflection Behaviour of Self Consolidating Concrete Beams Prestressed with CFRP Bars


Krem S., Soudki K., El-Gelani A., Ahmida F. G. F.

10th International Conference on Fibre-Reinforced Polymer (FRP) Composites in Civil Engineering (CICE), İstanbul, Turkey, 8 - 10 December 2021, vol.198, pp.2154-2168 identifier identifier

  • Publication Type: Conference Paper / Full Text
  • Volume: 198
  • Doi Number: 10.1007/978-3-030-88166-5_186
  • City: İstanbul
  • Country: Turkey
  • Page Numbers: pp.2154-2168
  • Keywords: Self consolidating concrete, Prestressed beams, CFRP
  • Istanbul Technical University Affiliated: No

Abstract

Self-consolidating concrete (SCC) offers several potential benefits that derived from its unique flow characteristics: improved productivity and quality of concrete construction. The current ACI 440.4R-04 design guidelines does not account for SCC in flexural deflection predication of beams prestressed with Fibre Reinforced Polymers (FRP) bars. This paper presents results of flexural testing of four beams prestressed with 12.7 mm Carbon FRP bars. Two beams made from SCC and two beams made from normal vibrated concrete NVC. The prestressing levels were 30% or 60% of the guaranteed tensile capacity of the CFRP bars. Beams were tested under a four-point static bending load under displacement control. Measurements of load, midspan deflection, strain in CFRP bars and in the concrete were collected using a data acquisition system. Results was compared to two methods for flexural deflection predictions: simplified method based on (ACI 440.4R-04), and detailed analytical method from literature. The simplified method was based on effective moment of inertia approximation while the detailed method was based on effective moment of inertia and effective centroid calculations. In both methods, the actual concrete modulus of elasticity was used. Prediction of the midspan deflection based on the simplified method for SCC beams was unconservative after cracking. The experimental results correlated well with the detailed method at higher loads range for both types of concrete.