Flexural behavior of RC continuous T-beams reinforced with hybrid CFRP/ steel bars (experimental and numerical study)

Abstract

This study presents experimental and numerical investigations to understand the response and failure of hybrid RC continuous T-beams reinforced in flexure by both Carbon Fiber Reinforced Polymer (CFRP) bars and steel bars at sagging and hogging regions. Three RC continuous T-beams were constructed experimentally and studied to discuss three parameters which are the type of reinforcement material, the relation between sagging and hogging reinforcement, and the moment redistribution. The control beam was reinforced with steel rebars that have been designed to fail in flexure. The second beam was reinforced with hybrid CFRP/ steel bars at the sagging and hogging regions. The sagging region of the third one was reinforced with steel bars while the hogging region was reinforced with CFRP bars. All critical sections at the tested specimens are designed to have the same axial stiffness for the reinforcement bars. Experimental results revealed that the moment redistribution ratio and mode of failure depend on the type of reinforcement bars and using the hybrid bars at both critical regions helped to control the serviceability limits of the beams.This study also suggests and validates a 3D numerical model to simulate the performance and failure of hybrid reinforced RC continuous T-beams using the finite element (FE) software “ANSYS”. The results agreed with the experimental observations that indicated significant effect of the type of reinforcement material at sagging and hogging regions on the failure mode and the redistribution of the moment of the RC continuous beams.

Keywords

• continuous beams
• hybrid reinforcement
• cfrp bars
• moment redistribution
• numerical