Composite GFRP bars as reinforcement of concrete members under axial force and bending moment

Piotr Szymczak

Department of Concrete Structures; Faculty of Civil Engineering, Architecture and Environmental Engineering; Lodz University of Technology (Poland)

Paweł Olbryk

Department of Concrete Structures; Faculty of Civil Engineering, Architecture and Environmental Engineering; Lodz University of Technology (Poland)

Maria Kamińska

Department of Concrete Structures; Faculty of Civil Engineering, Architecture and Environmental Engineering; Lodz University of Technology (Poland)

Abstract

This paper discusses concrete members reinforced internally with composite GFRP bars (Glass Fibre Reinforced Polymer). The studies are focused on members under axial force and bending moment. Experimental studies of 4 RC columns loaded with compressive axial force, longitudinally and transversally reinforced with GFRP bars were discussed. Columns had cylinder shape with the nominal diameter of 200mm and height of 600mm. Longitudinal reinforcement contained six bars with 11mm diameter and transversal reinforcement of continuous spiral bars # 4 and #8 with spacing equal to 45mm and 60mm. Studies show that the GFRP reinforcement has very good adhesion to concrete and,in failure state reaches stresses adequate to longitudinal strains of members. This paper proves that the interaction curves can be determined on the same strain state basis as used in RC members according to EC2.

Keywords:

composite GFRP, reinforcement, axial compression, interaction curves