C. Ramesh Babu ¹, S. Prabavathy ¹, M. Saranya ¹

Affiliations
1 Department of Civil Engineering, Mepco Schlenk Engineering College, Sivakasi - 626005, Tamil Nadu, IN

Abstract

Background/Objectives: An extensive experimental and analytical investigation was carried out to explore the behaviour of circular concrete filled GFRP tubes (CFFTs) using NSC (Normal Strength Concrete), HSC (High Strength Concrete) and UHSC (Ultra High Strength Concrete). Methods/Statistical Analysis: The experimental study explored the compressive behaviour of 27 CFFTs having three different diameters 75, 100 and 150mm of constant thickness 3mm. Un confined concrete strength up to 98 MPa was achieved under normal curing conditions. Findings: The research findings prove that adequately confined high strength CFFTs can exhibit highly ductile behaviour and they are highly sensitive to the level of confinement. The GFRP tubes with UHSC infill could not maintain the load carrying capacity after attaining initial peak strengths. A newer methodology using shell elements was adapted for simulation of CFFTs in ANSYS and the results agreed with that of the experimental investigation. Applications/Improvements: The investigation explored that specimen size does not have major influence on strain reduction factor. New values of strength and strain enhancement ratios K1 and K2 has been arrived.

Keywords

Analytical, Circular, Concrete, Compressive Behavior, Experimental, GFRP.

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G. Lavanya ¹, C. Ramesh Babu ¹, S. Prabavathy ¹

Affiliations
1 Department of Civil Engineering, Mepco Schlenk Engineering College, Sivakasi, Virudhunagar - 626005, Tamil Nadu, IN

Abstract

Objective: An exploratory research on developing finite element model for studying the axial compressive behaviour of square and rectangular UHSC filled GFRP tubes was conducted. Methods/Statistical Analysis: The well-known fact of deviation in uniformity of confinement in square and rectangular concrete filled GFRP tubes was focused in the nonlinear finite element model. A square and rectangular cross section having same thickness 3mm was chosen keeping two different corner radii 30, and 40mm. The unconfined concrete strength was limited to 120 MPa. The simulation of UHSC filled GFRP tubes were done using ANSYS using elements SOLID 65 for concrete and MEMBRANE 41 for GFRP tube. Findings: The research findings from this investigation on verification by ACI code (ACI committee 440, 2002) revealed that the square CFFTs offer better confinement when compared with rectangular CFFTs and the corner radii significantly affected the ultimate load capacity of the square and rectangular CFFTs. Applications/Improvements: The study has come up with newer method of simulation of GFRP tubes using shell elements assuming perfect bonding between concrete and the tubes. This is the first kind of study in existing FEA database using shell elements. The results agreed with those predicted by the code.

Keywords

Behaviour, Compressive, GFRP, Rectangular, Square, Ultra High Strength Concrete.

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